May 30, 2023 – Compared with meat eaters, individuals who followed vegan or vegetarian diets had lower levels of certain fats of their blood that may clog arteries and potentially result in heart disease and stroke, recent research shows.
The results – published on 24 May within the European Heart Journal – come from a meta-analysis (a study that summarizes all the outcomes from smaller studies) of 30 generally short, small, randomized controlled trials published between 1982 and 2022.
In each study, researchers randomly assigned some people to proceed following an omnivorous weight-reduction plan (meat, dairy, and plants) while assigning others to either a vegan or vegetarian weight-reduction plan – on average for about 7 months.
At the top of this era, levels of some blood lipids were lower in those that had followed a plant-based weight-reduction plan than in those that had followed an omnivorous weight-reduction plan.
Specifically, that they had 7% lower total levels of cholesterol, 10% lower LDL cholesterol (or “bad” cholesterol) levels, and 14% lower apolipoprotein B (ApoB) levels.
ApoB is the primary protein of LDL cholesterol and might function one other indicator of heart problems.
There was no significant difference in triglycerides, one other sort of fat that, in high concentrations, is linked to heart attacks and strokes.
“Vegetarian and vegan diets were associated with a 14% reduction in all artery-clogging lipoproteins, as indicated by apolipoprotein B,” said lead creator Ruth Frikke-Schmidt, MD, PhD, of the University of Copenhagen in a press release.
“This is one-third the effect of taking cholesterol-lowering drugs such as statins,” she said, “and would reduce the risk of cardiovascular disease by 7% in someone who follows a plant-based diet for five years.”
She speculated that combining statins with a plant-based weight-reduction plan would likely produce a greater (synergistic) effect.
Importantly, the outcomes were similar for people of various ages, with different body mass indexes and different health status living on different continents.
“If people start eating a vegetarian or vegan diet at a young age,” says Frikke-Schmidt, “the potential to reduce the risk of cardiovascular disease caused by clogged arteries is significant.”
In addition, recent studies have shown that net greenhouse gas emissions might be reduced by 35 to 49 percent if populations in high-income countries switched to a plant-based weight-reduction plan, she noted.
Not all plant-based diets are the identical
In an editorialKevin C. Maki, PhD, of Indiana University, and Carol Kirkpatrick, MPH, PhD, of Idaho State University, wrote that the brand new study provides evidence that healthy vegan and vegetarian diets may reduce the chance of heart disease and stroke.
“Although it is not necessary to completely eliminate foods such as meat, poultry, and fish/seafood to follow a recommended dietary pattern,” they noted, “reducing consumption of such foods is a reasonable option for those who prefer to do so.”
Other experts not involved on this research agree: by comments They donated to the British Science Media Center.
“Although vegetarian and vegan diets can be very healthy and beneficial in terms of cardiovascular risk, it is important that they are well planned to include nutrients that may be present in only small amounts in the diet, such as iron, iodine, vitamin B12 and vitamin D,” said Duane Mellor, PhD, of Aston University in Birmingham, UK.
Some people “may find it easier to stick to a Mediterranean diet, which includes plenty of fruit, vegetables, pulses, whole grains, fish, eggs and low-fat dairy products, and only small amounts of meat,” says Tracy Parker, a heart health dietitian on the British Heart Foundation in London.
“There is a lot of evidence that this type of diet can help reduce the risk of heart and circulatory disease by improving cholesterol and blood pressure levels, reducing inflammation and controlling blood sugar levels,” she said.
Aedin Cassidy, PhD, at Queen's University in Belfast, UK, noted that “nNot all plant-based diets are the same.” She said that healthy diets dominated by fruits, vegetables and whole grains improve health, but “other plant-based diets (e.g., those containing refined carbohydrates, processed foods high in fat/salt, etc.)” do not.
This well-done analysis of 30 clinical trials involving more than 2,000 participants “underscores the worth of a vegetarian weight-reduction plan in reducing the chance of heart attack or stroke by lowering blood levels of cholesterol,” said Dr. Robert Storey of the University of Sheffield in the UK.
But “the liver's tendency to provide an excessive amount of cholesterol is hereditary. This implies that high cholesterol is more influenced by our genes (DNA) than by our weight-reduction plan,” he said.
“This explains why statins are needed to dam cholesterol production in people who find themselves at increased risk of, or who’ve already had, a heart attack, stroke or other condition related to cholesterol deposits within the blood vessels.”
Bottom line
“Plant-based diets are a key tool to shift food production to more environmentally sustainable forms while reducing the burden of cardiovascular disease in an ageing population,” said Frikke-Schmidt.
“We should eat a varied and plant-rich diet, not too much, and quench our thirst with water.”