We’ve got an interesting trial to review this week. It was written by a New Zealand/Australian research collaboration, with Pham as the lead author. The title almost put me off. “Plasma Amino Acid Appearance and Status of Appetite Following a Single Meal of Red Meat or a Plant-Based Meat Analog: A Randomized Crossover Clinical Trial” was more than a mouthful (Ref 1). However, the article itself was well laid out and easier to read than the heading.
The rationale for the study was explained in the introduction to the paper. Plant-Based meat analogs (PBMAs) (i.e., fake meats) are becoming increasingly common and are being promoted to all consumers, not just vegans and vegetarians. They are claimed to be better for us and the environment, but “evidence of digestive efficacy, nutritional quality, and health benefits is still scarce.” The researchers noted that “nutritional differences in protein content and quality between red meat and PBMAs have not been thoroughly assessed.” The researchers thus set out to compare meat vs a plant product (Beyond Burger) to try to fill a gap in our knowledge about the relative nutritional merits of each.
We have done a couple of Monday notes to date in this area. The most recent one, July 2021, reviewed the nutritional profiles of meat vs plant burgers (Ref 2). A year earlier, a July 2020 note explored the amino acids in plant (chickpeas) vs animal foods (eggs) (Ref 3). Both of those notes examined the nutrients contained in different foods. It’s one thing to examine what food contains. It’s another to examine the effect it has once digested. That’s what this study aimed to do.
The study was primarily focused on protein. Proteins are made up of chemical 'building blocks' called amino acids. Four groups of amino acids were analysed: essential; non-essential; branched chain; and non-proteogenic amino acids. Essential amino acids are ones that we must consume – our body doesn’t make them. Non-essential amino acids can be made by the body. The branched-chain amino acids (BCAAs) are a group of three essential amino acids: leucine, isoleucine and valine. The word "proteinogenic" means "protein creating". Non-proteogenic amino acids are amino acids that are not naturally encoded in the genetic code of any organism. That’s just for background – don’t worry about the definitions – the study will give us a general review of protein quality in the body after each meal.