The Aging Brain


As researchers home in on biomarkers that will help doctors track whether their patients are progressing toward dementias like Alzheimer’s disease (AD), how should treatment and policy change? Three experts traced what we’ve learned about the aging brain, how we can apply scientific findings to give patients better care, and what social policies would help society navigate the medical advances during an event last week at the American Association for the Advancement of Science (AAAS) in Washington, DC.

“There’s very exciting research that suggest that the process of AD has been going on for 10 years to 20 years before we see evidence of the disease,” said Reisa Sperling of Harvard Medical School. Why exciting, when we don’t currently have any treatments that have proved effective in people? “I believe that we have good biomarkers and neuroimaging to [find people at risk] and potentially help treat them,” she said.

“We need to start thinking about prevention trials even though we don’t know the mechanism yet,” to see if we can decrease the likelihood or slow the progression in people who show biomarkers or high genetic risk, she said. “If we could just delay dementia for 5 years, we would save 50 percent of the Medicare costs for dementia” in the U.S. Four secondary prevention trials are starting or are expected to start in the next year, she said, among very specific subgroups of people at risk or at the earliest identifiable stages of the disease.

While researchers still lack definitive research, there are some lifestyle changes that “have good effects in heart health and suggestions of benefits for brain health,” said Richard Hodes, who directs the research program of the National Institute on Aging (NIA) at the National Institutes of Health. These include staying mentally challenged, socially engaged, and physically active, and managing vascular risks (like high blood pressure).

While researchers weren’t surprised to learn that staying mentally active has brain benefits, said Marilyn Albert of the Johns Hopkins University School of Medicine, “they were a little surprised about the physical activity data.” Some possible reasons for the brain benefits could be reduced harmful inflammation and oxidative stress, she said, as well as improved blood delivery from a strengthened vascular system. In addition, “when you’re more physically active there might be more trophic factors produced in the brain,” she said; these are proteins that promote neuron health. These findings are based on observational studies, though, and are not definitive; randomized, controlled, clinical trials are ongoing.

It may be that the “prescription” for healthy aging differs among people, Albert said, based partly on whether they are at risk due to genetic, cardiovascular, or personal factors such as how social they like to be.

Some aspects of cognitive and physical ability do fade as we age, but for most people it does not reach a level of disability until they are over 85, the experts said. “Disability is not inevitable,” said Hodes. And the good news is the proportion of people declared disabled in the United States at all ages has steadily declined over the past decades. But, he said, disability rates are currently rising among the youngest Americans, perhaps tied to the rise in obesity. “We’re seeing the possibility that our chronic disability numbers will go back up because of increased obesity,” Hodes said. [See a recent article in The Atlantic on teens and obesity.]

They had a lot more to say; check out video of the full event here.

The session was the inaugural event in the Neuroscience and Society Series, presented by the AAAS Scientific Responsibility, Human Rights and Law Program and the Dana Foundation. Sperling, Hodes, and Albert also are members of the Dana Alliance for Brain Initiatives. The next event will be Oct. 23. To join one of the ongoing clinical trials, see listings at NIH’s and the Alzheimer’s Association’s Find a Clinical Trial page.

–Nicky Penttila

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: