Study Links Planetary Health Diet to Reduced Cardiovascular Risk

A comprehensive study lasting two decades examined over 65,000 postmenopausal women, discovering that strict adherence to the Planetary Health Diet correlates with a significant reduction in cardiovascular disease risk. Participants who closely followed this diet exhibited a 28% lower risk of developing overall cardiovascular diseases compared to those whose diets were least aligned with its principles.

The Planetary Health Diet prioritises nutritious foods such as fruits, vegetables, whole grains, legumes, nuts, and unsaturated fats, while advising limits on red and processed meats, added sugars, refined grains, and saturated fats. Moderate adherence to the diet also provided benefits, with any improvement in eating habits linked to a decrease in health risks.

Donya Shahamati, a doctoral student in public health at the University of California, Irvine, said, "Our results suggest that people may not need to follow a perfect or very restrictive diet to see potential heart-health benefits." She highlighted the importance of these findings for the postmenopausal demographic, noting that cardiovascular risk tends to elevate with age, particularly after menopause.

Shahamati will present these findings at NUTRITION 2026, a major conference hosted by the American Society for Nutrition later this month in National Harbor, Maryland.

"Transitioning towards a more plant-focused diet can result from small, achievable changes," Shahamati noted. Suggested modifications include filling half of one’s plate with vegetables more frequently, using olive oil or avocado instead of butter, choosing oatmeal or whole-grain cereals for breakfast, or incorporating a meat-free meal each week.

The research followed 66,892 women participating in the Women’s Health Initiative, a national long-term health study funded by the National Heart, Lung and Blood Institute. All participants were free from cardiovascular diseases at the start of the study between 1994 and 1998, and they provided comprehensive information concerning their diet and lifestyle.

Utilising data gathered from a food frequency questionnaire completed at the study's inception, researchers assigned a Planetary Health Diet Index score to each participant. This score reflected the extent to which their diet aligned with the recommended guidelines of the Planetary Health Diet. Participants were divided into five groups based on their diet’s adherence level, and the study tracked their cardiovascular health over approximately 20 years.

Through rigorous analysis, the researchers controlled for factors that may influence cardiovascular risk, such as age, race, education, income, tobacco use, alcohol consumption, physical activity, body mass index, and total caloric intake. Shahamati explained that the study examined not only the overall incidence of cardiovascular disease but also specifically assessed coronary heart disease, stroke, and heart failure, confirming consistent patterns across these outcomes.

Results indicated that women whose diets were most aligned with the Planetary Health Diet exhibited the lowest probabilities of cardiovascular complications, alongside reduced risks of heart failures and strokes in comparison to those with the least diet adherence. Importantly, the study found a linear association, where each 10-point rise in the Planetary Health Diet Index score correlated with an increased reduction in risk.

However, the researchers cautioned that observational studies like this one cannot definitively establish causation between diet and reduced cardiovascular risk. They highlighted the need for ongoing exploration into dietary impacts on health, particularly in older populations, to identify additional factors that could assist in promoting healthy aging and preventing chronic diseases.