How following the Mediterranean diet may help women live longer, healthier lives: study shows lower risk of death
- Heavy on fruit, vegetables and whole grains, with olive oil as the main source of fat, the Mediterranean diet’s flexibility makes it adaptable to many cuisines
- A study that tracked women for 25 years shows the Mediterranean diet reduces their risk of death from any cause – including cancer and cardiovascular disease
One of the best diets for health keeps getting better.
The relationship held up even when researchers accounted for other factors that influence longevity, including age, exercise habits and smoking history.
The findings were published last month in the journal JAMA Network Open.
The Mediterranean diet is heavy on fruit, vegetables and whole grains. Extra virgin olive oil, which is rich in antioxidants, is the main source of fat. Protein comes from lean sources like beans, legumes and nuts as well as fish, poultry, eggs and low-fat or fat-free dairy produce.
Wine is welcome in low to moderate amounts, while red and processed meats, butter and confectionery are eaten sparingly or not at all.
They turned to the Women’s Health Study, which enrolled tens of thousands of female health professionals who were at least 45 years old. When the women joined the study in the mid-1990s, they answered 131 questions about the foods they ate.
The researchers used those answers to give each woman a score between 0 and 9 that reflected the degree to which they were following the Mediterranean diet.
If they were above the median when it came to consumption of vegetables, fruit, nuts, whole grains, legumes or fish, they got one point. Ditto if they were above the median on their ratio of monounsaturated (good) to saturated (bad) fatty acids.
Those with total scores between zero and three were categorised as having “low” adherence to the Mediterranean diet. A total of four or five was classified as “intermediate”, and a sum between six and nine was considered “high”.
The Women’s Health Study ended in 2004, but researchers kept checking in with the participants once a year. Ahmad and his colleagues focused on the 25,315 women who had both diet data and a host of biomedical measurements from when they entered the study.
By November 2023, 3,879 of the women had died. But the risk of being among them wasn’t the same for everyone.
Compared to the women in the low adherence group, those in the intermediate group were 16 per cent less likely to die during the study period, while the risk of death for those who most closely maintained the Mediterranean diet was 23 per cent lower, according to the study.
The most influential factor – among the roughly 40 biomarkers the researchers could test – was a group of metabolites, substances made or used when the body breaks down food, drugs, chemicals, or its own tissue, that appeared to explain 14.8 per cent of the benefit.
A woman’s body mass index and a measure of how well her body processes triglycerides – a common type of fat that accounts for about 95 per cent of all dietary fats – were each responsible for 10.2 per cent of the reduced risk of death, and insulin resistance accounted for 7.4 per cent.
The study suggests that making even modest improvements in these factors could help people get more longevity out of the Mediterranean diet, Ahmad said.
Dr Frank Hu, a professor of nutrition and epidemiology at the Harvard TH Chan School of Public Health, said the study offers “new insights” into why people who embrace the Mediterranean diet tend to live longer.
“It suggests that the health benefits in reducing mortality are explained by its effects on harmful blood metabolites, inflammation, insulin resistance and body weight rather than by reducing total and LDL cholesterol,” said Hu, who wasn’t involved in the work.
The study comes with several caveats, including the fact that 96 per cent of the participants were white women. That means the results may not generalise to the population at large.
In addition, the women were asked about their eating habits only once, so there’s no way to know whether their diets changed as they got older.
However, Mercedes Sotos Prieto, a nutritional epidemiologist at the Autonomous University of Madrid, said the findings about the reduced risk of death are in line with research she has conducted using data from the Nurses Health Study and the Health Professionals Follow-up Study that assessed diet multiple times.
Sotos Prieto, who did not work on the new study, said the Mediterranean diet is “golden” because it includes a variety of tasty foods and does not forbid anything. That makes it easy for people to stick with it for a long time, she said.
Hu added that the diet’s flexibility makes it adaptable to many cuisines.