Plant-based meat alternatives (PBMAs) are increasing in popularity, especially among younger and health-conscious consumers who want to replace animal meat in their diet. A recent study published in the Canadian Journal of Cardiology determines the cardioprotective effect of PBMAs in Canadians.
Study: Animal vs plant-based meat: a hearty debate. Image Credit: Natalia Sem / Shuttersotck.com
What are PBMAs?
PBMAs are highly processed foods used as meat substitutes. They appear, taste, and feel like animal meat but are synthesized using plant-based proteins like wheat, soy, pea, and fungal.
Over six million Canadians ate little or no meat in 2018, whereas about 25% of Canadians in a 2020 survey considered reducing their food intake. The reduction in animal meat consumption for ethical, environmental, or nutritional reasons has increased PBMA consumption.
PBMAs generally have a lower mean energy density, total fat, saturated fat, and protein, as well as higher fiber content, than meat. PBMAs provide most micronutrients found in meat products while also offering a healthier nutritional profile compared to most animal meat products. Nevertheless, PBMAs also have a higher sodium content, which could increase blood pressure and the risk of cardiovascular diseases (CVDs).
Since PBMAs are produced from extracts of whole foods or are synthesized in a laboratory, they are also considered ultra-processed foods. In general, ultra-processed food consumption is associated with an increased risk of total mortality and CVDs by 21% and over 35%, respectively. These risks are raised by 2% and 4%, respectively, for each one-serving increase in daily ultra-processed food consumption.
Thus, despite the potential benefits associated with consuming PBMAs, there remains an urgent need to reduce the consumption of ultra-processed food products. Nevertheless, further research is needed to elucidate whether PBMAs are unhealthier than meat products.
About the study
The current study involved analyzing one systematic review of PBMAs and 12 controlled trials, some of which were randomized.
Some trials did not report apolipoprotein B (ApoB) values, considered the most accurate CVD risk predictor compared to total or low-density lipoprotein (LDL) cholesterol levels. Different control diets in the studies and various combinations of PBMAs contributed to heterogeneity in the analysis.
What does the study show?
Although PBMAs comprise a broad nutritional spectrum, their consumption is associated with better overall cardiovascular health than meat products. These benefits are likely due to their lower saturated fat content, as well as higher polyunsaturated fats and dietary fiber content. Even with matched fiber and fatty acid content, PBMAs appear to be cardioprotective as compared to meat.
Currently, available PBMAs have lower saturated fats and higher polyunsaturated fats than the substitutes used in most of the trials included in the current meta-analysis. Thus, the cardioprotective effect estimate of PBMAs is likely conservative.
In several trials, replacing meat with PBMAs was associated with reduced total and LDL cholesterol, ApoB-100, and body weight. The cholesterol-lowering effects of PBMAs may be due to various factors, such as substituting olive oil for butter, mayonnaise, dairy fat, or margarine. These types of dietary substitutions are associated with reduced cardiometabolic risk and CVD mortality in other studies.
Olive oil, for example, is high in polyphenols, which reduce inflammation, improve endothelial function, and lower blood pressure levels. However, many studies noted the use of non-representative tropical oils like coconut oils, which are 90% saturated fat, as the primary fat source, rather than commonly used vegetable oils.
PBMA protein
Increased legume consumption is beneficial for CVD risk. In western countries, soy protein is among the most common base of PBMA synthesis and is consistently associated with reduced CVD risk by up to 16%. Soy is rich in polyunsaturated fats and fiber, with potentially cardioprotective isoflavones.
Pea protein is another major source of non-soy-based legume protein in PBMAs. Recent studies indicate that consuming 400 grams of legumes each week may reduce the risk of CVDs by over 10%; however, this benefit cannot be directly extrapolated to PBMAs, which contain only processed protein.
Wheat gluten and mycoprotein are also commonly used in PBMAs. The potential health-promoting benefits of wheat gluten require additional investigation, as it may simply be a marker for whole grain intake rather than a protective food.
Mycoprotein is popular among fitness enthusiasts. It stimulates muscle mass and strength, similar to the effects associated with a meat-rich or soy-rich vegan diet. Moreover, mycoprotein may promote satiety; however, its impact on cholesterol levels remains unclear.
Conclusions
Replacing meat with PBMAs may be cardioprotective.”
Additional studies are needed to investigate the effects of PBMAs with more unsaturated fats on CVD risk factors, the optimal amounts and types of PBMAs, and the foods they should replace. The translation of these effects into actual reductions in adverse cardiovascular events like heart attacks and strokes must also be confirmed.
Although no adverse impacts were observed on CVD risk, despite their ultra-processed food classification, prospective long-term trials are essential to confirm the safety of PBMAs.