Blood sodium levels may affect cognition in older adults

A new study has found that lower level of sodium in the blood—known as hyponatremia—is linked with declines in cognitive function with advancing age. The results, which are described in an upcoming issue of the Clinical Journal of the American Society of Nephrology (CJASN), raising the possibility that addressing sodium levels may help preserve cognition as individuals age.

09 feb 2018--Hyponatremia occurs when the sodium level in the blood falls below 135 mmol/L. Mild hyponatremia was once thought to be asymptomatic, but recent studies suggest that it may be associated with higher risks of attention deficits, gait disturbances, falls, cardiovascular events, and even premature death. Severe hyponatremia has been linked with cognitive impairment and neurological disturbances, but the association between different levels of serum sodium and cognition in older adults had been uncertain.
To investigate, Kristen Nowak, PhD, MPH (University of Colorado Anschutz Medical Campus) and her colleagues examined information on 5435 asymptomatic community-dwelling men aged >65 years who were followed for a median of 4.6 years. A total of 100 men had serum levels indicative of hyponatremia.
The researchers found that slightly lower sodium levels in the blood were related to both cognitive impairment and declines in cognitive function over time. Compared with men with sodium levels of 141-142 mmol/L, men with levels of 126-140 mmol/L were 30% more likely to have cognitive impairment at baseline and 37% more likely to experience cognitive decline over time. The investigators also found an association of high serum sodium (143-153 mmol/L) with cognitive decline over time.
"Slightly lower sodium levels in the blood are likely to be unnoticed in clinical practice," said Dr. Nowak. "Because both slightly lower serum sodium levels and mild changes in cognitive function are common occurrences with advancing age, future research on this topic is important—including determining whether correcting lower sodium levels affects cognitive function."

More information: "Serum Sodium and Cognition in Older Community-Dwelling Men," Clinical Journal of the American Society of Nephrology (2018). DOI: 10.2215/CJN.07400717


Provided by American Society of Nephrology

Post-lunch napping tied to better cognition in elderly

Moderate post-lunch napping is tied to better cognition in older adults, according to a study published online Dec. 20 in the Journal of the American Geriatrics Society.

29 dec 2016--Junxin Li, Ph.D., from Johns Hopkins University in Baltimore, and colleagues examined associations between self-reported post-lunch napping and structured cognitive assessments in older Chinese adults (≥65 years).
The researchers found that 57.7 percent of participants reported napping (mean time, 63 minutes). There was a significant association between cognitive function and napping (P < 0.001). Moderate nappers had better overall cognition than non-nappers (P < 0.001) or extended nappers (P = 0.01). Non-nappers also had significantly poorer cognition compared to short nappers (P = 0.03). After controlling for demographic characteristics, body mass index, depression, instrumental activities of daily living, social activities, and nighttime sleep duration, moderate napping was significantly associated with better cognition than non- (P = 0.004), short (P = 0.04), and extended napping (P = 0.002).
"Longitudinal studies with objective napping measures are needed to further test this hypothesis," the authors write.

More information: Full Text (subscription or payment may be required)

Midlife physical activity is associated with better cognition in old age

A new study of 3050 twins finds moderately vigorous physical activity – i.e., more strenuous than walking – to be associated with better cognition in a 25-year follow-up.

15 sept 2016--A long-term follow-up study of 3050 twins from the Finnish Twin Cohort has shown that midlife, moderately vigorous physical activity is associated with better cognition at old age. The association was statistically independent of midlife hypertension, smoking, education level, sex, obesity and binge drinking. "This suggests that the beneficial influence of physical activity on the brain and cognition is not solely based on decreasing vascular risk factors", says researcher Paula Iso-Markku from the University of Helsinki.
The association was studied first in all individuals of the cohort, and then by comparing later cognition in pairs where one twin was more physically active than the other.
Increasing the volume of physical activity was not, however, associated with increased memory-protecting benefits. Instead, quite a moderate amount of physical activity was found to be sufficient for memory-protecting benefits, and only the most inactive group of twins stood out with a significantly higher risk for cognitive impairment.
"Overall, the study shows that moderately vigorous physical activity, meaning more strenuous than walking, is associated with better cognition after an average of 25 years", states Professor Urho Kujala from the University of Jyväskylä.
This finding is in accordance with earlier animal model studies, which have shown that physical activity increases the amount of growth factors in the brain and improves synaptic plasticity.
The prevalence of dementia has increased with aging populations both in Finland and globally. Although the incidence of dementia seems to have decreased in less senior generations, the total prevalence of dementia is still expected to rise. No cure for dementia exists, but during the last decade research has produced an abundance of new information on dementia prevention. The traditional vascular risk factors (elevated blood pressure, hypercholesterolemia, obesity, diabetes and lack of exercise) have also been associated with dementia risk. "However, few long-term, high-quality, follow-up studies on physical activity and cognition have been published, and it has remained unclear what type and amount of exercise is needed to safeguard cognition", Iso-Markku says.
The study, published in the Journal of Alzheimer's Disease, was conducted by scientists at the universities of Helsinki, Jyväskylä and Turku. The twins provided information on physical activity through questionnaire surveys from 1975 and 1981 (mean age in 1981: 49 years), while cognition was assessed by validated telephone interviews conducted between 1999 and 2015.

