Monday, April 24, 2017

Chili peppers and marijuana calm the gut


You wouldn't think chili peppers and marijuana have much in common. But when eaten, both interact with the same receptor in our stomachs, according to a paper by UConn researchers published in the April 24 issue of the journal Proceedings of the National Academy of Sciences. The research could lead to new therapies for diabetes and colitis, and opens up intriguing questions about the relationship between the immune system, the gut and the brain.

Touch a chili pepper to your mouth and you feel heat. And biochemically, you aren't wrong. The capsaicin chemical in the pepper binds to a receptor that triggers a nerve that fires off to your brain: hot! Those same receptors are found throughout the gastrointestinal tract, for reasons that have been mysterious.

Curious, UConn researchers fed capsaicin to mice, and found the mice fed with the spice had less inflammation in their guts. The researchers actually cured mice with Type 1 diabetes by feeding them chili pepper. When they looked carefully at what was happening at a molecular level, the researchers saw that the capsaicin was binding to a receptor called TRPV1, which is found on specialized cells throughout the gastrointestinal tract. When capsaicin binds to it, TRPV1 causes cells to make anandamide. Anandamide is a compound chemically akin to the cannabinoids in marijuana. It was the anandamide that caused the immune system to calm down. And the researchers found they could get the same gut-calming results by feeding the mice anandamide directly.

The brain also has receptors for anandamide. It's these receptors that react with the cannabinoids in marijuana to get people high. Scientists have long wondered why people even have receptors for cannabinoids in their brains. They don't seem to interact with vital bodily functions that way opiate receptors do, for example.

"This allows you to imagine ways the immune system and the brain might talk to each other. They share a common language," says Pramod Srivastava, Professor of Immunology and Medicine at UConn Health School of Medicine. And one word of that common language is anandamide.

Srivastava and his colleagues don't know how or why anandamide might relay messages between the immune system and the brain. But they have found out the details of how it heals the gut. The molecule reacts with both TRPV1 (to produce more anandamide) and another receptor to call in a type of macrophage, immune cells that subdue inflammation. The macrophage population and activity level increases when anandamide levels increase. The effects pervade the entire upper gut, including the esophagus, stomach and pancreas. They are still working with mice to see whether it also affects disorders in the bowels, such as colitis. And there are many other questions yet to be explored: what is the exact molecular pathway? Other receptors also react with anandamide; what do they do? How does ingesting weed affect the gut and the brain?

It's difficult to get federal license to experiment on people with marijuana, but the legalization of pot in certain states means there's a different way to see if regular ingestion of cannabinoids affects gut inflammation in humans.

"I'm hoping to work with the public health authority in Colorado to see if there has been an effect on the severity of colitis among regular users of edible weed," since pot became legal there in 2012, Srivastava says. If the epidemiological data shows a significant change, that would make a testable case that anandamide or other cannabinoids could be used as therapeutic drugs to treat certain disorders of the stomach, pancreas, intestines and colon.

It seems a little ironic that both chili peppers and marijuana could make the gut chill out. But how useful if it's true.


Total fruit and vegetable consumption is higher among consumers of frozen fruits and vegetables


New research presented today via poster presentation at the 2017 Experimental Biology meeting shows consumers who eat frozen fruits and vegetables eat more fruits and vegetables overall. In fact, consumers of frozen fruits and vegetables also have significantly greater intakes of key nutrients, such as potassium, fiber and calcium.

The study, presented by Maureen Storey, PhD, and supported by the Frozen Food Foundation, analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2011-2014. When consumers of frozen fruits and vegetables were compared to non-consumers of frozen fruits and vegetables, the study results show:

  • Frozen fruit and vegetable consumers eat more total fruits and vegetables than non-consumers;
  • Consumers of frozen fruits and vegetables have significantly higher intakes of nutrients of concern - potassium, dietary fiber, calcium, and vitamin D; and
  • Adult consumers of frozen fruits and vegetables have significantly lower BMI than non-consumers.
"At a time when Americans are only eating half of the recommended daily intake of fruits and vegetables, our research shows that eating frozen fruits and vegetables can help fill the gap in fruit and vegetable consumption," said Dr. Storey. "In addition to increased consumption of nutrients of concern, frozen fruit and vegetable consumers also had a higher intake of vitamins A and C."

The U.S. Department of Agriculture and U.S. Department of Health and Human Services 2015-2020 Dietary Guidelines for Americans (DGAs) define calcium, potassium, dietary fiber and vitamin D as nutrients of public health concern because low intakes are associated with health concerns. Specifically, the guidelines attribute low intake of fiber and potassium to decreased fruit and vegetable consumption.

"This research adds substantiation to the growing body of evidence that supports the important role frozen fruits and vegetables can play to help Americans meet daily intake recommendations set by the DGAs," said Frozen Food Foundation President and CEO Alison Bodor. "While this research focused on fruits and vegetables, frozen foods and beverages also provide consumers with nutritious and convenient meals options while minimizing food waste."


Daily consumption of sodas, fruit juices and artificially sweetened sodas affect brain


Data from the Framingham Heart Study (FHS) has shown that people who more frequently consume sugary beverages such as sodas and fruit juices are more likely to have poorer memory, smaller overall brain volumes and smaller hippocampal volumes--an area of the brain important for memory. Researchers also found that people who drank diet soda daily were almost three times as likely to develop stroke and dementia when compared to those who did not consume diet soda.

These findings appear separately in the journals Alzheimer's & Dementia and the journal Stroke.

"Our findings indicate an association between higher sugary beverage intake and brain atrophy, including lower brain volume and poorer memory," explained corresponding author Matthew Pase, PhD, fellow in the department of neurology at Boston University School of Medicine (BUSM) and investigator at the FHS.

"We also found that people drinking diet soda daily were almost three times as likely to develop stroke and dementia. This included a higher risk of ischemic stroke, where blood vessels in the brain become obstructed and Alzheimer's disease dementia, the most common form of dementia," he said.

Excess sugar is known to have adverse effects on health. Diet soft drinks are often touted as a healthier alternative to regular soda. However both sugar and artificially-sweetened beverage consumption has been linked to cardiometabolic risk factors, which increases the risk of cerebrovascular disease and dementia.

In these studies approximately 4,000 participants over the age of 30 from the community-based FHS were examined using Magnetic Resonance Imaging (MRI) and cognitive testing to measure the relationship between beverage intake and brain volumes as well as thinking and memory. The researchers then monitored 2,888 participants age 45 and over for the development of a stroke and 1,484 participants age 60 and older for dementia for 10 years.

The researchers point out that preexisting conditions such as cardiovascular disease, diabetes and high blood pressure did not completely explain their findings. For example, people who more frequently consumed diet soda were also more likely to be diabetic, which is thought to increase the risk of dementia. However, even after excluding diabetics from the study, diet soda consumption was still associated with the risk of dementia.

Although the researchers suggest that people should be cautious about regularly consuming either diet sodas or sugary beverages, it is premature to say their observations represent cause and effect. Future studies are needed to test whether giving people artificial sweeteners causes adverse effects on the brain.


Want to stay mentally healthy in older age?


Stimulating the brain by taking on leadership roles at work or staying on in education help people stay mentally healthy in later life, according to new research.

The large-scale investigation published in the journal PLOS Medicine and led by the University of Exeter, used data from more than 2,000 mentally fit people over the age of 65, examined the theory that experiences in early or mid life which challenge the brain make people more resilient to changes resulting from age or illness - they have higher "cognitive reserve".

The analysis, funded by the Economic and Social Research Council (ESRC) found that people with higher levels of reserve are more likely to stay mentally fit for longer, making the brain more resilient to illnesses such as dementia.

The research team included collaborators from the universities of Bangor, Newcastle and Cambridge.

Linda Clare, Professor of Clinical Psychology of Ageing and Dementia at the University of Exeter, said: "Losing mental ability is not inevitable in later life. We know that we can all take action to increase our chances of maintaining our own mental health, through healthy living and engaging in stimulating activities. It's important that we understand how and why this occurs, so we can give people meaningful and effective measures to take control of living full and active lives into older age.

"People who engage in stimulating activity which stretches the brain, challenging it to use different strategies that exercise a variety of networks, have higher 'Cognitive reserve'. This builds a buffer in the brain, making it more resilient. It means signs of decline only become evident at a higher threshold of illness or decay than when this buffer is absent."

The research team analysed data from 2,315 mentally fit participants aged over 65 years who took part in the first wave of interviews for the Cognitive Function and Ageing Study Wales (CFAS-Wales).

They analysed whether a healthy lifestyle was associated with better performance on a mental ability test. They found that a healthy diet, more physical activity, more social and mentally stimulating activity and moderate alcohol consumption all seemed to boost cognitive performance.

Professor Bob Woods of Bangor University, who leads the CFAS Wales study, said: "We found that people with a healthier lifestyle had better scores on tests of mental ability, and this was partly accounted for by their level of cognitive reserve.

"Our results highlight the important of policies and measures that encourage older people to make changes in their diet, exercise more, and engage in more socially oriented and mentally stimulating activities."

Professor Fiona Matthews of Newcastle University, who is principal statistician on the CFAS studies, said "Many of the factors found here to be important are not only healthy for our brain, but also help at younger age avoiding heart disease".

Professor Clare is supported by the National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care South West Peninsula (NIHR PenCLAHRC).

Testing our the efficacy of brain stimulation is part one aspect of the PROTECT (Platform for Research Online to investigate Genetics and Cognition in Ageing) trial, which involves Professor Clare. It has already recruited 20,000 people over the age of 50. They are taking part in Exeter-led research to establish which lifestyle measures can make a meaningful difference to keep people stay physically and mentally active in older age.


Skip the soda, opt for the stairs to feel more energized



A midday jolt of caffeine isn't as powerful as walking up and down some stairs, according to new research from the University of Georgia.

