Engaging in moderate physical activity may slow progression of Alzheimer's

People at risk for Alzheimer's disease who do more moderate-intensity physical activity, but not  are more likely to have healthy patterns of glucose metabolism in their brain, according to a new UW-Madison study. Light-intensity physical activity did no thave a similar effect.

Results of the research were published today online in Journal of Alzheimer's Disease. Researchers used accelerometers to measure the daily physical activity of participants, all of whom are in late middle-age and at high genetic risk for Alzheimer's disease, but presently show no cognitive impairment.

Activity levels were measured for one week, quantified, and analyzed. This approach allowed scientists to determine the amount of time each subject spent engaged in light, moderate, and vigorous levels of physical activity. Light physical activity is equivalent to walking slowly, while moderate is equivalent to a brisk walk and vigorous a strenuous run. Data on the intensities of physical activity were then statistically analyzed to determine how they corresponded with glucose metabolism--a measure of neuronal health and activity--in areas of the brain known to have depressed glucose metabolism in people with Alzheimer's disease. To measure brain glucose metabolism, researchers used a specialized imaging technique called 18F-fluorodeoxyglucose positron emission tomography (FDG-PET).

Moderate physical activity was associated with healthier (greater levels of) glucose metabolism in all brain regions analyzed. Researchers noted a step-wise benefit: subjects who spent at least 68 minutes per day engaged in moderate physical activity showed better glucose metabolism profiles than those who spent less time.

"This study has implications for guiding exercise 'prescriptions' that could help protect the brain from Alzheimer's disease," said Dougherty. "While many people become discouraged about Alzheimer's disease because they feel there's little they can do to protect against it, these results suggest that engaging in moderate physical activity may slow down the progression of the disease."

"Seeing a quantifiable connection between moderate physical activity and brain health is an exciting first step," said Okonkwo. He explained that ongoing research is focusing on better elucidating the neuroprotective effect of exercise against Alzheimer's disease. To investigate this further, the team is recruiting individuals with concerns about their memory for a national clinical trial called EXERT to test whether physical exercise can slow the progression of early memory problems caused by Alzheimer's disease.

Encouraging, but inconclusive evidence on interventions to prevent cognitive decline, dementia

The public is enormously concerned about dementia and cognitive impairment, and a wide range of programs and products, such as diets, exercise regimens, games, and supplements, purport to keep these conditions at bay. It is difficult for individuals, health care providers and policy makers to ascertain what has been demonstrated to prevent or reduce risk.

To help sort through the data and to understand the quality and weight of current evidence for possible interventions, the National Institute on Aging (NIA) at the National Institutes of Health, commissioned experts for an extensive scientific review and to provide recommendations for public health messaging and future research priorities. In response to that request, a National Academies of Sciences, Engineering and Medicine (NASEM) committee has concluded that current evidence does not support a mass public education campaign to encourage people to adopt specific interventions to prevent cognitive decline or dementia.

Importantly, the committee also cited “encouraging although inconclusive” evidence for three specific types of interventions — cognitive training, blood pressure control for people with hypertension, and increased physical activity. Based on that evidence, the committee recommended providing the public with accurate information about their potential positive impacts for some conditions while more definitive research on these and other approaches moves forward. The committee suggested that health care providers might include mention of the potential cognitive benefits of these interventions when promoting their adoption for the prevention or control of other diseases and conditions.

The full NASEM report, “Preventing Cognitive Decline and Dementia: A Way Forward,” can be viewed at www.nationalacademies.org/dementia (link is external).

The committee’s recommendations are based in large part on an NIA-requested and supported systematic evidence review by the Agency for Healthcare Research and Quality’s (AHRQ) Evidence-based Practice Center (EPC). The Minnesota EPC categorized hundreds of studies by strength and quality for the AHRQ part of the project.

“We’re all urgently seeking ways to prevent dementia and cognitive decline with age,” said NIA Director Richard J. Hodes, M.D. “But we must consider the strength of evidence -- or lack thereof -- in making decisions about personal and public investments in prevention. I am grateful for the National Academies’ and AHRQ’s careful reviews, which recognize the progress research has made in beginning to answer such questions, while pointing the way for additional studies. This report will be very instructive for what we can tell the public now, as critical research continues.”