More information: Paula Iso-Markku et al. Midlife Physical Activity and Cognition Later in Life: A Prospective Twin Study, Journal of Alzheimer's Disease (2016). DOI: 10.3233/JAD-160377


Provided by University of Helsinki

Orange juice could help improve brain function in elderly people

Drinking orange juice could help improve brain function in elderly people, according to new research from the University of Reading.

25 may 2015--The study saw a group of 37 healthy adults (mean age 67 years) consuming 500ml (just under a pint) of orange juice, daily over an eight week period. At the beginning and end of the eight weeks their memory, reaction time and verbal fluencywas measured. These were then combined into one overall score known as 'global cognitive function'.

The adults showed an 8% overall improvement in global cognitive function after orange juice consumption compared to a control drink (matched for taste and calories) given during a different eight week period. Although subtle, these improvements are significant. 

One of the tests of verbal memory required learning a list of words which are then recalled immediately and after a 30 minute delay. An 8% improvement equates to remembering one more word from a shopping list of 15 items. Small improvements such as this over an eight week period could translate into substantial improvements over the lifespan. 

While the researchers are not recommending that people drink 500ml of orange juice every day, they believe these findings show that the constituents of orange juice could play an important role in providing brain-boosting nutrients as part of a healthy, balanced diet. They also wish to reinforce the importance of being aware of the nutritional content of fresh fruit juice drinks, relative to daily recommended intake of sugar.

Dr Daniel Lamport, from the University's School of Psychology and Clinical Language Sciences and co-author of the study, said: "The population is ageing rapidly across the world. Estimates suggest that the number of persons aged 60 or over could triple by 2100. It's therefore imperative that we explore simple, cost-effective ways to improve cognitive function in old age."

Orange juice is a major source of a group of naturally occurring plant phytochemicals known as flavonoids, being particularly rich in a sub-class of flavonoids, known as flavanones. Recent studies from the School of Chemistry, Food and Pharmacy have shown that flavonoids may improve memory through the activation of signalling pathways in the hippocampus, a part of the brain that is associated with learning and memory. 

This study is thought to be one of the first to show that regularly consuming orange juice flavanones could have a positive effect on older people's cognition.

Dr Lamport continued: "Small, easily administered changes to the daily diet, such as eating more flavonoid-rich fruits and vegetables, have the potential to substantially benefit brain health. We know that people find it difficult to sustain big changes to their diet but simple alterations are much easier to maintain permanently.

"More research on the positive effects of flavonoids on cognition is still needed. However, this is an important discovery which strengthens the growing body of evidence that flavonoid rich foodstuffs could play a big role in tackling cognition decline in old age."

Previous Reading research has shown that other flavonoid rich foods such as blueberries are beneficial for cognition. Research is still ongoing to determine the exact mechanisms by which flavonoids may exert benefits to the brain. Several mechanisms have been proposed such as improved blood flow in the brain and protecting neurons against oxidative damage and increasing the efficiency with which neurons transmit signals.

More information: "Chronic consumption of flavanone-rich orange juice is associated with cognitive benefits: an 8-wk, randomized, double-blind, placebo-controlled trial in healthy older adults." Am J Clin Nutr 2015 ajcn.088518; First published online January 14, 2015. DOI: 10.3945/ajcn.114.088518

Provided by University of Reading

Mediterranean diet plus olive oil or nuts associated with improved cognitive function

Credit: Wikipedia.

Supplementing the plant-based Mediterranean diet with antioxidant-rich extra virgin olive oil or mixed nuts was associated with improved cognitive function in a study of older adults in Spain but the authors warn more investigation is needed, according to an article published online by JAMA Internal Medicine.

