Switching to a vegan diet — even for a month — can physically alter the body's inflammation and aging markers, according to a report released from UC San Diego researchers.
A UCSD team was joined by researchers from University of Freiburg in Germany to run a randomized clinical trial. Participants were assigned either a vegan diet or a meat-rich diet. Those who went vegan showed changes in DNA methylation — a biological process that regulates whether genes are more or less active — that were linked to immune function, metabolism and cancer- related pathways, the paper's authors write.
"Our genes are not our destiny," said Jerome Mertens, associate professor of neurosciences at UCSD School of Medicine and co-senior author of the study. "The remarkable finding isn't simply that one diet outperformed another. It's that the epigenome responded measurably in just four weeks, showing that our biology is far more dynamic — and responsive to everyday choices — than we often assume."
The findings were published Monday in MedComm and suggest dietary choices can "rapidly influence molecular processes associated with long-term health." The trial had a total of 48 participants who were assigned one of the two diets after a week of following the same diet.
Researchers examined more than 800,000 methylation sites across the genome before and after the intervention. Rather than looking for changes in individual genes alone, the researchers "focused on broader biological patterns that changed in response to diet," according to a statement from UCSD.
The vegan diet also changed the immune system to a less inflammatory state. According to the researchers, the DNA methylation analyses predicted lower proportions of neutrophils — immune cells that drive inflammation — and higher proportions of CD4 T cells, which help regulate immune responses. Those predictions matched blood cell measurements collected during an original trial.
"That agreement told us we weren't just seeing changes on a computer screen — we were detecting real and meaningful biological changes," said Lukas Karbacher, UC San Diego School of Medicine neuroscience graduate student and first author of the study.
The vegan diet showed evidence of less-active genes that have been linked with cancer and of slowed "epigenetic clocks," mathematical biomarkers estimating a person's biological age based on DNA methylation patterns rather than years lived.
Because the observed DNA changes were modest and spread across hundreds of thousands of sites in the genome, "larger and longer studies will be needed to confirm the findings and determine whether the molecular changes translate into measurable reductions in disease risk," the UCSD statement said.
