A study of around 7,500 adults links healthier dietary patterns to favourable biological ageing markers. But does that bring us any closer to finding the perfect anti-ageing diet?
You can probably name a few foods you are supposed to eat more often. Vegetables, lean protein, healthy fats…But choosing which healthy diet to follow is another matter.
Mediterranean? Plant-based? The blood-pressure-friendly DASH diet? Each comes with its own rules, benefits and enthusiastic supporters. If your goal is to age well, which one deserves a place on your plate?
A study published in Nature Communications offers a reassuring possibility: more than one healthy eating pattern may be linked to favourable signs of biological ageing. The search for one perfect diet could be missing the bigger picture.
What Does Your Diet Have To Do With Ageing?
Your birthday tells you how many years you have lived, but it does not capture every aspect of how your body is ageing.
To investigate that distinction, researchers led by Germany’s German Center for Neurodegenerative Diseases, or DZNE, examined eating habits alongside DNA methylation: chemical marks on DNA that help regulate gene activity.
Some patterns of these marks change with age. Researchers can use them to calculate “epigenetic clocks”, which estimate aspects of biological ageing from a blood sample.
The team analysed 6,470 adults aged 30 to 95 in Germany’s Rhineland Study, then examined data from another 1,034 participants in the EPIC-Potsdam study. They compared diet-quality scores with three ageing measures.
What Are These Measures?
The researchers used three tools – GrimAge, DNAm PhenoAge and DunedinPACE – to assess biological ageing through chemical marks on DNA in blood samples.
GrimAge and DNAm PhenoAge generate age estimates that reflect patterns associated with health and mortality risk, allowing researchers to assess whether participants appear biologically older or younger than expected for their chronological age. DunedinPACE estimates the rate at which the body is ageing.
Together, these measures provide different perspectives on biological ageing.
What Can Chemical Marks On DNA Tell Us About Ageing?
DNA carries the instructions our cells use to function. DNA methylation adds small chemical tags to that DNA, helping regulate how genes are used without changing the genetic code itself.
As we age, the pattern of these tags changes. Some sites gain methylation, while others lose it. Researchers can analyse these patterns using tools called “epigenetic clocks” to estimate aspects of biological ageing, including whether someone appears older or younger than expected for their actual (or chronological) age.
Which Eating Patterns Did Scientists Examine?
The researchers did not assign people to diets. They scored participants’ reported food intake against ten established measures.
These included Mediterranean, DASH, MIND, Nordic and EAT–Lancet dietary patterns, the Alternate Healthy Eating Index etc. These measures included an unhealthful plant-based diet index and a dietary inflammatory index. For these two scores, lower values represented healthier eating.
The study also found that being a “healthy eater” depended partly on the yardstick. Only 18 of the 6,470 participants ranked in the healthiest quarter across all ten measures.
In other words, someone could eat well by one definition but not tick the boxes in another definition.
Was One Diet Better For Biological Ageing?
Healthier eating generally tracked with more favourable ageing markers, but the results were not identical across every measure.
All ten diet-quality scores were significantly associated with DunedinPACE, which estimates the pace of ageing. The direction depended on the score: healthier patterns were linked to a slower estimated pace, while less healthy patterns were linked to a faster one.
DASH and Nordic scores showed the most consistent associations across all three ageing measures after the researchers accounted for multiple statistical comparisons.
However, that does not crown either diet the ultimate anti-ageing menu.
The associations were modest, and the study did not test what would happen if the same person switched from one diet to another. The EAT–Lancet score, for example, was associated with DunedinPACE but not the other two ageing measures.
While several healthy dietary patterns were associated with favourable ageing markers, the strength and consistency of those associations varied across measures.
Does This Mean Eating Better Will Make Me Younger?
The study was an observational one, meaning researchers compared existing eating habits with molecular measurements. It was not a randomised trial, so they did not randomly assign diets and demonstrate that changing food intake slowed ageing.
Besides that, there are many other factors to the differences in results.
- People who eat differently may also differ in other ways. Statistical adjustments help, but cannot eliminate every alternative explanation.
- Dietary questionnaires depend on what people remember and report – which can mean inaccurate reporting
- The study looked at DNA methylation, and did not look at extra years of life, dementia diagnoses etc.
Both cohorts were predominantly German and of European ancestry, so the findings may not apply in the same way to populations with different backgrounds and eating habits.
What Does This Mean For My Next Meal?
The World Health Organization’s guidance on healthy eating emphasises variety, balance and foods such as vegetables, fruit, whole grains and pulses, while limiting excess salt, free sugars and unhealthy fats.
Practical changes could include adding vegetables to a rice meal, choosing wholegrain options more often, asking for less gravy, or opting for less sugar and oil in familiar foods and drinks.
A useful starting question is: what could make the meals you already enjoy more balanced?
