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Mediterranean Diet Has Varied Effects On Cognitive Decline Among Different Races, Study Shows

Posted:  Tuesday, August 05, 2014

According to research Mediterranean diet, renowned for its heart-health effects, may also give a brain boost to the elderly. The Mediterranean diet is characterized by the use of virgin olive oil as the main fat, and advises heavy consumption of nuts, fruits and vegetables. It also recommends moderate consumption of fish and seafood and low consumption of dairy and red meat.

The team of researchers, including Ben-Gurion University of the Negev (BGU Prof. Danit R. Shahar RD, Ph.D, analysed an NIH/NIA prospective cohort study [Health ABC] conducted over eight years in the U.S. to measure the effects of adherence to a Mediterranean diet. Prof. Shahar is affiliated with the BGU S. Daniel Abraham International Center for Health and Nutrition, Department of Public Health, Faculty of Health Sciences.

The Mediterranean-style diet (MedDiet) has fewer meat products and more plant-based foods and monounsaturated fatty acids from olive and canola oil than a typical American diet.

To assess the association between MedDiet score and brain function, the researchers used data of several Modified Mini-Mental State Examinations (3MS) on 2,326 participating older adults (70-79). The 3MS is an extensively used and validated instrument designed to measure several cognitive domains to screen for cognitive impairment and commonly used to screen for dementia.

Researchers analyzed data from observational studies and one randomized controlled trial. Nine studies found that people with higher adherence to a Mediterranean diet had better brain function, lower rates of mental decline and a reduced risk of Alzheimer's disease.

"In a population of initially well-functioning older adults, we found a significant correlation between strong adherence to the Mediterranean diet and a slower rate of cognitive decline among African American, but not white, older adults. Our study is the first to show a possible race-specific association between the Mediterranean diet and cognitive decline."

The researchers note that further studies in diverse populations are necessary to confirm association between the MedDiet and cognitive decline, and to pinpoint factors that may explain these results.

While the Mediterranean diet is known for being heart healthy, several studies have shown that this eating pattern can protect from various diseases of the brain. Some studies attribute this protective effect to the consumption of foods rich in antioxidants such as olive oil, fruit, vegetables and nuts while others also see benefits of individual foods in the Mediterranean diet such as extra virgin olive oil and walnuts.

The bottom line is that one reason the Mediterranean diet has such health potential is that it’s delicious and easy, and it sets people up for success. “The diet has evolved over thousands of years in this region of the world. It’s not at all about deprivation. You can have a good percentage of healthful fat—olive oil, avocados, and nuts—which makes everything taste great. And the foods have lots of flavor; they’re fresh and local. It’s about a lifestyle, not a diet. If you go to the Mediterranean, you’ll observe that people don’t think of their eating style as a diet, it’s just the way they live.