November 16, 2016
More good news on the healthy living front. Researchers report that keeping weight down, eating a heart-healthy diet and getting regular physical activity can reduce the likelihood of developing many of the brain changes typical of early Alzheimer’s disease. The findings add to a growing body of evidence that a healthy lifestyle can be good for the brain too.
Scientists at the Semel Institute for Neuroscience and Behavior studied 44 men and women, aged 40 to 85, with mild memory problems. None had memory problems that were serious enough to suggest a diagnosis of Alzheimer’s disease or other forms of dementia.
The study participants completed detailed questionnaires about what they ate and how much they exercised, as well as height and weight measurements to detect their body mass index, or BMI. A high BMI is associated with being overweight or obese.
The study participants also underwent brain scans using a specialized technology known as positron emission tomography. PET scans can detect two of the telltale signs of impending Alzheimer’s disease: the buildup of toxic beta-amyloid proteins that form plaques in the spaces between brain cells; and the tangled proteins called tau that accumulates within brain cells. Both amyloid plaques and neurofibrillary tangles are hallmarks of Alzheimer’s disease.
The researchers found that overall, having a healthy body mass index, engaging in regular physical activity and eating a Mediterranean-style diet were all linked to lower levels of plaques and tangles in the brain. The Mediterranean diet, typical of those living in Mediterranean countries and considered good for the heart, is rich in fruits and vegetables, legumes, whole grains and fish, and low in meat and dairy products. It also relies on moderate amounts of heart-healthy fats like olive oil rather than saturated fats like butter.
“The fact that we could detect this influence of lifestyle at a molecular level before the beginning of serious memory problems surprised us,” said Dr. David Merrill, a researcher at UCLA and the lead author of the study. The findings appeared in the American Journal of Geriatric Psychiatry.
Earlier studies have linked a heart-healthy lifestyle to a lower risk of Alzheimer’s disease in old age. Healthy lifestyle factors have been shown, for example, to be associated with reduced shrinkage of the brain, a risk factor for Alzheimer’s.
This new study, while modest in term of size, is clearly demonstrating how lifestyle factors directly influence the buildup on plaques and tangles in the brains of people with subtle memory loss who have not yet been diagnosed with dementia, Dr. Merrill said.
Many factors contribute to the onset of Alzheimer’s, including advancing age and genetic risk factors. “This study reinforces the importance of living a healthy life to prevent Alzheimer’s, even before the development of clinically significant dementia,” Dr. Merrill said.
The researchers plan to continue to study how stress and other lifestyle factors may affect brain health.
By www.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: David A. Merrill, MD, PhD; PrabhaSiddarth, PhD; Cyrus A. Rajj; et al: “Modifiable Risk Factors and Brain Positron Emission Tomography Measures of Amyloid and Tau in Nondemented Adults with Memory Complaints.” American Journal of Geriatric Society, Sept. 2016