The committee noted potential effects, as well as limitations of the evidence, for:

Cognitive training 

Interventions aimed at enhancing reasoning, memory, and speed of processing, to delay or slow age-related cognitive decline were found promising, based primarily on conclusions from the NIA-funded Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial and bolstered by additional data from prospective observational studies on the benefits of cognitively stimulating activities.

The committee cautioned, however, that it could not draw conclusions about the relative effectiveness of different cognitive training approaches or techniques. It also noted that there was no evidence to support the notion that beneficial long-term cognitive effects suggested by the ACTIVE trial could be applied to computer based brain training applications being offered commercially, as the suite of cognitive interventions in the ACTIVE trial were substantially different.

The committee found no evidence to suggest that cognitive training might prevent, delay or slow development of Mild Cognitive Impairment (MCI) or Alzheimer’s, however.

Blood pressure management for people with hypertension 

Encouraging but inconclusive evidence suggests that blood pressure management, particularly in midlife, might prevent, delay or slow clinical Alzheimer’s-type dementia, according to the committee. While clinical trials in this area do not offer strong support for blood pressure management against Alzheimer’s, prospective population studies and what we have learned about the natural history and biology of the disease make it plausible, then, that blood pressure management for people with hypertension would also reduce their risk of dementia and cognitive decline, the report said.

The committee pointed out the known cardiovascular benefits from well-managed blood pressure, which would be experienced while Alzheimer’s prevention is potentially addressed.

Increased physical activity 

Citing the many known health benefits of physical activity, the committee pointed to growing evidence that among these is the possible reduced risk of age-related cognitive decline. Here, too, the experts turned to what they called encouraging but inconclusive evidence, noting that clinical trials results in this area suggest effectiveness, taken together with observational studies and knowledge of neurobiological processes. There was not sufficient evidence to support increased physical activity as a preventive intervention for MCI or Alzheimer’s disease, however. Further, the committee could not find sufficient evidence to help determine which specific types of physical activity might be particularly effective for preventing cognitive decline and dementia.



In communicating with the public, the committee said, the NIH, the Centers for Disease Control and Prevention and other organizations should present potential benefits of the three interventions as they apply to cognitive decline, MCI, and Alzheimer’s dementia, while pointing out the limitations of the evidence. There are considerable challenges in presenting such nuanced messages, it added, as the public likely will not draw fine distinctions among the three conditions or about levels of evidence.

The committee expressed optimism for the future of research to provide answers that the public and providers are seeking. Substantial knowledge has been gained since the last comprehensive evidence review in 2010, and this complex and exciting area of discovery will continue to grow with investments in research. In addition to encouraging ongoing research in the three areas for which it found evidence most developed, the committee recommended as priority areas for further study: new anti-dementia treatments; treatments for diabetes and depression; dietary interventions; lipid-lowering treatments; sleep quality interventions; social engagement, and vitamin B12 plus folic acid supplementation.

For its evidence review, the AHRQ’s EPC examined the scientific literature on 13 classes of interventions associated with preventing, slowing, or delaying the onset of clinical Alzheimer’s-type dementia and MCI. The AHRQ report, issued in March 2017, found that most approaches showed no evidence of benefit to delay or prevent age-related cognitive decline, MCI, or Alzheimer’s dementia. It concluded that, at present, there is not sufficient strength of evidence to justify large-scale investing in public health activities aimed at preventing dementia; some results may be viewed as potential added benefits to already identified public health interventions.

Eating fish may reduce arthritis symptoms

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In the study of 176 patients, frequency of fish consumption was assessed by a food frequency questionnaire assessing usual diet in the past year.

"If our finding holds up in other studies, it suggests that fish consumption may lower inflammation related to rheumatoid arthritis disease activity," said Dr. Sara Tedeschi, lead author of the Arthritis Care & Research study. "Fish consumption has been noted to have many beneficial health effects, and our findings may give patients with rheumatoid arthritis a strong reason to increase fish consumption."

