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Researchers looked at levels of LDL, or low-density lipoproteins — often called “bad” cholesterol because a buildup can increase the risk of stroke and heart disease. In study particpants, LDL levels dropped 10% and total cholesterol declined 7% for people following a plant-based diet when compared with those who eat both meat and plants, the study found.
“This corresponds to a third of the effect of taking cholesterol-lowering medications such as statins, and would result in a 7% reduction in the risk of cardiovascular disease in someone who maintained a plant-based diet for five years,” said lead author Dr. Ruth Frikke-Schmidt, professor of clinical biochemistry and chief physician at the Rigshospitalet in Copenhagen, Denmark.
“Importantly, we found similar results across continents, ages, different ranges of body mass index, and among people in different states of health,” Frikke-Schmidt said in a statement. “If people start eating vegetarian or vegan diets from an early age, the potential for reducing the risk of cardiovascular disease caused by blocked arteries is substantial.”
The analysis was based on results from 30 randomized clinical trials, with over 2,300 of them published between 1982 and 2022. Those studies investigated the impact of vegetarian or vegan diets on all types of cholesterol and apolipoprotein B (apoB), a protein in blood considered to be a good measure of how much bad fat and cholesterol is in the body.
The meta-analysis is the first to focus specifically on the effect of diet on concentrations of apoB, the authors said. Results showed being vegan or vegetarian was associated with a 14% reduction in apolipoprotein B levels.
“This large analysis supports what we already know: that including more plant-based foods in your diet is good for your heart,” Tracy Parker, a senior dietitian at the British Heart Foundation in Birmingham, said in a statement. She was not involved with the study.
However, the study also highlighted that the impact of diet on cholesterol may be limited for people who “inherit the tendency for their livers to produce too much cholesterol, meaning that high cholesterol is more strongly influenced by our genes (DNA) than by our diet,” said Robert Storey, professor of cardiology at the University of Sheffield in the United Kingdom, in a statement.
“This explains why statins are needed to block cholesterol production in people who are at higher risk of, or have already suffered from, a heart attack, stroke or other illness related to cholesterol build-up in blood vessels,” said Storey, who was not involved in the study.
Statin treatment is superior to plant-based diets in reducing fats and cholesterol levels, Frikke-Schmidt said in a statement. “However, one regimen does not exclude the other, and combining statins with plant-based diets is likely to have a synergistic effect, resulting in an even larger beneficial effect,” she added.
Expert tips on starting a plant-based diet
Anyone considering becoming a vegetarian or vegan should be sure it is well planned to include enough iron, iodine, vitamin B12 and vitamin D, said registered dietitian Duane Mellor, a senior teaching fellow at Aston University’s Medical School in Birmingham, UK.
“If someone is thinking about making a dietary change, it can be useful to discuss these with a health professional and perhaps a dietitian so that it is designed to be nutritionally adequate, help address their health concern and ideally be enjoyable,” said Mellor, who was not involved in the study.
In addition, people who transition to a plant-based diet should still be mindful about the kinds of foods they’re consuming.
“Not all plant-based diets are equal,” said Aedin Cassidy, professor and director for interdisciplinary research at the Institute for Global Food Security in Queen’s University Belfast, in a statement.
Only healthy plant-based diets, characterized by fruits, vegetables and whole grains, improve health, while other plant diets that include refined carbohydrates and processed foods high in fat, sugar and salt do not, said Cassidy, who was not involved in the study. Such foods include the all-popular french fries and fried doughnuts, as well as many other bakery items and sweets.
If people have trouble adjusting to a full vegetarian or vegan lifestyle, Parker said, consider trying the Mediterranean diet, which focuses mostly on fruit, vegetables, legumes, whole grains and fish, with few eggs and minimal low-fat dairy, and very little meat.
“There is considerable evidence that this type of diet can help lower your risk of developing heart and circulatory diseases by improving cholesterol and blood pressure levels, reducing inflammation, and controlling blood glucose levels,” Parker said in a statement.