Research published on 30th November 2023 in which the effect of diet in 22 pairs of identical twins was studied found that a plant-based diet improves cardiovascular health in as little as eight weeks. The participants with a plant-based diet had significantly lower low-density lipoprotein cholesterol (LDL-C) levels, insulin, and body weight, all of which are associated with improved cardiovascular health, than the omnivore participants.

The study, titled “Cardiometabolic Effects of Omnivorous vs Vegan Diets in Identical Twins. A Randomized Clinical Trial” was published in JAMA Network Open. It was authored by Matthew J. Landry and collaborators from Stanford University, US.

From May to July 2022, researchers selected 44 healthy participants without cardiovascular disease from the Stanford Twin Registry and matched one twin from each pair with either a plant-based or omnivore diet. Both diets were considered healthier than the average standard American diet, with vegetables, legumes, fruits and whole grains and void of sugars and refined starches, but the plant-based diet was entirely plant-based (except for honey).

The average baseline LDL-C level for the plant-based participants was 110.7 mg/dL and 118.5 mg/dL for the omnivore participants, but it dropped to 95.5 for plant-based and 116.1 for omnivores at the end of the study. The authors found the most improvement over the first four weeks of the diet change (when their entire meals were provided by the researchers). The participants on a plant-based diet also showed about a 20% drop in fasting insulin (a higher insulin level is a risk factor for developing diabetes). 

Christopher Gardner, PhD, the Rehnborg Farquhar Professor and one of the authors, said to Stanford Medicine, “Our study used a generalizable diet that is accessible to anyone because 21 out of the 22 vegans followed through with the diet. This suggests that anyone who chooses a vegan diet can improve their long-term health in two months, with the most change seen in the first month.”

“Originally from Catalonia, but resident in the UK for several decades, Jordi is a vegan zoologist and author, who has been involved in different aspects of animal protection for many years. In addition to scientific research, he has worked mostly as an undercover investigator, animal welfare consultant, and animal protection campaigner. He has been an ethical vegan since 2002, and in 2020 he secured the legal protection of all ethical vegans in Great Britain from discrimination in a landmark employment tribunal case that was discussed all over the world. He is also the author of the book, ‘Ethical Vegan: a personal and political journey to change the world’.