In a new study published in the journal Physiology and Behavior, researchers in the UGA College of Education found that 10 minutes of walking up and down stairs at a regular pace was more likely to make participants feel energized than ingesting 50 milligrams of caffeine--about the equivalent to the amount in a can of soda.

"We found, in both the caffeine and the placebo conditions, that there was not much change in how they felt," said Patrick J. O'Connor, a professor in the department of kinesiology who co-authored the study with former graduate student Derek Randolph. "But with exercise they did feel more energetic and vigorous. It was a temporary feeling, felt immediately after the exercise, but with the 50 milligrams of caffeine, we didn't get as big an effect."

The study aimed to simulate the hurdles faced in a typical office setting, where workers spend hours sitting and staring at computer screens and don't have time for a longer bout of exercise during the day. For the study, participants on separate days either ingested capsules containing caffeine or a placebo, or spent 10 minutes walking up and down stairs--about 30 floors total--at a low-intensity pace.

O'Connor wanted to compare an exercise that could be achieved by people in an office setting, where they have access to stairs and a little time to be active, but not enough time to change into workout gear, shower and change back into work clothes.

"Office workers can go outside and walk, but weather can be less than ideal. It has never rained on me while walking the stairs," said O'Connor. "And a lot of people working in office buildings have access to stairs, so it's an option to keep some fitness while taking a short break from work."

Study participants were female college students who described themselves as chronically sleep deprived--getting less than 6½ hours per night. To test the effects of caffeine versus the exercise, each group took some verbal and computer-based tests to gauge how they felt and how well they performed certain cognitive tasks. Neither caffeine nor exercise caused large improvements in attention or memory, but stair walking was associated with a small increase in motivation for work.

O'Connor added that there is still much research to be done on the specific benefits of exercising on the stairs, especially for just 10 minutes. But even a brief bout of stair walking can enhance feelings of energy without reducing cognitive function. "You may not have time to go for a swim, but you might have 10 minutes to walk up and down the stairs."


Both sugary and diet drinks correlated with accelerated brain aging


Americans love sugar. Together we consumed nearly 11 million metric tons of it in 2016, according to the US Department of Agriculture, much of it in the form of sugar-sweetened beverages like sports drinks and soda.

Now, new research suggests that excess sugar -- especially the fructose in sugary drinks--might damage your brain. Researchers using data from the Framingham Heart Study (FHS) found that people who drink sugary beverages frequently are more likely to have poorer memory, smaller overall brain volume, and a significantly smaller hippocampus -- an area of the brain important for learning and memory.

But before you chuck your sweet tea and reach for a diet soda, there's more: a follow-up study found that people who drank diet soda daily were almost three times as likely to develop stroke and dementia when compared to those who did not.

Researchers are quick to point out that these findings, which appear separately in the journals Alzheimer's & Dementia and Stroke, demonstrate correlation but not cause-and-effect. While researchers caution against over-consuming either diet soda or sugary drinks, more research is needed to determine how -- or if -- these drinks actually damage the brain, and how much damage may be caused by underlying vascular disease or diabetes.

"These studies are not the be-all and end-all, but it's strong data and a very strong suggestion," says Sudha Seshadri, a professor of neurology at Boston University School of Medicine (MED) and a faculty member at BU's Alzheimer's Disease Center, who is senior author on both papers. "It looks like there is not very much of an upside to having sugary drinks, and substituting the sugar with artificial sweeteners doesn't seem to help."

"Maybe good old-fashioned water is something we need to get used to," she adds.

Matthew Pase, a fellow in the MED neurology department and an investigator at the FHS who is corresponding author on both papers, says that excess sugar has long been associated with cardiovascular and metabolic diseases like obesity, heart disease, and type 2 diabetes, but little is known about its long-term effects on the human brain. He chose to study sugary drinks as a way of examining overall sugar consumption. "It's difficult to measure overall sugar intake in the diet," he says, "so we used sugary beverages as a proxy."

For the first study, published in Alzheimer's & Dementia on March 5, 2017, researchers examined data, including magnetic resonance imaging (MRI) scans and cognitive testing results, from about 4,000 people enrolled in the Framingham Heart Study's Offspring and Third-Generation cohorts. (These are the children and grandchildren of the original FHS volunteers enrolled in 1948.) The researchers looked at people who consumed more than two sugary drinks a day of any type -- soda, fruit juice, and other soft drinks -- or more than three per week of soda alone. Among that "high intake" group, they found multiple signs of accelerated brain aging, including smaller overall brain volume, poorer episodic memory, and a shrunken hippocampus, all risk factors for early-stage Alzheimer's disease. Researchers also found that higher intake of diet soda--at least one per day--was associated with smaller brain volume.

In the second study, published in Stroke on April 20, 2017, the researchers, using data only from the older Offspring cohort, looked specifically at whether participants had suffered a stroke or been diagnosed with dementia due to Alzheimer's disease. After measuring volunteers' beverage intake at three points over seven years, the researchers then monitored the volunteers for 10 years, looking for evidence of stroke in 2,888 people over age 45, and dementia in 1,484 participants over age 60. Here they found, surprisingly, no correlation between sugary beverage intake and stroke or dementia. However, they found that people who drank at least one diet soda per day were almost three times as likely to develop stroke and dementia.

Although the researchers took age, smoking, diet quality, and other factors into account, they could not completely control for preexisting conditions like diabetes, which may have developed over the course of the study and is a known risk factor for dementia. Diabetics, as a group, drink more diet soda on average, as a way to limit their sugar consumption, and some of the correlation between diet soda intake and dementia may be due to diabetes, as well as other vascular risk factors. However, such preexisting conditions cannot wholly explain the new findings.

"It was somewhat surprising that diet soda consumption led to these outcomes," says Pase, noting that while prior studies have linked diet soda intake to stroke risk, the link with dementia was not previously known. He adds that the studies did not differentiate between types of artificial sweeteners and did not account for other possible sources of artificial sweeteners. He says that scientists have put forth various hypotheses about how artificial sweeteners may cause harm, from transforming gut bacteria to altering the brain's perception of "sweet," but "we need more work to figure out the underlying mechanisms."



Diet high in animal protein is associated withnon-alcoholic fatty liver disease


 A large epidemiological study presented today found that a diet high in animal protein was associated with a higher risk of non-alcoholic fatty liver disease (NAFLD), a condition in which fat builds up in the liver. These findings from The Rotterdam Study, presented at The International Liver Congress™ 2017 in Amsterdam, The Netherlands, also showed that fructose consumption per se might not be as harmful as previously assumed.

NAFLD is a major health concern, because it can lead to permanent scarring (cirrhosis) and subsequently to cancer and malfunction of the liver.1 This may result in life-threatening complications for which a liver transplant is needed. Additionally, NAFLD also contributes to an increased risk of cardiovascular diseases such as diabetes mellitus and atherosclerosis. NAFLD is diagnosed when accumulation of fat in the organ exceeds 5% of hepatocytes (the cells that make up the majority of the liver).2 It is estimated that approximately 1 billion people worldwide may have NAFLD with a prevalence of 20-30% in Western countries.3 It parallels one of world's most rapidly growing health concerns, obesity, which is also one of the most important risk factors in NAFLD.3 In its early stages NAFLD can be treated through diet and lifestyle changes, such as weight loss, but it can progress to more serious liver diseases.1 However, there is still a lot of debate whether weight loss alone is enough to reverse NAFLD, while emerging evidence suggests that the composition of the diet, rather than the amount of calories consumed, might also be important in NAFLD.

"A healthy lifestyle is the cornerstone of treatment in patients with NAFLD, but specific dietary recommendations are lacking," said Louise Alferink (MD), Erasmus Medical Centre, Rotterdam, The Netherlands, and lead author of the study. "The results from this study demonstrate that animal protein is associated with NAFLD in overweight elderly people. This is in line with a recently proposed hypothesis that a Western-style diet, rich in animal proteins and refined food items, may cause low-grade disturbances to the body homeostasis, glucose metabolism and acid based balance. Another interesting finding is that, although current guidelines advise against foods containing fructose, such as soda and sugar, our results do not indicate a harmful association of mono- and disaccharides with NAFLD per se. In fact, we even found a slight beneficial association, which was attenuated when adjusted for metabolic factors. These results should be interpreted with caution, but we hypothesise that increased consumption of healthy food items within the mono- and disaccharide-group, such as fruits and vegetables rich in antioxidants, could partly explain these results."

The Rotterdam Study is an ongoing population-based study that is being conducted in The Netherlands. A total of 3,440 people were included in the study of whom 1,040 (30%) were lean (body mass index [BMI] of less than 25 kg/m2) and 2,400 (70%) were overweight (BMI of 25 kg/m2 or greater). The average age was 71 years and NAFLD, as assessed by abdominal ultrasound, was present in 1,191 (35%) of the participants. Macronutrient intake was recorded using an externally validated 389-item food frequency questionnaire and analysed in quartiles using the nutrition density method (energy percentage). Furthermore, analyses were stratified for BMI to account for BMI-related differences in eating habits and dietary measurement errors.

Significant associations between macronutrients and NAFLD were found predominantly in overweight individuals. The results showed that total protein was associated with higher odds of NAFLD (ORQ4vs.Q1 1.37; 95% CI 1.08-1.73, Ptrend=0.005) and this association was mainly driven by animal protein (ORQ4vs.Q1 1.50; 95% CI 1.17-1.92, Ptrend=0.003). After adjustments for metabolic factors, animal protein but not total protein remained significantly associated. In addition, a diet rich in mono- and disaccharides was associated with a lower probability of developing NAFLD (ORQ4vs.Q1 0.67; 95% CI 0.51-0.89, Ptrend=0.006), though this association did not remain after metabolic factors were taken into account. Finally, substitution analyses were performed to examine whether replacing one macronutrient by another (isocaloric) macronutrient was associated with NAFLD. No consistent substitution effects were found, which stresses the need for a diverse diet.

