St. Petersburg, Florida--A new study suggests a diet laden with fish, olive oil, veggies and other foods common in Mediterranean-style cuisine may help ward off mild cognitive impairment, sometimes called borderline dementia. The study also suggests this diet reduces the chance of transitioning from mild cognitive decline to Alzheimer's disease.
"We know from previous research that a healthy diet like this is protective for cardiovascular risk factors like cholesterol, hypertension and diabetes. Now this current study shows it may help brain function too," says Nikolaos Scarmeas, assistant professor of clinical neurology at the Taub Institute for Research on Alzheimer's Disease and the Aging Brain at Columbia University Medical Center.
Scarmeas and other researchers at Columbia examined, interviewed and screened 1,393 individuals with healthy brains and 482 patients with mild cognitive impairment. Study participants were questioned about their eating habits.
The study, in this month's Archives of Neurology, reports that over an average of 4½ years of follow-up, 275 of the 1,393 study participants who did not have mild cognitive impairment developed the condition. Those who had the highest adherence to a Mediterranean diet — a menu rich in vegetables, legumes and fish, low in fat, meat and dairy, and high in monounsaturated fats like those in olive oil — had a 28% lower risk of developing mild cognitive impairment than the one-third of participants who had the lowest scores for Mediterranean diet adherence. The middle one-third group had a 17% lower risk of developing mild cognitive impairment than those who ate the fewest Mediterranean foods.
Of the 482 study participants who had mild cognitive impairment at the beginning of the study, 106 developed Alzheimer's disease roughly 4 years later. The one-third of participants with the highest scores for Mediterranean diet adherence had a 48% less risk of developing Alzheimer's than the one-third with the lowest diet scores.
Previous research has found a similar association for subjects with Alzheimer's disease, but this is the first report connecting a Mediterranean diet with decreased risk of mild cognitive impairment, says Scott Turner, program director of the Memory Disorders Program at Georgetown University. "The findings are important and intriguing."
Scarmeas says clinical studies that randomly assign people to a Mediterranean diet or another diet are needed to prove that a Mediterranean diet protects against cognitive decline.
But beginning healthier eating habits earlier than the golden years may be the key, says Duke University Medical Center aging expert Murali Doraiswamy. "Since Alzheimer's changes may start in the brain decades before memory loss occurs, what you eat starting in your midlife may be crucial," he says.