Strategies to Maintain Your Brain: Understanding the Evidence

The Alzheimer’s Association Maintain Your Brain® public education campaign is based on the best available science about brain health. The following reference list includes a representative sample of important studies in key areas. Selections are reviewed and approved by Alzheimer’s Association senior science staff and advisors.

While there is good science about important steps you can take now to help Maintain Your Brain, it’s important to recognize that we don’t have all the answers.

The Alzheimer’s Association is working on everyone’s behalf to fill the gaps in our knowledge. As scientific discovery moves forward, we will continue to provide you with the highest quality information. The most recent supporting evidence is always available in this section of our Web site.

Here are some things to keep in mind about the evidence for maintaining brain health:

• Insights about prevention apply to large population groups, not to individuals. Studies can show that factor X is associated with outcome Y, but cannot guarantee that any specific person will have that outcome. As a result, you can "do everything right" and still have a serious health problem or "do everything wrong" and live to be 100.

• Much of our current evidence comes from large epidemiological studies such as the Honolulu-Asia Aging Study, the Nurses’ Health Study, the Adult Changes in Thought Study and the Kungsholmen Project. These studies explore pre-existing behaviors and use statistical methods to relate those behaviors to health outcomes. This type of study can show an "association" between a factor and an outcome but cannot "prove" cause and effect. This is why we describe evidence based on these studies with such language as "suggests," "may show," "might protect," and "is associated with."

• The gold standard for showing cause and effect with a high degree of certainty is a clinical trial in which participants are randomly assigned to a prevention strategy or a control group. Researchers follow the two groups over time to see if their outcomes differ significantly.

• It is unlikely that some preventive strategies will ever be tested in randomized trials for ethical or practical reasons. One example is exercise. Definitively testing the impact of exercise on maintaining your brain would require a huge trial enrolling thousands of people and following them for many years. The expense and logistics of such a trial would be prohibitive. Since there are other known benefits of exercise and there is no drawback to physical activity approved by your health professional, there is little reason not to get off the couch.

The most important thing to remember is that you can help! Join the Alzheimer’s Association—participate, advocate and donate! Another way to help is to consider enrolling in a clinical trial. Prevention trials need healthy participants who are willing to make a long-term commitment to advancing our knowledge. You can find prevention trials currently recruiting in the Clinical Trials Index.

Overview of Brain Health and Aging

Hendrie, Hugh C.; Albert, Marilyn S.; Butters, Meryl A.; et al. “The NIH Cognitive and Emotional Health Project: Report of the Critical Evaluation Study Committee.” Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association January 2006; Vol. 2 (1): 12–32.
 Full text available free online (21 pages)

• An expert panel appointed by the National Institutes of Health (NIH) to assess current scientific knowledge about brain health and identify promising areas for further research finds that heart health, physical activity, freedom from chronic illness and a strong social support system may all help maintain mental sharpness and emotional well-being as we age. The panel identifies more than 40 factors that may influence cognitive and emotional health in older adults. Some of the most consistent findings link high blood pressure, diabetes, stroke and excess weight to an increased risk of cognitive decline. Evidence suggests that combinations of factors may be more significant over time than any single factor.

Stern, Paul C. and Carstensen, Laura, editors. The Aging Mind: Opportunities in Cognitive Research. Committee on Future Directions for Cognitive Research on Aging; National Academy Press, Washington, D.C., 2000; 288 pages. Available in full text online. Also available in single print copies for $37.00 from the National Academy Press at 1.888.624.8373.

• In 1999, the National Institute on Aging (NIA) asked the National Research Council to evaluate current understanding of how cognitive function changes with age and to identify future directions for research. The result was this 288-page report summarizing our current state of knowledge and recommending areas of greatest need and potential for further insight. Includes an extensive bibliography.

Fillitt, Howard M.; Butler, Robert N.; O’Connell, Alan. W.; Albert, Marilyn S.; and others. "Achieving and Maintaining Cognitive Vitality with Aging." Mayo Clnic Proceedings 2002; 77: 681 – 696.

• Co-sponsored and reviewed by the National Institute on Aging (NIA), this overview article summarizes recent research assessing the impact of various lifestyle factors and medical conditions on the health of the aging brain. Includes an extensive reference list.