A recent study of 10 different dietary patterns by DZNE (the German Centre for Neurodegenerative Diseases), has found that healthy eating, generally, is associated with slower biological ageing – and that there is more than one way to eat healthily. This after the teams had examined 10 diets considered healthy, including the Mediterranean, Nordic, and a plant-based diet, as well as the DASH diet, which is designed to help lower blood pressure.
Their research had involved 7 500 people – and concluded that in fact, there is no single eating plan that stands above all others.
The study was published in the journal Nature Communications.
Every dietary pattern examined was associated with slower biological ageing, as measured by chemical changes in DNA that reflect the body’s ageing process, they said. The findings were first identified using data from DZNE’s Rhineland Study and then independently confirmed in another population.
“Our study suggests that healthy eating goes hand in hand with slower biological ageing. The effects are not massive, but they are measurable and relevant for prevention. By slowing the ageing process, the risk of age-related diseases like dementia or cardiovascular disorders can be reduced. Thus, healthy eating contributes to healthy ageing," said Professor 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 ageing, 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 ageing through DNA
To investigate the connection between diet and ageing, the scientists analysed 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 ageing 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 ageing at the molecular level.
“We applied three different approaches, so-called epigenetic clocks, to read biological ageing from DNA methylation,” explained Juliana Tavares, a doctoral researcher at DZNE and lead author of the current publication. “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 ageing
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 emphasise 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,” said Tavares.
Despite those differences, the overall pattern was remarkably consistent. Better adherence to every one of the 10 diets was associated with slower biological ageing. 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,” said Tavares. “In summary: when it comes to slowing down the ageing 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 ageing among smokers. The link between healthier eating and slower biological ageing 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 added. “One explanation might be that there is just more health benefit to gain for smokers by eating healthily because of the enormous detrimental effects of smoking.”
Different diets share common ageing pathways
The scientists also investigated which biological processes might connect the different diets to slower ageing. 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 ageing 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% of the affected biological pathways were shared across all diets. These involve cell structure, cell signalling and metabolism – processes central to ageing and chronic disease.
“Therefore, it is understandable that the dietary patterns we examined were all linked with a slowing of biological ageing,” said 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.”
Study details
Associations between diet quality, epigenetic aging and epigenome in two population-based cohorts
Juliana Tavares, Dan Liu, Valentina Talevi, Fabian Eichelmann, Franziska Jannasch, Matthias Schulze, Ahmad Aziz, Ute Nöthlings, Monique Breteler.
Published in Nature Communications on 29 August 2026
Abstract
Several dietary patterns have been associated with better health outcomes. However, the extent to which adherence to different so-called healthy diets overlaps, whether these dietary patterns are equally beneficial, and whether they are associated with similar DNA methylation profiles, remains unclear. Therefore, we investigate the overlap in adherence to ten diet quality scores, and examine the associations of these scores with both biological ageing markers and DNA methylation profiles. We use data from the Rhineland Study, a large population-based cohort, and validated our findings using corresponding data from the EPIC-Potsdam cohort. Here, we show minimal overlap of participants classified in the highest quartile (top 25%) of adherence across different diet quality scores. Adherence to a healthy dietary pattern is associated with reduced epigenetic ageing, although associations differed in magnitude across diet quality scores. Different dietary patterns are associated with distinct methylation profiles, which however largely converged onto the same biological pathways. Our findings suggest that general adherence to a healthy dietary pattern could promote health through similar epigenetic mechanisms, despite variations in dietary composition.
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