A diet rich in plant-based foods could help protect against more than one serious disease at once, according to new research published in The Lancet Healthy Longevity.
In one of the largest studies of its kind, researchers from the University of Vienna and international partners analyzed dietary habits and health outcomes in over 400,000 adults across six European countries. They found that people who ate more fruits, vegetables, legumes and whole grains, and fewer animal-based foods, were significantly less likely to develop multimorbidity, defined as two or more chronic conditions such as cancer, diabetes or heart disease.
Adults who adhered most closely to a plant-based diet had up to a 32% lower risk of developing multiple chronic diseases compared to those with the least plant-based diets. The protective effect held true for both middle-aged adults and those over 60.
“You don’t have to cut out animal products entirely,” said study lead Reynalda Córdova, a nutritional epidemiologist at the University of Vienna. “Shifting towards a more plant-based diet can already have a positive impact.”
Researchers also noted that not all fats are equal. Diets higher in healthy plant foods, like olive oil, showed benefits, while processed meats and high intakes of red meat were linked to higher risks. Beyond health, co-author Karl-Heinz Wagner emphasized that plant-forward diets also reduce greenhouse gas emissions and land use, offering environmental benefits alongside improved well-being.
The findings reinforce existing dietary guidelines that recommend emphasizing plants while keeping meat and animal products to smaller portions. According to the study, this approach not only lowers the risk of individual chronic conditions but also helps prevent the compounding effects of multimorbidity, which is increasingly common with age.
The study drew on data from two major European research projects, the EPIC study and UK Biobank, and included participants from Italy, Spain, the UK, Germany, the Netherlands and Denmark.
This study was supported by national health research agencies and cancer organizations across Europe, as well as the National Research Foundation of Korea.