Epigenetic modifications, defined as temporary changes that happen without nucleotide mutation, are at the center of multiple studies. These modifications mainly modify DNA availability to control gene expression (1). Epigenetic marks, whether on the DNA itself or on the DNA spools called histones, are usually kept through cell division and are associated with many physiological and pathological processes (2). While DNA methylation generally silences gene expression (3), histone modifications (acetylation, methylation, ubiquitination, phosphorylation) will play different roles in gene accessibility (4).
Interestingly, while genes are inherited, epigenetic marks are influenced by various environmental factors throughout life, and epigenetic landscapes have been used in different research fields, including geroscience (5). A team from Standford University has recently compared the impact of diet on methylation profiles associated with aging (6). To limit the interindividual variability, thus increasing the significance of their results, their study compared the methylation profiles between 21 pairs of identical twins. During 8 weeks, one twin was on a plant-based diet while the other twin kept a healthy omnivorous diet during this period. As noted in previous studies (7, 8), they noticed specific methylation profiles for each diet. Interestingly, they observed that people with a plant-based diet, compared to omnivores, demonstrated significant decreases in overall epigenetic age acceleration, suggesting an anti-aging effect of vegetarian diets. These effects were systemic, having an impact mainly on the epigenetic clocks of heart, liver, hormones, inflammation, and metabolic systems (6).
Even though these types of studies usually come with large limitations, it is still interesting to see that diet changes can have a deep effect on such a short period. A vegan diet might not be a youth therapy, but this study emphasizes the role of nutrition on overall health, including aging.