The study claiming that a Mediterranean diet could reduce the risk of early death in women by a quarter has gained significant media attention. However, it is essential to delve deeper into the details of the study and the actual Mediterranean diet to understand the implications better.
First, it is crucial to note that the study focused on a fictitious version of the Mediterranean diet, which was constructed by academia.This version does not accurately represent the authentic Mediterranean diet, which comprises animal foods, vegetables, and some fruits, with white starchy carbohydrates. The discrepancy between the actual diet and the one studied raises questions about the applicability of the findings.
Secondly, the study's methodology involved reviewing 16 population studies that included around 700,000 women. The researchers primarily focused on cardiovascular disease (CVD) incidence rates. The CVD incident rate during the 12.5 years of follow-up was 4%, which equates to a fraction of one percent per year. The "quarter" difference mentioned in the headlines applies to this small incident rate, resulting in an absolute risk difference of only 6 in 10,000 per year.
Furthermore, the study did not comprehensively account for several factors that could impact CVD rates, such as smoking, age, alcohol consumption, exercise, income, education, diabetes, and hormone replacement therapy (HRT). The lack of adjustments for these factors in the reviewed studies weakens the overall conclusions drawn from the review.
In summary, while the headlines may be attention-grabbing, it is essential to recognise that the study's findings are based on a fictitious Mediterranean diet and do not account for important confounding factors. Consequently, it is misleading to suggest that women who consume this made-up Mediterranean diet are far less likely to die early than those who do not.