Breastfeeding may reduce a mother's heart attack and stroke risk

Breastfeeding is not only healthy for babies, it may also reduce a mother's risk of having a heart attack or stroke later in life, according to new research published in of the Journal of the American Heart Association, the Open Access Journal of the American Heart Association/American Stroke Association.

Previous studies have suggested that mothers get short-term health benefits from breastfeeding, such as weight loss and lower cholesterol, blood pressure and glucose levels after pregnancy. However, the long-term effects of breastfeeding on the risk of developing cardiovascular diseases in mothers are unclear. A new study in China found that women who breastfed their babies had about a ten percent lower risk of developing heart disease or stroke.

Researchers from the University of Oxford, the Chinese Academy of Medical Sciences and Peking University analyzed data from 289,573 Chinese women (average age 51) participating in the China Kadoorie Biobank study who provided detailed information about their reproductive history and other lifestyle factors. Nearly all were mothers and none had cardiovascular disease when they enrolled in the study. After eight years of follow-up, there were 16,671 cases of coronary heart disease, which includes heart attacks, and 23,983 stroke cases.

Researchers observed that:

Compared to women who had never breastfed, mothers who breastfed their babies had a 9 percent lower risk of heart disease and an 8 percent lower risk of stroke.
Among mothers who breastfed each of their babies for two years or more, heart disease risk was 18 percent lower and stroke risk was 17 percent lower than among mothers who never breastfed.
Each additional 6 months of breastfeeding per baby was associated with a 4 percent lower risk of heart disease and a 3 percent lower risk of stroke.
The researchers considered a range of risk factors for cardiovascular disease, including smoking, high blood pressure, obesity, diabetes and physical activity that could have biased results.

"Although we cannot establish the causal effects, the health benefits to the mother from breastfeeding may be explained by a faster "reset" of the mother's metabolism after pregnancy. Pregnancy changes a woman's metabolism dramatically as she stores fat to provide the energy necessary for her baby's growth and for breastfeeding once the baby is born. Breastfeeding could eliminate the stored fat faster and more completely," said co-author, Sanne Peters, Ph.D., a research fellow at the University of Oxford in the United Kingdom.

The authors noted that women who breastfeed may be more likely to engage in other beneficial health behaviors that lower their risk of cardiovascular disease compared to women who do not breastfeed.

Because this study was observational, relying on information provided by the mothers about their breastfeeding histories, it does not prove cause and effect. Results from observational studies such as this one must be confirmed by a different type of study that can prove that a behavior may results in an outcome.

Compared to women in China, breastfeeding duration is typically shorter among women in the United States. Ninety-seven percent of the women in this study breastfed each of their babies for an average of 12 months, compared to 30 percent of U.S. mothers in 2016, according to the World Health Organization. However, the U.S. Nurses' Health Study found only women with a lifetime duration of breastfeeding of 2 years or more had a significantly lower risk of coronary heart disease than those who never breastfed.

"The findings should encourage more widespread breastfeeding for the benefit of the mother as well as the child," said Zhengming Chen, M.B.B.S., D.Phil., senior study author and professor of epidemiology at the University of Oxford. "The study provides support for the World Health Organization's recommendation that mothers should breastfeed their babies exclusively for their first six months of life."

The American Heart Association suggests breastfeeding for 12 months if possible.

Extra-virgin olive oil preserves memory & protects brain against Alzheimer's

The Mediterranean diet, rich in plant-based foods, is associated with a variety of health benefits, including a lower incidence of dementia. Now, researchers at the Lewis Katz School of Medicine at Temple University (LKSOM) have identified a specific ingredient that protects against cognitive decline: extra-virgin olive oil, a major component of the Mediterranean diet. In a study published online June 21 in the Annals of Clinical and Translational Neurology, the researchers show that the consumption of extra-virgin olive oil protects memory and learning ability and reduces the formation of amyloid-beta plaques and neurofibrillary tangles in the brain -- classic markers of Alzheimer's disease.

The Temple team also identified the mechanisms underlying the protective effects of extra-virgin olive oil. "We found that olive oil reduces brain inflammation but most importantly activates a process known as autophagy," explained senior investigator Domenico Praticò, MD, Professor in the Departments of Pharmacology and Microbiology and the Center for Translational Medicine at LKSOM. Autophagy is the process by which cells break down and clear out intracellular debris and toxins, such as amyloid plaques and tau tangles.

