A 20-year study of more than 65,000 postmenopausal women found that higher adherence to the Planetary Health Diet was associated with a lower risk of total cardiovascular disease, coronary heart disease, stroke, and heart failure.
The findings showed that women whose diets followed the Planet Health Diet most closely had about a 28% lower risk of cardiovascular disease compared to women in the group that scored the lowest for adherence. However, even moderate adherence to the diet was associated with a lower risk.
The Planetary Health Diet emphasizes foods such as fruits, vegetables, whole grains, legumes, nuts and unsaturated fats, while limiting foods such as red and processed meats, added sugars, refined grains and saturated fats.
Our results suggest that people may not need to follow a perfect or very restrictive diet to see potential heart health benefits. This is particularly important for postmenopausal women because cardiovascular risk increases with age and tends to increase after menopause.”
Donya Shahamati, PhD student in public health, University of California, Irvine
Shahamati will present the findings at NUTRITION 2026, the American Society for Nutrition’s flagship annual meeting, held July 25-28 in National Harbor, Maryland, just outside Washington, DC
“The transition to a more plant-forward, higher-quality diet can be achieved through small, realistic changes,” Shahamati said. “These changes might include filling half your plate with vegetables more often, using avocado or olive oil in place of butter, choosing oatmeal or whole grains for breakfast, or trying a meatless meal once a week.”
For the new research, researchers followed 66,892 participants in the Women’s Health Initiative (WHI), a long-term national health study funded by the National Heart, Lung, and Blood Institute at the National Institutes of Health. All women included in the analysis were free of cardiovascular disease at the start of the study (1994-1998) and had complete information on diet and other important health and lifestyle factors.
Using information collected through a food frequency questionnaire administered at the start of the study, the researchers calculated a Planetary Diet Index score for each study participant, with higher scores indicating that a diet was more aligned with the Planetary Health Diet. The researchers then divided the women into five groups based on how closely their diets aligned with the Planetary Health Diet.
The women, who were about 63 years old at the start of the study, were followed for about 20 years to see who developed cardiovascular disease. When analyzing the data, the researchers adjusted for several factors that could influence cardiovascular risk, including age, race and ethnicity, education, income, smoking, alcohol consumption, physical activity, body mass index and total calorie intake.
“We didn’t just look at overall cardiovascular disease,” Shahamati said. “We also looked at coronary heart disease, stroke and heart failure separately. This helped us see if the pattern was similar across different types of cardiovascular outcomes.”
Overall, the results showed that women in the group whose diets were most closely aligned with the Planetary Health Diet had the lowest risk of cardiovascular disease. These women also had a reduced risk of heart disease, heart failure, and stroke compared to women in the lowest adherence group.
However, even moderate adherence to the diet was associated with a reduction in risk, with each 10-point increase in the Planetary Health Diet Index score associated with a further reduction in risk.
The researchers caution that an observational study like this cannot show that the diet directly caused the lower risk in women.
The research team is now investigating other aspects of nutrition and health in older adult populations. For example, they are looking at how diet quality changes over time in this population, information that could help support healthy aging and prevent chronic disease.