14 may 2015--Emerging evidence suggests associations between dietary habits and cognitive performance. Oxidative stress (the body's inability to appropriately detoxify itself) has long been considered to play a major role in cognitive decline. Previous research suggests following a Mediterranean diet may relate to better cognitive function and a lower risk of dementia. However, the observational studies that have examined these associations have limitations, according to the study background.

Emilio Ros, M.D., Ph.D., of the Institut d'Investigacions Biomediques August Pi Sunyer, Hospital Clinic, Barcelona, and Ciber Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, and coauthors compared a Mediterranean diet supplemented with olive oil or nuts with a low-fat control diet.

The randomized clinical trial included 447 cognitively healthy volunteers (223 were women; average age was nearly 67 years) who were at high cardiovascular risk and were enrolled in the Prevencion con Dieta Mediterranea nutrition intervention.

Of the participants, 155 individuals were assigned to supplement a Mediterranean diet with one liter of extra virgin olive oil per week; 147 were assigned to supplement a Mediterranean diet with 30 grams per day of a mix of walnuts, hazelnuts and almonds; and 145 individuals were assigned to follow a low-fat control diet.

The authors measured cognitive change over time with a battery of neuropsychological tests and they constructed three cognitive composites for memory, frontal (attention and executive function) and global cognition. After a median of four years of the intervention, follow-up tests were available on 334 participants.

At the end of the follow-up, there were 37 cases of mild cognitive impairment: 17 (13.4 percent) in the Mediterranean diet plus olive oil group; eight (7.1 percent) in the Mediterranean diet plus nuts group; and 12 (12.6 percent) in the low-fat control group. No dementia cases were documented in patients who completed study follow-up.

The study found that individuals assigned to the low-fat control diet had a significant decrease from baseline in all composites of cognitive function. Compared with the control group, the memory composite improved significantly in the Mediterranean diet plus nuts, while the frontal and global cognition composites improved in the Mediterranean diet plus olive oil group. The authors note the changes for the two Mediterranean diet arms in each composite were more like each other than when comparing the individual Mediterranean diet groups with the low-fat diet control group.

"Our results suggest that in an older population a Mediterranean diet supplemented with olive oil or nuts may counter-act age-related cognitive decline. The lack of effective treatments for cognitive decline and dementia points to the need of preventive strategies to delay the onset and/or minimize the effects of these devastating conditions. The present results with the Mediterranean diet are encouraging but further investigation is warranted," the study concludes.

More information: JAMA Intern Med. Published online May 11, 2015. DOI: 10.1001/jamainternmed.2015.1668

Provided by The JAMA Network Journals

Peak cognitive skills not strictly a feature of youth, study finds

New research is changing long-held ideas of how our minds age, painting a richer picture of different cognitive skills peaking across a lifetime, with at least one—vocabulary—peaking at a time when many are considering retirement.

23 mar 2015--The study, supported by results from tens of thousands of volunteers who participated in a series of online tests, also hinted that at least some cognitive skills are plastic and that their decline can be delayed by changes in education, environment, or lifestyle. Researchers' analysis of existing tests from different decades showed vocabulary skills peaking later and later in life, a trend they ascribe in part to improvements in education and the rise of white-collar jobs.

"What we're seeing is that, across adulthood, some things 'age' in the sense that processing speed does go down," said co-author Laura Germine, a research associate in Harvard's Psychology Department and a postdoctoral fellow at Harvard-affiliated Massachusetts General Hospital. "But other things are doing something very different from what is implied by the word 'aging.' They're maturing, they're getting refined over time. For the everyday person, the word 'aging' implies a breakdown of things. 'Ripening' might be better."

Germine conducted the research with Joshua Hartshorne, a postdoctoral fellow at the Massachusetts Institute of Technology. Published this month in the journal Psychological Science, it presents the results of a fine-grained analysis enabled by the many volunteers—more than 48,000—who went to www.testmybrain.org and www.gameswithwords.org and took a series of game-like tests that measured an array of cognitive skills, including brain processing speed, memory, emotional cognition, and so-called "crystalized intelligence," the application of learned knowledge such as vocabulary and arithmetic.

The results present a much more nuanced picture of changes in cognitive skills over a lifetime than that provided by current theoretical frameworks, Germine said. It has traditionally been believed that many cognitive skills peak early—late teens and 20s—and decline with age, with crystallized intelligence, thought to peak in the 40s, being the exception.