"This large population-based study indicates that increased dietary protein, in particular of animal origin, increases the likelihood of developing NAFLD and should be taken into account when counselling patients at risk of developing NAFLD," said Prof Philip Newsome, Centre for Liver Research & Professor of Experimental Hepatology, University of Birmingham, United Kingdom, and EASL Governing Board Member.


Wednesday, April 19, 2017

With beetroot juice before exercise, aging brains look 'younger'


Drinking a beetroot juice supplement before working out makes the brain of older adults perform more efficiently, mirroring the operations of a younger brain, according to a new study by scientists at Wake Forest University.

"We knew, going in, that a number of studies had shown that exercise has positive effects on the brain," said W. Jack Rejeski, study co-author. "But what we showed in this brief training study of hypertensive older adults was that, as compared to exercise alone, adding a beet root juice supplement to exercise resulted in brain connectivity that closely resembles what you see in younger adults."

While continued work in this area is needed to replicate and extend these exciting findings, they do suggest that what we eat as we age could be critically important to the maintenance of our brain health and functional independence.

Rejeski is Thurman D. Kitchin Professor and Director of the Behavioral Medicine Laboratory in the Department of Health & Exercise Science. The study, "Beet Root Juice: An Ergogenic Aid for Exercise and the Aging Brain," was published in the peer-reviewed Journals of Gerontology: Medical Sciences. One of his former undergraduate students, Meredith Petrie, was the lead author on the paper.

This is the first experiment to test the combined effects of exercise and beetroot juice on functional brain networks in the motor cortex and secondary connections between the motor cortex and the insula, which support mobility, Rejeski said.

The study included 26 men and women age 55 and older who did not exercise, had high blood pressure, and took no more than two medications for high blood pressure. Three times a week for six weeks, they drank a beetroot juice supplement called Beet-It Sport Shot one hour before a moderately intense, 50-minute walk on a treadmill. Half the participants received Beet-It containing 560 mg of nitrate; the others received a placebo Beet-It with very little nitrate.

Beets contain a high level of dietary nitrate, which is converted to nitrite and then nitric oxide (NO) when consumed. NO increases blood flow in the body, and multiple studies have shown it can improve exercise performance in people of various ages.

"Nitric oxide is a really powerful molecule. It goes to the areas of the body which are hypoxic, or needing oxygen, and the brain is a heavy feeder of oxygen in your body," said Rejeski.

When you exercise, the brain's somatomotor cortex, which processes information from the muscles, sorts out the cues coming in from the body. Exercise should strengthen the somatomotor cortex.

So, combining beetroot juice with exercise delivers even more oxygen to the brain and creates an excellent environment for strengthening the somatomotor cortex. Post-exercise analysis showed that, although the study groups has similar levels of nitrate and nitrite in the blood before drinking the juice, the beetroot juice group had much higher levels of nitrate and nitrite than the placebo group after exercise.
  • This research is among the latest in a series of findings concerning the effects of beets on health:
  • Drinking beet juice can increase blood flow to the brain in older adults, according to a 2010 study out of Wake Forest published in Nitric Oxide: Biology and Chemistry. This was the first study to link beet consumption and blood flow to the brain.
  • A daily does of beetroot juice significantly improved exercise endurance and blood pressure in elderly patients with heart failure with preserved ejection fraction, according to a Wake Forest study published in the Journal of the American College of Cardiology-Heart Failure in 2016.
  • Consuming whole beets improved running performance among fit adults, according to a 2012 study in the Journal of the Academy of Nutrition and Dietetics.
  • Beetroot juice helped chronic obstructive pulmonary disease (COPD) patients increase exercise time, according to a 2015 Wake Forest study published in Nitric Oxide: Biology and Chemistry.
  • Blood pressure dropped after drinking beetroot juice, according to a study published in Hypertension in 2008.

Differing recommendations for statin


Fewer people could be recommended for primary prevention statin therapy, including many younger adults with high long-term cardiovascular disease risk, if physicians adhere to the 2016 U.S. Preventive Services Task Force (USPSTF) recommendations for statin therapy compared with the 2013 American College of Cardiology/American Heart Association (ACC/AHA) guidelines, according to a study published by JAMA.

The 2013 ACC/AHA guidelines substantially expanded the population eligible for statin therapy by basing recommendations on an elevated 10-year risk of atherosclerotic cardiovascular disease (ASCVD). The 2016 USPSTF recommendations for primary prevention statin therapy increased the estimated ASCVD risk threshold for patients (including those with diabetes) and required the presence of at least one cardiovascular risk factor (i.e., hypertension, diabetes, dyslipidemia, or smoking) in addition to elevated risk.

Michael J. Pencina, Ph.D., of Duke University, Durham, N.C., and colleagues used National Health and Nutrition Examination Survey (NHANES) data (2009-2014) to assess statin eligibility under the 2016 USPSTF recommendations vs the 2013 ACC/AHA cholesterol guidelines among a nationally representative sample of 3,416 U.S. adults ages 40 to 75 years with fasting lipid data and triglyceride levels of 400 mg/dl or less, without prior cardiovascular disease (CVD).

The researchers found that if fully implemented, the USPSTF recommendations would be associated with statin initiation in 16 percent of adults without prior CVD, in addition to the 22 percent of adults already taking lipid-lowering therapy; in comparison, the ACC/AHA guidelines would be associated with statin initiation in an additional 24 percent of patients. Among the 8.9 percent of individuals in the primary prevention population who would be recommended for statins by ACC/AHA guidelines but not by USPSTF recommendations, 55 percent would be adults ages 40 to 59 years with an average 30-year cardiovascular risk greater than 30 percent, and 28 percent would have diabetes.

"If these estimates are accurate and assuming these proportions can be projected to the U.S. population, there could be an estimated 17.1 million vs 26.4 million U.S. adults with a new recommendation for statin therapy, based on the USPSTF recommendations vs the ACC/AHA guideline recommendations, respectively -- an estimated difference of 9.3 million individuals," the authors write.

"Alternative approaches to augmenting risk-based cholesterol guidelines, including those that explicitly incorporate potential benefit of therapy, should be considered."


Salty diet makes you hungry, not thirsty



We've all heard it: eating salty foods makes you thirstier. But what sounds like good nutritional advice turns out to be not true in the long-run. In a study carried out during a simulated mission to Mars, an international group of scientists has found exactly the opposite to be true. "Cosmonauts" who ate more salt retained more water, weren't as thirsty, and needed more energy.

For some reason, no one had ever carried out a long-term study to determine the relationship between the amount of salt in a person's diet and his drinking habits. Scientists have known that increasing a person's salt intake stimulates the production of more urine -- it has simply been assumed that the extra fluid comes from drinking. 

Not so fast! say researchers from the German Aerospace Center (DLR), the Max Delbrück Center for Molecular Medicine (MDC), Vanderbilt University and colleagues around the world. Recently they took advantage of a simulated mission to Mars to put the old adage to the test. Their conclusions appear in two papers in the current issue of The Journal of Clinical Investigation.

What does salt have to do with Mars? Nothing, really, except that on a long space voyage conserving every drop of water might be crucial. A connection between salt intake and drinking could affect your calculations -- you wouldn't want an interplanetary traveler to die because he liked an occasional pinch of salt on his food. The real interest in the simulation, however, was that it provided an environment in which every aspect of a person's nutrition, water consumption, and salt intake could be controlled and measured.

The studies were carried out by Natalia Rakova (MD, PhD) of the Charité and MDC and her colleagues. The subjects were two groups of 10 male volunteers sealed into a mock spaceship for two simulated flights to Mars. The first group was examined for 105 days; the second over 205 days. They had identical diets except that over periods lasting several weeks, they were given three different levels of salt in their food.

The results confirmed that eating more salt led to a higher salt content in urine -- no surprise there. Nor was there any surprise in a correlation between amounts of salt and overall quantity of urine. But the increase wasn't due to more drinking -- in fact, a salty diet caused the subjects to drink less. Salt was triggering a mechanism to conserve water in the kidneys.

Before the study, the prevailing hypothesis had been that the charged sodium and chloride ions in salt grabbed onto water molecules and dragged them into the urine. The new results showed something different: salt stayed in the urine, while water moved back into the kidney and body. This was completely puzzling to Prof. Jens Titze, MD of the University of Erlangen and Vanderbilt University Medical Center and his colleagues. "What alternative driving force could make water move back?" Titze asked.

Experiments in mice hinted that urea might be involved. Higher salt didn't increase their thirst, but it did make them hungrier. Also the human "cosmonauts" receiving a salty diet complained about being hungry.

The project revises scientists' view of the function of urea in our bodies. "It's not solely a waste product, as has been assumed," Prof. Friedrich C. Luft, MD of the Charité and MDC says. "Instead, it turns out to be a very important osmolyte -- a compound that binds to water and helps transport it. Its function is to keep water in when our bodies get rid of salt. Nature has apparently found a way to conserve water that would otherwise be carried away into the urine by salt."

The new findings change the way scientists have thought about the process by which the body achieves water homeostasis -- maintaining a proper amount and balance. That must happen whether a body is being sent to Mars or not. "We now have to see this process as a concerted activity of the liver, muscle and kidney," says Jens Titze.

"While we didn't directly address blood pressure and other aspects of the cardiovascular system, it's also clear that their functions are tightly connected to water homeostasis and energy metabolism."
 


 

Tuesday, April 18, 2017

High-fat, high-carb diet a cause of osteoarthritis


Saturated fat is a prime suspect in the onset of osteoarthritis after QUT scientists found it changed the composition of cartilage, particularly in the weight-bearing joints of the hip and knee.

