New research has revealed that vegetarian and vegan diets have a notable impact on reducing cholesterol and fats in the bloodstream. This study, published by the European Society of Cardiology, is rooted in an exhaustive analysis of randomized trials conducted over the past four decades, brings to light how adopting a plant-based diet could significantly decrease the risk of heart and blood vessel diseases, including stroke and heart attacks.
The study,, closely examined 30 randomized trials involving a total of 2,372 participants. Spanning the period from 1982 to 2022, these trials scrutinized the effect of plant-based diets versus meat-inclusive diets on various aspects of cardiovascular health.
The experts tracked levels of all types of cholesterol, including low-density lipoprotein cholesterol, often referred to as ‘bad’ cholesterol, triglycerides – a type of fat found in the blood – and apolipoprotein B (apoB), a protein that carries fat and cholesterol in the blood, indicating the total amount of harmful fats and cholesterol present in the body.
Despite several previous meta-analyses delving into the subject, none have been published since 2017. More significantly, none have considered variables such as continent, age, body mass index, and health status or specifically examined diet’s impact on apoB concentrations. This study’s approach makes it particularly enlightening.
Professor Ruth Frikke-Schmidt, chief physician at the Rigshospitalet in Copenhagen, Denmark, conducted the study in collaboration with medical student Caroline Amalie Koch and Dr. Emilie Westerlin Kjeldsen.
“We found that vegetarian and vegan diets were associated with a 14% reduction in all artery-clogging lipoproteins as indicated by apolipoprotein B. 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 Professor Frikke-Schmidt.
She added that while statin treatment has superior effects in reducing fats and cholesterol levels, it does not preclude the adoption of plant-based diets. Quite the contrary, combining statins with plant-based diets is likely to yield a synergistic effect, amplifying the beneficial impact.
Professor Frikke-Schmidt emphasized the significant potential for reducing the risk of cardiovascular disease caused by blocked arteries, especially if people adopt vegetarian or vegan diets early in life.
Participants in these studies had their diets randomized. They either followed a vegetarian or vegan diet or continued with an omnivorous diet for durations ranging from ten days to five years, with an average duration of 29 weeks. The findings, published in the European Heart Journal, are significant.
Compared to those on omnivorous diets, individuals on plant-based diets experienced a 7% average reduction in total cholesterol levels, a 10% reduction in LDL cholesterol levels, and a 14% reduction in apoB levels.
Professor Frikke-Schmidt underlined the broad applicability of the study’s results, stating that they found similar patterns across continents, ages, different body mass indexes, and health statuses. “We saw significant effects from both vegetarian and vegan diets and people ranging from a normal weight to obese.”
Cardiovascular disease (CVD) remains the leading cause of death worldwide, with over 18 million people succumbing to it annually. The United Nations’ Sustainable Development Agenda aims to reduce premature deaths from non-communicable diseases, including CVD, by a third by 2030. Additionally, attention has turned to our diets’ environmental impact.
“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%,” said Professor Frikke-Schmidt.
This research points to robust evidence that plant-based diets provide health benefits for people of various sizes, ages, and health conditions, the professor continued.
“Furthermore, populations globally are aging, 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,” said Professor Frikke-Schmidt.
This research could not assess the potential benefits of diets that directly compare fish versus omnivorous diets due to the absence of such studies in the scientific literature. “However, the Mediterranean diet is rich in plant-based foods and fish and is well-established as being beneficial in dietary guidelines,” said Professor Frikke-Schmidt.
Professor Kevin Maki of Indiana University School of Public Health Bloomington and Professor Carol Kirkpatrick, of Midwest Biomedical Research wrote an accompanying editorial to the study.
“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,” the experts noted.
“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.”
A major strength of the study is its comprehensive nature. To the authors’ knowledge, it’s the largest systematic review of the topic, and the first to include apoB. However, there were also limitations. For example, the individual randomized controlled trials were relatively small, many studies had participants on diets for less than a year, and the inability to blind participants to their diet assignment may have influenced their behaviors, affecting cholesterol and fat levels.
Both the researchers conducting the study and the authors of the editorial agree that more extensive studies with a longer duration are needed. These studies should include apoB and other biomarkers for conditions like inflammation and insulin resistance. This call for further research highlights the potential that lies ahead in understanding the impact of diet on our health, longevity, and the environment.
A plant-based diet, which is often synonymous with vegetarian or vegan diets, refers to a diet that is primarily composed of foods derived from plants. This includes fruits, vegetables, grains, nuts, seeds, and legumes. Some people following a plant-based diet may also include small amounts of animal products, such as dairy, eggs, fish, or meat, but the bulk of their nutrition comes from plant sources.
Plant-based diets are rich in essential nutrients, including vitamins, minerals, dietary fiber, and healthy fats. These nutrients contribute to overall health in several ways:
Plant-based diets are often low in saturated and trans fats, and high in fiber, which can help lower blood cholesterol levels and reduce the risk of heart disease. As mentioned in the study referenced in your previous question, adopting a plant-based diet can reduce total cholesterol, LDL cholesterol, and apolipoprotein B levels, which are linked to cardiovascular disease.
Plant-based diets tend to be lower in calories and higher in fiber, helping individuals feel full without consuming excessive calories, thus aiding in weight management and reducing the risk of obesity.
Many studies have found that a diet high in fruits, vegetables, and whole grains is associated with a reduced risk of certain types of cancer, including colorectal and breast cancer.
Plant-based diets can improve blood sugar control, decrease insulin resistance, and may reduce the risk of type 2 diabetes.
Some research suggests that individuals following a plant-based diet might live longer than those who consume a diet high in processed foods and red meat.
Beyond individual health benefits, plant-based diets can significantly impact environmental sustainability:
Livestock farming contributes to a large proportion of global greenhouse gas emissions. By reducing the consumption of animal products, plant-based diets can help decrease these emissions.
Animal agriculture requires more land than plant agriculture, both for the animals themselves and for the crops grown to feed them. Transitioning to plant-based diets would reduce the demand for land, potentially allowing for more sustainable land use practices.
Producing animal-based foods typically requires more water than growing plant-based foods. By shifting to plant-based diets, we can reduce water usage and contribute to water conservation efforts.
Livestock farming is a significant cause of deforestation and habitat destruction, leading to a loss of biodiversity. By reducing the need for animal agriculture, plant-based diets can help preserve habitats and protect biodiversity.
In conclusion, a shift toward plant-based diets has significant potential benefits for both human health and the environment. However, it’s important to note that a plant-based diet needs to be well-planned to ensure it provides all necessary nutrients.
In particular, individuals on a plant-based diet need to carefully source nutrients that are commonly found in animal products, such as Vitamin B12, iron, calcium, and omega-3 fatty acids. Consulting with a registered dietitian or a healthcare provider can be beneficial when transitioning to a plant-based diet.