The view that there is a broad decline in most cognitive skills likely emerged due to limitations in the population that can be easily tested for studies on aging, Germine said. Because most adults are busy working and raising families, they have little time to come to a lab and participate in experiments. Instead, she said, such tests are most often taken by college students and by retirees, giving psychologists a good view of the two ends of the lifespan but much less data about what goes on in between.

"Regular old adults have been some of the hardest participants to get for this kind of research," Germine said.

The Web-based tests used by Germine and Hartshorne (who runs gameswithwords.org) are different because they can be done from any computer and take just a few minutes, making them more accessible to working adults. The trick in designing such tests, Germine said, is to make them engaging so that participants feel rewarded enough to take a second test, or to tell others.

The two began working together as Ph.D. students at Harvard after Germine published results from online testing in 2011 showing that the ability to recognize and remember faces peaks between ages 30 and 34, later than was thought. Hartshorne approached Germine because work he was doing on a different aspect of memory also showed a later peak than the accepted average.

Because Hartshorne too had gathered his data through Web-based experiments, the pair worried they were measuring some quirk of people in their late 20s and early 30s who used the Internet. So they obtained the results of older, paper-based tests of intelligence and memory, broke down the data, and reanalyzed it to see if it revealed the same unexpected peaks as the Web findings. To their relief, it did.

The pair then continued with the study released this month, which shows a series of cognitive peaks through life. Peak mental processing speed occurs, as expected, in late teens and early 20s and declines relatively rapidly afterward. But other skills peak at different times. Working memory climbs in the late 20s to early 30s, and then declines only slowly over time. Social cognition, the ability to detect others' emotions, peaks even later—in the 40s to age 50—and doesn't start to significantly decline until after 60.

"That fits with absolutely no theoretical framework that we currently have," Germine said.

Crystalized intelligence, measured as vocabulary skills, didn't have a peak. Instead, it continued to improve as respondents aged, until 65 to 70. The result was so startling, it sent Germine and Hartshorne back again to paper tests—this time the large-scale General Social Survey. Their first look at the GSS indicated that vocabulary skills peaked decades earlier than in their study, from 45 to 50. But before dismissing their own results, the researchers decided to break down the GSS by decade.

From 1974 through 1987, they found, vocabulary skills peaked in the early 40s. From 1988 through 1997, they peaked at around 50, and from 1998 to 2012, they peaked at 65, matching their data.

Germine attributed the change in vocabulary skills over time to broader changes in society, including an increased emphasis on education, both early in life and lifelong; the rise of white-collar jobs that require more reading and writing; and to a general improvement in nutrition and physical well-being, factors that support cognitive health.

Baby boomers "are the most educated generation of all generations that have ever retired," Germine said.

Though the research enriches scientific understanding of changes in cognition, in many ways it only confirms what people in their homes, schools, and workplaces already know, Germine said.

"A lot of people have this intuition that one matures as one gets older. It's not just because there's more information in the brain, there's lots of other things, too. As we get older, we get better at solving certain kinds of problems, though we may not have the quickness of our 20s. It's a rich process of change. … In a lot of ways, our results are surprising from a theoretical standpoint, but they also kind of really make sense."

Provided by Harvard University

Forget about forgetting: The elderly know more and use it better

What happens to our cognitive abilities as we age? If your think our brains go into a steady decline, research reported this week in the journal Topics in Cognitive Science may make you think again. The work, headed by Dr. Michael Ramscar of Tübingen University, takes a critical look at the measures usually thought to show that our cognitive abilities decline across adulthood. Instead of finding evidence of decline, the team discovered that most standard cognitive measures, which date back to the early twentieth century, are flawed. "The human brain works slower in old age," says Ramscar, "but only because we have stored more information over time."

22 jan 2014--Computers were trained, like humans, to read a certain amount each day, and to learn new things. When the researchers let a computer "read" only so much, its performance on cognitive tests resembled that of a young adult. But if the same computer was exposed to the experiences we might encounter over a lifetime – with reading simulated over decades – its performance now looked like that of an older adult. Often it was slower, but not because its processing capacity had declined. Rather, increased "experience" had caused the computer's database to grow, giving it more data to process – which takes time.

