Scientists found that 10 different healthy diets were linked to slower biological aging

There's more than one way to eat your way toward healthier aging

DZNE - German Center for Neurodegenerative Diseases

A large study involving approximately 7,500 people suggests that eating a healthy diet may help slow biological aging, and there is no single eating plan that stands above all others. Scientists at the German Center for Neurodegenerative Diseases (DZNE) 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.

Every dietary pattern examined was associated with slower biological aging, as measured by chemical changes in DNA that reflect the body's aging process. The findings were first identified using data from DZNE's Rhineland Study and then independently confirmed in another population. The research was published in Nature Communications.

"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. Thus, healthy eating contributes to healthy aging," says Prof. Monique Breteler, Director of Population Health Sciences at DZNE and head of the Rhineland Study. 

"Importantly, there is probably no single 'correct' diet. According to our data, various dietary patterns are associated with slower aging, some more, some less. That is an encouraging finding, because it leaves room to tailor healthy eating to personal and cultural preferences, budget and taste."

Measuring Biological Aging Through DNA

To investigate the connection between diet and aging, the scientists analyzed dietary information and blood samples from roughly 7,500 men and women. The initial analysis included 6,470 participants in DZNE's Rhineland Study in Bonn, Germany. The researchers then tested their findings using data from another 1,034 people enrolled in the EPIC-Potsdam Study, conducted by the German Institute of Human Nutrition Potsdam-Rehbrücke (DIfE).

Rather than relying only on participants' chronological ages, the team looked for molecular signs of aging in their blood. Specifically, they measured DNA methylation, a process involving chemical modifications to DNA that help regulate gene activity and influence how cells function.

These chemical patterns change in relatively predictable ways as people grow older, allowing scientists to estimate biological age. Unlike chronological age, which simply measures how long someone has been alive, biological age offers clues about how the body is aging at the molecular level.

"We applied three different approaches, so-called epigenetic clocks, to read biological aging from DNA methylation," explains Juliana Tavares, a doctoral researcher at DZNE and lead author of the current publication. "To this end, we leveraged state-of-the-art technology, which allowed us to cover about 850,000 sites in the DNA. This is roughly twice as many as in most previous studies."

Ten Healthy Diets Linked to Slower Aging

The next step was to determine how closely each participant followed the 10 dietary patterns. Researchers compared reported food consumption with the recommendations for each diet and assigned scores reflecting how well individuals followed those guidelines.

Because the diets emphasize different foods and nutritional goals, a person could receive a high score for one eating pattern while scoring poorly on another. In fact, participants who met one definition of healthy eating often did not meet the requirements of other diets.

"One and the same person could therefore rank high on one diet score and low on another. In other words: People who ate healthily by one standard were often not the same people who ate healthily by another. According to our data, hardly anyone counts as a healthy eater by every standard at once," says Tavares.

Despite those differences, the overall pattern was remarkably consistent. Better adherence to every one of the 10 diets was associated with slower biological aging. Some eating patterns showed stronger associations than others, but the absolute differences were relatively small.

"While there are measurable differences between the diets, they are modest in absolute terms. It's the big picture what matters," says Tavares. "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."

A Surprising Finding Among 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 nonsmokers, 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," says Tavares, "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."

Different Diets Share Common Aging Pathways

The scientists also investigated which biological processes might connect the different diets to slower aging. Although each eating pattern was associated with changes at a distinct collection of DNA methylation sites, the underlying biological pathways were surprisingly similar.

More than 70% of the affected 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.

The researchers identified some differences that reflected the specific goals of individual diets. For example, the DASH diet was associated with pathways related to heart health, while the MIND diet, which was developed to support brain health, showed distinct associations with pathways involved in memory and cognitive function.

"More than 70 percent of the affected biological pathways were shared across all diets. These involve cell structure, cell signaling and metabolism -- processes central to aging and chronic disease. Therefore, it is understandable that the dietary patterns we examined were all linked with a slowing of biological aging," says Tavares. 

"A few pathways were diet-specific, and they matched each diet's main objectives: heart-related pathways were unique to the DASH diet, and pathways related to cognition and memory were unique to the so-called MIND diet, which aims to support brain health. You don't need a perfect diet -- that may be the most practical message here. But moving forward, the diet-specific pathways point to future research on targeted dietary interventions. This could be helpful in designing targeted health recommendations."

Journal Reference:

1. Juliana F. Tavares, Dan Liu, Valentina Talevi, Fabian Eichelmann, Franziska Jannasch, Matthias B. Schulze, N. Ahmad Aziz, Ute Nöthlings, Monique M. B. Breteler. Associations between diet quality, epigenetic aging and epigenome in two population-based cohorts. Nature Communications, 2026; 17 (1) DOI: 10.1038/s41467-026-77064-4