A Plant-Based Meat Alternative is More Beneficial than Red Meat for Heart Health

by | Mar 30, 2021 | 2020, Blood Lipids, Cardiovascular Health, Fruits and Vegetables, Vegetarianism, Weight Control

Written by Joyce Smith, BS. This study suggests that a plant-based diet is associated with decreased trimethylamine N-oxide (TMAO) levels, weight and low density lipoprotein (LDL) cholesterol and offers a healthy alternative to a red meat diet. 

Replacing animal-based foods with plant-based diets offers many health and environmental benefits 1. Plant-based alternative meats (plant-meats) which include  vegetarian products that mimic traditional burgers, or meats have been available for years but have only recently become increasingly  popular 2, as seen in sales increases of 37% between  2017 and 2019 3. Most plant-based meat products can be classified as ultra-processed food which have been implicated in higher caloric intake and weight gain 4. Compared to fresh, minimally processed foods, plant-meats are also relatively high in saturated fat and sodium, and metabolically linked to hypercholesterolemia and hypertension 5,6. Yet their high fiber content has been shown to lower LDL cholesterol 7, and is associated with reduced cardiovascular disease risk and obesity 8.

In a sixteen-week, randomized, cross-over study 9 with no washout period, 36 participants consumed either a plant-based (n=18) or meat diet of primarily red meat (n=18) for 8 weeks, then switched over for the remaining 8 weeks. Participants ate primarily beef and pork, some ate a small amount of chicken and logged their food intake using a nutrition tracking software. They had two unannounced 24-hour dietary recall interviews as well as biweekly surveys regarding the amount of servings consumed. Primary outcome was fasting serum TMAO levels. Secondary outcomes included blood lipids, glucose, insulin, blood pressure and weight.

Of the participants, 67% were mostly female, 69% Caucasian, and 83% were college educated. They were 21-75 years old and had body mass indices (BMI) that varied from 18 to 39 kg/m. In the  first eight-week phase, participants who ate red meat had significantly increased TMAO levels compared to those on the plant-based diet (P=0.02). However, when the groups switched diets, those who transitioned from meat to plant had a significant decrease in TMAO levels (P = 0.007). Researchers attribute these findings to a specific gut bacteria species that may be responsible for the initial step of converting TMA to TMAO in the gut. They flourish in the gut of heavy red meat eaters and may be non-existent in those who avoid red meat. Thus a vegetarian diet that might blunt the ability of the bacteria to produce TMAO could potentially be a strategy for decreasing cardiovascular risk. These findings are in alignment with a study by Koeth et al. 10 which explored the effect of feeding L-carnitine, abundant in red meat, to vegetarians and found no increase in TMAO, suggesting this may be due to the microbiomes that favor a vegetarian diet. The 16S microbiome analysis done in the current study was not able to identify these changes.

In addition to decreased TMAO production, health benefits included a significant decrease in weight and LDL cholesterol in the plant –meat diet versus the red meat diet of the participants, while fasting IGF-1, insulin, glucose, HDL cholesterol, and triglycerides, and blood pressure did not differ significantly between the plant-meat and meat-based diets. Plant-based meat products have been categorized as ultra-processed foods that have weight-gaining potential compared to whole foods 4. However, this study demonstrated a significant reduction in weight and LDL cholesterol which aligns with the decreased saturated fat and higher fiber content found in plant-based foods 7,8. A switch to plant-based meats encourages a global shift to a more sustainable food system 11 and may benefit the environmental, animals and society as well 1,2,11  as providing a potentially healthy alternative for cardiovascular health 5. This study found several benefits and no adverse effects of consuming plant-based meats and its significant finding of the potential role of a plant-based microbiome in negating TMAO production definitely warrants further research.

Source: Crimarco, Anthony, Sparkle Springfield, Christina Petlura, Taylor Streaty, Kristen Cunanan, Justin Lee, Priya Fielding-Singh et al. “A randomized crossover trial on the effect of plant-based compared with animal-based meat on trimethylamine-N-oxide and cardiovascular disease risk factors in generally healthy adults: Study With Appetizing Plantfood—Meat Eating Alternative Trial (SWAP-MEAT).” The American Journal of Clinical Nutrition 112, no. 5 (2020): 1188-1199.

© The Author(s) on behalf of the American Society for Nutrition 2020.

Posted March 30, 2021.

Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from  the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.

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