Technology now allows researchers to make quantitative estimates of the number of words an adult can be expected to learn across a lifetime, enabling the Tübingen team to separate the challenge that increasing knowledge poses to memory from the actual performance of memory itself. "Imagine someone who knows two people's birthdays and can recall them almost perfectly. Would you really want to say that person has a better memory than a person who knows the birthdays of 2000 people, but can 'only' match the right person to the right birthday nine times out of ten?" asks Ramscar.

The answer appears to be "no." When Ramscar's team trained their computer models on huge linguistic datasets, they found that standardized vocabulary tests, which are used to take account of the growth of knowledge in studies of ageing, massively underestimate the size of adult vocabularies. It takes computers longer to search databases of words as their sizes grow, which is hardly surprising but may have important implications for our understanding of age-related slowdowns. The researchers found that to get their computers to replicate human performance in word recognition tests across adulthood, they had to keep their capacities the same. "Forget about forgetting," explained Tübingen researcher Peter Hendrix, "if I wanted to get the computer to look like an older adult, I had to keep all the words it learned in memory and let them compete for attention."

The research shows that studies of the problems older people have with recalling names suffer from a similar blind spot: there is a far greater variety of given names today than there were two generations ago. This cultural shift toward greater name diversity means the number of different names anyone learns over their lifetime has increased dramatically. The work shows how this makes locating a name in memory far harder than it used to be. Even for computers.

Ramscar and his colleagues' work provides more than an explanation of why, in the light of all the extra information they have to process, we might expect older brains to seem slower and more forgetful than younger brains. Their work also shows how changes in test performance that have been taken as evidence for declining cognitive abilities in fact demonstrates older adults' greater mastery of the knowledge they have acquired.

Take "paired-associate learning," a commonly used cognitive test that involves learning to connect words like "up" to "down" or "necktie" to "cracker" in memory. Using Big Data sets to quantify how often different words appear together in English, the Tuebingen team show that younger adults do better when asked to learn to pair "up" with "down" than "necktie" and "cracker" because "up" and "down" appear in close proximity to one another more frequently. However, whereas older adults also understand which words don't usually go together, young adults notice this less. When the researchers examined performance on this test across a range of word pairs that go together more and less in English, they found older adult's scores to be far more closely attuned to the actual information in hundreds of millions of words of English than their younger counterparts.

As Prof. Harald Baayen, who heads the Alexander von Humboldt Quantitative Linguistics research group where the work was carried out puts it, "If you think linguistic skill involves something like being able to choose one word given another,younger adults seem to do better in this task. But, of course, proper understanding of language involves more than this. You have also to not put plausible but wrong pairs of words together. The fact that older adults find nonsense pairs – but not connected pairs – harder to learn than young adults simply demonstrates older adults' much better understanding of language. They have to make more of an effort to learn unrelated word pairs because, unlike the youngsters, they know a lot about which words don't belong together."

The Tübingen research conclude that we need different tests for the cognitive abilities of older people – taking into account the nature and amount of information our brains process. "The brains of older people do not get weak," says Michael Ramscar. "On the contrary, they simply know more."

More information: Michael Ramscar, Peter Hendrix, Cyrus Shaoul, Petar Milin, Harald Baayen. (2014) The Myth of Cognitive Decline: Non-Linear Dynamics of Lifelong Learning. Topics in Cognitive Science, 6, 5-42.onlinelibrary.wiley.com/doi/10.1111/tops.12078/full

Provided by Universitaet Tübingen

Researchers say genes and vascular risk modify effects of aging on brain and cognition

Efforts to understand how the aging process affects the brain and cognition have expanded beyond simply comparing younger and older adults.

