SOPHIA ANTIPOLIS, France — A new study suggests that plant-based diets can reduce cholesterol and blood fat levels, thereby decreasing the risk of heart and blood vessel diseases. Vegetarians and vegans experienced a seven-percent reduction in their risk of cardiovascular disease over five years, compared to omnivores. However, this was only a third of the effect of taking statins. Researchers propose that a combination of a plant-based diet and statins could further enhance the benefits.
The researchers scrutinized 30 randomized trials involving just over 2,300 participants, published between 1982 and 2022. These trials evaluated how vegetarian and vegan diets influence all types of cholesterol compared to omnivorous diets, wherein participants continued to consume meat and dairy.
The studies examined three types of cholesterol. The first two types are low-density lipoprotein cholesterol (LDL) — also known as “bad” cholesterol — and triglycerides, a type of fat found in the blood. The third type is apolipoprotein B (apoB), a protein responsible for transporting fat and cholesterol in the blood. ApoB serves as a reliable indicator of the total amount of harmful fats and cholesterol in the body.
Through analyzing apoB, researchers found that vegetarian and vegan diets were associated with a 14-percent reduction in all artery-clogging lipoproteins. Compared to those following an omnivorous diet, vegetarians and vegans observed a 10-percent reduction in LDL cholesterol levels. On average, these individuals experienced a seven-percent decrease in total cholesterol from the beginning of the study.
“We found that vegetarian and vegan diets were associated with a 14% reduction in all artery-clogging lipoproteins as indicated by apoliprotein B,” reports Professor Ruth Frikke-Schmidt, a chief physician at the Rigshospitalet in Denmark, in a media release. “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.”
“Statin treatment is superior to plant-based diets in reducing fats and cholesterol levels. 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.”
Scroll down to see a list of the healthiest diet, according to heart experts
Professor Frikke-Schmidt emphasizes the significant potential of plant-based diets in mitigating the risk of cardiovascular disease caused by blocked arteries, especially if implemented from an early age. Notably, the study found similar results across continents, various body mass index ranges, and individuals with diverse health statuses.
Participants in the study were randomly assigned to follow either a vegetarian or vegan diet or to continue their regular consumption of meat and dairy. The diet duration ranged from ten days to five years, with an average of 29 weeks.
“We saw significant effects from both vegetarian and vegan diets and people ranging from a normal weight to obese,” says Professor Frikke-Schmidt.
Cardiovascular disease (CVD) causes over 18 million deaths worldwide each year, making it the leading cause of death. It is accountable for one in four premature deaths in the UK, with individuals from poorer areas being more susceptible to cardiovascular issues. CVD encompasses coronary heart disease, angina, heart attack, high blood pressure, and stroke.
The United Nations’ Sustainable Development Agenda aims to reduce premature deaths from non-communicable diseases like CVD by a third by 2030. The agenda also emphasizes the environmental impact of our dietary choices.
The researcher notes that recent systematic reviews have revealed that if populations in high-income countries transition to plant-based diets, this could lower net emissions of greenhouse gases by 35 to 49 percent. The study provides strong evidence that plant-based diets are beneficial to our health for people of various sizes, ages, and health conditions.
“Furthermore, populations globally are aging and, as a consequence, the cost of treating age-related diseases such as atherosclerotic cardiovascular disease is increasing,” the researcher points out. “Plant-based diets are key instruments for changing food production to more environmentally sustainable forms, while at the same time reducing the burden of cardiovascular disease. We should be eating a varied, plant-rich diet, not too much, and quenching our thirst with water.”
The study did not elucidate the potential benefits of a pescatarian diet due to a lack of sufficient studies.
“However, the Mediterranean diet is rich in plant-based foods and fish and is well-established as being beneficial in dietary guidelines,” says Frikke-Schmidt.
“The results reported by Koch et al add to the body of evidence supporting favorable effects of healthy vegan and vegetarian dietary patterns on circulating levels of LDL-C [LDL cholesterol] and atherogenic lipoproteins, which would be expected to reduce ASCVD [atherosclerotic CVD] risk,” adds Professor Kevin Maki from the Indiana University School of Public Health Bloomington, who did not take part in the research.
“While it is not necessary to entirely omit foods such as meat, poultry, and fish/seafood to follow a recommended dietary pattern, reducing consumption of such foods is a reasonable option for those who prefer to do so.”
To the authors’ knowledge, this is the largest systematic review of the topic and is the first to include apoB. However, the study has certain limitations. The trials were relatively small, the length of time participants were on the diets was under a year in many cases, and blinding participants to their diet assignments was not possible. These factors could have influenced other behaviors of the participants and may have affected their cholesterol and fat levels.
The study is published in the European Heart Journal.
Which diets are the best for your heart?
A new report from the American Heart Association (AHA) ranked popular diets based on their impact on heart health. Their top tier diets included:
- DASH: Describes an eating pattern that’s like the Dietary Approaches to Stop Hypertension (DASH) diet, emphasizing vegetables, fruits, whole grains, legumes, nuts and seeds, and low-fat dairy and includes lean meats and poultry, fish and non-tropical oils.
- Mediterranean: This pattern limits dairy; emphasizes vegetables, fruit, whole grains, legumes, nuts and seeds, fatty fish and extra virgin olive oil; and includes moderate drinking of red wine.
- Vegetarian/Pescatarian: A plant-based eating pattern that includes fish.
- Vegetarian/Ovo/Lacto: Plant-based eating patterns that include eggs (ovo-vegetarian), dairy products (lacto-vegetarian) or both (ovo-lacto vegetarian).
- Vegetarian/Vegan: A plant-based eating pattern that includes no animal products.
The DASH-style (Dietary Approaches to Stop Hypertension) diets, designed to treat or limit high blood pressure, obtained a perfect score in meeting all of the AHA’s guidance.
South West News Service writer Alice Clifford contributed to this report.