Exercise May be the Best Medicine for Alzheimer's

New research out of the University of Maryland School of Public Health shows that exercise may improve cognitive function in those at risk for Alzheimer’s by improving the efficiency of brain activity associated with memory. Memory loss leading to Alzheimer’s disease is one of the greatest fears among older Americans. While some memory loss is normal and to be expected as we age, a diagnosis of mild cognitive impairment, or MCI, signals more substantial memory loss and a greater risk for Alzheimer’s, for which there currently is no cure.

The study, led by Dr. J. Carson Smith, assistant professor in the Department of Kinesiology, provides new hope for those diagnosed with MCI. It is the first to show that an exercise intervention with older adults with mild cognitive impairment (average age 78) improved not only memory recall, but also brain function, as measured by functional neuroimaging (via fMRI). The findings are published in the Journal of Alzheimer’s Disease.

“We found that after 12 weeks of being on a moderate exercise program, study participants improved their neural efficiency – basically they were using fewer neural resources to perform the same memory task,” says Dr. Smith. “No study has shown that a drug can do what we showed is possible with exercise.”

Recommended Daily Activity: Good for the Body, Good for the Brain

Two groups of physically inactive older adults (ranging from 60-88 years old) were put on a 12-week exercise program that focused on regular treadmill walking and was guided by a personal trainer. Both groups – one which included adults with MCI and the other with healthy brain function – improved their cardiovascular fitness by about ten percent at the end of the intervention. More notably, both groups also improved their memory performance and showed enhanced neural efficiency while engaged in memory retrieval tasks.

The good news is that these results were achieved with a dose of exercise consistent with the physical activity recommendations for older adults. These guidelines urge moderate intensity exercise (activity that increases your heart rate and makes you sweat, but isn’t so strenuous that you can’t hold a conversation while doing it) on most days for a weekly total of 150 minutes.

Measuring Exercise’s Impact on Brain Health and Memory

One of the first observable symptoms of Alzheimer’s disease is the inability to remember familiar names. Smith and colleagues had study participants identify famous names and measured their brain activation while engaged in correctly recognizing a name – e.g., Frank Sinatra, or other celebrities well known to adults born in the 1930s and 40s. “The task gives us the ability to see what is going on in the brain when there is a correct memory performance,” Smith explains.

Tests and imaging were performed both before and after the 12-week exercise intervention. Brain scans taken after the exercise intervention showed a significant decrease in the intensity of brain activation in eleven brain regions while participants correctly identified famous names. The brain regions with improved efficiency corresponded to those involved in the pathology of Alzheimer’s disease, including the precuneus region, the temporal lobe, and the parahippocampal gyrus.

The exercise intervention was also effective in improving word recall via a “list learning task,” i.e., when people were read a list of 15 words and asked to remember and repeat as many words as possible on five consecutive attempts, and again after a distraction of being given another list of words.

“People with MCI are on a very sharp decline in their memory function, so being able to improve their recall is a very big step in the right direction,” Smith states.

The results of Smith’s study suggest that exercise may reduce the need for over-activation of the brain to correctly remember something. That is encouraging news for those who are looking for something they can do to help preserve brain function.

Dr. Smith has plans for a larger study that would include more participants, including those who are healthy but have a genetic risk for Alzheimer’s, and follow them for a longer time period with exercise in comparison to other types of treatments. He and his team hope to learn more about the impact of exercise on brain function and whether it could delay the onset or progression of Alzheimer’s disease.

Green Coffee Beans = Weight Loss

A new review article evaluates if clinical data support the use of green coffee for weight loss. A literature search was conducted that yielded 5 clinical trials and 1 meta-analysis. Studies were evaluated for quality in accordance to clinical practice and US Food and Drug Administration guidelines.

The amount of weight loss ranged from approximately 1 to 8 kg, with the meta-analysis finding a statistically significant difference in body weight, with a mean difference of −2.47 kg between green coffee and placebo (95% confidence interval = −4.23 to −0.72).

The duration of trials varied between 4 and 12 weeks, and the dose of chlorogenic acid varied from 81 to 400 mg.

My Health Practics In Question Again

My health practices have been shaken up considerably over the years, but never more so than the last few days.

First came the report that fish oil supplementation seems to increase the risk of prostate cancer, which I discussed here, noting all the benefits of fish oil.

