Mediterranean diet reduces risk of stroke in women – but not in men

Ancel and Margaret Keys, an American team of husband and wife, were the first to report the benefits of the Mediterranean diet in 1975. Since then, food has become particularly famous for its effects on cardiovascular health. What is less known is if the diet has different benefits for men and women. Our last study provides some clarification on this subject.

We found that eating a Mediterranean diet could reduce the risk of stroke by more than a fifth in women aged 40 and over, but this does not appear to have a significant impact on the risk of stroke in women. men. We also found that in men and women at high risk of cardiovascular disease, those who followed a Mediterranean diet had a 13% lower risk of stroke, although this reduction was largely due to women.

In our analysis, the Mediterranean diet as a whole seems to be more protective against the risk of stroke than the individual foods that it contains. When we analyzed individual foods, there were few significant associations with the risk of stroke. The benefits seem to come from the additive effects of the combination of a diet rich in fish, fruits, vegetables, nuts and beans, cereals and potatoes. A Mediterranean diet also has a lower intake of meat and dairy products and a lower unsaturated to saturated fat ratio.

Although studies have investigated whether the effect of the Mediterranean diet on the prevention of stroke is important, only two previous studies have examined the difference in associations between men and women. We believe this is the first study to study the relevance of the Mediterranean diet in people with different risk levels of cardiovascular disease.

Most previous studies have been conducted on people at high risk for cardiovascular disease. Population studies (which corresponded to our study) have not studied the risk of stroke in people according to their risk of cardiovascular disease.

The traditional Mediterranean diet developed in Greece – and the key components are well known: olive oil as the main source of fat, high consumption of fish, fruits, vegetables, nuts and legumes and low consumption of meat and dairy products. But we know from our previous research that foods that contribute to the Mediterranean diet vary depending on whether one lives in a Mediterranean country or not, resulting in differences in nutrient intake. These differences could affect the risk of illness. The risk of disease in different countries could therefore vary due to differences in the type of Mediterranean diet. That's why we wanted to study the risk of stroke in people in the UK.

Before our study, only one study in the UK used a food frequency questionnaire and another small study using a diary method. Diary methods are considered more accurate than food frequency questionnaires because they are a real record of what a person eats at a given time, not a diet memory at a given time.

For our study, we looked at food diaries of 23,232 people, aged 40 to 77, in Norfolk, UK, to find out if following a Mediterranean diet could prevent stroke of any type.

We measured the Mediterranean diet by calculating a score based on proximity to the traditional Mediterranean diet. We also measured blood cholesterol and blood pressure and collected other important factors that affect the risk of stroke, such as diabetes and smoking. We took all of that into account in our analysis. During the 17-year follow-up period, 2,009 people in our study had a stroke.

Women benefit the most

We found that women benefit the most from the Mediterranean diet. Their risk of stroke was reduced by 22%. This means that if 14 women per 10,000 people suffer a stroke, the risk would be reduced to 11 women per 10,000 – three lives saved out of 10,000. There was no statistically significant reduction in the risk of stroke. Stroke in men having a Mediterranean diet. Future research needs to investigate why men and women respond differently to the Mediterranean diet and whether this is due to differences in risk factors that affect women only or whether women respond differently to risk factors such as blood pressure and diabetes. . For this, we need randomized controlled trials.

One of the limitations of our study was that we measured the diet at the beginning of the study and so we can not exclude the possibility that people's diets changed during the study period.

We also were unable to look at racial diversity as the study was conducted in Norfolk, UK, where there is insufficient diversity to understand the relationship between diet and stroke for a non-white population . This would also be important for research in the future, as black people of African or Caribbean descent are at higher risk of stroke than other people in the UK.