Research, published today in Scientific Reports, conducted by Professor Yin Xiao, from QUT's Institute of Health and Biomedical Innovation and his team, in collaboration with Professor Lindsay Brown and his team at University of Southern Queensland, is possibly the first study to investigate the association between osteoarthritis and common dietary fatty acids.

The researchers studied the effects on joints of diets rich in a variety of saturated fatty acids found in such foods as butter, coconut oil, palm oil and animal fat, and simple carbohydrates - a high-fat, high carbohydrate diet common to "junk food".

"Our findings suggest that it's not wear and tear but diet that has a lot to do with the onset of osteoarthritis," Professor Xiao said.

"The main function of cartilage is to seal the bone ends in a joint and absorb pressure on the bones during weight-bearing movement such as walking.

"We found that a diet containing simple carbohydrates together with 20 per cent saturated fats produced osteoarthritic-like changes in the knee.

"Saturated fatty acid deposits in the cartilage change its metabolism and weaken the cartilage, making it more prone to damage. This would, in turn, lead to osteoarthritic pain from the loss of the cushioning effect of cartilage.

"We also found changes in the bone under the cartilage on a diet rich in saturated fat."

PhD student Sunder Sekar said the team tested lauric acid, a saturated fatty acid found in coconut oil.

"Interestingly, when we replaced the meat fat in the diet with lauric acid we found decreased signs of cartilage deterioration and metabolic syndrome so it seems to have a protective effect," Mr Sekar said.

He said fatty acids could cause tissue inflammation in the entire "joint environment".

"We tested a variety of saturated fats and found that long term use of animal fat, butter, and palm oil could weaken the cartilage.

"Replacement of traditional diets containing coconut-derived lauric acid with palm oil-derived palmitic acid or animal fat-derived stearic acid has the potential to worsen the development of both metabolic syndrome and osteoarthritis."

Professor Xiao's previous research has found that antioxidants and anti-cholesterol drugs could slow the progression of joint damage caused by fatty acids.

Wednesday, April 12, 2017

Exercise associated with improved heart attack survival



Exercise is associated with improved survival after a heart attack, according to research published today in the European Journal of Preventive Cardiology. The chances of survival increased as the amount of exercise rose.

"We know that exercise protects people against having a heart attack," said last author Professor Eva Prescott, professor of cardiovascular prevention and rehabilitation, University of Copenhagen, Denmark. "Animal studies suggest that myocardial infarctions are smaller and less likely to be fatal in animals that exercise. We wanted to see if exercise was linked with less serious myocardial infarctions in people."

The study included 14 223 participants of the Copenhagen City Heart Study who had never had a heart attack or stroke. Levels of physical activity were assessed at baseline in 1976-1978 and classified as sedentary, light, moderate, or high.2

Participants were followed through registries until 2013. A total of 1 664 participants had a myocardial infarction, of whom 425 died immediately.

The investigators compared levels of physical activity between those who died immediately from their myocardial infarction and those who survived. They found that patients who exercised were less likely to die from their myocardial infarction.

There was a dose-response relationship between exercise and death from myocardial infarction. Patients with light or moderate/high physical activity levels were 32% and 47% less likely to die from their myocardial infarction, respectively, than sedentary patients.

Professor Prescott said: "Patients who were sedentary were more likely to die when they got a myocardial infarction and patients who did exercise were more likely to survive. There was also a dose-response relationship, so that the odds of dying if people got a myocardial infarction declined with the level of exercise they did, reaching an almost 50% reduction for those who were the most physically active."

"One possible explanation is that people who exercise may develop collateral blood vessels in the heart which ensure the heart continues to get enough blood after a blockage," she continued. "Exercise may also increase levels of chemical substances that improve blood flow and reduce injury to the heart from a heart attack."

Professor Prescott said: "This was an observational study so we cannot conclude that the associations are causal. The results need to be confirmed before we can make strong recommendations. But I think it's safe to say that we already knew exercise was good for health and this might indicate that continuing to exercise even after developing atherosclerosis may reduce the seriousness of a heart attack if it does occur."


Restrictions on trans-fatty acid consumption associated with decrease in hospitalization for heart attack


There has been a greater decline in hospitalizations for cardiovascular events (heart attack and stroke combined) in New York counties that enacted restrictions on trans-fatty acids in eateries compared with counties without restrictions, according to a study published by JAMA Cardiology.

Consumption of trans-fatty acids (TFAs) is associated with an elevated risk for cardiovascular disease. Trans-fatty acids primarily enter the diet via partially hydrogenated oils (PHOs) used in baked goods, yeast breads, fried foods, chips, crackers, and margarine. Given the harmful effects of TFAs, many have advocated minimizing or eliminating their use. New York City was the first large metropolitan area in the United States to restrict TFAs in eateries, starting July 2007. Similar TFA restrictions were subsequently enacted in additional New York State (NYS) counties. The U.S. Food and Drug Administration plans a nationwide restriction in 2018. Public health implications of TFA restrictions are not well understood.

Eric J. Brandt, M.D., of the Yale University School of Medicine, New Haven, Conn., and colleagues conducted a study of residents in counties with TFA restrictions vs counties without restrictions from 2002 to 2013 using NYS Department of Health's Statewide Planning and Research Cooperative System and census population estimates, and included residents who were hospitalized for heart attack or stroke.

In 2006, the year before the first restrictions were implemented, there were 8.4 million adults in highly urban counties with TFA restrictions and 3.3 million adults in highly urban counties without restrictions. Twenty-five counties were included in the nonrestriction population and 11 in the restriction population. Three or more years after restriction implementation, the population with TFA restrictions experienced significant additional decline beyond temporal trends in heart attack and stroke events combined (-6.2 percent) and heart attack (-7.8 percent) and a nonsignificant decline in stroke (-3.6 percent) compared with the nonrestriction populations.

"Our results show the potential benefit of the FDA's comprehensive restriction on PHOs, which is the source of TFAs in most packaged food," the authors write.

Some "healthy" foods may not be good for you


A researcher is suggesting the types of cooking oils people consume may be sabotaging their efforts to stay healthy and avoid illnesses such as diabetes.

Sanjoy Ghosh, a Michael Smith Health Research Foundation Scholar and a professor at UBC's Okanagan campus, has recently published research that concludes a high consumption of polyunsaturated fatty acids (PUFA) but not monounsaturated fatty acids (MUFA) can lead to sedentary, in fact, lazy behaviour especially in women .

Ghosh says not that long ago, heart disease was linked to saturated fats--an idea that has become increasingly controversial in recent years. This thinking instigated the intentional removal of saturated fatty acids from most food supplies in favour of MUFA and PUFA. Essentially all fats in our 'convenience' foods like potato chips, energy bars, crackers or burgers use cooking oils like corn, sunflower and soybean and margarine--all rich in MUFAs and PUFAs.

For his research, Ghosh collaborated with UBC biologist and data analyst Jason Pither, the first-author of the study, to examine data from 21 countries in Europe. They worked specifically with data relating to pre-teen girls and then, in a second study, the blood glucose levels of adult women. In putting details such as the amount of time each week spent watching TV along with other filters like a country's per capital GDP, urbanization, and even latitude, they came out with a clear connection to the consumption of n-6 polyunsaturated fatty acids and an increase in sedentary behaviour.

In particular, a significant correlation was observed in sedentary behaviour of the 11-year-old girls and PUFA in their diets.

"Our study does present new evidence that dietary PUFA is strongly associated with sedentary behavior among pre-teen girls and weakly associated with diabetes among adult women across Europe," says Ghosh, recommending for more trials and studies to confirm his findings.

"This data is extremely significant," says Ghosh. "Nobody has made this connection and it's time for an intervention. And if someone is beginning an exercise program without taking a close look at the fats, especially PUFA they are consuming, or changing what they're eating, then it might be doomed to failure."

Foods and oils with higher amounts of polyunsaturated fats include:
  • Walnuts.
  • Sunflower seeds.
  • Flax seeds or flax oil.
  • Fish, such as salmon, mackerel, herring, albacore tuna, and trout.
  • Corn oil.
  • Soybean oil.
  • Safflower oil.


Statins reduce the risk of heart attacks for individuals with normal cholesterol levels can also


Most major heart attacks occur in people with normal cholesterol

For decades, national guidelines on which Americans should take cholesterol-lowering medications relied heavily on an individual's level of bad cholesterol (LDL). In 2013, new guidelines moved to treatment based on a person's overall heart attack risk.

"The data on statins clearly shows that individuals with normal cholesterol levels can also reduce their risk of heart attacks," said Michael Miedema, MD, MPH, cardiologist with Minneapolis Heart Institute® and principal investigator for a Minneapolis Heart Institute Foundation® study of the new guidelines.

However, the study found that more than half of the patients had not seen a physician in the two years prior to their heart attacks.

"The more recent cholesterol guidelines are clearly a big step in the right direction, but we need to have better systems and incentives in place to get patients the assessment and treatments that could potentially be life-saving," Miedema said.

When the more recent cholesterol guidelines were applied, the patients were twice as likely to be eligible for a statin prior to their heart attacks compared to the older guidelines that relied on cholesterol levels. Seventy-nine percent were statin eligible according to the newer guidelines, compared to 39 percent that qualified by the older guidelines.

"Heart disease is a multifactorial process, and factors others than cholesterol, like smoking or high blood pressure, can raise your risk even if your cholesterol is normal. In fact, we found that the average cholesterol levels in this group of individuals were quite average," Miedema said.

Minneapolis Heart Institute Foundation researchers analyzed risk factor data, cholesterol values, and prior medical encounters in 1,062 patients who were treated for STEMI heart attacks between January 1, 2011 and December 31, 2014 as part of Minneapolis Heart Institute® regional STEMI program. A STEMI, or ST-Elevation Myocardial Infarction, is one of the most serious cardiovascular events, as it can frequently lead to severe damage to the heart and even cardiac arrest.

