Plant-based alternatives and real meat: are they equivalent?

US research highlights all the nutritional differences between the two products

US research recently published in Scientific Reports, a journal of the Nature group, highlights significant nutritional differences between beef and plant-based analogues. The assessment was made through metabolomic analysis ("A metabolomics comparison of plant-based meat and grass-fed meat indicates large nutritional differences despite comparable Nutrition Facts panels". Scientific Reports volume 11, Article number: 13828_2021). By 2050, global food systems will have to meet the dietary needs of nearly 10 billion people. To do so in a healthy and sustainable way, some argue that a shift towards the consumption of more plant-based foods and less meat is needed, particularly in Western countries. This has raised doubts as to whether new plant-based products are healthy and nutritionally adequate alternatives to meat.

Modern alternatives mimic the protein content of meat by using vegetable protein isolates (e.g. soy, peas, potatoes, mung beans, rice, mycoprotein and/or wheat) and are sometimes fortified with vitamins and minerals found in red meat (e.g. vitamins B12, zinc and iron) to provide an even more direct nutritional substitute.

A team of US researchers used metabolomics to assess these nutritional aspects and provide an in-depth comparison of the metabolite profiles of grass fed ground meat and a popular plant-based meat alternative, both of which are sometimes considered healthier and more environmentally friendly sources of 'meat'. To provide an in-depth comparison of metabolite profiles, 18 samples from popular plant-based meat alternatives and 18 samples of grass fed minced meat were examined, matched according to portion size (113 g) and fat content (14 g).

Metabolomic analysis thus revealed that the metabolites in the two types of samples differed by 90%: 171 out of 190 metabolites profiled. Several metabolites were found exclusively (22 metabolites) or in greater quantities in beef (51 metabolites). Nutrients such as docosahexaenoic acid (ω-3), niacinamide (vitamin B3), glucosamine, hydroxyproline and the antioxidants allantoin, anserine, cysteamine, spermine and squalene were only present in beef. Several other metabolites were found exclusively (31 metabolites) or in larger quantities (67 metabolites) in the plant alternative to meat, such as ascorbate (vitamin C), phytosterols and several phenolic antioxidants such as loganin, sulphur, syringic acid, tyrosol and vanillic acid.

The large differences in metabolites belonging to various nutrient classes (e.g. amino acids, dipeptides, vitamins, phenols, tocopherols and fatty acids) with physiological, anti-inflammatory and/or immunomodulatory roles indicate that these products should not really be regarded as nutritionally interchangeable, but could be seen as complementary in terms of the nutrients provided. However, it was not possible to establish whether either source was healthier to consume.

Therefore, the researchers concluded that caution is needed when classifying foods as equivalent for consumers simply on the basis of their protein content ("protein foods"), as is typical in dietary recommendations.