NATION – Eating less meat could have benefits for the heart, research has found. Changing dietary habits and increasing physical activity levels can reduce the risk of cardiovascular disease later in life.
Plant-based diets have been linked to a reduced risk of cardiovascular disease compared to an omnivorous diet rich in meats and processed meats. A new observational study suggests that a flexitarian diet — involving limiting the intake of meat instead of its complete exclusion — was associated with lower cardiovascular risk than an omnivorous diet. The study underscores the benefits of increasing the consumption of plant-based foods in lieu of meat for improving cardiovascular health, but larger studies are needed to confirm these results.
Reducing the consumption of meat has been gaining popularity due to the potential health benefits and smaller environmental footprint. While studies have supported the beneficial effects of a plant-based diet on cardiovascular and overall health, whether a flexitarian diet involving a primarily plant-based diet that allows a limited amount of meat can confer similar advantages is unknown.
A new study published in BMC Nutrition shows that a flexitarian diet was associated with lower levels of several cardiovascular biomarkers than an omnivorous diet.
Lindsay Malone, registered dietitian and instructor at Case Western Reserve University, said, “This study shows that you do get some protective benefits from eating plant-based most of the time. You don’t have to be 100% vegan to reap the benefits.”
Experts on having a flexitarian diet
“Making the shift to exclusively plant-based is difficult, and many people don’t want to make that shift. It doesn’t have to be an either/or decision. You can improve your health by eating more plant-based foods.”
— Lindsay Malone, registered dietitian
Diet can affect heart health
Cardiovascular diseases are the foremost cause of death across the globe, accounting for nearly 18 million deaths annually. Lifestyle modifications, including dietary changes and physical activity, reduce the risk of cardiovascular disease later in life.
Studies have shown that an omnivorous diet rich in meats and processed meats is associated with an increased risk of cardiovascular disease than plant-based diets. However, there is limited scientific evidence on whether a flexitarian diet consisting of a limited intake of animal protein confers cardiovascular health benefits similar to a vegetarian diet.
How a flexitarian diet affects the heart
The study consisted of 94 participants aged 25 to 45 years who had been adhering to a vegan, omnivorous, or flexitarian diet for at least a year prior to the study. The researchers used questionnaires to assess the participants’ dietary habits and lifestyle factors.
Individuals consuming less than 50 g of meat per day were categorized as flexitarians, whereas those consuming 170 g or more of meat were classified as omnivores. The third group consisted of vegans who completely abstained from the consumption of animal products.
Blood samples were obtained from the participants on the day of the study to evaluate cardiovascular disease biomarkers. In addition, the researchers also measured the participants’ blood pressure, body mass index, and the stiffness of arteries during the visit.
Less meat, lower cholesterol
The assessment of blood biomarkers suggested that flexitarians and vegans had better cardiovascular health than omnivores. Specifically, flexitarians and vegans showed lower levels of total cholesterol and low-density lipoprotein (LDL) cholesterol than omnivores. Vegans also showed lower fasting insulin levels than omnivores and flexitarians, though the difference lost significance when the researchers adjusted for cofounders.
Moreover, flexitarians and vegans had lower metabolic syndrome severity scores, which is a composite measure of several cardiovascular risk factors, including blood glucose levels, blood pressure, cholesterol levels, and weight.
Studies have found that increased stiffness of arteries is associated with cardiovascular diseases. In the present study, flexitarians showed reduced arterial stiffness than both vegans and omnivores.
A comparison of the dietary habits of the participants revealed that omnivores consumed not only more meat but also sweets, alcohol, and dairy products than vegans and flexitarians. In contrast, vegans and flexitarians consumed more fruits, vegetables, and nuts/seeds than omnivores.
Sugar may negatively affect heart health
The researchers then assessed the association between different food groups and cardiovascular risk. The consumption of sweets, soft drinks, dairy products, and meat was associated with blood biomarkers of cardiovascular risk, such as low-density lipoprotein and total cholesterol.
“One interesting finding is the association between LDL cholesterol, soft drinks, and sweets. Meat and saturated fat are usually the target for LDL cholesterol, but here we see that sugar and high glycemic foods can play a role as well.” — Malone
Does diet quality change outcomes?
One of the strengths of the study was that the association between diet and cardiovascular risk was examined after controlling for variables such as total activity levels and body mass index.
Megan Hilbert, a registered dietitian at Top Nutrition Coaching, said, “Because this was a well-controlled study (that controlled for variables like age, BMI, health, and smoking status), we were able to parse out diet quality’s effect on health status much more accurately.”
However, Hilbert noted that the study had a few limitations.
“With a small sample size of 94 participants, these findings are not generalizable, and thus, larger studies will need to be conducted to confirm these findings,” she said.
“In future studies, it would be beneficial to assess other factors of diet quality (like fiber content, antioxidant/polyphenol intake, etc.) as these have been shown to have positive impacts on cardiovascular risk, gut health, weight status, blood sugar regulation, etc. which all have an impact on the health parameters measured,” added Hilbert.
Malone noted that the study had an observational design, and hence, these results do not establish causation.
“Dietary studies are notoriously difficult because there is more than one variable. For example, study participants who avoid meat also eat more beans. Where is the benefit coming from? The reduction of meat or the addition of beans? It’s impossible to know, but in all likelihood, it’s a combination of factors working together to improve cardiovascular health parameters – more fiber, more phytonutrients, less saturated fat, nitrates, gut health, etc,” she explained.
Going flexitarian is a good first step
Claire Cohen, a registered naturopathic nutritional therapist at Nat-Nut Nutritional Therapy, said the study may help people assess their current diets to see if they can further reduce their cardiovascular disease risk.
“The study’s findings have significant potential to contribute to improved health outcomes by identifying dietary patterns associated with reduced risk of chronic diseases; this can help individuals make informed choices that support their long-term health goals,” she said.
Cohen also said that the flexitarian diet is a better place to start than going completely vegan at once.
“Individuals interested in taking control of their own health find the flexitarian style of eating simpler to sustain over the long term than a strictly vegan diet. This way of eating also ensures nutrient deficiencies are unlikely. Vegan diets generally need to supplement particular vitamins and minerals. These may not be as well absorbed or utilized by the body as the equivalents from whole foods.”
