Could switching to a plant-based diet lower you risk of stroke

According to a new study, vegetarian and vegan diets are associated with lower levels of cholesterol and fats in your blood.

The researchers on this study state that this means plant-based diets can play a significant role in reducing blocked arteries, reducing the risk of heart and blood vessel diseases such as stroke.

The researchers examined at 30 randomised 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 known as ‘bad’ cholesterol), triglycerides (a type of fat or ‘lipid’ found in the blood) and apoliprotein B (apoB – a protein that helps to carry fat and cholesterol in blood and is a good indicator of the total amount of bad fats and cholesterol in the body).

Despite previous meta-analyses having investigated these, none have been published since 2017, none have addressed the impact of continent, age, body mass index, and none have looked specifically at the effect of diet on concentrations of apoB.

Professor Ruth Frikke-Schmidt, Chief Physician at the Rigshospitalet in Copenhagen, Denmark, who conducted the study in collaboration with medical student Ms Caroline Amalie Koch and Dr Emilie Westerlin Kjeldsen, also from the Rigshospitalet, says: “We found that vegetarian and vegan diets were associated with a 14 per cent reduction in all artery-clogging lipoproteins as indicated by apoliprotein B. This corresponds to a third of the effect of taking cholesterol-lowering medications such as statins, and would result in a 7 per cent 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.

“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. Importantly, we found similar results across continents, ages, different ranges of body mass index, and among people in different states of health.”

The participants in the 30 studies were randomised to follow either a vegetarian or vegan diet or to continue with an omnivorous diet. The length of time on the diets ranged from ten days to five years, with an average of 29 weeks.

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

Prof. Frikke-Schmidt, says: “We saw significant effects from both vegetarian and vegan diets and people ranging from a normal weight to obese.”

Cardiovascular disease is the leading cause of death globally, with over 18 million people dying from diseases like stroke each year.

The United Nations’ Sustainable Development Agenda states that premature deaths from non-communicable diseases, such as CVD, should be reduced by a third by 2030. In addition, there is an increased focus on the effect of what we eat on the environment.

Prof. Frikke-Schmidt, says: “Recent systematic reviews have shown that if the populations of high-income countries shift to plant-based diets, this can reduce net emissions of greenhouse gases by between 35% to 49%. Our study provides robust evidence that plant-based diets are good for our health for people of different sizes, ages and health conditions.

“Furthermore, populations globally are ageing and, as a consequence, the cost of treating age-related diseases such as atherosclerotic cardiovascular disease is increasing. 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.”