An NIA-funded study at Columbia University Medical Center has found an association between a Mediterranean diet and a reduced risk of mild cognitive impairment (MCI). Previous studies have found an association of this diet with a reduced risk of Alzheimer’s disease. Many people with MCI ultimately develop Alzheimer’s. A Mediterranean diet includes vegetables, legumes, fruits, cereals, fish, and mono-unsaturated fats; mild to moderate alcohol use; and low intake of saturated fats, dairy products, meat, and poultry.
The researchers recruited 1,393 cognitively normal participants and 482 participants with MCI. Subjects were divided into three groups, characterized by low, medium, and high adherence to a Mediterranean diet. After an average 4.3 years, 275 of the cognitively normal participants had developed MCI, and 106 of the participants with MCI had progressed to Alzheimer’s disease. The high-adherence groups had a 28 percent and 48 percent lower risk of developing MCI and progressing to Alzheimer’s, respectively, than those in the low-adherence group did. Those in the medium-adherence group had a 17 percent and 45 percent lower risk of MCI and Alzheimer’s, respectively, than did those in the low-adherence group.
Researchers speculated that a Mediterranean diet may improve cholesterol and blood sugar levels and blood vessel health or reduce inflammation, all of which have been associated with MCI, but more research is needed to determine whether it has the effect suggested in this epidemiological study.
Scarmeas, N., et al. Mediterranean diet and mild cognitive impairment. Arch Neurol. 2009. 66(2):216-25.