A recently published report funded by the National Institutes of Health (NIH) reviews the extensive literature on cognitive decline and Alzheimer’s disease in search of factors that might delay or prevent these age-related conditions. Of all the factors reviewed, including diet and dietary supplements, physical exercise, social engagement, and other leisure activities, only cognitive training was found to have a high level of evidence for being associated with a decreased risk of cognitive decline. So, if you want to engage in activities that are known to be associated with a reduced risk of cognitive decline, this report says that cognitive training is the only thing that currently fits the bill.

The nearly 800-page manuscript was prepared by the Duke Evidence-based Practice Center for the Agency of Healthcare Research and Quality (AHRQ), a part of the U.S. Department of Health and Human Services. This exhaustive report was created to support the NIH State-of-the-Science Conference “Preventing Alzheimer’s Disease and Cognitive Decline.” The conference brought together health experts with specific expertise in aging and age-related changes in cognition to discuss the current state of knowledge related to treatments for age-related cognitive decline and Alzheimer’s disease. The report takes a very conservative approach to its evaluation of risk factors and potential treatments for age-related problems of cognition. In fact, only cognitive training was found to have a high degree of evidence for reducing the risk of age-related cognitive decline. Hundreds of studies were reviewed, and while many studies offered evidence that was suggestive of reducing risks, most were correlational, rather than experimental, in nature. For instance, some studies showed a relationship between eating a “Mediterranean diet” and reduced risk of cognitive decline. But these studies typically just ask people about their diet and correlate these factors to cognitive performance. Conversely, there have been several randomized, controlled trials that have shown improved cognitive performance through cognitive training. This higher degree of rigor earned cognitive training the “high degree of evidence” designation in this report.

Of course, that’s not to say you shouldn’t take care of yourself in other ways. Other factors such as a diet high in vegetables and omega-3 fatty acids, physical activity, and some leisure activities were found to be associated with a decreased risk of cognitive decline, albeit with a low level of evidence. In other words, these things are likely good for your brain, but the authors did not feel there was enough evidence to say so definitively. Given that most of these lifestyle factors are good for you in other ways, there’s certainly no harm in eating better, getting more exercise, or spending more time with friends and family. If you want to see how your lifestyle may be affecting your brain health, take our Brain Grade test.

This report is just another reason to make cognitive training — like Lumosity.com — a regular part of your brain health routine.

Training with cognitive exercises can improve targeted mental functions, conclude the authors of a review article published recently in the journal Alzheimer’s and Dementia.  The authors (Kathryn Papp and Stephen Walsh from the University of Connecticut and Peter Snyder from Brown University) reviewed ten randomized controlled trials involving cognitive training interventions in healthy adults published since 1992.  They find that specific abilities such as memory, reasoning, and speed of processing can be improved through targeted training programs.  This is an important conclusion, and it is consistent with the growing evidence in support of the effectiveness of cognitive training.

The authors point out that the benefits of cognitive training tend to be specific to the trained domain.  So, if you want improved memory — train on games designed to improve memory.  If you want improved attention — train with attention games, and so on.  The relationship to physical exercise is apparent.  If you want big biceps — do curls.  If you want ripped abs — do sit ups.  Lumosity was designed with these principles in mind.  This is why the site contains over 30 games targeting cognitive functions spanning speed of processing, memory, attention, flexibility, and problem solving — a complete gym for the brain.

It is also clear from this review that there is still much to learn.  Few of the studies have follow-up testing longer than a few months, and many of them lack measures of real-world benefits such as activities of daily living.  However, where longer follow-ups and real-world benefits are measured, benefits are seen to be long lasting and quite general.  For example, in the ACTIVE study of cognitive training in normal healthy older adults, benefits to activities of daily living are seen 5 years after the training intervention ended.

While there is still much to learn, the weight of the evidence is showing that cognitive training can be highly effective when properly designed and executed.

Newswise— Individuals with higher education levels appear to score higher on cognitive tests despite having evidence of brain plaques associated with Alzheimer’s disease, according to a report in the November issue of Archives of Neurology, one of the JAMA/Archives journals.

The cognitive reserve hypothesis holds that individuals with greater cognitive (thinking, learning and memory) abilities are able to delay symptoms of Alzheimer’s disease despite underlying changes in the brain, according to background information in the article. Education is commonly used as a substitute measure of cognitive reserve. “Adjusting for level of Alzheimer disease pathological burden determined at autopsy, greater education has been associated with better cognitive function during life,” the authors write. “Education interacts with Alzheimer disease pathological burden such that a greater pathological burden is required to show an effect on cognition among persons with more education.”

Catherine M. Roe, Ph.D., and colleagues at the Washington University School of Medicine, St. Louis, studied 37 individuals with dementia of the Alzheimer type and 161 individuals without dementia between 2003 and 2008. Participants reported their education history and took cognitive tests. They were injected with a marker known as carbon 11–labeled Pittsburgh Compound B ([11C]PiB) and then underwent a 60-minute positron emission tomography (PET) scan of the brain. Recent studies have shown that [11C]PiB adheres to beta-amyloid brain plaques associated with Alzheimer’s disease, allowing researchers to identify these characteristics of the disease in living patients.

The level of [11C]PiB uptake interacted significantly with years of education in predicting cognitive test scores. Among individuals whose brains took up higher levels of [11C]PiB, indicating the presence of beta-amyloid plaques, performance on the test increased with increasing education levels. Education was not associated with cognitive scores among those with low [11C]PiB uptake, indicating no plaques.