"Brain cells from mice fed diets enriched with extra-virgin olive oil had higher levels of autophagy and reduced levels of amyloid plaques and phosphorylated tau," Dr. Praticò said. The latter substance, phosphorylated tau, is responsible for neurofibrillary tangles, which are suspected of contributing to the nerve cell dysfunction in the brain that is responsible for Alzheimer's memory symptoms.

Previous studies have suggested that the widespread use of extra-virgin olive oil in the diets of people living in the Mediterranean areas is largely responsible for the many health benefits linked to the Mediterranean diet. "The thinking is that extra-virgin olive oil is better than fruits and vegetables alone, and as a monounsaturated vegetable fat it is healthier than saturated animal fats," according to Dr. Praticò.

In order to investigate the relationship between extra-virgin olive oil and dementia, Dr. Praticò and colleagues used a well-established Alzheimer's disease mouse model. Known as a triple transgenic model, the animals develop three key characteristics of the disease: memory impairment, amyloid plagues, and neurofibrillary tangles.

The researchers divided the animals into two groups, one that received a chow diet enriched with extra-virgin olive oil and one that received the regular chow diet without it. The olive oil was introduced into the diet when the mice were six months old, before symptoms of Alzheimer's disease begin to emerge in the animal model.

In overall appearance, there was no difference between the two groups of animals. However, at age 9 months and 12 months, mice on the extra virgin olive oil-enriched diet performed significantly better on tests designed to evaluate working memory, spatial memory, and learning abilities.

Studies of brain tissue from both groups of mice revealed dramatic differences in nerve cell appearance and function.

"One thing that stood out immediately was synaptic integrity," Dr. Praticò said. The integrity of the connections between neurons, known as synapses, were preserved in animals on the extra-virgin olive oil diet. In addition, compared to mice on a regular diet, brain cells from animals in the olive oil group showed a dramatic increase in nerve cell autophagy activation, which was ultimately responsible for the reduction in levels of amyloid plaques and phosphorylated tau.

"This is an exciting finding for us," explained Dr. Praticò. "Thanks to the autophagy activation, memory and synaptic integrity were preserved, and the pathological effects in animals otherwise destined to develop Alzheimer's disease were significantly reduced. This is a very important discovery, since we suspect that a reduction in autophagy marks the beginning of Alzheimer's disease."

Dr. Praticò and colleagues plan next to investigate the effects of introducing extra-virgin olive oil into the diet of the same mice at 12 months of age, when they have already developed plaques and tangles. "Usually when a patient sees a doctor for suspected symptoms of dementia, the disease is already present," Dr. Praticò added. "We want to know whether olive oil added at a later time point in the diet can stop or reverse the disease."

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Antimicrobial products can do more harm than good

 

Are you buying antimicrobial or antibacterial soaps? According to over 200 scientists and medical professionals, you may want to save your money. A consensus statement published today in the peer-reviewed scientific journal Environmental Health Perspectives concludes that common antimicrobial products do not provide health benefits and cause health and environmental harm. The statement also calls for greater caution in using antimicrobial chemicals in everyday products.

"People think antimicrobial hand soaps offer better protection against illness. But generally, antimicrobial soaps perform no better than plain soap and water," said Barbara Sattler, RN, DrPH, FAAN, environmental health professor at the University of San Francisco. Last fall, the U.S. Food and Drug Administration (FDA) determined that 19 different antimicrobial chemicals, including infamous triclosan and triclocarban, were not effective and should not be marketed for use in over-the-counter consumer wash products. Now, 200 scientists say the FDA's decision does not go far enough to protect consumers and the environment.

In consumer soaps and washes, brands are using different additives. "I was happy that the FDA finally acted to remove these chemicals from soaps. But I was dismayed to discover at my local drugstore that most products now contain substitutes that may be worse," said Arlene Blum, PhD, Executive Director of Green Science Policy Institute. Antimicrobials are also commonplace in products where you wouldn't expect them, including paints, exercise mats, flooring, apparel, food storage containers, home textiles, electronics, kitchenware, school supplies, and countertops.

