As an unprecedented number of Americans approach middle and old age, there is growing public concern about the loss of mental acuity that often is attributed to aging. Medical advances have dramatically increased the likelihood of surviving into the period of life that has been associated both with wisdom and mental decline. It is becoming more and more common to enter into the eighth and ninth decades of life in generally good physical health, increasing the probability that the body will outlive the mind.  Maintaining cognitive competency is crucial for personal independence and quality of life.  Factor in the growing evidence that how one lives in earlier stages of life, including our food choices, affects cognitive aging; we all should be paying a little more attention to what we feed our brains.

It is now clear that significant cognitive decline is not an inevitable consequence of advanced age.  Several recent studies have demonstrated an association between eating a Mediterranean-style diet and slower cognitive decline in the elderly.[i]   A well-designed prospective study published last year in the American Journal of Nutrition analyzed data from a continuing study of 3,790 Chicago residents 65 and older that began in 1993. The researchers tested the subjects’ mental acuity at three-year intervals, and tracked their degree of adherence to the Mediterranean diet on a 55-point scale. High scores for adherence to the diet were associated with slower rates of cognitive decline, even after controlling for smoking, education, obesity, and hypertension.

Another study, presented at the American Academy of Neurology’s April 2010 meeting in Toronto, analyzed the diets of 712 New Yorkers.  MRI brain scans taken an average of 6 years later revealed brain infarcts in one third of the study participants.  Brain infarcts are small areas of dead brain tissue caused by silent strokes that may show no symptoms. Recent research has suggested that brain infarcts may be responsible for decreasing cognitive function as we age.  In this study, the group who most closely followed a Mediterranean-style diet was 36% less likely to have the damaging brain infarcts than the group who least followed the diet, and moderate followers were 21% less likely to have damage than the lowest-tier group.  A third study published in the February 2009 issue of Archives of Neurology found that eating a Mediterranean diet was possibly associated with a reduced risk of developing mild cognitive impairment (MCI) and of MCI advancing to Alzheimer’s disease.

Benefits of the Mediterranean diet may be due to the it’s positive impact on cholesterol levels, blood sugar levels, vascular health, or inflammation reduction; all of which have been linked with cognitive impairment. Is this proof positive that the Mediterranean diet can prevent stokes and dementia?  No. Although there is a lot of data suggesting beneficial effects of a Mediterranean diet on a number of chronic medical conditions, diet alone is not the only factor,.  Diet is but one component of a healthy lifestyle, and that includes regular exercise, prevention or treatment of diabetes, hypertension, high cholesterol, obesity—if they exist, and avoidance of smoking gives you your best chance to remain cognitively intact as you age.

[i] Tangney C, Kwasny M, et al. Adherence to a Mediterranean-type dietary pattern and cognitive decline an a community population. Am J Clin Nutr December 2010 ajcn.007369