The research, which was published on November 30 in JAMA Network Open, found that eating a vegan diet was associated with improved heart health, increased weight loss, and even delayed aging after just eight weeks.
22 sets of identical twins, healthy adults with an average age of forty, were observed by Stanford University researchers over an eight-week diet experiment. Every twin pair had one member who was allocated at random to follow a vegan diet, meaning they would only eat plant-based meals and avoid dairy, meat, eggs, and other animal products. Each pair’s other twin was given an omnivorous diet that consisted of a minimum of one serving of fish, beef, or poultry, one egg, and one and a half servings of dairy products each day.
The goal of both diets was to provide a well-rounded intake of whole grains, legumes, and vegetables while avoiding processed carbohydrates and added sweets. During the first four weeks, participants received free meals from a meal delivery service; thereafter, they cooked their own meals and snacks under the supervision of a dietician who was always available.
Researchers discovered that after the trial, vegan diet participants shed more weight than their meat-eating peers and had lower insulin and cholesterol levels.
However, according to Christopher Gardner, senior author of the study and Stanford medical professor, “the most interesting part of the study” was that the vegans were also biologically younger based on health-related markers.
“Based on these results and thinking about longevity, most of us would benefit from going to a more plant-based diet,” he stated in a press release.
Numerous studies have attempted to compare the diets of vegans and omnivores; however, the results may be biased due to various factors, such as the possibility that vegans are in some other way more health-conscious or that their socioeconomic backgrounds or resources differ.
Gardner stated in a news statement that using twins allowed the study to specifically account for factors like genetics and upbringing, yielding vital data that also happened to be enjoyable.
“Not only did this study provide a groundbreaking way to assert that a vegan diet is healthier than the conventional omnivore diet, but the twins were also a riot to work with,” he stated. “They dressed the same, they talked the same and they had a banter between them that you could have only if you spent an inordinate amount of time together.”
Going vegan might not be necessary to improve your health.
According to Gardner’s press release, all but one of the vegan twins were able to maintain their diet throughout the trial, indicating that it might be a simple method for people to learn how to eat healthier.
Dietitians have previously told Insider that sustainability is essential for a healthy diet because you can only reap the benefits of an eating plan if you can stick with it over time.
But the greater weight loss may have been explained by the vegan participants’ self-reporting that they weren’t as satisfied with their diet. Furthermore, not all of them chose to stay vegan after the study; one said she switched to vegetarianism, according to a follow-up interview conducted at Stanford.
Gardner, who claimed to have been “mostly vegan” for four decades, stated that even if you don’t give up animal-based foods entirely, attempting to eat more beans, healthy grains, vegetables, and nuts may benefit your long-term health.
In the news release, he stated, “Eating more plant-based foods is more important than going strictly vegan.”