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Short-term vegan diet for 8 weeks may help reduce biological age
Last reviewed: 02.07.2025
A recent study compared the effects of an eight-week vegan diet and an omnivorous diet on biological age measures that measure overall health and the risk of age-related diseases such as heart disease and Alzheimer's disease.
Context of the study
The researchers estimated biological age by measuring levels of DNA methylation — epigenetic changes that affect gene expression without changing the DNA itself. Previous studies have linked elevated levels of DNA methylation to aging.
The experimental intervention included 21 pairs of identical twins, allowing better control for genetic and age-related variables. One pair of twins was excluded due to non-compliance with the study conditions, leaving 21 pairs (42 individuals) for the final analysis.
Research methods
After initial assessments, one twin from each pair was randomly assigned to a healthy plant-based vegan diet or a healthy omnivorous diet for eight weeks. The study consisted of two four-week phases: In the first phase, participants were provided with food, and in the second phase, participants prepared their own food following instructions from dietitians.
The omnivore group received daily intakes of animal products such as meat, eggs and dairy, while the vegan group avoided animal products entirely.
The researchers tracked the participants' dietary habits using random 24-hour surveys and food diaries conducted by registered dietitians.
Results
The study found that participants who followed a vegan diet showed a significant reduction in epigenetic age, while those who followed an omnivorous diet did not. Only those who followed a vegan diet for eight weeks showed a reduction in biological age in five organ systems, including the cardiac, hormonal, hepatic, inflammatory, and metabolic systems.
Discussion of results
The study’s lead author, Dr. Varun Dwarka, noted that the observed changes occurred in just eight weeks, confirming the diet’s rapid impact on epigenetic health. Other experts, such as Raghav Sehgal, a PhD candidate in computational biology and bioinformatics at Yale University, have suggested that a vegan diet may impact epigenetic aging by improving inflammatory and metabolic pathways in the body.
Opinions and Conclusions
Dr. Thomas Holland, a professor at the RUSH Institute for Healthy Aging in Chicago, noted that while the use of identical twins is important, the eight-week period may not be long enough to observe long-term effects, and that the results may not be universally applicable due to the small sample size.
Dr. Lucia Aronica of Stanford University also emphasized that other diets, such as the Mediterranean diet, which includes both plant and animal products, can also be effective in reducing epigenetic age. She added that both plant and animal products play an important role in maintaining the epigenome.
Conclusion
While the vegan diet shows promise, it should be viewed as one of many potential diets that may promote healthy aging, rather than a definitive solution. More research is needed to better understand the mechanisms and long-term effects of different diets on epigenetic health.