A large-scale study involving approximately 7,500 participants indicates that adhering to various healthy dietary patterns can slow biological aging. Researchers from the German Center for Neurodegenerative Diseases (DZNE) analyzed data to determine if specific eating plans offered superior benefits. The findings, published in Nature Communications, suggest that no single diet is uniquely superior, but rather that multiple approaches contribute to healthier aging.
DNA Methylation and Epigenetic Clocks
The research team moved beyond chronological age to assess biological aging through molecular markers. They measured DNA methylation, which involves chemical modifications to DNA that regulate gene activity. These chemical patterns change in predictable ways as people age, allowing scientists to estimate biological age with greater precision than simple birth dates.
Juliana Tavares, a doctoral researcher at DZNE and lead author of the study, explained that the team applied three different epigenetic clocks to read biological aging from DNA methylation. The researchers utilized advanced technology to cover approximately 850,000 sites in the DNA. This coverage is roughly double the number of sites examined in most previous studies, providing a more comprehensive view of the aging process at the molecular level.
The initial analysis included 6,470 participants from the Rhineland Study in Bonn, Germany. To ensure the reliability of the results, the team independently confirmed the findings using data from 1,034 additional people enrolled in the EPIC-Potsdam Study, conducted by the German Institute of Human Nutrition Potsdam-Rehbrücke.

Multiple Diets Show Similar Benefits
The scientists investigated 10 different dietary patterns, including the Mediterranean, Nordic, plant-based, and DASH diets. The DASH diet was specifically developed to help reduce blood pressure. Researchers compared reported food consumption with the recommendations for each diet and assigned scores reflecting how well individuals followed those guidelines.
Every dietary pattern examined was associated with slower biological aging. While some eating patterns showed stronger associations than others, the absolute differences were relatively small. The study found that participants who met one definition of healthy eating often did not meet the requirements of other diets. In fact, hardly anyone counted as a healthy eater by every standard at once.
“While there are measurable differences between the diets, they are modest in absolute terms. It’s the big picture what matters,” Tavares said. “In summary: When it comes to slowing down the aging process, there isn’t just one healthy diet, but indeed a whole repertoire of possible diets with a positive effect.”

More than 70 percent of the affected biological pathways were shared across all 10 diets. These processes help regulate essential functions such as cellular structure, communication between cells, and metabolism. They also play important roles in aging and the development of chronic diseases. Some pathways were diet-specific, such as heart-related pathways for the DASH diet and pathways related to cognition and memory for the MIND diet.
Unexpected Findings in Smokers
One unexpected result emerged when researchers examined the association between diet and aging among smokers. The link between healthier eating and slower biological aging was stronger in smokers than in non-smokers, even though smokers did not generally have healthier diets. The researchers have not yet determined what biological processes might explain this difference.
One possibility is that the extensive damage caused by smoking leaves greater room for measurable improvements associated with healthier eating. However, the finding does not lessen the well-established dangers of tobacco use.
“Smoking is very harmful to health,” Tavares said. “One explanation for our findings might be that there is just more health benefit to gain for smokers by eating healthy because of the enormous detrimental effects of smoking.”

Prof. Monique Breteler, Director of Population Health Sciences at DZNE and head of the Rhineland Study, emphasized the preventive potential of these findings. “Our study suggests that healthy eating goes hand in hand with slower biological aging. The effects are not massive, but they are measurable and relevant for prevention. By slowing the aging process, the risk of age-related diseases such as dementia or cardiovascular disorders can be reduced.”
The study concludes that healthy eating contributes to healthy aging and that there is likely no single correct diet. This leaves room to tailor healthy eating to personal and cultural preferences, budget, and taste.
Source: ScienceDaily