“The results support the hypothesis that cognitive reserve influences the association between Alzheimer disease pathological burden and cognition,” the authors write. “Based on autopsy data, there may be a ceiling effect when extensive beta-amyloid pathological burden is present as in late-stage dementia of the Alzheimer type. Presumably, as the Alzheimer disease pathological burden increases, a greater proportion of highly educated participants reaches the threshold for dementia and the initial advantage provided by cognitive reserve decreases. Longitudinal imaging of beta-amyloid pathology in vivo will soon allow us to determine whether these inferences from cross-sectional studies are accurate.”

Reference: Arch Neurol. 2008;65[11]:1467-1471

There is some new evidence that Alzheimer’s disease is much more likely for people whose parents both have the neurodegenerative disorder than if only one parent has it. Researchers examined families in which both parents have Alzheimer’s, and found that their children ended up with the disease 42% of the time.

This finding supports the evidence that genes play an important role in determining whether you end up with Alzheimer’s. One of the genetic components responsible for the disease is known as the gene Apolipoprotein E (ApoE). Fortunately your genes do not entirely determine your fate. Your lifestyle is important too, and although we do not have control of our genetic makeup, we can control how we live. With the proper cognitive and physical exercise, brain food, and even attitude toward life, one can better buffer their brain from later years of cognitive decline and delay the risk of dementia.

The incidence of Alzheimer’s increases with age, and is typically diagnosed after the age of 65. By then, there’s not much you can do to slow the disease. So what can you do earlier to help your chances of preserving cognitive function? For me personally, I have been implementing some of the brain health tips on this blog, as well as training my brain with Lumosity, as part of my daily routine. This is not just to practice what I preach, but rather to address a concern I have when I constantly need to remind my parents about certain things, such as taking their meds. I’d rather start my cognitive training regimen early so that when I someday reach my parents’ age my brain will be in the best condition it can be.

The article does offer some hope:

“…notes Richard Suzman, Ph.D., director of the NIA’s Behavioral and Social Research Program. ‘Research is now beginning to suggest that interventions – such as controlling hypertension and diabetes or perhaps cognitive training – might help maintain or improve mental abilities with age. As such interventions are tested and widely applied, we should be able to track their impact through this type of research.’”

“Our results suggest that fresh apples, banana and orange in our daily diet along with other fruits may protect neuron cells against oxidative stress-induced neurotoxicity and may play an important role in reducing the risk of neurodegenerative disorders such as Alzheimer’s disease,” Lee concluded.

One of the top brain foods you can have in your diet is fish. This brain food, also in pill form, is a good source of omega-3 fatty acids that the body alone cannot produce. Recently, scientists from UCLA further discovered that omega-3 fatty acid docosahexaenoic acid, or DHA, increases the production of a protein called LR11, which is known to destroy the beta amyloid plaques that are associated with Alzheimer’s. A fish diet may possibly be a deterrent against this debilitating neurodegenerative disease. With that said, take care of that brain of yours by eating right and exercising, both physically and mentally.

Researchers from Stanford might have found a biological marker for Alzheimer’s disease via a simple blood test. This is exciting news given that it might predict the onset of the disease several years before the symptoms begin. The procedure involves examining 18 key proteins in the blood that are typical in Alzheimer’s patients. Preliminary tests have been 90% accurate at detecting the disease. Dr Susanne Sorensen, of the Alzheimer’s Society, said that “Early diagnosis is essential if we are ever to develop treatments that can change the course or halt the progression of dementia rather than just treat the symptoms.”

The first Alzheimer’s diseased brain I ever touched looked horrific. The cortex was shriveled, the ventricles were large, cavernous voids, and when I stained the sample I saw a galaxy of proteinaceous tangles and masses. The brain had clearly been degenerating steadily for over a decade, and it was difficult to imagine how the patient could have functioned. I was shocked to discover that, according to his charts, the patient’s dementia had only been detectable for a few years. In contrast, certain brains I analyzed appeared dramatically more intact, yet came from patients who had suffered from severe dementia for over a decade.

These patients exemplify the dramatically different ways people can respond to neurodegenerative changes. Even when confronted with the same disease and comparable severity, people vary considerably in the extent of cognitive decline. Specifically, people with higher levels of education and occupational attainment are more successful at coping with the same amount of brain damage.

One hypothesis that accounts for this discrepancy is the concept of cognitive reserve. The cognitive reserve hypothesis posits that people who have challenged their minds for significant portions of their lives (i.e. they didn’t just start playing Sudoku at the age of 60) can compensate for brain damage or degeneration by recruiting alternate brain networks as backup or “reserve.” In support of this hypothesis, functional brain imaging shows that “high-functioning” older adults activate significantly more areas of their brains than both “low-functioning” older adults and young adults when performing certain cognitive tasks. This indicates neural compensation; the “high-functioning” old engage in alternative neural strategies in response to neural deficits or declines in cognitive abilities. Importantly, this type of compensation may be facilitated by a more flexible organization of the brain, which results from early cognitive experience.

Of course, people who did not start challenging themselves until later in life should not despair. Other requisites of compensation, such as plasticity (including the birth of new neurons and enhanced signaling between neurons), may be improved by cognitive experience throughout life (although the earlier the better). Further, in a complementary aspect of cognitive reserve, people who challenge their brains throughout life may be able to protect their existing brain networks. Intellectually stimulating activities may increase the efficiency and capacity of these networks, enabling them to withstand a greater degree of age-related change while maintaining intact functioning (again, the earlier the better).

“To maintain or improve the cognitive performance of all adults.”

Last week they published a call to action for improving the cognitive fitness of the world. These organizations want brain health to be considered just as important as maintaining a healthy heart, or addressing cancer. Their suggested initiatives include supporting public health research, and reviewing the literature to determine the types of physical activity that are best for the brain (hint: look to weight-bearing aerobic activity like running or walking).

You can download the Brain Health Road Map here.