We all know that the food we eat has an effect on health. There is plenty of evidence that the risks of developing health conditions, like heart disease and diabetes, are directly related to our diets. Now a new systematic review finds evidence that diet effects brain function as well.

(Here on EBL, we’ve written before about the Mediterranean diet’s impact on cardiovascular disease and cancer. This type of diet involves consuming healthy fats, plenty of fruits and vegetables, and small amounts of meat products and fish.)

The new review, published in the journal Epidemiology, looked at studies that quantified the impact of a Mediterranean diet on brain function, including the risks of developing dementia and Alzheimer’s disease.

The reviewers found a total of 12 studies – 11 observational studies and one randomized, controlled trial – that examined the association between a Mediterranean diet and cognitive function. In nine of the 12 studies, researchers found that people who followed a Mediterranean diet tended to have better cognitive function, lower rates of cognitive decline, and reduced risk of Alzheimer’s disease. Results for mild cognitive impairment were inconsistent.

The review did have some limitations. Many of the studies used different methods to measure food choices and cognitive function, making it difficult to compare the results. And the results of some studies were not statistically robust.

On the whole, reviewers concluded that a Mediterranean diet does reduce the risk for cognitive impairment. But more evidence is needed to clarify exactly how diet impacts our brain, and develop specific diet plans that delay or reduce the risk of dementia.

The take home message: Eating healthy foods is good for your body in many ways. While we might not fully understand all of the causes and implications for eating well, the evidence shows that adding more fruits and vegetables to your diet is certainly worth the effort.