Are BCAAs Worth the Hype?

The basic unit of protein is an amino acid. There are 20 amino acids that comprise our muscle protein, with 9 of them considered as essential amino acids (EAAs). Unlike non-essential amino acids (NEAAs), EAAs must be obtained from the foods we eat since our bodies are unable to make them. To allow for our muscles to grow, all 20 amino acids (EAAs+NEAAs) must be available in our system.

9 Essential Amino Acids:

Histidine

*Isoleucine

*Leucine

Lysine

Methionine

Phenylalanine

Threonine

Tryptophan

*Valine

*Branched-chain amino acids

A commonly asked question is whether branched-chain amino acids (BCAAs), which include leucine, isoleucine, and valine, are beneficial to our muscle gains. These 3 BCAAs are among the 9 EAAs listed above. While studies have shown leucine’s role in stimulating muscle protein synthesis, all the other amino acids or building blocks must still be present to trigger muscle growth. In simpler terms, if leucine is the fire, we still need the wood (aka the rest of the amino acids) to create a full-blown bonfire. (1)

 Once in our gut, amino acids must be absorbed into our bloodstream to be utilized for various processes such as for synthesizing muscles, neurotransmitters, immune system components, and transport proteins. However, similar to a traffic jam on a highway, an overconsumption of amino acids can lead to a “pile up” in our intestines as they wait to be carried into our bloodstream. In fact, when BCAAs are consumed in excess, this could limit absorption of the other EAAs as they compete with BCAAs to enter the blood. Overconsumption of BCAAs can also result in insulin resistance, diabetes, and vitamin B6 deficiency. In this case, the powerlifter sipping on BCAAs throughout the day is not enhancing muscle hypertrophy, but possibly dealing with the adverse effects of BCAAs. (2)(3)

 No need to worry. We can still achieve our desired gains without spending even more money on supplement companies. Individuals consuming a diet consisting of animal meat (red meat, poultry, pork, seafood), dairy food, and eggs do not require BCAAs given that these foods are categorized as complete proteins, meaning that they already provide us with the complete EAA profile. Not only do these foods provide us with complete EAAs, but they also contain important vitamins and minerals necessary for our health. Even when supplementation is required to meet the proper daily protein intake (at least 1.6g/kg of bodyweight), whey protein is a superior option to BCAAs. Therefore, no need to consume both BCAAs and whey protein, especially if you are consuming high quality protein powder (which I always highly recommend!).

Vegetarians and vegans may consider BCAA supplementation since most vegetables do not contain all 9 EAAs. This does not mean that BCAA is necessary. With a good balance of vegetables, legumes (beans, peas, lentils), grains, nuts, and seeds, people following plant-based diets can get the full EAA profile when these foods are consumed together.

What about EAA supplements then? While only a few studies have shown EAAs to be a superior form to BCAAs, whey protein (containing both EAAs + NEAAs) may still be better choice to support muscle building mechanisms. (4)(5) Remember that supplement companies do a great job marketing their products, which can easily convince us to fall for the next popular thing! Always remember that any whole food diet will trump a food source made of powder form. All in all, while supplementation has its time and place, we should always come back to filling our diets with well-balanced whole food ingredients to optimally nourish our bodies inside out.

1.     Peter J. Garlick, The Role of Leucine in the Regulation of Protein Metabolism, The Journal of Nutrition, Volume 135, Issue 6, June 2005, Pages 1553S–1556S, https://doi.org/10.1093/jn/135.6.1553S

2.     Wolfe R. R. (2017). Branched-chain amino acids and muscle protein synthesis in humans: myth or reality?. Journal of the International Society of Sports Nutrition, 14, 30. https://doi.org/10.1186/s12970-017-0184-9

3.     Smith, P. W. (2020). What You Must Know About Vitamins Mineral Herbs and So Much More (2nd ed.). Square One Publishers.

4.     Moberg, M et al. Activation of mTORC1 by leucine is potentiated by branched-chain amino acids and even more so by essential amino acids following resistance exercise. Am J Physiol Cell Physiol . 2016 Jun 1;310(11):C874-84.

 5.     Churchward-Venne, T. A., Burd, N. A., Mitchell, C. J., West, D. W., Philp, A., Marcotte, G. R., Baker, S. K., Baar, K., & Phillips, S. M. (2012). Supplementation of a suboptimal protein dose with leucine or essential amino acids: effects on myofibrillar protein synthesis at rest and following resistance exercise in men. The Journal of physiology, 590(11), 2751–2765. https://doi.org/10.1113/jphysiol.2012.228833