Tuesday, April 11, 2017

Fresh fruit consumption linked to lower risk of diabetes and diabetic complications


In a research article published in PLOS Medicine, Huaidong Du of the University of Oxford, Oxford, United Kingdom and colleagues report that greater consumption of fresh fruit was associated with a lower incidence of diabetes, as well as reduced occurrence of complications in people with diabetes, in a Chinese population.

Although the health benefits of diets including fresh fruit and vegetables are well established, the sugar content of fruit has led to uncertainty about associated risks of diabetes and of vascular complications of the disease. Du and colleagues studied nearly 500,000 people participating in the China Kadoorie Biobank over about 7 years of follow-up, documenting new cases of diabetes and recording the occurrence of vascular disease and death in people with pre-existing diabetes.

The researchers found that people who reported elevated consumption of fresh fruit had a lower associated risk of developing diabetes in comparison with other participants (adjusted hazard ratio [aHR] 0.88, 95% CI 0.83-0.93), which corresponds to an estimated 0.2% reduction in the absolute risk of diabetes over 5 years.

In people with diabetes, higher consumption of fresh fruit was associated with a lower risk of mortality (aHR 0.83, 95% CI 0.74-0.93 per 100g fruit/d), corresponding to an absolute decrease in risk of 1.9% at 5 years, and with lower risks of microvascular and macrovascular complications.

In addition to the health benefits of consuming fresh fruit, Du and colleagues emphasize the value of their findings for Asian populations where fruit consumption is commonly restricted in people with diabetes. The main limitation of this observational study is that the effects of fruit consumption can be difficult to distinguish from those of participants' other dietary and behavioural characteristics.

Monday, April 10, 2017

Life skills are important for wellbeing in later life



Life skills, such as persistence, conscientiousness and control, are as important to wealth and wellbeing in later life as they are when people are much younger, according to new research led by UCL.

Five life skills - emotional stability, determination, control, optimism and conscientiousness - play a key role in promoting educational and occupational success in early life but little has been known about their importance in later life.

In the study, published in the journal PNAS, the academics looked at the impact of these attributes in over 8,000 men and women aged 52 and older who took part in the English Longitudinal Study of Aging.

The researchers found that people who have more life skills enjoy a range of benefits including greater financial stability, less depression, low social isolation, better health and fewer chronic diseases.

They benefitted from favourable objective biomarkers in the blood including lower levels of cholesterol and of C-reactive protein, a marker of inflammation relevant to a number of different diseases. They also had smaller waistlines, where fat accumulation is particularly relevant to metabolic and cardiovascular diseases, than people with few life skills.

"No single attribute was more important than others. Rather, the effects depended on the accumulation of life skills," said Professor Andrew Steptoe (UCL Epidemiology and Public Health), who co-led the research.

The study found a range of health and social outcomes depending on the number of life skills a person has. For example, the proportion of participants reporting significant depressive symptoms declined from 22.8% among those with low life skills to 3.1% in those with four or five skills.

Nearly half the people who reported the highest levels of loneliness had the fewest skills, declining to 10.5% in those with four or five attributes. Regular volunteering rose from 28.7% to 40% with increasing numbers of life skills.

In terms of health, the proportion of respondents who rated their health as only fair or poor was 36.7% among those with low life skills, falling to 6% in participants with a higher number of attributes.. People with more skills walked significantly faster than those with fewer- walking speed is an objective measure predicting future mortality in older population samples.

Although causal conclusions cannot be drawn from observational studies, the researchers took cognitive function, education and family background into account, ruling them out as being responsible for the outcomes associated with life skills.

"There is research on individual factors such as conscientiousness and optimism in adults, but the combinations of these life skills has not be studied very much before", said Steptoe.

"We were surprised by the range of processes - economic, social, psychological, biological, and health and disability related - that seem to be related to these life skills. Our research suggests that fostering and maintaining these skills in adult life may be relevant to health and wellbeing at older ages."


Patients uncertain about how to best manage their cholesterol



People who have high cholesterol may understand they need to manage their condition, but many aren't sure how to do that, nor do they feel confident they can, according to a new survey from the American Heart Association.

The survey was conducted as part of Check.Change.Control.Cholesterol™, the association's new initiative to help people better understand and manage their overall risk for cardiovascular disease, especially as it relates to cholesterol. Participants included nearly 800 people from across the country with either a history of cardiovascular disease (e.g. heart attack, stroke) or at least one major cardiovascular disease risk factor, (e.g. high blood pressure, high cholesterol or diabetes).

"We wanted to get a sense of what people know about their cholesterol risk and its connection to heart disease and stroke, as well as how people engage with their healthcare providers to manage their risks," said Mary Ann Bauman, M.D., a member of the American Heart Association's cholesterol advisory group. "We found even among those people at the highest risk for heart disease and stroke, overall knowledge was lacking and there was a major disconnect between perceptions about cholesterol and the significance of its health impact."

High cholesterol is a known risk factor for heart disease and stroke, causing about 2.6 million deaths each year. Yet, nearly half (47 percent) of survey respondents with a known history of or at least one risk factor for heart disease or stroke, had not had their cholesterol checked within the past year. Respondents with high cholesterol reported more recent testing, although 21 percent of them had not had their cholesterol checked in the past year.

Among other survey findings:

Most people with high cholesterol said they understood the importance of managing their cholesterol, being confused, discouraged and uncertain about their ability to do so.
82 percent of all respondents identified a link between cholesterol and risk for heart disease and stroke.
Overall, people with a history of cardiovascular had lower perceptions of their real medical risk of cardiovascular disease.
Patients with a history of cardiovascular disease are at high risk for having another cardiovascular disease event, but among these patients, only 29 percent recognized they were high risk for another cardiovascular disease event.
Primary care providers were the healthcare professionals who participants talked about cholesterol with most often, and were more likely the ones to first diagnose high cholesterol.
The most common treatment recommendation given by healthcare providers were medication (79 percent), exercise (78 percent) and diet modifications (70 percent).
Patients with high cholesterol felt they were least informed about what should be their target body weight, the differences between the types of cholesterol (LDL vs HDL) and goals for cholesterol management.
Nearly 94.6 million, or 40 percent, of American adults, have total cholesterol above 200 mg/dL with approximately 12 percent over 240 mg/dL.

"Research suggests even modestly elevated cholesterol levels can lead to heart disease later in life, but these survey results show an alarming lack of communication between healthcare providers and those most at risk for cardiovascular disease," Bauman said. "Current guidelines call for lifestyle modifications as a first line treatment, but that's often not enough. We also need to talk to patients about other risk factors, including genetics and family history, to determine the most effective course of treatment for each individual."

The Check.Change.Control.Cholesterol™ initiative combines a public awareness campaign with guideline-based best practices to help providers and patients work together to identify cardiovascular health risks and agree on a treatment plan to improve health. Through the initiative, a pilot project will be carried out in select practices across the country. Learnings from the pilot project will help structure a national clinical initiative to be rolled out next year.

A national cholesterol summit will convene on April 11 in Dallas to bring together cholesterol patients, healthcare providers and other stakeholder leaders to discuss gaps in cholesterol management goals -- from diagnosis to treatment to adherence. The group's goal is to identify tangible, actionable solutions that can be implemented through the new cholesterol initiative.

###

Check.Change.Control.Cholesterol™ is nationally supported by Sanofi and Regeneron. Learn more about the new initiative at heart.org/CheckChangeControlCholesterol.

Weak grip a strong predictor of metabolic disease and disability in adults


A simple test to determine a person's grip strength may be a predictor of developing metabolic disorders in middle or older age, a new cross-continental study has found.

The test locations, demographics and methodology all were selected for a reason.

"Prevalence of chronic disease is highest in the U.S. and China," says Mark Peterson, Ph.D., M.S., FACSM, assistant professor of physical medicine and rehabilitation at Michigan Medicine and a member of the U-M Global Research, Education and Collaboration in Health and Institute for Healthcare Policy and Innovation. "There's a dire need to identify midlife predictors of disability and diabetes in both populations."

Peterson is the lead author on a new study, published in Journals of Gerontology Series A: Medical Sciences, that investigated if normalized grip strength -- which is defined as a person's grip strength divided by their body mass -- could serve as a biomarker for both cardiometabolic disease and physical disability in American and Chinese adults.

He teamed up with colleagues from the U-M School of Public Health, Michigan Medicine's Global REACH, the Institute for Social Science Survey and the National School of Development at Peking University in Beijing, China.

One reason for the study's geographic focus: "China represents a unique population," Peterson says. "It's the world's largest population of diabetics, which imposes a huge health and economic burden on their entire country."

He adds, "In 2015, China and the U.S. had a combined $320 billion in diabetes-related health care costs, according to the International Diabetes Federation. The aging populations in both countries are growing because of improved medical care of older adults and longer life expectancy. While on one hand that's great, on the other, it represents two populations that have increasing prevalence estimates of diabetes, cardiovascular health issues and functional impairments. The longer people live with those health issues, the greater the burden is to society."

Analyzing data sets

The research team used data on middle-aged and older adults from the U.S. National Health and Nutrition Examination Survey from 2011 to 2012 and 2013 to 2014, and the 2011 portion of the China Health and Retirement Longitudinal Study. These surveys were selected because they included measures of muscle strength capacity and the necessary information pertaining to disability and cardiometabolic diseases.

"We wanted to examine grip strength in particular because it is highly associated with overall body strength," Peterson says. "To asses someone's grip strength using a handgrip dynamometer takes less than 10 seconds, which makes it extremely attractive to adopt in a clinical or community setting at the population level."

