New Delhi, July 29 (IANS): Eating a vegan diet for eight weeks can help reduce biological age estimations, according to a small study.

Knowing biological age can help understand the risk of diabetes or dementia. The research, published in the journal BMC Medicine, showed that the age reduction observed was based on levels of DNA methylation -- a type of chemical modification of DNA (known as an epigenetic modification) that alters gene expression but not DNA itself.

The new study, a randomised, controlled trial of 21 pairs of adult identical twins, investigated the molecular effects of a short-term vegan diet.

The team instructed one-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 a half servings of dairy each day -- and the other half to eat a vegan diet for the same length of time.

The team found decreases in estimates of biological age -- known as epigenetic ageing clocks -- in participants who ate a vegan diet but not among those that ate an omnivorous diet.

People on a vegan diet also had decreases in the ages of the heart, hormone, liver, and inflammatory and metabolic systems. They also lost two kilograms more on average than those who ate an omnivorous diet due to differences in the calorie contents.

The findings are unclear, said the team stressing the need to investigate further the relationship between dietary composition, weight, and ageing.