"Customers may think added antimicrobials are a way to reduce infections, but in most products there is no evidence that they do," said Ted Schettler, MD, MPH, Science Director of the Science and Environmental Health Network. In 2016, Dr. Schettler authored a report on antimicrobials in hospital furnishings for the nonprofit Health Care Without Harm.

"Added antimicrobials are marketed as beneficial in building products from countertops to doorknobs and light switches" said Bill Walsh, President of Healthy Building Network, which recently produced a white paper on antimicrobial building products . "Antimicrobial preservatives are useful in certain products like paints, but we found claims about health benefits to be largely invalid." Nevertheless, sales of "antimicrobial" performance products are projected to grow.

Scientists and health professionals agree that non-medical uses of antimicrobials should be reduced. "Environmental and human exposures to triclosan and triclocarban are widespread, affecting pregnant women, developing fetuses, and breast-feeding babies," said Rolf Halden, PhD, PE professor of engineering at Arizona State University. "We must develop better alternatives and prevent unneeded exposures to antimicrobial chemicals."

Studies link green leafy vegetables and academic achievement in pre-adolescent children

 

Researchers can look into your eyes to determine whether you're getting your lutein, a pigment found in green leafy vegetables that is known to accumulate in the brain. Two new studies find that children with higher lutein levels in the eye tend to do better than others on tests of cognition and academic achievement, even after accounting for other factors known to influence academic performance such as IQ, gender, body composition and physical fitness.

"In the United States and much of the rest of the world, children and adults often fail to meet the recommended daily intakes of foods like fruits and vegetables," said University of Illinois kinesiology and community health professor Naiman Khan , who led the new research with Anne M. Walk, a cognitive neuroscientist and postdoctoral researcher at Illinois.

"We often focus on how diet affects childhood obesity, but we haven't really studied how it can affect cognition or achievement in childhood," Khan said.

Lutein is a yellow pigment found in leafy vegetables, egg yolks and fortified food products. It is best known for its protective role against macular degeneration, a condition afflicting the retina that can lead to loss of vision, most often in older adults.

"Lutein has many benefits to the body, including its function as an antioxidant, protecting our brain cells from free radicals and our retinas from both free radicals and damage caused by blue light when we are outside in sunlight," said Matt Kuchan, lead nutritional scientist at the global healthcare company Abbott, which collaborated on the study.

"Studies of lutein and a closely related pigment, zeaxanthin, suggest that they play a role in overall brain health," Kuchan said.

"We know that lutein preferentially accumulates in the brain relative to all the other pigments you can eat, including beta carotene," Khan said.

"We also know that these pigments are found in high quantities in the infant brain," Walk said. "That suggests they're important in some way for brain development."

Previous studies have found associations between lutein and the preservation of cognitive function in aging. But none have looked at its role in cognition in children, the researchers said.

In a study reported in the International Journal of Psychophysiology, Khan and his colleagues measured lutein levels in the eyes of 49 children 8- to 10-years old. The team also recorded the children's brain activity using EEG while they were engaged in a challenging cognitive task.

The researchers found that a spike in brain activity, called a P3 potential because it typically occurs about 300 milliseconds after a stimulus, tended to be lower in children with higher lutein levels, and the children tended to perform better on the task.

"The P3 potential is usually looked at as a marker of resource allocation or cognitive engagement," Walk said. "In this case, it appears that children with more lutein in the eye had higher performance and needed less cognitive engagement to accurately perform the task."

In a second study of 8- and 9-year-old children, reported in the journal Nutritional Neuroscience, the team found that those with higher lutein levels did better on standardized academic test than those with lower levels. The findings held true even when accounting for other factors known to contribute to better academic performance.

"All these factors -- the physical measures of fitness, IQ, socioeconomic status, body mass index and the amount of lutein in the children's eyes -- together explain about half of the variability achievement among participants. If you take lutein out of the equation, your ability to predict a child's performance becomes less accurate," Khan said.

"These results do not causally prove that lutein is responsible for the differences seen in performance," Khan said. "However, the new studies are a first step in understanding the potential role of lutein as a food component that may be important for childhood cognition."