The research team analyzed normalized grip strength for 4,544 U.S. and 6,030 Chinese study participants 50 years of age and older. The study group also had blood samples taken for nonfasting glycated hemoglobin and answered a questionnaire about impairments of functional limitation related to mobility. A subsample of 2,225 adults had fasting measures for glucose, insulin and triglycerides.
Using weighted logistic regression models, the team assessed the association between normalized grip strength and diabetes, hyperglycemia, hypertriglyceridemia, low HDL cholesterol, hypertension and physical disability. They controlled for age, sex and numerous socio-demographic characteristics.

A strong connection

Perhaps the largest finding of the study was that low normalized grip strength was greatly associated with both cardiometabolic diseases and physical disabilities in middle-age to older adults, both men and women, and in both the U.S. and Chinese populations.

For every 0.05 decrement in normalized grip strength in U.S. and Chinese adults, respectively, there were:
    - 49 percent and 17 percent increased odds for diabetes - 46 percent and 11 percent increased odds of hyperglycemia
    - 15 percent and 11 percent increased odds of hypertriglyceridemia
    - 22 percent and 15 percent increased odds of low HDL cholesterol
    - 19 percent and 10 percent increased odds of hypertension
    - 36 percent and 11 percent increased odds for disability status
Other highlights from the research team included:
    - Prevalence of physical disabilities was higher among older adults (65 years old and older) compared to middle-aged adults (50 years old to 64.9 years old) in both populations. - In U.S. adults, physical disability status, obesity and abdominal obesity were more prevalent, and diabetes prevalence was higher with increasing age in U.S. men.
    - In Chinese adults, diabetes prevalence was higher for women than men in both middle-aged and older adults.
    - Diabetes was more prevalent in U.S. than Chinese men in both age categories, but more prevalent in Chinese women than U.S. women.
    - Normalized grip strength was higher in Chinese men and women than U.S. men and women in both age categories.

Friday, April 7, 2017

Increased pulse consumption could address nutrition issues related to the health of the overall human population, as well as the planet.


A special issue of Annals published by the New York Academy of Sciences, stresses how increased pulse consumption could address nutrition issues related to the health of the overall human population, as well as the planet.

Pulses are members of the legume family and include beans. dried peas, edible lentils, and chickpeas. They are high in protein and fiber, and low in fat. They are affordable, have a high nutrient density, and contribute to the sustainability of agricultural systems as a nitrogen fixing crop. The United Nations supports the increase of pulse production and consumption by 10% by 2020, as well as improving market access to the legumes. As a food source, pulses have the potential to offer cost-effective solutions for global nutrition as well as health and sustainability concerns, if consumed in greater amounts.

In one of the papers, experts in food processing, human health, food and nutritional security, global trade, agriculture, and environmental science have developed a common vision and action plan to reach the United Nation's goals for pulse consumption by 2020. They agreed that a committed group of pulse industry stakeholders must work together to create a research agenda focused on shifting consumer behavior towards greater pulse consumption.

Authors highlight the needs for multi-sectoral partnerships to realize these goals through developing policies, regulations, guidelines and public intervention programs promoting pulse consumption. Data from the research community must be leveraged to offer effective evidence-based solutions. More importantly such research must then be incorporated into a comprehensive communications agenda that addresses consumers' lack of familiarity with pulses as a beneficial food source.

Secondly, the authors emphasized that to meet the goals, experts must provide solutions to increase pulse yields while reducing input costs through improved, integrated crop-management practices. New technologies must be utilized to improve pulse varieties that are adapted to local agro-climatic conditions, suited for mechanical harvest, and possess traits valued by global markets and end users. Additionally barriers to access in existing and emerging markets should be addressed.


Thursday, April 6, 2017

Mayo Clinic second opinion: 98 percent of those patients go home with a new or refined diagnosis


Many patients come to Mayo Clinic for a second opinion or diagnosis confirmation before treatment for a complex condition. In a new study, Mayo Clinic reports that as many as 88 percent of those patients go home with a new or refined diagnosis -- changing their care plan and potentially their lives. Conversely, only 12 percent receive confirmation that the original diagnosis was complete and correct.

These findings were published online today in the Journal of Evaluation in Clinical Practice. The research team was led by James Naessens, Sc.D., a health care policy researcher at Mayo Clinic.

Why get a second opinion

When people are sick, they look to their doctor to find solutions. However, physicians don't always have the answers. Often, because of the unusual nature of the symptoms or complexity of the condition, the physician will recommend a second opinion. Other times, the patient will ask for one.

This second opinion could lead to quicker access to lifesaving treatment or stopping unnecessary treatments. And a second opinion may reduce stress in a patient's extended family, when they learn the new diagnosis does not carry dire genetic implications. These scenarios can result from diagnostic error.

Odds are good the diagnosis will be adjusted

To determine the extent of diagnostic error, the researchers examined the records of 286 patients referred from primary care providers to Mayo Clinic's General Internal Medicine Division in Rochester over a two-year period (Jan. 1, 2009, to Dec. 31, 2010). This group of referrals was previously studied for a related topic. It consisted of all patients referred by nurse practitioners and physician assistants, along with an equal number of randomly selected physician referrals.

The team compared the referring diagnosis to the final diagnosis to determine the level of consistency between the two and, thus, the level of diagnostic error. In only 12 percent of the cases was the diagnosis confirmed.

In 21 percent of the cases, the diagnosis was completely changed; and 66 percent of patients received a refined or redefined diagnosis. There were no significant differences between provider types.

"Effective and efficient treatment depends on the right diagnosis," says Dr. Naessens. "Knowing that more than 1 out of every 5 referral patients may be completely [and] incorrectly diagnosed is troubling -- not only because of the safety risks for these patients prior to correct diagnosis, but also because of the patients we assume are not being referred at all."

Risks of cost containment

To manage costs in a health care environment with ever-increasing costs, health insurers often limit access to care outside their network, effectively limiting referrals. Further, primary care providers may be more confident in their diagnostic expertise than warranted in a particular case, or patients may lack the knowledge or assertiveness to request a referral.

"This may prevent identification of diagnostic error, and could lead treatment delays, complications leading to more costly treatments, or even patient harm or death," says Dr. Naessens. "We want to encourage second opinions when the provider is not certain."

The National Academy of Medicine cites diagnostic error as an important component in determining the quality of health care in its new publication, Improving Diagnosis in Health Care.

Despite the pervasiveness of diagnostic errors and the risk for serious patient harm, diagnostic errors have been largely unappreciated within the quality and patient safety movements in health care. Without a dedicated focus on improving diagnosis, these errors will likely worsen as the delivery of health care and the diagnostic process continue to increase in complexity.

"Referrals to advanced specialty care for undifferentiated problems are an essential component of patient care," Dr. Naessens says. "Without adequate resources to handle undifferentiated diagnoses, a potential unintended consequence is misdiagnosis, resulting in treatment delays and complications, and leading to more costly treatments."

The researchers identified costs associated with second opinions, and Dr. Naessens notes, "Total diagnostic costs for cases resulting in a different final diagnosis were significantly higher than those for confirmed or refined diagnoses, but the alternative could be deadly."

He says that he and his team are pleased by the National Academy of Medicine's call for dedicated federal funding for improved diagnostic processes and error reduction. They also plan further research on diagnostic errors and hope to identify ways to improve the process.

Long-term antibiotic use in early to mid-life linked to cancer-inducing polyps



Long term antibiotic use in early to mid life may be linked to a heightened risk of abnormal growths in the colon and rectum--known as polyps or colorectal adenomas -- which precede the development of most cases of bowel cancer, reveals research published online in the journal Gut.

The findings add to emerging evidence that the type and diversity of bacteria in the gut, referred to as the 'microbiome,' may have a key role in the development of cancer, say the researchers.

Previous research has indicated that exposure to antibiotics may be associated with a heightened risk of developing bowel cancer, but these studies have involved relatively short monitoring periods, so undermining the strength of the associations found. And the potential association with polyp risk has not been explored.

To try and get round these issues, the research team drew on data from the Nurses Health Study. This has been monitoring the health of 121,700 US nurses who were all aged between 30 and 55 when they entered the study in 1976. Since joining, study participants have filled in detailed questionnaires every two years on demographics, lifestyle factors, medical history and disease development, and every four years on their dietary habits.

For the purposes of the current study, analysis of the data was restricted to 16,642 women who were aged 60 and older in 2004, able to provide a history of antibiotic use between the ages of 20 and 59, and who had had at least one bowel investigation (colonoscopy) between 2004 and 2010.

During this period, 1195 adenomas were newly diagnosed in this group.

Recent use of antibiotics within the past four years wasn't associated with a heightened risk of an adenoma diagnosis, but long term use in the past was.

Compared with those who hadn't taken antibiotics for any extended period in their 20s and 30s, those who had taken them for two months or more were 36% more likely to be diagnosed with an adenoma.

This association held true irrespective of whether the adenoma was considered high or low risk for bowel cancer, but was stronger for growths located in the proximal, rather than the distal, colon.

The proximal colon refers to the caecum (pouch at the junction of the small and large intestines), ascending colon, hepatic flexure (the sharp bend between the ascending and transverse colon), transverse colon, and the splenic flexure (the sharp bend between the transverse colon and descending colon). The distal colon refers to the descending or sigmoid colon.
Similarly, women who had taken antibiotics for two months or more during their 40s and 50s were 69% more likely to be diagnosed with an adenoma than those who hadn't taken these drugs for any extended period.

Once again, this association held true, irrespective of whether the adenoma was high or low risk for bowel cancer, and was more strongly linked to proximal colon adenomas.

And compared with women who had not been on antibiotics for any length of time from their 20s to their 50s, those who had taken these drugs for more than 15 days between the ages of 20 and 39, and between the ages of 40 and 59, were 73% more likely to be diagnosed with an adenoma.

This is an observational study so no firm conclusions can be drawn about cause and effect, added to which the researchers didn't gather information on the type or formulation of antibiotic taken, and some adenomas might have been present before antibiotics were used.

