Vegan diet may slow aging

By Dr. Priyom Bose, Ph.D.Reviewed by Benedette Cuffari, M.Sc.Jul 31 2024

A recent BMC Medicine study investigates whether vegan and omnivorous diets differentially impact an individual's epigenetic clock.

Study: Unveiling the epigenetic impact of vegan vs. omnivorous diets on aging: insights from the Twins Nutrition Study (TwiNS). Image Credit: Art_Photo / Shutterstock.com

Delaying the consequences of aging through lifestyle modifications

Although medical advances have increased life expectancy, age-related diseases, and impairments continue to negatively affect the quality of life in older adults. Furthermore, aging is associated with significantly higher healthcare costs, which increases financial stress on social insurance systems.

Geroscience is an emerging field of science that aims to delay or reverse the molecular changes that occur due to aging. Several factors, such as diet, sleep, medication, and social factors, can slow the aging process, which could subsequently delay or prevent the incidence of age-related chronic diseases.

Several studies have assessed how dietary choices influence the aging process and overall health outcomes. However, additional research is needed to elucidate the epigenetics that connect diet with aging.

Epigenetic modifications, such as DNA methylation, play a crucial role in gene expression regulation. To date, it remains unclear whether DNA methylation is influenced by vegan or omnivorous diets and how this process and other epigenetic modulations may regulate the aging process.

One previous study indicated that specific components of a vegan diet, such as vegetables and fruits, positively impact epigenetic aging. Nevertheless, the availability of certain vitamins and nutrients, such as choline, vitamin B12, and vitamin D, could be limited in a vegan diet. Therefore, it is essential to understand whether deficiencies in essential "epi-nutrients" impact epigenetic regulation.

Epigenetic clocks derived from DNA methylation patterns are considered powerful tools for estimating biological aging and predicting age-related outcomes. Clinical factors are incorporated with DNA methylation patterns to improve the reliability and sensitivity of epigenetic clocks.

About the study

The current single-site, randomized, and parallel-group dietary intervention trial compared the effects of healthy vegan and omnivorous diets by analyzing blood DNA methylation patterns, age-related risk factors, and health biomarkers in healthy twins.

Study participants were randomly assigned to either a healthy vegan or omnivorous diet for eight weeks. Individuals assigned to the omnivorous group received animal products, such as six to eight ounces of meat, one egg, and 1.5 servings of dairy, whereas the vegan group avoided all animal products. 

The twin-pair study design enables control for age, genetic, and sex differences while simultaneously examining DNA methylation patterns based on diet. A differential methylation analysis was conducted to identify potential DNA methylation markers associated with a healthy vegan or omnivorous diet.

The primary study outcome was based on DNA methylation profiles after the eight-week dietary intervention. Secondary outcomes included insulin, glucose, triglycerides, high-density lipoprotein C (HDL-C), vitamin B12, trimethylamine N-oxide (TMAO) levels, and body weight. Blood methylome levels were also assessed to quantify methylation.

To clarify whether diet impacted biological age and telomere length, several biological age and telomere length predictors derived from DNA methylation were quantified. To this end, both principal component (PC)-based clocks, including the skin+blood Horvath (Horvath2) GrimAge and DNAm telomere clocks, as well as non-PC clocks, such as the Zhang clock based on the elastic net (Zhang-EN) and BLUP (Zhang-BLUP) method, were included. Whereas the second-generation multi-omic informed OMICmAge, the third generation informed the DunedinPACE clock.

Study findings

The study cohort comprised 21 pairs of identical twins with a mean age of 39.9 years and no history of chronic diseases. In the vegan group, a significant reduction in epigenetic age metrics, including PC GrimAge, DunedinPACE, and PC PhenoAge, was observed after eight weeks compared to baseline levels. A significant decrease in the composite systems age metrics associated with inflammation, heart, liver, metabolic, and hormones was also observed in the vegan group.

Assessment of telomere length using quantitative polymerase chain reaction (qPCR) assay indicated no significant change among vegan or omnivore cohorts. Moreover, the experimental findings suggest neither diet influenced the overall mitotic clock values. The blood analysis revealed that the basophil levels significantly increased in the vegan group and decreased in the omnivore group. 

An epigenetic biomarker proxies (EBP) analysis identified changes in the vegan and omnivorous groups, indicating a significant diet-based interaction. An epigenome-wide analysis indicated differentially methylated loci specific to each diet, thereby providing insights into the affected pathways.

Conclusions

Short-term benefits of a calorie-restricted vegan diet were observed compared to an omnivorous diet based on epigenetic age clocks among healthy twins. In the future, the long-term effects of a vegan diet on epigenetic health must be assessed.