Healthy eating slows down biological aging

Researchers tested 10 dietary approaches that are generally considered healthy: among them are the Mediterranean, Scandinavian, and plant‑based diets, as well as the DASH diet (which is often recommended for blood pressure control) and the MIND diet, which is focused on supporting brain health. It turned out that all these options are associated with slower age‑related changes at the molecular level.

To measure biological aging, the scientists used so‑called epigenetic clocks — special methods that read out chemical changes in DNA (methylation). These changes occur with age and reflect how “old” the organism appears at the molecular level, regardless of its chronological age. Blood samples from approximately 5,500 participants were used for the analysis: data from the Rhineland study in Bonn and an independent sample from the EPIC‑Potsdam project. Modern technologies made it possible to evaluate about 850,000 DNA regions — this is roughly twice as many as in most previous studies.

Each participant’s dietary habits were compared with the recommendations for each of the 10 diets, and points were assigned based on the level of compliance. It turned out that the same person could fit well into one diet and only weakly comply with another. Almost no one scored high on all standards at once — this shows that “healthy eating” can be understood in different ways. But the main point is: the higher the rating of dietary quality according to any of these approaches, the slower the molecular aging processes proceeded.

The link between diet quality and the slowing of aging was particularly noticeable among smokers. At the same time, they did not eat better than non‑smokers on their own. Scientists suggest that due to the severe harm caused by smoking, even small improvements in diet produce a more pronounced positive effect.

Despite the differences between diets, the mechanisms of their influence largely coincide. In more than 70 % of cases, the same biological pathways were affected — those responsible for cell structure, signal transmission between cells, and metabolism. These are the key processes associated with aging and chronic diseases. At the same time, certain diets also have their own specific features: for example, the DASH diet had a stronger effect on pathways related to the heart, while the MIND diet had an impact on processes important for memory and cognitive functions.

According to Monique Breteler, head of the population health department at DZNE, the effect of a healthy diet is not enormous, but it is quite measurable and important for prevention. By slowing down aging at the molecular level, proper nutrition helps reduce the risk of age‑related diseases, including dementia and cardiovascular problems.

An important practical conclusion of the study is this: there’s no need to strive for an ideal diet. It’s enough to move towards a more balanced diet — and this will already contribute to longevity and health. And understanding which specific biological processes are activated by different diets will help provide more accurate and personalized recommendations in the future.