Nevertheless, there is a plausible biological explanation for the associations found, they suggest.

Antibiotics fundamentally alter the gut microbiome, by curbing the diversity and number of bacteria, and reducing resistance to 'hostile' bugs, they say. Previous research points to depletion of certain types of bacteria and an abundance of others in patients with bowel cancer.
This might all have a crucial role the development of bowel cancer, added to which the bugs that require antibiotics may induce inflammation, which is a known risk for the development of bowel cancer, say the researchers.

"The findings, if confirmed by other studies, suggest the potential need to limit the use of antibiotics and sources of inflammation that may drive tumour formation," conclude the researchers.

Monthly high-dose vitamin D supplementation does not prevent cardiovascular disease


Results of a large randomized trial indicate that monthly high-dose vitamin D supplementation does not prevent cardiovascular disease, according to a study published by JAMA Cardiology.

Studies have reported increased incidence of cardiovascular disease (CVD) among individuals with low vitamin D status. To date, randomized clinical trials of vitamin D supplementation have not found an effect, possibly because of using too low a dose of vitamin D. Robert Scragg, M.B.B.S., Ph.D., of the University of Auckland, New Zealand, and colleagues randomly assigned adults (age 50 to 84 years) to receive oral vitamin D3 (n = 2,558; an initial dose of 200,000 IU, followed a month later by monthly doses of 100,000 IU) or placebo (n = 2,552) for a median of 3.3 years.

Of the 5,108 participants included in the primary analysis, the average age was 66 years; 25 percent were vitamin D deficient. Cardiovascular disease occurred in 303 participants (11.8 percent) in the vitamin D group and 293 participants (11.5 percent) in the placebo group. Similar results were seen for participants with vitamin D deficiency at study entry and for other outcomes such as heart attack, angina, heart failure, hypertension, and stroke.

The authors write that the results of this study do not support the use of monthly high-dose vitamin D for the prevention of CVD. "The effects of daily or weekly dosing on CVD risk require further study."

As kids' weight climbs, power of supplements drops


Body weight plays a significant role in how much benefit children may get from consuming "good" fats, new research suggests.

The researchers compared fatty acid uptake after kids took a supplement to both overall body weight and body-mass index. The more a child weighed, the smaller the measurement was of two key omega-3 fatty acids in their bloodstream. And the higher the BMI category, the lower the levels of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).

The study provides important information to parents trying to ensure their kids get an appropriate amount of omega-3 fatty acids and also highlights the need for weight-appropriate dosing of supplements and medications, say researchers from The Ohio State University. Their study appears in the journal PLOS ONE.

Most of the science behind omega-3 benefits has concentrated on adults, infants and small children. But a growing body of research is looking at their role in the health of older children. In particular, omega-3 consumption has been shown to lower blood pressure and increase good cholesterol (HDL) in children 8 to 15 years old.

Omega-3 fatty acids are found naturally in foods including salmon, walnuts and soybeans. Parents looking to feed their children more of these foods should be mindful that as they gain weight they'll need more of them to make a difference, said lead author Lisa Christian, an associate professor of psychiatry in the Institute for Behavioral Medicine Research at Ohio State's Wexner Medical Center.

"While this study just looked at fatty acid supplements, it's important to recognize that weight differences could factor into how children and adults respond to many types of medications," Christian said.

"Weight, rather than age, may be more meaningful when determining recommended doses. The difference in size between a 7-year-old and a 10-year-old can be quite significant," she said.

The data comes from a trial conducted by Mary Fristad, professor of psychiatry, psychology and nutrition, and Eugene Arnold, professor emeritus of psychiatry and behavioral health. Their work looked at fatty-acid supplementation in 64 children with mood disorders. The 7- to 14-year-old children took either an omega-3 supplement or a placebo for 12 weeks. Those who took the supplement received 2,000 milligrams of omega-3 fatty acids in the form of four capsules daily.

"We have a growing body of evidence that omega-3 fatty acids are beneficial for physical and mental health. This paper gives us more information about an important question about taking omega-3 supplements -- how much is a good amount," Fristad said of the new study.

Given fluctuations in BMI percentile measures as children grow, it would seem to make the most sense to base dosing on weight alone, Christian said.

The study also points to a need to consider weight-related differences in all studies of omega-3 intake in adults and children, the researchers wrote in their study.


Regular exercise, not BMI, before stroke may predict disability later


A new study suggests it's the amount of regular exercise people get, not the amount of body fat they have, that may predict just how well they recover from a stroke. The study is published in the April 5, 2017, online issue of Neurology®, the medical journal of the American Academy of Neurology.

"We found that those who exercised vigorously three times a week or more three years prior to stroke were more likely to be independent before and after stroke, compared to those who were inactive" said study author Pamela Rist, ScD, of Harvard University in Boston and a member of the American Academy of Neurology. "We also found that a person's body mass index was not a factor in predicting their level of disability after stroke."

Body mass index is a measure of a person's body fat based on their height and weight. Having too much body fat may be a risk to a person's health.

For the study, researchers followed 18,117 people who were initially stroke free for an average of 12 years. Participants were interviewed every other year about their ability to do basic activities like getting dressed, bathing, eating and getting out of bed; and more complex activities including taking medications as prescribed, grocery shopping, preparing meals and managing money.

They were also asked their height, weight and whether they participated in vigorous physical activity or exercise three times a week or more during the past year. Vigorous physical activity was defined as participating in sports, heavy housework or a job that required physical labor.

During the study, 1,374 of the participants had a stroke and survived, and 479 people had a stroke and died before the next round of interviews. Of those who did not have a stroke, 45 percent were physically active, compared to 43 percent of those who had a stroke and survived and 26 percent of those who had a stroke and died.

Among stroke survivors, those who were physically inactive were 18 percent less likely to be taking care of their basic activities such as bathing on their own three years after stroke than those who exercised regularly. They also were 16 percent less likely to be taking care of more complex activities such as managing money on their own. The study showed similar differences between inactive and active people three years before a stroke occurred.

In addition, researchers say their study suggests that being physically active does not protect against the disabling effects of a stroke itself.

"Our study was able to show that being physically inactive before stroke predicts a higher risk of being dependent both before and after stroke," said Rist. "Research is needed to look into whether more intense activity could improve stroke outcomes and whether people can change their activity patterns to improve stroke outcomes."

Limitations of the study include that the information was self-reported. There was a lack of information on the various stroke subtypes. Also, some in the study may have already had physical limitations at the start of the study that prevented them from being physically active.

High fat, high sugar diet during pregnancy 'programs' for health complications


Eating a high fat and high sugar diet when pregnant leads to metabolic impairments in both the mother and her unborn child, which may "program" them for potential health complications later in life, researchers have shown.

In a study carried out in pregnant mice, a team of academics found that an obesity-causing high fat and high sugar diet disrupted processes within the pregnant mother's body, leading to poor metabolic control. These changes were found just prior to birth and may make her more susceptible to conditions such as type 2 diabetes and heart disease, as well as to further fat accumulation, in later motherhood.

The exact impact on her child during pregnancy was harder to ascertain, but the researchers found that metabolic dysfunction in the mother compromised the flow of nutrients to the foetus, altering its growth and metabolism at critical stages during its development. This strongly suggests that an obesogenic diet (a diet which promotes obesity) also has consequences for foetal development. It may also explain why babies from mothers who are obese or eat obesogenic diets during pregnancy have a tendency to develop conditions such as obesity, hypertension and type 2 diabetes as adults.

In particular, the researchers found that a higher than recommended intake of fat and sugar exacerbates and distorts metabolic changes which occur naturally as a result of the pregnancy, so that the mother can appropriately allocate nutrients to the foetus.

The study was carried out by a team of researchers at the University of Cambridge. The lead author is Dr Amanda Sferruzzi-Perri, from St John's College, Cambridge, and the Centre for Trophoblast Research in the Department of Physiology, Development and Neuroscience. She said that the findings were especially relevant for women in western countries.

"In places like the UK, the US and Australia, many women of child-bearing age are also eating higher amounts of fat and sugar than the National Dietary Recommendations," she said. "We know that obesity during pregnancy is a risk factor for health complications for mother and baby both during and after pregnancy. This study offers insight into the mechanisms operating during pregnancy that may cause this."

The study involved feeding a diet that contained high amounts of fat and sugar to pregnant mice. The researchers then assessed the impact of this on both the metabolism of the mother and her levels of body fat, compared to mice which were fed a more balanced diet.

They related these changes in whole-body metabolism to the expression of proteins in the mother's tissues, which are responsible for processing and storing nutrients, as well as to the supply of nutrients, growth and metabolism of her developing foetuses. All of the experiments were carried out in line with the UK Home Office Animals (Scientific Procedures) Act 1986.

Overall, the researchers found that excessive consumption of sugar and fat compromised the mother's glucose tolerance and her sensitivity to insulin - the hormone that controls blood sugar levels.

Specifically, they found that the mother's ability to respond to insulin was reduced in tissues like her muscle and fat, which take up glucose from the circulation. By contrast, the sensitivity of the maternal liver to insulin was increased, which reduces glucose production during pregnancy. As a result, the mother was unable adequately to control glucose levels or produce enough glucose to support the pregnancy.

The high fat, high sugar diet also changed the expression of proteins in the mother's body that control fat storage, leading to an increase in body fat. Collectively, the researchers suggest that these effects promote a "pre-diabetic state" in the mother, resembling many aspects of gestational diabetes; a pregnancy complication which affects up to 5% of women in the UK.

One of the main reasons for this may be that an obesogenic diet exaggerates natural metabolic changes associated with pregnancy. "During a normal pregnancy, the mother's body will change the way it handles nutrients so that some can be freed up for the foetus," Sferruzzi-Perri explained. "The mother's metabolism is shifted to an insulin resistant, glucose intolerant state, such that her own glucose use is limited in favour of foetal supply. We think that in cases where the mother has a high fat, high sugar diet, these metabolic changes are exacerbated or perturbed."

