German Study Links Plant-Based Diet Quality to Biological

A study from the German Center for Neurodegenerative Diseases (DZNE) has found that the quality of a plant-based diet significantly influences the rate of biological aging. The research analyzed data from 6,470 adults in the Rhineland Study and confirmed findings in 1,034 participants from the EPIC-Potsdam Study.

Researchers measured chemical tags on DNA and used three epigenetic clocks to estimate biological age. They compared these aging markers against ten different dietary scoring systems. The study specifically examined three scores related to plant-based eating: one for overall plant food intake, one for healthy plant foods, and one for unhealthy plant foods.

Diet Scores and Aging Effects

Higher scores on the overall plant-based and healthy plant-based indices were associated with slower biological aging. Conversely, higher scores on the unhealthy plant-based index were linked to faster aging. Every dietary pattern studied showed a connection to aging pace on at least one of the three epigenetic clocks.

Professor Monique Breteler, Director of Population Health Sciences at DZNE and head of the Rhineland Study, commented on the findings. "Our study suggests that healthy eating goes hand in hand with slower biological aging," she said. "The effects are not massive, but they are measurable and relevant for prevention."

The EAT-Lancet Diet's Weak Link

The EAT-Lancet diet, which is designed for both human and planetary health, showed the weakest association with aging. It registered an effect on only one of the three epigenetic clocks. The study authors suggest this may be due to the diet's restrictive design, which places caps on even healthy food groups and allows zero intake of several nutrient-rich ones.

Lead author Juliana Tavares, a doctoral researcher at DZNE, highlighted a key complexity in defining a healthy diet. One and the same person could therefore rank high on one diet score and low on another, Tavares explained. According to the study data, hardly anyone qualified as a healthy eater by every dietary standard simultaneously.

Common Biological Pathways

The research found that while each diet left a unique signature on DNA markers, more than 70% of the underlying biological processes affected were common across all the dietary patterns. The association between a healthy diet and slower aging was most pronounced among participants who smoked.

The authors caution that their work demonstrates an association, not proof of cause and effect. They also note that the study population was predominantly of German and European ancestry, which may limit the generalizability of the findings. Juliana Tavares summarized the core insight, stating that for slowing aging, there isn't just one healthy diet but a whole repertoire of possible diets with a positive effect.