An accumulating body of evidence suggests that a Mediterranean diet has a number of brain benefits. Recently, a group of researchers followed a population of 20,197 individuals with an average age of 65 to examine whether a greater adherence to a Mediterranean diet at the start of the study was associated with a lower risk of later having a stroke.
The Mediterranean diet is characterized by high consumption of plant foods, a high intake of olive oil, low levels of saturated fat, limited consumption of meat and dairy products, and a moderate intake of fish and alcohol. The self-reported diets of participants in this study were ranked on a scale of one to nine, according to the degree to which they were in accordance with the Mediterranean diet at the start of the study. Of the participants, 25 percent scored high on the Mediterranean Diet Scale (score of 6 to 9), 41 percent scored intermediate (4 to 6) and 34 percent scored low (0 to 3). The researchers then followed up with the participants for an average of 6.5 years, and found that 565 had suffered either an ischemic (497) or hemorrhagic stroke (68).
When the researchers looked at the potential association between Mediterranean diet and stroke risk, they found that having a high Mediterranean diet score was associated with a significantly lower risk of ischemic stroke. There was no association found between Mediterranean diet score and hemorrhagic stroke, but this could potentially be due to the far lower numbers of hemorrhagic strokes in this population. In their analysis, researchers found that each one point increase in Mediterranean diet score was associated with a 5 percent reduction in ischemic stroke risk.
Those individuals with low Mediterranean diet scores were also more likely to have hypertension or diabetes, and to be obese, sedentary, or smokers. However, the researchers were able to statistically control for each of these characteristics, and found that they did not impact the statistical significance of the association of the Mediterranean diet with ischemic strokes. Additional analysis took into account the potential impact of age, race, geographic region, sex, income, education, history of heart disease, body mass index, and blood pressure medication use. Taking all these factors into account only minimally impacted the degree to which Mediterranean diet was associated with lower ischemic stroke risk.
There are some limitations to this study. For example, the participants’ reports on their diet were only taken at one point in time, with no data available about dietary changes after the start of the study. Additionally, there is always the chance that an unidentified, unaccounted for variable could be responsible for the association seen. But overall, this finding is consistent with other evidence suggesting health benefits from the Mediterranean diet, and reinforces other research showing the impact of diet and nutrition on brain health.