A fresh study suggests that a well-known dairy food many people already eat could play a role in slowing biological ageing.
The research, published in the journal Aging in May 2026, looked at how a 12-week lifestyle programme affected DNA methylation-based ageing markers in overweight men aged 50 to 74. The trial was small and exploratory, but it adds to growing interest in whether everyday diet and exercise habits can influence the body’s ageing rate, not just weight or fitness.
Research published in the journal Aging looked at how a simple dietary adjustment combined with consistent exercise influenced the health of men aged 50 to 74 over the course of three months.
The study focused on 48 overweight men in Japan. Half were assigned to a guided health programme, while the remaining participants continued with their normal routines (via Fox News).
Those in the intervention group were told to eat 100g of the dairy product each day and were also given personalised nutritional guidance. That advice included avoiding overeating, limiting unnecessary snacking, and cutting out sugary beverages.
They were also instructed to walk or use a stepper for roughly 30 minutes a day at least three times per week.
To assess the effects of the programme, researchers took blood samples from all 48 men before and after the trial. They also examined DNA for chemical changes linked with cellular ageing.
Scientists relied on a tool known as DunedinPACE, which measures the current speed of ageing in the body rather than simply looking at a person’s age in years. The study also examined other epigenetic clocks and several GrimAge-derived biomarkers, though the clearest signal was seen in DunedinPACE.
The findings showed that the men who ate probiotic yogurt — the dairy product highlighted in the study — and kept up regular exercise experienced a meaningful drop in the rate of ageing compared with the control group.
On average, their pace of biological ageing slowed by about 2.2%. Researchers noted that a comparable reduction had previously been seen in a two-year study in the US, where participants cut their daily calorie intake by 25%.
Interestingly, the slower ageing rate did not appear to be directly tied to weight loss. The researchers found no clear connection with body mass index or with the exact number of exercise sessions completed.
The study also identified improvement in a particular DNA marker associated with kidney function.
Still, researchers cautioned against attributing the benefit to yogurt alone. Because the study combined probiotics, dietary changes, and exercise, they said the outcome cannot be pinned on any one factor by itself. Instead, the slower ageing effect appears to stem from the combination of all three.
The findings are encouraging, but they come with important limits. The trial involved only 48 men, it lasted just 12 weeks, and it was not designed to show whether the changes would translate into longer-term health benefits. The yogurt used in the study also contained Bifidobacterium longum BB536, a specific probiotic strain, so the results may not apply to all yogurts.
Even so, the study adds to a broader body of research suggesting that regular physical activity, better diet quality and fermented foods may work together to support healthier ageing. Scientists say larger and longer studies will be needed to confirm whether the effect holds up over time and whether it matters clinically.