May 25, 2017
Older men and women who ate a Mediterranean-style diet showed less shrinkage of the brain than their peers who did not eat foods typical of the Mediterranean region. The Mediterranean diet, rich in vegetables and fruits, whole grains, fish and “good” fats like olive oil and low in meats and saturated fats, has long been heralded for heart health.
The findings add to a growing body of evidence that what you eat can benefit brain health and may help to delay the onset of Alzheimer’s disease and other forms of dementia. That evidence has led the National Institute on Aging, part of the National Institutes of Health, to undertake a major new study to further elucidate how diet impacts the aging brain.
“As we age, the brain shrinks and we lose brain cells which can affect learning and memory,” said Michelle Luciano of the University of Edinburgh in Scotland, the lead author of the latest report. “This study adds to the body of evidence that suggests the Mediterranean diet has a positive impact on brain health.” The findings appeared in the journal Neurology, from the American Academy of Neurology.
For the study, researchers collected information on the eating habits of 967 Scottish people around age 70. Nonehad dementia at the start of the study. Their diets were ranked according to how closely they adhered to a Mediterranean diet.
Some had MRI brain scans around age 73 to measure their brain volumes, and again at age 76. Preservation of brain volume is associated with healthy aging and less memory loss, while shrinkage of the brain has been tied to brain aging and an increased risk of Alzheimer’s and dementia.
The researchers found that those participants who ate a Mediterranean-style diet showed less brain shrinkage, while those who least closely followed the diet showed the greatest loss of brain volume. The impact of diet was about half the effects of normal aging, the researchers reported.
The researchers considered factors like low levels of education, advancing age, and medical problems like diabetes or high blood pressure, all of which can increase the chances of developing dementia. Still, diet had a significant impact on brain health.
The findings suggest that “diet may be able to provide long-term protection to the brain,” said Dr. Luciano. The effects, he noted, may be due not to any particular food in the Mediterranean diet, but to all of the dietary components “in combination.”
The findings come as the National Institute on Aging is starting a major, new $14.5 million study to better understand how diet affects the aging brain and the course of Alzheimer’s disease. The study, being conducted at Rush University Medical Center in Chicago and the Harvard School of Public Health in Boston, will enroll600 volunteers aged 65 to 84 who do not have Alzheimer’s or serious memory problems, but who are overweight and do not eat a heart-healthy diet.
“We hope to determine whether a specific diet affects or prevents the development of Alzheimer’s disease,” said Martha Clare Morris, a nutritional epidemiologist at Rush and the principal investigator of the study. “Trials to examine whether a change in diet will help prevent Alzheimer’s disease and other dementias have been largely neglected. The results of this study should help us to improve brain health by developing new dietary guidelines for clinical use and for public health education.”
The trial will last three years and include dietary counseling, medical consultations and group support. Some participants will follow the so-called MIND diet, which earlier studies have shown has benefits for brain health. It incorporates many components of the Mediterranean-style, including nine “brain-healthy food groups,” such as chicken and fish, green leafy vegetables and berries, and nuts – and five unhealthy groups: red meat, butter and stick margarine, cheese, pastries and sweets, and fried or fast food.
To learn more about the MIND trial, visit ClinicalTrials.gov athttps://clinicaltrials.gov/ct2/show/NCT02817074
Many other factors besides diet, including the genes you inherit and advancing age, play an important role in who ultimately develops Alzheimer’s. Still, the findings add to a growing body of evidence that a heart-healthy lifestyle, and what you eat, may help keep the brain young.
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: Rush University Medical Center. Michelle Luciano, PhD; Janie Corley, PhD, Simon R. Cox, PhD, et al: Mediterranean-type diet and brain structural change from 73 to 76 years in a Scottish cohort. Neurology, published online Jan. 4, 2017