These effects, the researchers suggest, may alter the mother's disposition to develop health complications after she has given birth as well - a phenomenon that they refer to as a "metabolic memory", putting her at greater risk of type 2 diabetes, obesity and cardiovascular problems in later life.

The study also found that the defects in the mother's metabolism impaired nutrient flow to the foetus, as they resulted in the preferential storage of nutrients within the mother's tissues, in favour of allocating these to the developing foetus.

Because the placenta also plays an important role in nutrient allocation (as previous studies have shown), the babies of mice fed the obesogenic diet were still born at a normal size. However, because the foetus receives different amounts of nutrients and shows defects in its ability to use these during development, the researchers believe that the child will still be more susceptible to metabolic dysfunction later in life.

"We still don't know what the exact consequences for the foetus are, but the findings match existing research which already suggests that the individual will suffer from these metabolic problems during adulthood," Sferruzzi-Perri said. "This is because changes to the nutrient and oxygen supply, at a stage when individual organs are developing, can cause a permanent change in the structure and function of certain tissues."

Eating potassium-rich foods= lower blood pressure


Eating potassium-rich foods like sweet potatoes, avocados, spinach, beans, bananas -- and even coffee -- could be key to lowering blood pressure, according to Alicia McDonough, PhD, professor of cell and neurobiology at the Keck School of Medicine of the University of Southern California (USC).

"Decreasing sodium intake is a well-established way to lower blood pressure," McDonough says, "but evidence suggests that increasing dietary potassium may have an equally important effect on hypertension."

Hypertension is a global health issue that affects more than one billion people worldwide. The World Health Organization estimates that hypertension is responsible for at least 51 percent of deaths due to stroke and 45 percent of deaths due to heart disease.

McDonough explored the link between blood pressure and dietary sodium, potassium and the sodium-potassium ratio in a review article published in the April 2017 issue of the American Journal of Physiology - Endocrinology and Metabolism. The review looked at population, interventional and molecular mechanism studies that investigated the effects of dietary sodium and potassium on hypertension.

McDonough's review found several population studies demonstrating that higher dietary potassium (estimated from urinary excretion or dietary recall) was associated with lower blood pressure, regardless of sodium intake. Interventional studies with potassium supplementation also suggested that potassium provides a direct benefit.

McDonough reviewed recent studies in rodent models, from her own lab and others, to illustrate the mechanisms for potassium benefit. These studies indicated that the body does a balancing act that uses sodium to maintain close control of potassium levels in the blood, which is critical to normal heart, nerve and muscle function.

"When dietary potassium is high, kidneys excrete more salt and water, which increases potassium excretion," McDonough says. "Eating a high potassium diet is like taking a diuretic."

Increasing dietary potassium will take a conscious effort, however. McDonough explains that our early ancestors ate primitive diets that were high in fruits, roots, vegetables, beans and grains (all higher in potassium) and very low in sodium. As a result, humans evolved to crave sodium -- but not potassium. Modern diets, however, have changed drastically since then: processed food companies add salt to satisfy our cravings, and processed foods are usually low in potassium.

"If you eat a typical Western diet," McDonough says, "your sodium intake is high and your potassium intake is low. This significantly increases your chances of developing high blood pressure." When dietary potassium is low, the balancing act uses sodium retention to hold onto the limited potassium, which is like eating a higher sodium diet, she says.

But how much dietary potassium should we consume? A 2004 Institute of Medicine report recommends that adults consume at least 4.7 grams of potassium per day to lower blood pressure, blunt the effects of dietary sodium and reduce the risks of kidney stones and bone loss, McDonough says. Eating ¾ cup of black beans, for example, will help you achieve almost 50 percent of your daily potassium goal.

McDonough recommends developing public policies to increase intake of dietary potassium from plant-based sources. She also advocates adding potassium content to nutrition labels to help raise consumers' awareness of economical sources of potassium.


Multivitamins not associated with heart disease risk, regardless of initial dietary intake



More than half of older American adults take a daily multivitamin supplement, but evidence of any clear health benefits is scarce. The Physicians' Health Study II (PHS II) remains the only randomized, large-scale, long-term trial to test whether a daily multivitamin reduced cardiovascular disease risk, and researchers found that after 11 years of follow up, there was no significant difference in risk of major cardiovascular disease (CVD) events among men who took a multivitamin compared to those that took a placebo. In a new study, published this week in JAMA Cardiology, investigators examined whether multivitamins might help prevent CVD events among those in the PHS II with less nutritious diets. However, their results suggest that baseline nutritional status has no clear impact on whether a daily multivitamin affects the risk of CVD or overall mortality.

The PHS II includes more than 14,000 US male physicians over 50 years of age who have completed comprehensive food frequency questionnaires. By studying this population over time in a randomized clinical trial, the research team was able to eliminate many confounding variables. The team also had the opportunity to evaluate a wide range of dietary factors, including intake of fruits and vegetables, whole grains, nuts, dairy products, and red and processed meats, along with key nutrients such as vitamin B6, vitamin B12, vitamin D, and others. Overall, the investigators found that foods, nutrients, dietary patterns or supplement use assessed before the start of the clinical trial had no measurable influence on the effectiveness of a multivitamin on CVD risk in middle-aged and older men.

"Intuitively, many had thought that men with 'poor' nutritional status at baseline may benefit more from long-term multivitamin use on cardiovascular outcomes; however, we did not see any evidence for this in our recent analysis," said corresponding author Howard Sesso, ScD, MPH, of the Division of Preventive Medicine and the Division of Aging at BWH. "Given the continued high prevalence of multivitamin use in the US, it remains critical for us to understand its role on nutritional status and other long-term health outcomes through clinical trials such as PHS II and other new research initiatives."


Deep sleep may act as fountain of youth in old age


As we grow old, our nights are frequently plagued by bouts of wakefulness, bathroom trips and other nuisances as we lose our ability to generate the deep, restorative slumber we enjoyed in youth.

But does that mean older people just need less sleep?

Not according to UC Berkeley researchers, who argue in an article published April 5 in the journal Neuron that the unmet sleep needs of the elderly elevate their risk of memory loss and a wide range of mental and physical disorders.

"Nearly every disease killing us in later life has a causal link to lack of sleep," said the article's senior author, Matthew Walker, a UC Berkeley professor of psychology and neuroscience. "We've done a good job of extending life span, but a poor job of extending our health span. We now see sleep, and improving sleep, as a new pathway for helping remedy that."

Unlike more cosmetic markers of aging, such as wrinkles and gray hair, sleep deterioration has been linked to such conditions as Alzheimer's disease, heart disease, obesity, diabetes and stroke, he said.

Though older people are less likely than younger cohorts to notice and/or report mental fogginess and other symptoms of sleep deprivation, numerous brain studies reveal how poor sleep leaves them cognitively worse off.

Moreover, the shift from deep, consolidated sleep in youth to fitful, dissatisfying sleep can start as early as one's 30s, paving the way for sleep-related cognitive and physical ailments in middle age.

And, while the pharmaceutical industry is raking in billions by catering to insomniacs, Walker warns that the pills designed to help us doze off are a poor substitute for the natural sleep cycles that the brain needs in order to function well.

"Don't be fooled into thinking sedation is real sleep. It's not," he said.

For their review of sleep research, Walker and fellow researchers Bryce Mander and Joseph Winer cite studies, including some of their own, that show the aging brain has trouble generating the kind of slow brain waves that promote deep curative sleep, as well as the neurochemicals that help us switch stably from sleep to wakefulness.

"The parts of the brain deteriorating earliest are the same regions that give us deep sleep," said article lead author Mander, a postdoctoral researcher in Walker's Sleep and Neuroimaging Laboratory at UC Berkeley.

Aging typically brings on a decline in deep non-rapid eye movement (NREM) or "slow wave sleep," and the characteristic brain waves associated with it, including both slow waves and faster bursts of brain waves known as "sleep spindles."

Youthful, healthy slow waves and spindles help transfer memories and information from the hippocampus, which provides the brain's short-term storage, to the prefrontal cortex, which consolidates the information, acting as the brain's long-term storage.

"Sadly, both these types of sleep brain waves diminish markedly as we grow old, and we are now discovering that this sleep decline is related to memory decline in later life," said Winer, a doctoral student in Walker's lab.

Another deficiency in later life is the inability to regulate neurochemicals that stabilize our sleep and help us transition from sleep to waking states. These neurochemicals include galanin, which promotes sleep, and orexin, which promotes wakefulness. A disruption to the sleep-wake rhythm commonly leaves older adults fatigued during the day but frustratingly restless at night, Mander said.

Of course, not everyone is vulnerable to sleep changes in later life: "Just as some people age more successfully than others, some people sleep better than others as they get older, and that's another line of research we'll be exploring," Mander said.

Meanwhile, non-pharmaceutical interventions are being explored to boost the quality of sleep, such as electrical stimulation to amplify brain waves during sleep and acoustic tones that act like a metronome to slow brain rhythms.

However, promoting alternatives to prescription and over-the-counter sleep aids is sure to be challenging.

"The American College of Physicians has acknowledged that sleeping pills should not be the first-line kneejerk response to sleep problems," Walker said. "Sleeping pills sedate the brain, rather than help it sleep naturally. We must find better treatments for restoring healthy sleep in older adults, and that is now one of our dedicated research missions."

Also important to consider in changing the culture of sleep is the question of quantity versus quality.

"Previously, the conversation has focused on how many hours you need to sleep," Mander said. "However, you can sleep for a sufficient number of hours, but not obtain the right quality of sleep. We also need to appreciate the importance of sleep quality.

"Indeed, we need both quantity and quality," Walker said.