Did a study endorsed by a Nobel Prize winner claim that the vegan diet can cause a variety of health benefits? No, that's not entirely true: The research did not focus on the vegan diet. It showed that a combination of lifestyle changes - diet, activity, stress management, and social support - provided health benefits to the very small pilot group. The research has previously been shown to have some flaws.
The claims originated from an article (archived here) published by Live Love Fruit on April 17, 2018, under the title "Study: Vegan Diet Causes More Than 500 Genes to Change in 3 Months." It opened:
Our progress in understanding human genes has been an incredible one at that. While we don't have that many genes (about 25,000 in each cell, compared to tiny water fleas who have over 30,000!), scientists have recently discovered ways to control the very small amount we do have. Scientists call it epigenetics - how changes in gene activity can occur without changing our actual DNA.
One way we can influence our genes without changing their basic structure is through the foods we eat. Nobel Prize winner Elizabeth Blackburn found that a vegan diet caused more than 500 genes to change in only three months! The vegan diet was found to turn ON genes that prevent disease and turn OFF genes that cause breast cancer, heart disease, prostate cancer, and other illnesses.
But, before I get into that, I want to talk about tiny caps at the end of each strand of DNA that protect our chromosomes - telomeres!
Users on social media saw this:
Study: #Vegan Diet Causes More Than 500 Genes to Change in 3 Months-- plantfullness (@plantfullness) August 17, 2018
The vegan diet was found to turn ON genes that prevent disease and turn OFF genes that cause breast #cancer, heart disease, prostate cancer, & other illnesses. #plantbased #plantbaseddiethttps://t.co/3DTQxPiEFA pic.twitter.com/E3EF5hgNub
The article claimed that a vegan diet "caused more than 500 genes to change in only three months!" This was measured in terms of "telomere length," which is effectively what protects our chromosomes. It said the study was endorsed by Nobel Prize winner Elizabeth Blackburn, but it failed to mention that the first author of the study is Dean Ornish. According to a fact-check by Forbes:
The first author of the new paper is Dean Ornish, whose career has been devoted to demonstrating the benefits of a comprehensive lifestyle program consisting of radical changes in diet and exercise, accompanied by stress management and social support. The senior author of the paper is Elizabeth Blackburn, who won the Nobel Prize for her discovery of telomeres and their significance. In the paper Ornish and colleagues report on a long-term followup study in a small group of people with low-risk prostate cancer who agreed to follow Ornish's rigorous program.
The Forbes article offered several "words of caution" about these claims.
There is a large gap between the conclusions of the paper, which sensibly state that the study was very small and needs to be replicated in larger populations, and Ornish's statements, which promise that aging can be reversed at the cellular level, seemingly for all people at all ages. Here are a number of reasons why you should be very cautious before drinking this Kool-Aid, despite its resemblance to the elixir of youth.
This was not a randomized trial. Patients in the treatment group agreed to intense and highly demanding lifestyle changes. They were compared with a group who had similar risk factors but who clearly did not share their high level of motivation. There is no way to know what other important differences might exist between the two groups.
This was a very small trial. The original 2008 trial enrolled 30 patients-- there were no controls-- and 24 patients had sufficient blood samples to assess telomerase activity. In the new report only 10 patients had adequate blood samples available for analysis. This severely limits the generalizability of the findings.
What caused the changes (if there were changes)? The Ornish program is famous for containing multiple interventions, including drastic reductions in dietary fat and sugar, significant increases in exercise , as well as yoga classes and group therapy. There is no way to know the relative importance, or lack of importance, of any of the individual components of his program.
Evan Anderson, a writer for a pro-vegan blog, also took issue with the claims in the study. He wrote:
As we've discussed before, the health benefits of a vegan lifestyle have yet to be conclusively demonstrated. One of the reasons is that research such as Ornish's does not isolate the veganism variable from the other variables. For instance, it could be that case that the exercise portion of the lifestyle intervention accounts for these apparent changes. It could also be the case -- though unlikely -- that the lifestyle intervention would be even more effective without the plant-based diet. And it could also be the case that the diet is solely responsible. We simply don't know.
As to the specific claim that going vegan can cause changes to genes in three months, Anderson has his doubts:
It was not just a plant-based diet, but regular exercise, more social support, etc. These changes cannot be attributed to veganism, but Ornish isn't doing much of anything to make this point clear. (As an aside, I previously read an article that quoted Ornish as saying that the 500 genes changed in a positive way "every time," a claim that I simply don't buy.)
Either way, the study's sample size was very small, and the controls involved a variety of strict lifestyle changes. The article is misleading for suggesting that the health benefits from the study are directly related to adopting a vegan diet.
NewsGuard, a company that uses trained journalists to rank the reliability of websites, describes livelovefruit.com as:
A website that promotes healthy living and veganism, which has promoted unsubstantiated medical claims.
According to NewsGuard, the site does not maintain basic standards of accuracy and accountability. Read their full assessment here.