Short-term vegan diet associated with reductions in biological age estimates

Following a vegan diet for eight weeks has been shown to reduce estimates of biological age based on levels of DNA methylation, a type of chemical modification of DNA (called an epigenetic modification) that alters gene expression but not the DNA itself.

Previous studies have reported that increased levels of DNA methylation are associated with aging. The new findings, based on a small randomized controlled trial of 21 adult identical twin pairs, Published in BMC Medicine.

Varun Dwaraka, Christopher Gardner and colleagues investigated the molecular effects of a short-term vegan diet by instructing one twin to follow an omnivorous diet containing 170 to 225 grams of meat, one egg, and 1.5 servings of dairy products for eight weeks, while the other twin followed a vegan diet for the same period.

Seventy-seven percent of the sample was female (32), the average age of participants was 40 years old, and the average BMI was 26 kilograms per square meter. For the first four weeks of the study, participants ate prepared meals, and for the second four weeks, after receiving nutrition lessons from a health educator, participants ate self-prepared meals.

The authors investigated the effect of diet on DNA methylation levels by analysing blood samples taken from subjects at the start of the study and at weeks 4 and 8. They used DNA methylation levels to infer the biological age of subjects and their organ systems.

By the end of the study, the authors observed a decline in estimated biological age (known as the epigenetic aging clock) in participants who followed a vegan diet but not in those who followed an omnivorous diet. They also observed a decline in the age of the cardiac, hormonal, liver, inflammatory and metabolic systems in participants who followed a vegan but not an omnivorous diet for eight weeks.

The authors caution that it is unclear to what extent the differences observed between participants on the different diets can be attributed to the dietary content. The authors note that differences in the calorie content of the meals provided during the first four weeks of the study led to participants on a vegan diet losing an average of 2 kilograms more weight than those on an omnivorous diet.

The researchers suggest that these differences in weight loss may have contributed to the differences in epigenetic age observed between the two groups, and they add that further studies are needed to explore the relationships between diet, weight, and aging, as well as the long-term effects of a vegan diet.