Plant-based diets may play a big role in reducing blocked arteries, study finds

Vegetarian and vegan diets are linked to lower levels of cholesterol and blood fats, according to an analysis of all evidence from randomized trials published since 1982.

The authors of the study published in the European journal of the heart today (Thursday), say this means plant-based diets can play an important role in reducing blocked arteries, thereby reducing the risk of heart and vascular diseases, such as strokes and heart attacks .

The researchers reviewed 30 randomized trials with a total of 2,372 participants, published between 1982 and 2022, that quantified the effect of vegetarian or vegan diets versus omnivorous diets on levels of all types of cholesterol (total cholesterol), low-density lipoprotein cholesterol (LDL cholesterol, often called “bad” cholesterol), triglycerides (a type of fat or “lipid” found in the blood) and apoliprotein B (apoB – a protein that helps to transport fats and cholesterol in the blood and is a good indicator of the total amount of bad fats and cholesterol in the body). Although previous meta-analyses have investigated this, none have been published since 2017, none have addressed the impact of continent, age, body mass index and health status , and none specifically examined the effect of diet on apoB concentrations.

Professor Ruth Frikke-Schmidt, chief medical officer at Rigshospitalet in Copenhagen, Denmark, who conducted the study with medical student Ms Caroline Amalie Koch and Dr Emilie Westerlin Kjeldsen, also from Rigshospitalet, said: “We found that vegetarian and vegan diets were associated with a 14% reduction in all artery-clogging lipoproteins, as indicated by apoliprotein B. This is one-third the effect of taking cholesterol-lowering drugs such as statins, and would lead to a 7% reduction in the risk of cardiovascular disease in someone who followed a plant-based diet for five years.Statin therapy is superior to plant-based diets in reducing fat and However, one diet does not exclude the other, and combining statins with herbal diets is likely to have a synergistic effect, resulting in an even greater beneficial effect.

“If people start following a vegetarian or vegan diet at an early age, the potential for reducing the risk of cardiovascular disease caused by clogged arteries is significant. Importantly, we found similar results across all continents, ages, different body mass index ranges and among people in different health states.”

Participants in the 30 studies were randomized to follow a vegetarian or vegan diet or to continue with an omnivorous diet (which includes meat and dairy). The duration of the diets ranged from ten days to five years, with an average of 29 weeks.

Compared to people on an omnivorous diet, those on a plant-based diet experienced an average reduction in total cholesterol of 7% from levels measured at the start of the studies, a 10% reduction in cholesterol LDL and a 14% reduction in apoB levels.

We found significant effects of vegetarian and vegan diets and people ranging from normal weight to obese.”

Professor Ruth Frikke-Schmidt, Chief Medical Officer of the Rigshospitalet in Copenhagen, Denmark

More than 18 million people die each year from cardiovascular disease (CVD) worldwide, making it the leading cause of death. The United Nations Sustainable Development Agenda states that premature deaths from non-communicable diseases, such as cardiovascular disease, should be reduced by one-third by 2030. In addition, there is increasing emphasis about the effect of what we eat on the environment.

“Recent systematic reviews have shown that if people in high-income countries adopt plant-based diets, it can reduce net greenhouse gas emissions by 35-49%. Our study provides strong evidence that plant-based diets are good. for our health for people of different sizes, ages and health conditions,” Professor Frikke-Schmidt said. “Furthermore, the world’s populations are aging and, as a result, the cost of treating age-related diseases such as atherosclerotic cardiovascular disease is increasing. Plant-based diets are key instruments in shifting food production towards more environmentally friendly forms, while reducing the burden of cardiovascular disease in time.We should have a varied diet, rich in plants, not too much, and quench our thirst with water.

The meta-analysis by Professor Frikke-Schmidt and colleagues could not assess the potential benefits of diets that directly compare fish diets to omnivorous diets due to the lack of such studies in the scientific literature. “However, the Mediterranean diet is rich in plant-based foods and fish and is well established as beneficial in dietary guidelines,” she said.

Professor Kevin Maki, Indiana University School of Public Health Bloomington, and Midwest Biomedical Research, USA, and Professor Carol Kirkpatrick, Midwest Biomedical Research and Idaho State University, USA, who did not participate research, comment in an accompanying editorial: “The results reported by Koch et al add to the body of evidence supporting the favorable effects of healthy vegan and vegetarian diets on circulating levels of LDL-C (LDL cholesterol) and atherogenic lipoproteins, which should reduce the risk of ASCVD (atherosclerotic CVD). Although it is not necessary to omit foods such as meat, poultry and fish/seafood entirely to follow a recommended diet, reducing the consumption of these foods is a reasonable option for those who prefer the TO DO.”

A strength of the study is that, to the authors’ knowledge, it is the largest systematic review on the subject, and the first to include apoB. However, limitations include that the individual randomized controlled trials were relatively small, the length of time participants were on a diet was less than a year in many studies, and it was impossible not to tell participants which diet they were on. were submissive, and it could have influenced their other behaviors that could affect cholesterol and fat levels.

The researchers and editorial authors say more studies that are larger, longer in duration, and include apoB and other biomarkers for conditions such as inflammation and insulin resistance are required.