A short-term vegan diet associated with reductions in biological age estimates

Eating a vegan diet for eight weeks is associated with reductions in biological age estimates based on levels of DNA methylation – a type of chemical modification of DNA (known as an epigenetic modification) that changes gene expression, but not the DNA itself .

Previous research has reported that increased DNA methylation levels are associated with aging. The new findings, which are based on a small, randomized, controlled trial of 21 pairs of adult identical twins, are published in BMC medicine.

Varun Dwaraka, Christopher Gardner and colleagues examined the short-term molecular effects of a vegan diet by instructing half of each twin pair to eat an omnivorous diet for eight weeks, including between 170 and 225 grams of meat, one egg and one and half a serving of dairy every day – and the other half to follow a vegan diet for the same amount of time.

The sample consisted of 77% women (32), and the participants were on average 40 years old and had an average body mass index of 26 kilograms per square meter. During the first four weeks of the study, participants ate meals prepared for them, and during the second four weeks, participants ate meals they prepared themselves after receiving nutrition lessons from health educators.

The authors examined the effects of diet on levels of DNA methylation by analyzing blood samples collected from participants at baseline, week four and week eight of the study. They used DNA methylation levels to infer the biological ages of participants and their organ systems.

Towards the end of the study, the authors found a decline in estimates of biological age – known as epigenetic aging clocks – in participants who ate a vegan diet, but not in those who ate an omnivorous diet. They also observed a decrease in the age of the heart, endocrine, liver, and inflammatory and metabolic systems of participants who ate a vegan, but not omnivorous, diet for eight weeks.

The authors caution that the extent to which the observed differences between participants eating different diets can be attributed to their dietary composition is unclear. They note that participants who ate a vegan diet lost an average of two pounds more than those who ate an omnivorous diet, due to differences in the calorie content of the meals provided during the first four weeks of the study.

They suggest that these variations in weight loss may have contributed to the observed differences in epigenetic age between the two groups. Further research is needed to investigate the relationship between nutritional composition, weight and aging, in addition to the long-term effects of vegan diets, they add.