Dementia Rates Are Slowing, but Alzheimer’s Cases Continue to Rise

August 11, 2016

Experts estimate that more than five million Americans live with Alzheimer’s disease. By some estimates, that number will triple in coming decades. However, there are new hopes.

A large new study found that although cases of Alzheimer’s are still increasing at an alarming rate, the rate of increase appears to be slowing. The findings suggest that higher levels of education and heart-healthy lifestyle measures may be helping to perhaps prevent, or at least delay, the onset of dementia.

Treatments to prevent or cure Alzheimer’s remain as urgently needed as ever. But until researchers find a way to effectively treat the disease, the findings underscore that you can take steps to delay Alzheimer’s onset.

“Our study offers hope that some dementia cases might be preventable — or at least delayed,” said study author Dr. Sudha Seshadri, a professor of neurology at Boston University School of Medicine. “Effective prevention could diminish in some measure the projected explosion in the number of persons affected with the disease in the next few decades.”

The large study, of more than 5,200 participants in the ongoing Framingham Heart Study in Massachusetts, provides the strongest evidence to date to suggest that better education and improvements in heart health are helping to stave off dementia. The findings were published in The New England Journal of Medicine.

Declines in dementia risk were observed during the past several decades in the United States, but only in those who had at least a high-school education. The study also looked at heart disease risk factors like smoking, high blood pressure and obesity, and found that better control of cardiovascular factors also lowered the risk of developing dementia.

The strongest declines occurred in those with so-called vascular dementia, caused by restricted blood flow in the brain and often linked to heart disease.  But declines also occurred in those with Alzheimer’s disease, though the results were not as clear-cut, in part because of the small number of Alzheimer’s cases in the study population. Many people with Alzheimer’s also show signs of vascular dementia as well.

The findings underscore that education and healthier lifestyles appear to be an important part of Alzheimer’s prevention. Current drugs to treat the disease may ease symptoms for a time but do not stop the disease’s relentless downward progression.

One reason that education may help to curb Alzheimer’s onset, scientists speculate, is that it helps to build so-called cognitive reserve, or a rich connection of brain cells. Challenging the brain with intellectual stimulation may build a more robust brain, so that if some brain cells die off, enough remain to keep memory and thinking intact. That’s one reason why studies suggest that keeping your brain active by doing crossword puzzles, reading books, learning a new language or to play a musical instrument may help to ward off Alzheimer’s in old age.

Studies also show that regular physical activity improves blood vessel health, including in the brain. Regular exercise may also boost levels of nerve growth factors in the brain. Exercise also helps to curb obesity and diabetes, and studies show that both being overweight or having diabetes increase the risk for developing Alzheimer’s disease.

Alzheimer’s is an extremely complex disease, and researchers are still trying to understand its causes. Even if you do everything right, you might still get Alzheimer’s eventually, but most likely with a delayed onset. Indeed, taking steps to improve heart health, and to challenge the brain, may mean a more robust memory and better thinking skills in old age.

By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.

Source:  Claudia L. Satizabal, Ph.D., Alexa S. Beiser, Ph.D., Vincent Chouraki, M.D., Ph.D., et al: Incidence of Dementia over Three Decades in the Framingham Heart Study. New England Journal of Medicine, Vol. 374, pages 523-532, Feb. 11, 2016


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