Next came the report that light drinking may not offer health benefits after all. However, I have documented the many apparent benefits of moderate alcohol consumption here, and while this study will make me feel less guilty when I don't have a drink, I will continue moderate drinking for pleasure, and, I still believe, for health benefits.

The latest disturbing study brings into question the cardiovascular health benefits of resveratrol supplements, which I take religiously, and anti-oxidant supplements in general.

And to top it all off, an article in The Atlantic questions the values of supplements as well, particularly anti-oxidants and focuses on the dangers of vitamins A, C, E, and beta-carotene, all of which I did take but quit some time ago.

Resveratrol counteracts exercise benefits in older men

In older men, a natural antioxidant compound found in red grapes and other plants -- called resveratrol -- blocks many of the cardiovascular benefits of exercise, according to research published today [22 July 2013] in The Journal of Physiology.

Resveratrol has received widespread attention as a possible anti-aging compound and is now widely available as a dietary supplement; much has been made of its role in explaining the cardiovascular health benefits of red wine, and other foods. But now, new research at The University of Copenhagen surprisingly suggests that eating a diet rich in antioxidants may actually counteract many of the health benefits of exercise, including reduced blood pressure and cholesterol.

In contrast to earlier studies in animals in which resveratrol improved the cardiovascular benefits of exercise, this study in humans has provided surprising and strong evidence that in older men, resveratrol has the opposite effect.

What is emerging is a new view that antioxidants are not a fix for everything, and that some degree of oxidant stress may be necessary for the body to work correctly. This pivotal study suggests that reactive oxygen species, generally thought of as causing aging and disease, may be a necessary signal that causes healthy adaptations in response to stresses like exercise. So too much of a good thing (like antioxidants in the diet) may actually be detrimental to our health.

Lasse Gliemann, a PhD student who worked on the study at The University of Copenhagen, explains how they conducted the research, and the results they found: "We studied 27 healthy, physically inactive men around 65 years old for 8 weeks. During the 8 weeks all of the men performed high-intensity exercise training and half of the group received 250 mg of resveratrol daily, whereas the other group received a placebo pill (a pill containing no active ingredient). The study design was double-blinded, thus neither the subjects nor the investigators knew which participant that received either resveratrol or placebo.

"We found that exercise training was highly effective in improving cardiovascular health parameters, but resveratrol supplementation attenuated the positive effects of training on several parameters including blood pressure, plasma lipid concentrations and maximal oxygen uptake."

Ylva Hellsten, the leader of the project, says:"We were surprised to find that resveratrol supplementation in aged men blunts the positive effects of exercise training on cardiovascular health parameters, in part because our results contradict findings in animal studies.

"It should be noted that the quantities of resveratrol given in our research study are much higher than what could be obtained by intake of natural foods."

This research adds to the growing body of evidence questioning the positive effects of antioxidant supplementation in humans.

Michael Joyner, from The Mayo Clinic USA, says how the study has wider implications for research: "In addition to the surprising findings on exercise and resveratrol, this study shows the continuing need for mechanistic studies in humans. Too often human studies focus on large scale outcomes and clinical trials and not on understanding the basic biology of how we adapt."

Skipping breakfast may increase coronary heart disease risk

Here's more evidence why breakfast may be the most important meal of the day: Men who reported that they regularly skipped breakfast had a higher risk of a heart attack or fatal coronary heart disease in a study reported in the American Heart Association journal Circulation.

Researchers analyzed food frequency questionnaire data and tracked health outcomes for 16 years (1992-2008) on 26,902 male health professionals ages 45-82. They found:

Men who reported they skipped breakfast had a 27 percent higher risk of heart attack or death from coronary heart disease than those who reported they didn't.
The men who reported not eating breakfast were younger than those who did, and were more likely to be smokers, employed full time, unmarried, less physically active and drank more alcohol.

Men who reported eating late at night (eating after going to bed) had a 55 percent higher coronary heart disease risk than those who didn't. But researchers were less convinced this was a major public health concern because few men in the study reported this behavior.

During the study, 1,572 of the men had first-time cardiac events.

"Skipping breakfast may lead to one or more risk factors, including obesity, high blood pressure, high cholesterol and diabetes, which may in turn lead to a heart attack over time," said Leah E. Cahill, Ph.D., study lead author and Postdoctoral Research Fellow in the Department of Nutrition at Harvard School of Public Health in Boston, Mass.

