In recent years, an increasing number of scientific publications have been revealing evidence about the health benefits of a vegan diet. Researchers have shown, for example, that a vegan diet can help people cope better with type 1 diabetes, improve cardiovascular health, reduce urinary tract infections and ease menstrual pain.
Now a US study published at the end of July has found a link between a vegan diet and longer life expectancy.
To reach this conclusion, researchers followed 22 identical twins for eight weeks. Of the 44 participants, 22 agreed to follow a diet without any animal products, while their twin continued to eat a diet featuring meat.
The researchers wanted to study the potential beneficial effects of a vegan diet on longevity, in terms of epigenetics, which takes into account how environment and behaviours can lead to chemical changes in gene expression (known as methylations).
Hence the interest in carrying out this study on twins, who have very similar DNA, but whose genes can be modified by lifestyle factors such as diet.
More specifically, this research looked at the epigenetic clock (also known as biological age), ie, age calculated on the basis of methylations.
“The specific epigenetic clock and predictor effects of a vegan diet, compared to an omnivorous diet, remain underexplored despite potential impacts on aging-related outcomes,” the work’s authors point out.
Weight loss, cholesterol, insulin levels
At the end of the experiment, researchers were able to observe that the twins who followed a vegan diet showed significant decreases in overall epigenetic age acceleration, which the researchers attribute directly to the benefits of plant-based diets.
“Notably, our findings reveal significant reductions in key system-specific disease processes, including inflammation, heart, liver, metabolic, and hormonal systems,” the researchers note.
This may not be the first time you’ve heard of this study: it was actually featured in the American documentary “You are what you eat: A Twin Experiment,” released in January 2024 on the Netflix platform.
It follows the daily lives of four sets of twins (eight individuals in all) who took part in the same study. The documentary details the experience of these siblings, who adopted two different diets (vegan and omnivorous) over an eight-week period.
At the end of the film, viewers learn that within two months, those who followed a diet devoid of animal products showed reduced cholesterol levels, as well as weight loss and better regulation of fasting insulin levels, compared with participants who followed an omnivorous diet.