10 may 2012--"Everybody ages differently. By looking at genetic variations and individual differences in markers of vascular health, we begin to understand that preventable factors may affect our chances for successful aging," said Wayne State University psychology doctoral student Andrew Bender, lead author of a study supported by the National Institute on Aging of the National Institutes of Health and now in press in the journal Neuropsychologia.
The report, "Age-related Differences in Memory and Executive Functions in Healthy APOE ε4 Carriers: The Contribution of Individual Differences in Prefrontal Volumes and Systolic Blood Pressure," focuses on carriers of the ε4 variant of the apolipoprotein (APOE) gene, present in roughly 25 percent of the population. Compared to those who possess other forms of the APOE gene, carriers of the ε4 allele are at significantly greater risk for Alzheimer's, dementia and cardiovascular disease.
Many studies also have shown that nondemented carriers of the APOE ε4 variant have smaller brain volumes and perform less well on cognitive tests than carriers of other gene variants. Those findings, however, are not consistent, and a possible explanation may come from examining interactions between the risky genes and other factors, such as markers of cardiovascular health. Prior research in typical samples of older adults has shown that indeed other vascular risk factors — such as elevated cholesterol, hypertension or diabetes — can exacerbate the impact of the APOE ε4 variant on brain and cognition, but it is unclear if such synergy of risks is present in healthy adults.
Thus, Wayne State researchers evaluated a group of volunteers from 19 to 77 years of age who self-reported as exceptionally healthy on a questionnaire that screened for a number of conditions, representing a "best case scenario" of healthy aging. The research project, led by Naftali Raz, Ph.D., professor of psychology and director of the Lifespan Cognitive Neuroscience Research Program at WSU's Institute of Gerontology, tested different cognitive abilities known for their sensitivity to aging and the effects of the APOE ε4 variant. Those abilities include speed of information processing, working memory (holding and manipulating information in one's mind) and episodic memory (memory for events).
Researchers also measured participants' blood pressure, performed genetic testing to determine which APOE variant participants carried, and measured the volumes of several critical brain regions using a high-resolution structural magnetic resonance imaging brain scan. Bender and Raz showed that for older APOE ε4 carriers, even minor increases in systolic blood pressure (the higher of the two numbers that are reported in blood pressure measures) were linked with smaller volumes of the prefrontal cortex and prefrontal white matter, slower speed of information processing, reduced working memory capacity and worse verbal memory. Notably, they said, that pattern was not evident in those who lacked the ε4 gene variant.
The study concludes that the APOE ε4 gene may make its carriers sensitive to negative effects of relatively subtle elevations in systolic blood pressure, and that the interplay between two risk factors, genetic and physiological, is detrimental to the key brain structures and associated cognitive functions.
"Although genes play a significant role in shaping the effects of age and vascular risk on the brain and cognition, the impact of single genetic variants is relatively small, and there are quite a few of them. Thus, one's aging should not be seen through the lens of one's genetic profile," cautioned the study's authors. They continued, "The negative impact of many genetic variations needs help from other risk factors, and while there isn't much one can do about genes, a lot can be done about vascular risk factors such as blood pressure or cholesterol."
"Everybody should try to keep those in check, although people with certain genetic variants more so than others." Raz said. "Practically speaking, even with the best deck of genetic cards dealt to you, it still makes sense to reduce risk through whatever works: exercise, diet or, if those fail, medication."
Because the study is part of a longitudinal project, he and Bender said the immediate future task now is to determine how the interaction between risky genes and vascular risk factors affect the trajectory of age-related changes — not differences, as in this cross-sectional study — in brain and cognition.
Provided by Wayne State University

Diet, nutrient levels linked to cognitive ability, brain shrinkage

New research has found that elderly people with higher levels of several vitamins and omega 3 fatty acids in their blood had better performance on mental acuity tests and less of the brain shrinkage typical of Alzheimer's disease – while "junk food" diets produced just the opposite result.

29 dec 2011--The study was among the first of its type to specifically measure a wide range of blood nutrient levels instead of basing findings on less precise data such as food questionnaires, and found positive effects of high levels of vitamins B, C, D, E and the healthy oils most commonly found in fish.

The research was done by scientists from the Oregon Health and Science University in Portland, Ore., and the Linus Pauling Institute at Oregon State University. It was published today in Neurology, the medical journal of the American Academy of Neurology.

"This approach clearly shows the biological and neurological activity that's associated with actual nutrient levels, both good and bad," said Maret Traber, a principal investigator with the Linus Pauling Institute and co-author on the study.

"The vitamins and nutrients you get from eating a wide range of fruits, vegetables and fish can be measured in blood biomarkers," Traber said. "I'm a firm believer these nutrients have strong potential to protect your brain and make it work better."

The study was done with 104 people, at an average age of 87, with no special risk factors for memory or mental acuity. It tested 30 different nutrient biomarkers in their blood, and 42 participants also had MRI scans to measure their brain volume.

"These findings are based on average people eating average American diets," Traber said. "If anyone right now is considering a New Year's resolution to improve their diet, this would certainly give them another reason to eat more fruits and vegetables."

