Restaurant staff work on Mnisikleous Street in Athens, Greece.Giorgos Arapekos/Reuters
The well-studied Mediterranean diet has earned a solid reputation for its impressive list of health benefits.
It’s associated with a lower risk of hypertension, Type 2 diabetes, heart disease, certain cancers, cognitive decline, dementia and depression.
Now, the plant-forward eating pattern has once again made headlines for its healthy aging benefits, bringing good news for women.
According to the new research, higher adherence to the Mediterranean diet can guard against stroke in women, both ischemic and hemorrhagic stroke.
Here’s a breakdown of the study, its noteworthy findings and Mediterranean diet components to include in your everyday diet.
Ischemic vs. hemorrhagic strokes
Ischemic strokes, the most common type, account for about 85 per cent of cases. They’re caused when blood flow gets cut off to part of the brain by a blood clot or narrowing of the arteries.
Older age, family history, diabetes, high cholesterol, obesity, poor diet, sleep apnea and heart conditions such as atrial fibrillation and heart failure increase the likelihood of ischemic stroke.
A hemorrhagic stroke occurs when a blood vessel in the brain bursts, causing bleeding that damages brain cells.
Lifestyle-related risk factors include high blood pressure, high cholesterol, smoking, heavy alcohol consumption and obesity.
While previous studies have shown an association between the Mediterranean diet and lower risk of stroke, there’s limited data on the diet’s effect on the risk of specific types of stroke, especially hemorrhagic stroke.
The latest research
For the new study, researchers from the U.S. and Greece examined the relationship between Mediterranean diet adherence and the occurrence of stroke overall and by subtype in women.
Published Feb. 4 in the journal Neurology Open Access, the study involved 105,614 women who were enrolled in the California Teachers Study.
At the beginning of the study, participants, who were on average 53 years old and had no history of stroke, provided detailed dietary information. This data was then used to calculate their adherence to the Mediterranean diet, with a higher score indicating closer adherence.
Mediterranean diet adherence defined
Mediterranean diet scores were based on participants’ regular intake of nine Mediterranean diet components.
Higher intakes of beneficial diet components including vegetables (excluding potatoes), fruit, cereal grains, legumes (e.g., kidney beans, chickpeas, lentils) and fish were each awarded one point.
Participants also gained one point for using olive oil in their regular diet.
As well, consuming less meat, less dairy and mild to moderate amounts of alcohol (no more than 30 g per day) each scored a point. One standard drink – 5 ounces of wine, 12 ounces 5 per cent beer or 1.5 ounces of distilled spirits – contains 15 g of alcohol.
Zero points were given for low intakes of each beneficial Mediterranean diet component, higher meat and dairy intakes, higher alcohol intakes and if olive oil wasn’t consumed.
Scores were tallied, with a final score ranging from 0 to 9. A score of 0 to 2 indicated low Mediterranean diet adherence; a score of 6 to 9 indicated high adherence.
High adherence to Mediterranean diet protective
During a follow-up period of 21 years, the researchers documented 4,083 strokes, of which 3,358 were ischemic strokes and 725 were hemorrhagic strokes.
Women who had the highest adherence to the Mediterranean diet had a significantly lower risk of all types of strokes.
After accounting for other stroke risk factors – age, race/ethnicity, smoking, body mass index, physical activity, calorie intake, hypertension, diabetes, high cholesterol, atrial fibrillation – the researchers found that women in the high adherence group had an 18 per cent lower risk of having a stroke compared to those with low adherence.
Their risk of experiencing an ischemic stroke was 16 per cent lower and they were 25 per cent less likely to have a hemorrhagic stroke.
Limitations, strengths
The study found an association between the Mediterranean diet and lower risk of stroke; it did not prove the diet directly caused this protective effect.
As well, dietary information was self-reported by participants, which can be prone to error, and was collected only once at the beginning of the study.
Even so, the study is noteworthy.
It is among the largest and longest-term studies of women, with detailed assessment of stroke risk factors, to investigate the relationship between diet and risk of stroke subtypes.
And it’s the first to find that a healthy diet can lower the risk of hemorrhagic stroke, addressing an important gap in the science.
While the study involved women only, it doesn’t mean that men can’t also benefit from following a Mediterranean diet. Previous studies that enrolled both men and women have found that following this healthy eating pattern can reduce stroke risk.
Women and stroke risk
The new findings are especially relevant given that women are disproportionately affected by stroke.
Women have an overall higher lifetime incidence of stroke compared to men, in part because of the sharp risk in stroke risk the occurs at menopause and afterwards.
According to the Heart and Stroke Foundation of Canada, 45 per cent more women than men die from stroke and, because they live longer, more women are living with the effects of stroke.
The findings add to mounting evidence that a healthy diet is critical for preventing stroke.
Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan.
