Study Finds No Heart Health Benefits in Plant-Based Meat Alternatives

Researchers have evaluated the effects of ingesting an eight-week randomized controlled trial consisting of an omnivorous animal-based diet (ABMD) vs a plant-based meat analog (PBMA) diet (PBMD) in The American Journal of Clinical Nutrition. Their research, which included 82 participants, used linear mixed-effects models to show that while dietary exposures did differ in how they affected dietary trans-fat (which increased in the ABMD cohort), dietary fiber, potassium, and sodium (all of which showed increases in the PBMD cohort), there were no discernible improvements in cardiometabolic health biomarkers (lipid-lipoproteins).

These results demonstrate that, in contrast to marketing claims and the authors’ a priori premise, PBMD does not statistically significantly improve cardiovascular health over standard ABMD in the Asian cohort under study. All together, these findings suggest that future PBMA development should prioritize nutritional quality.

Context
Although humans are omnivores by nature, historically many geographically disparate human cultures have mostly followed plant-based meat diets due to religious and cultural mandates. This observation is especially common in Asian and Indian regions, where a number of religious organizations forbid their adherents from consuming meat or animal products. PBD has seen a rise in popularity worldwide in recent years, mostly due to worries about the environment, human health, and animal welfare.

Vegetarian and vegan diets have been shown to be superior to meat-based diets (MBDs) in terms of cardiometabolic outcomes, according to prior research. Additionally, a progressive switch from ABDs to PBDs may lower the risk of chronic, non-transmittable disorders, according to large, data-rich controlled trials. These findings, along with the previously noted worldwide surge in demand in plant-based meat substitutes (PBMAs), encouraged the creation of these products. These food items seek to fulfill the moral and health requirements of vegetarian and vegan foods while imitating the organoleptic qualities of meat-based foods.

Regretfully, there is still a dearth of scientific data supporting the health benefits of PBMAs because they are still relatively new. Although several research have linked PBMA consumption to weight loss, their results regarding cardiometabolic risk are currently confusing. Moreover, the majority of study on the subject is done with American and European cohorts, depriving the rest of the globe of data. In spite of their hereditary susceptibility to metabolic disorders, Asians are conspicuously absent from the literature.

Concerning the study
According to the current study’s hypothesis, replacing ABDs with PBMDs will progressively enhance cardiovascular health in people, as evidenced by a predicted decline in negative cardiometabolic risk markers. They put their theory to the test on a cohort of Singaporeans gathered through public sources (print and digital advertisements) at the Clinical Nutrition Research Centre in Singapore. Participants in the sample screening process completed questionnaires on their lifestyle, frequency of food consumption, and medical histories.

Participants in the study had to be adult Chinese males and females (>30 to ≤70 y) who were omnivores (consuming at least 20g of meat daily) and had increased blood glucose levels but no diabetes. Participants who smoke regularly and those who are obese (BMI f ≥27.5 kg/m2 or waist circumference greater than 88 cm for women and 102 cm for men) were not included in the study.

The conventional anthropometric measurement techniques for height, weight, and waist circumference were used to assess the chosen participants. Using the capillary finger prick method, data on blood glucose, glycated hemoglobin, and fasting (>10 hours) were recorded. Following baseline assessments, participants were randomized to either the PBMD or ABMD cohort. Participants in the eight-week parallel design randomized controlled study were asked to gradually replace their usual eating habits with diets based on animal or plant analogs provided by the research.

“These included a selection of 6 frozen foods that were broadly categorized as follows: 1) beef mince, 2) pork mince, 3) chicken breast, 4) burger patty, 5) sausage, and 6) chicken nuggets provided via scheduled deliveries to each participant’s home. Corresponding to this list, the PBMD group was provided with the following foods: 1) Impossible Beef (Impossible Foods), 2) OmniMeat Mince (OmniFoods), 3) Chickened Out Chunks (The Vegetarian Butcher), 4) Beyond Burger (Beyond Meat), 5) Beyond Sausage Original Brat (Beyond Meat), and 6) Little Peckers (The Vegetarian Butcher).”

Changes in low-density lipoprotein levels linked to food were the main outcome of interest for this study; other established cardiovascular risk factors came in second. Participants completed three-day food journals, which were collected every two weeks during the study period, as part of the data collection process. In order to determine the macro- and micronutrient profiles unique to each participant and to confirm that they were following the intervention, this dietary data was processed. Plasma insulin and fructosamine concentrations were measured using serologic tests. The changes in cardiometabolic risk factors after the food substitution were evaluated using a continuous glucose monitor.

Study results
96 of the 213 people who were screened at baseline satisfied the requirements for study inclusion, and they were divided into the ABMD and PBMD groups in a 1:1 ratio. Fourteen subjects withdrew during the next eight weeks, leaving forty PBMD and forty ABMD datasets for final analyses. The majority of participants (61%), with an average age of 59, were female. The estimated mean vascular age of the participants was 56, which was healthier than the whole population. Due to a small baseline difference in BMI (PBMD being ~1.3 kg/m2 greater than AMBD), this was adjusted for in linear mixed models.

Dietary assessments showed that both proteins and saturated fats had temporal effects, with values significantly higher at the end of the intervention than at the beginning. Conversely, a decrease in the consumption of carbohydrates was noted. The AMBD group showed the greatest gains in protein, whereas the PBMD cohort showed the greatest decreases in potassium, sodium, and cholesterol. Overall, it was found that study intervention compliance was high: 87% for PBMD participants and 95% for ABMD individuals.

Remarkably, no changes were seen in lipid-lipoprotein profiles (LDL cholesterol, the major result of interest, did not change). Measurable changes in secondary outcomes of interest were excluded by the inability of the Framingham 10-y CVD risk indices to distinguish between baseline and final values within a cohort or between cohorts. Similarly, there were no improvements in weight or BMI over the eight-week period. Nonetheless, during the course of the trial, the waist circumferences of both groups showed net reductions.

In conclusion
To sum up, this study did not find any statistically significant cardiometabolic improvements in Asian (more especially, Singaporean) people when PBMDs were substituted for ABMDs. Current-generation plant-based blood replacement drugs (PBMDs) do not accurately reflect the cardiovascular benefits of the plant meals that make them up, despite the manufacturers’ marketing claims to the contrary and the authors’ apriori hypothesis. This could be because important nutrients are lost during the processing of the plant foods to make the PBMDs.

For more information: Plant-Based Meat Analogs and Their Effects on Cardiometabolic Health: An 8-Week Randomized Controlled Trial Comparing Plant-Based Meat Analogs With Their Corresponding Animal-Based Foods,  The American Journal of Clinical Nutrition, https://doi.org/10.1016/j.ajcnut.2024.04.006