Among the findings and observations:

• The most favorable cognitive outcomes and brain size measurements were associated with two dietary patterns – high levels of marine fatty acids, and high levels of vitamins B, C, D and E.
• Consistently worse cognitive performance was associated with a higher intake of the type of trans-fats found in baked and fried foods, margarine, fast food and other less-healthy dietary choices.
• The range of demographic and lifestyle habits examined included age, gender, education, smoking, drinking, blood pressure, body mass index and many others.
• The use of blood analysis helped to eliminate issues such as people's flawed recollection of what they ate, and personal variability in nutrients absorbed.
• Much of the variation in mental performance depended on factors such as age or education, but nutrient status accounted for 17 percent of thinking and memory scores and 37 percent of the variation in brain size.
• Cognitive changes related to different diets may be due both to impacts on brain size and cardiovascular function.

The epidemiology of Alzheimer's disease has suggested a role for nutrition, the researchers said in their study, but previous research using conventional analysis, and looking in isolation at single nutrients or small groups, have been disappointing. The study of 30 different blood nutrient levels done in this research reflects a wider range of nutrients and adds specificity to the findings.

The study needs to be confirmed with further research and other variables tested, the scientists said.

Provided by Oregon State University

Moderate drinking protects against Alzheimer's and cognitive impairment

Moderate social drinking significantly reduces the risk of dementia and cognitive impairment, according to an analysis of 143 studies by Loyola University Chicago Stritch School of Medicine researchers.

20 aug 2011--Researchers reviewed studies dating to 1977 that included more than 365,000 participants. Moderate drinkers were 23 percent less likely to develop cognitive impairment or Alzheimer's disease and other forms of dementia.

Wine was more beneficial than beer or spirits. But this finding was based on a relatively small number of studies, because most papers did not distinguish among different types of alcohol.

Results are reported in the journal Neuropsychiatric Disease and Treatment. The authors are Edward J. Neafsey, PhD. and Michael A. Collins, PhD., professors in the Department of Molecular Pharmacology and Therapeutics.

Heavy drinking (more than 3 to 5 drinks per day) was associated with a higher risk of cognitive impairment and dementia, but this finding was not statistically significant.

"We don't recommend that nondrinkers start drinking," Neafsey said. "But moderate drinking -- if it is truly moderate -- can be beneficial." Moderate drinking is defined as a maximum of two drinks per day for men and 1 drink per day for women.

Among the studies reviewed, 74 papers calculated the ratios of risk between drinkers and non-drinkers, while 69 papers simply stated whether cognition in drinkers was better, the same or worse than cognition in nondrinkers. Neafsey and Collins did a meta-analysis of the studies that calculated risk ratios and found that moderate drinkers were 23 percent less likely to develop dementia or cognitive decline.

Other findings:

• The protective effect of moderate drinking held up after adjusting for age, education, sex and smoking.
• There was no difference in the effects of alcohol on men and women.
• The beneficial effect of moderate drinking was seen in 14 of 19 countries, including the United States. In 3 of the remaining 5 countries, researchers also found a benefit, but it was not strong enough to be statistically significant.
• The findings were similar across different types of studies (longitudinal cohort studies, case-control studies and cross-sectional studies).

It is unknown why moderate drinking can have a beneficial effect. One theory suggests that the well-known cardiovascular benefits of moderate alcohol consumption, such as raising good HDL cholesterol, also can improve blood flow in the brain and thus brain metabolism.

A second possible explanation involves "sick quitters." According to this theory, nondrinkers have a higher risk of cognitive impairment and dementia because the group includes former heavy drinkers who damaged their brain cells before quitting. But the analysis by Neafsey and Collins did not support this explanation. They found that in studies that excluded former heavy drinkers, the protective effect of moderate drinking still held up.

Neafsey and Collins suggest a third possible explanation: Small amounts of alcohol might, in effect, make brain cells more fit. Alcohol in moderate amounts stresses cells and thus toughens them up to cope with major stresses down the road that could cause dementia.

For people who drink responsibly and in moderation, there's probably no reason to quit. But because of the potential for alcohol to be abused, Neafsey and Collins do not recommend that abstainers begin drinking.

The researchers note that there are other things besides moderate drinking that can reduce the risk of dementia, including exercise, education and a Mediterranean diet high in fruits, vegetables, cereals, beans, nuts and seeds. Even gardening has been shown to reduce the risk of dementia.

Moreover, there are times when people should never drink, including adolescence, pregnancy and before driving, the researchers said.

