Researchers have found that switching to a strict vegetarian diet for just one month can cause amazing changes in DNA, linked to reduced inflammation and slower aging, compared to those who eat a lot of meat.
The results showed that vegetarians had biological markers indicating a less inflammatory immune system, with reduced activity in genes associated with cancer pathways, and a slowing of the biological clock of aging, highlighting the rapid impact of diet on the body's cells and long-term health.
In the study, published in the journal MedComm, researchers randomly assigned 48 adults to two groups: one following a strict vegetarian diet and the other a meat-rich diet, for a full month, with the same number of calories in both diets to rule out the effect of weight loss.
The researchers took blood samples before and after the experiment, then examined the DNA for changes at more than 800,000 points in the genome where methylation occurs, a process that controls gene switching. They found that a plant-based diet was associated with a decrease in pro-inflammatory cells, an increase in cells that maintain immune balance, the suppression of cancer-related genes, enhanced gene activity responsible for lowering cholesterol, improved insulin response, and strengthened DNA repair.
The biggest surprise was the effect of a plant-based diet on the "biological clock of aging," a tool that uses DNA to measure the rate of aging at the cellular level. Switching to a plant-based diet appeared to slow this clock down in just one month, suggesting that dietary changes affected pathways linked to health, not just the passage of time, according to researcher Jerome Mertens. However, the researchers acknowledge that the study was small and the genetic changes were modest, calling for larger and longer studies to confirm whether a plant-based diet can truly reduce disease risk, especially since participants were free to consume processed plant-based foods, which could have influenced the results.
Dr. Max Sturtz, co-author of the study, adds that the findings reinforce the growing evidence that nutrition can shape biology at the molecular level, and that the next step is to find out if these genetic changes persist over time and translate into tangible improvements in health, which requires broader clinical studies.
Previous studies have shown that vegetarians are less likely to develop heart disease, diabetes, and cancer, but experts warn that a vegetarian diet may lead to a deficiency in vitamin B12, an essential nutrient for nerve and blood health that is not found in plants, but rather in meat, fish, eggs, and milk. Therefore, vegetarians are advised to take B12 supplements daily.
