When it comes to protein, there is a lot of debate about which type is more bioavailable. Animal proteins are often referred to as high-quality proteins due to their high content of essential amino acids (EAAs) and greater bioavailability. However, determining the bioavailability of amino acids is complex and invasive. To make matters more complicated, data collected from different models (humans, pigs, and rats) can lead to variability between studies.
Animal ProteinsResearchers have mainly focused on vegetable proteins or the effect of food processing on animal proteins. Generally speaking, plant proteins in their original food matrix (legumes, cereals, nuts) are less digestible (about 80%) than animal proteins (meat, eggs, milk; about 93%). Food processing has a limited impact on animal protein, but its effect could be greater on plant protein. There is limited data on the effect of intestinal disorders on protein digestibility, except for gastric bypass where paradoxical effects have been described.
Animal proteins have a higher digestibility than plant proteins and a better profile of essential amino acids in relation to dietary needs. This means that animal proteins can more easily provide the daily requirement for essential amino acids than plant proteins. On average, animal protein sources have greater benefits for muscle development gram by gram than plant proteins. The administration of pancreatic enzymes partially restored protein absorption in a dose-dependent manner.
Increasing protein intake can provide many health benefits such as weight loss, better body composition, better blood sugar control, and greater satiety. Studies have shown that fortifying plant-based proteins with free amino acids (leucine, lysine and sulfur amino acids) could be an effective strategy to improve their anabolic effect. If you follow an all-plant-based diet, be sure to mix and match plant sources for a complete amino acid profile and aim to consume at least 1.5 grams per kilo of body weight to absorb enough functional protein. Increasing protein intake could help achieve the essential amino acid requirements recommended for the human diet.
Combining vegetable proteins with animal proteins can activate muscle protein anabolism in a similar way to proteins of high nutritional quality such as milk proteins (whey). The free essential amino acids used to strengthen plant-based proteins could be digested and absorbed faster than their constituent amino acids. In digestive disorders, there is little data on the bioavailability of proteins and amino acids. Animal sources are richer in vitamin B12, vitamin D, the omega-3 fatty acid DHA, heme iron, zinc and vitamin K2 than plant sources.
However, experimental conditions do not allow conclusions to be drawn about the absence of any alteration of protein absorption in environmental enteric dysfunction (EED). Plant-based protein sources that have been tested to date are characterized by having a PDCAAS lower than 100% and therefore lower than that of animal proteins.