Provided by Loyola University Health System

Exercise has numerous beneficial effects on brain health and cognition, review suggests

It's no secret that exercise has numerous beneficial effects on the body. However, a bevy of recent research suggests that these positive effects also extend to the brain, influencing cognition. In a new review article highlighting the results of more than a hundred recent human and animal studies on this topic, Michelle W. Voss, of the University of Illinois at Urbana-Champaign, and her colleagues show that both aerobic exercise and strength training play a vital role in maintaining brain and cognitive health throughout life. However, they also suggest that many unanswered questions remain in the field of exercise neuroscience—including how various aspects of exercise influence brain physiology and function and how human and animal studies relate to each other—and issue the call for further research to fill in these gaps.

27 july 2011--The article, "Exercise, Brain and Cognition Across the Lifespan," is published in the online edition of the Journal of Applied Physiology.

Methodology

Using the findings from 111 recent studies, the researchers write a brief review showcasing the effects of aerobic exercise and strength training on humans ranging in age from children to elderly adults. They relate these findings to those in lab animals, such as rats and mice, which provide a window on the pathways through which exercise may enhance brain function.

Results

The review suggests that aerobic exercise is important for getting a head start during childhood on cognitive abilities that are important throughout life. For example, physical inactivity is associated with poorer academic performance and results on standard neuropsychological tests, while exercise programs appear to improve memory, attention, and decision-making. These effects also extend to young and elderly adults, with solid evidence for aerobic training benefiting executive functions, including multi-tasking, planning, and inhibition, and increasing the volume of brain structures important for memory. Although few studies have evaluated the effects of strength training on brain health in children, studies in older adults suggest that high-intensity and high-load training can improve memory.

Animal studies, primarily models that test the influence of aerobic exercise, suggest a variety of mechanisms responsible for these effects. For example, exercise appears to change brain structure, prompting the growth of new nerve cells and blood vessels. It also increases the production of neurochemicals, such as BDNF and IGF-1, that promote growth, differentiation, survival, and repair of brain cells.

Though this collection of studies clearly reveals the beneficial effects of exercise on the brain, it also highlights gaps in the scientific literature. For example, the review authors note that more research is needed on how exercise type might promote different effects on brain health and cognition. Similarly, they say, future research that integrates human and animal work will be necessary, such as studies that incorporate exercise over animals' life spans to understand the effects of exercise at different time points, or human studies that include measures of BDNF, IGF-1, or other neurobiological markers.

Importance of the Findings

The reviewed studies suggest that both aerobic exercise and strength training can have significant positive effects on brain health and function, but more research is needed to better elucidate these effects.

"It is increasingly prevalent in the print media, television, and the Internet to be bombarded with advertisements for products and programs to enhance mental and physical health in a relatively painless fashion through miracle elixirs, computer-based training, or gaming programs, or brief exercise programs," the authors say. "Although there is little convincing scientific evidence for such claims, there have been some promising developments in the scientific literature with regard to physical activity and exercise effects on cognitive and brain health."

Provided by American Physiological Society

Diastolic Blood Pressure Linked to Impaired Cognition

Ten-point rise associated with 7 percent higher odds of impairment in middle-aged and older

31 aug 2009-- Higher diastolic blood pressure (DBP) may be associated with a greater risk of impaired cognitive status in middle-aged and older individuals, according to research published in the Aug. 25 issue of Neurology.

Georgios Tsivgoulis, M.D., of the University of Alabama in Birmingham, and colleagues analyzed data from nearly 20,000 African-American and Caucasian men and women ages 45 years and older with no history of stroke or transient ischemic attack.

The researchers found that higher DBP was associated with impaired cognitive status after adjusting for a variety of factors, including age, sex, race, smoking and diabetes. A 10 mm Hg rise in DBP was associated with 7 percent higher odds of cognitive impairment. Systolic blood pressure (SBP) and pulse pressure were not linked to impaired cognitive status.

"It is intriguing that DBP but not SBP (nor pulse pressure) was independently related to impaired cognitive status in our data set. Experimental studies have shown that small cerebral arterioles, which are influenced profoundly by DBP, undergo vascular atrophy progressively with age. Neuropathologic data indicate that elevated DBP levels accelerate this process and lead to formation of ischemic white matter lesions in subcortical areas of the brain. Moreover, higher DBP levels have been associated with the severity of white matter disease both cross-sectionally and longitudinally in large randomly selected samples from two population-based studies," the authors write.

Several authors reported financial relationships with pharmaceutical companies.

Abstract
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