A Mediterranean diet may reduce small-vessel damage to the brain, according to a new study published in the Archives of Neurology. In other words, a diet made up of fruits, vegetables, olive oil, legumes, whole grains, little red meat and a glass of red wine here and there may be good for your brain.
Researchers from University of Miami and Columbia University analyzed food frequency questionnaires filled out by 966 participants in the Northern Manhattan Study, a study designed to identify risk factors for stroke and coronary disease. Study participants then underwent brain MRI scans to analyze the white matter hyperintensity volume, which is a sign of small vessel disease. Researchers found that people who closely followed a Mediterranean diet had fewer brain lesions than those who had higher-fat and more red meat-based diets. People who exercised more were also more likely to consume foods associated with the Mediterranean diet.
"Normally, these lesions are associated with hypertension, high-cholesterol, diabetes and age," said Dr. Clinton Wright, associate professor of neurology at Miller School of Medicine at the University of Miami Medical Center and senior author of the study. "We saw that there was a relationship between diet and this marker of small vessel disease. Those who adhered to a more Mediterranean diet had less small vessel damage."
Small vessel disease is a condition in which the small arteries in the heart become narrowed. The disease can cause signs of heart disease, including chest pain and artery blockages, and it is most common in women and diabetics, according to Mayo Clinic. The lesions are also linked to cognitive disorders, including Alzheimer's disease.
"Of course, this was an association study, and we'd need randomized trials to prove this association," said Wright.
The Mediterranean diet has already been associated with reducing the risk of heart disease and dementia.
As Wright explained, the brain is made up of grey matter and white matter. Grey matter is made up billions of cell bodies and neurons, while white is the connection between those neurons.
"They're like wires that connect computers," said Wright. "When small vessels get damaged due to hypertension or diabetes or smoking and the like, those little vessels get damaged in a way that they become thicker and blood doesn't flow to the brains as well, or there is fluid from the vessel leaking out, and that's what causes those white matter lesions."
Dr. Ken Fujioka, director of nutrition and metabolic research at Scripps Health Clinic in San Diego, said the biggest single difference in the Mediterranean diet versus many other diets is the high amount of monounsaturated fats (found in vegetable oils, fish, nuts oils and avocadoes) that have been shown to have multiple health benefits.
Fujioka said he agreed with the findings, but said, "as we move forward we will get to a point for some people [where] this will be the best diet, but for others, a different diet might be better and the future is trying to find out which diet [is best] for which patient."
Authors note that, because the study was observational, it's difficult to decipher whether the results were due to overall healthy dietary patterns or to the foods themselves, but Wright said he hopes the observational research will be a jumping off point for clinical trials and experiments. While Dr. David Katz, director of the Yale Prevention Center, said this confirms past research that has positive health benefits in the Mediterranean diet, and it puts emphasis on brain health.
"The topic that the health of the brain and the health of the body are largely one and the same deserves more attention than it gets," said Katz.