Lawmakers Briefed on Strategies to Prevent Dementia

Martha Snyder Taggart, BrightFocus Editor, Science Communications
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Can dementia be prevented? That’s a question the American Psychological Association posed when it brought in an expert panel to discuss the topic at a Senate briefing last week.

The July 11 briefing examined the impact of lifestyle interventions—what you might call “healthy living”—on preventing dementia from all causes, including Alzheimer’s disease. 

While dementia is rarely seen before age 65, an estimated half of all people in later age will develop either the symptoms or the pathology of dementia, asserted Robert Wilson, PhD, a neuropsychologist at the Rush Alzheimer’s Disease Center affiliated with Rush University in Chicago. By “pathology,” he means physical changes in the brain, such as beta amyloid deposits and tau tangles associated with Alzheimer’s disease (AD); shrinking of the hippocampus, a two-sided part of the brain responsible for memory and spatial navigation; decreases in brain derived neurotropic factor, which is like a nutrient-rich “fertilizer” for the brain; and other factors, such as strokes and circulatory factors that can cause dementia.

So the bad news is that half of us, in old age, will experience changes in our brains that are characteristic of dementia, including AD.

But the good news is that up to half of all dementia is not explained by such factors—and might be in part preventable. Experts have speculated that dementia’s onset is in part determined by a person’s “cognitive reserve,” which is strengthened by good physical health, mental fitness, a healthy lifestyle, and attitudinal factors.

For example, cognitive stimulation has been shown to protect against 10-30% of the risk of dementia, and appears even stronger if lifelong habits of cognitive activity—things like reading, puzzles, and problem solving—are practiced during childhood and middle age,

In the fight against AD and other forms of dementia, prevention can make a difference, according to Wilson, who served as an investigator in the Rush Memory and Aging Project. Granted, dementia cannot be prevented forever, and even mentally active and healthy individuals may reach a “tipping point” where existing pathological changes catch up. “Some cognitive decline may be inescapable in the years immediately preceding death,” he said, “and that appears related to neuronal lifespan.”

However, epidemiologists have projected that if dementia could be postponed by as long as three years, in part through preventive factors, then many people would die of alternative causes—and would escape the most-feared ailment of old age, which is dementia.

Sounds like an argument for “aging well,” if ever there were one!

Even with Mild Cognitive Impairment, It’s Not Too Late to Improve Mental Functioning

Although there’s no cure for Alzheimer’s disease and most other causes of age-related dementia, we are lucky to have a “toolbox for identifying people at risk,” said Glenn E. Smith, PhD, LP, a psychologist in the Division of Neurocognitive Disorders at the Mayo Clinic, Rochester, MN.

Dementia from Alzheimer’s disease or other causes can diagnoses in many ways, including by imaging plaques, tangles, and the size of the hippocampus; however, cognitive testing is by far the most effective way to assess people at risk for cognitive decline, he said.

At Mayo, he has developed what he described as a “holistic intervention” for people who are found to have mild cognitive impairment (MCI) that is consistent with early Alzheimer’s disease and other forms of dementia. Both the patient and a partner are encouraged to enroll in the 10-day intensive program because “we’ve found that people do better if they are supported in their attempts to modify their lifestyle,” Smith said.

Together, they engage in a five-point program of physical exercise; brain fitness exercises; group therapy to improve social engagement; wellness education focusing on diet, sleep and mood regulation; and memory compensation training.

Unfortunately, most of the interventions used in the program are not reimbursed by Medicare. Nonetheless, Smith professed there is “great hope for primary and secondary prevention models for MCI.”

Just one of these interventions, brain fitness, has been found in previous studies to achieve a measurable impact comparable to the difference in cognitive functioning between a 70-year-old and an 80-year-old, he said.

Even Bigger Impact from Preventing Chronic Diseases in Middle Age

An agile mind is not enough, however; one must also take care of the body, according to a presentation by Margaret Gatz, PhD, professor of psychology, gerontology and preventive medicine at the University of Southern California.  She ran through a list of common chronic diseases afflicting Americans, many of them partially preventable. Each of these diseases, if they begin at midlife, has a pronounced impact on risk of dementia, Gatz said. Diabetes at midlife is associated with a 2.5 times  increased risk of dementia; high blood pressure  with a 3.5 times increased risk; being overweight with a 2 times increased risk;  obesity  with a 3.5 times increased risk; and lipid disorders, such as high cholesterol or other lipid risk factors, with a 2.5 times increased risk, she asserted.

On the flip side, modest physical exercise can cut the risk of dementia in half, she said, and so can an enriched diet that includes daily fruits and vegetables and fish consumption at least once weekly. However, exercise and diet won’t work their magic overnight—these habits also must begin in middle age to reduce the risk of dementia.

Like the other speakers, she called for a strategy of wellness to avert dementia. A five-year delay in the onset at old age, in addition to improving quality of life at the end of one’s days, would result in a $40 billion savings in our nation’s Medicaid and Medicare bill, she said.

And that might be enough to pay for the entire array of wellness programs that have been shown to be effective, most of which are not reimbursable by Medicare.

At the briefing, APA circulated a list of policy recommendations in support of research and programs addressing the growing public health burden of dementia. Among other things, it called for robust funding for the National Institutes of Health and for the U.S. Center for Disease Control’s Healthy Brain Initiative; reauthorization of the Older Americans Act supporting programs to promote independent living and the needs of family caregivers; support for geriatrics training and programs under the Public Health Service Act; and funding for the Administration for Community Living project to address aging-related mental and behavioral health issues.

Glossary Terms

  • Mild cognitive impairment (MCI)  is a condition between normal age-related memory loss and dementia. Individuals with MCI have persistent memory problems (for example, difficulty remembering names and following conversations and marked forgetfulness) but are able to perform routine activities without more than usual assistance. Individuals with MCI are at risk of developing Alzheimer's disease or other forms of dementia.

  • Cognitive reserve is the brain's capacity to compensate for damage.

  • Amyloid is a general term for protein fragments that the body produces normally. Beta amyloid is a protein fragment snipped from an amyloid precursor protein (APP). In a healthy brain, these protein fragments are broken down and eliminated. In Alzheimer's disease, the fragments accumulate to form hard, insoluble plaques.

  • The hippocampus is a part of the brain that plays a significant role in the formation of long-term memories. The plural of hippocampus is hippocampi.

  • In Alzheimer’s disease, tau collects in fibrous deposits known as “tau tangles” that appear to damage and destroy neighboring brain cells. Left untreated, these tangles, in most cases, become toxic to neurons, and is associated with memory loss, cognitive difficulties, and other outward symptoms of Alzheimer’s disease.