"Our study group has spent decades studying the health effects of diet quality and composition, and now this new data also suggests overall dietary habits can be important to lower risk of coronary heart disease," said Eric Rimm, Sc.D., senior author and Associate Professor of Epidemiology and Nutrition, Harvard School of Public Health and Associate Professor of Medicine at the Harvard Medical School.

Men who reported eating breakfast ate on average one more time per day than those who skipped breakfast, implying that those who abstained from breakfast were not eating additional make-up meals later in the day. Although there was some overlap between those who skipped breakfast and those who ate late at night, 76 percent of late-night eaters also ate breakfast, researchers said.

The study collected comprehensive questionnaire data from the participants and accounted for many important factors such as TV watching, physical activity, sleep, diet quality, alcohol intake, medical history, BMI, and social factors like whether or not the men worked full-time, were married, saw their doctor regularly for physical exams, or smoked currently or in the past.

While the current study group was composed of men who were of 97 percent white European descent, the results should also apply to women and other ethnic groups, but this should be tested in additional studies, researchers said.

"Don't skip breakfast," Cahill said. "Eating breakfast is associated with a decreased risk of heart attacks. Incorporating many types of healthy foods into your breakfast is an easy way to ensure your meal provides adequate energy and a healthy balance of nutrients, such as protein, carbohydrates, vitamins and minerals. For example, adding nuts and chopped fruit to a bowl of whole grain cereal or steel-cut oatmeal in the morning is a great way to start the day."

Light Drinking My Not Offer Health Benefits After All

As a class, people who don't drink at all have a higher mortality risk than light drinkers. But nondrinkers are a diverse bunch, and the reasons people have for abstaining affects their individual mortality risk, in some cases lowering it on par with the risk for light drinkers, according to a University of Colorado study.

Multiple studies have shown that the likelihood of dying for people who drink increases as they consume more alcohol. Those same studies have shown that a person's mortality risk also increases at the other end of the spectrum — among people who choose not to drink at all — though the risk is still much less than for heavy drinkers.

Some researchers have hypothesized that the increased mortality among nondrinkers could be related to the fact that light alcohol consumption — drinking, on average, less than one drink a day — might actually protect people from disease and reduce their stress levels.

But researchers at the University of Colorado Boulder, working with colleagues at the University of Colorado Denver, decided to examine whether characteristics of different subgroups of nondrinkers could explain the increased mortality risk.

"Among nondrinkers, people have all sorts of background reasons for why they don't drink," said sociology Professor Richard Rogers, director of CU-Boulder's Population Program in the Institute of Behavioral Science. "We wanted to tease that out because it's not really informative to just assume that nondrinkers are a unified group."

For the new study, published in last month's issue of the journal Population Research and Policy Review, Rogers and his colleagues relied on data collected in 1988 by the National Health Interview Survey about the drinking habits of more than 41,000 people from across the United States. The researchers also had access to information about which respondents died between taking the survey and 2006.

During the survey, nondrinkers were asked to provide their reasons for not drinking. Possible answers ranged from "don't socialize very much" to "am an alcoholic" to "religious or moral reasons."

The research team divided nondrinkers into three general categories: "abstainers," or people who have never had more than 12 drinks in their lives; "infrequent drinkers," or people who have fewer than 12 drinks a year; and "former drinkers." Each category was further divided using a statistical technique that grouped people together who gave similar clusters of reasons for not drinking.

The team then calculated the mortality risk for each subgroup compared with the mortality risk for light drinkers, and they found that the risks varied markedly.

Abstainers who chose not to drink for a cluster of reasons that included religious or moral motivations, being brought up not to drink, responsibilities to their family, as well as not liking the taste, had similar mortality risks over the follow-up period to light drinkers.

"So this idea that nondrinkers always have higher mortality than light drinkers isn't true," Rogers said. "You can find some groups of nondrinkers who have similar mortality risks to light drinkers."

The other subgroup of abstainers — whose largest reason for not drinking appeared to be a dislike of the taste and to a lesser degree family responsibilities, religious or moral motivations or upbringing — had a 17 percent higher mortality risk over the follow-up period compared with light drinkers.

The scientists also found that infrequent drinkers generally had a slightly higher mortality risk than light drinkers. Former drinkers, however, had the highest mortality risk of all nondrinkers. Former drinkers whose cluster of reasons for not drinking now included being an alcoholic and problems with drinking, for example, had a 38 percent higher mortality risk than light drinkers over the follow-up period.

By comparison, people who drink between one and two drinks per day, on average, have a 9 percent higher mortality rate than light drinkers, while people who drink between two and three drinks per day have a 49 percent higher mortality. People who consume more than three drinks per day had a 58 percent higher mortality risk over the follow-up period compared with light drinkers.

Despite confirming that some subgroups of nondrinkers have a higher mortality rate than light drinkers, it doesn't necessarily follow that those people's mortality rates would fall if they began drinking, Rogers said. For example, people who were problem drinkers in the past might increase their mortality risk further by starting to drink again.

Also, people who don't drink at all, as a group, have lower socioeconomic characteristics than light drinkers, which could be one of the underlying causes for the mortality differences, Rogers said. In that case, starting to drink without changing a person's socioeconomic status also would not likely lower mortality rates.

"I think the idea that drinking could be somewhat beneficial seems like it's overstated," Rogers said. "There may be other factors that lower mortality for light drinkers. It's not just the act of drinking."

Vigorous exercise may lower stroke risk

Here's yet another reason to get off the couch: new research findings suggest that regularly breaking a sweat may lower the risk of having a stroke.

A stroke can occur when a blood vessel in the brain gets blocked. As a result, nearby brain cells will die after not getting enough oxygen and other nutrients. A number of risk factors for stroke have been identified, including smoking, high blood pressure, diabetes and being inactive.

For this study, published in the journal Stroke, Michelle N. McDonnell, Ph.D., from the University of South Australia, Adelaide and her colleagues obtained data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. REGARDS is a large, long-term study funded by the NIH National Institute of Neurological Disorders and Stroke (NINDS) to look at the reasons behind the higher rates of stroke mortality among African-Americans and other residents living in the Southeastern United States.

"Epidemiological studies such as REGARDS provide an important opportunity to explore race, genetics, environmental, and lifestyle choices as stroke risk factors," said Claudia Moy, Ph.D., program director at NINDS.

Over 30,000 participants supplied their medical history over the phone. The researchers also visited them to obtain health measures such as body mass index and blood pressure. At the beginning of the study, the researchers asked participants how many times per week they exercised vigorously enough to work up a sweat. The researchers contacted participants every six months to see if they had experienced a stroke or a mini-stroke known as a transient ischemic attack (TIA). To confirm their responses, the researchers reviewed participants' medical records.

The researchers reported data for over 27,000 participants who were stroke-free at the start of the study and followed for an average of 5.7 years. One-third of participants reported exercising less than once a week. Study subjects who were inactive were 20 percent more likely to experience a stroke or TIA than participants who exercised four or more times a week.

The findings revealed that regular, moderately vigorous exercise, enough to break a sweat, was linked to reduced risk of stroke. Part of the protective effect was due to lower rates of known stroke risk factors such as hypertension, diabetes, obesity and smoking.

"Our results confirm other research findings but our study has the distinct advantage of including larger numbers, especially larger numbers of women as well as blacks, in a national population sample so these provide somewhat more generalizable results than other studies," said Virginia Howard, Ph.D., senior author of the study from the School of Public Health, University of Alabama at Birmingham.

The researchers also looked at the data according to gender. After the researchers accounted for age, race, socioeconomic factors (education and income) and stroke risk factors, the results revealed that men who exercised at least four times a week still had a lower risk of stroke than men who exercised one to three times per week. In contrast, there was no association between frequency of exercise and stroke risk among women in the study. However, there was a trend towards a similar reduction in stroke risk for those who exercised one to three times a week and four or more times a week compared to those who were inactive.

"This could be related to differences in the type, duration, and intensity of physical activity between men and women," said Dr. Howard. "This could also be due to differences in the perception of what is intense physical activity enough to work up a sweat."

The results should encourage doctors to stress the importance of exercise when speaking with their patients, Dr. Howard said.

"Physical inactivity is a major modifiable risk factor for stroke. This should be emphasized in routine physician check-ups along with general education about the benefits of exercise on stroke risk factors including high blood pressure, diabetes and being overweight or obese," she said.

The study suggests that men should consider exercising at least four times a week.

REGARDS will continue to assess stroke risk factors to look for long-term patterns in the study population. "Findings from this study, including the current physical activity results, will ultimately help us to identify potential targets for immediate intervention as well as for future clinical trials aimed at preventing stroke and its consequences," said Dr. Moy.