Study: “Whey twice as good as BCAAs”

Geschatte leestijd: 4 minutenBCAAs increase protein synthesis, muscle growth, only to a limited extent. The muscle response to whey is twice as high. That’s the conclusion of researchers from the University of Stirling.

BCAAs vs Whey

BCAAs vs. whey is an uneven battle. You take a team of 20* players and compare the results with the same team minus 17 players. The outcome will then be predictable unless specific rules give an advantage to a team of only three players.

Whey contains all amino acids including the nine essential amino acids that our body cannot produce itself. BCAAs are the three branched-chain amino acids that strength athletes have been interested in for their specific role in determining muscle mass. I recently wrote a summary article about BCAAs (with references to more extensive articles). The short conclusion was that BCAAs offer little added value in a diet where sufficient protein is already consumed. Under normal circumstances, protein intake is the last thing you reduce in a diet. For example, a few days before a competition. If you think it reduces water retention. When it comes to the rules of building a good physique, there seem to be few rules that would allow a team of 3 players to win against a team of 20 players.

Researchers from the University of Stirling in collaboration with the universities of Exeter and Birmingham showed what happens when you pit these two teams against each other. They published their findings in Frontiers in Physiology [1]. They invited 10 experienced weightlifters and gave them 5.6 grams of BCAAs or a placebo. Then they monitored protein synthesis. They also looked at the effect on mTORC1 (recently nicely explained by Peter).

The BCAAs increased protein synthesis by 22% more than a placebo. However, this is 50% less than the effect whey had in two previous studies referenced by the researchers [2,3]. The main cause would be the lack of essential amino acids when only BCAAs are taken. In this study, BCAA intake also lowered phenylalanine levels. Previous studies have also shown that BCAAs in general, or leucine in particular, can lower levels of other essential amino acids [4 to 7]. This partly explains the advantage when taking a source of amino acids that also supplements these essential amino acids. This seems particularly important when taken after exercise. When taken at rest, there seems to be no lowering effect of BCAAs on other essential amino acids. Previous research showed a 100% increase in protein synthesis with BCAA intake at rest [8]. However, this protein synthesis is much lower than after exercise, so that 100% at rest sounds more impressive than it is.

* Depending on which count you use

Conclusion

The researchers therefore conclude:

Amino acids are the building blocks of proteins and the special class of amino acids, known as BCAA, stimulate the muscle growth response. These supplements are considered to be an important part of the nutrition plan for many bodybuilders, weightlifters and others seeking muscle growth. Our results show that the common practice of taking BCAA supplements in isolation will stimulate muscle protein synthesis — the metabolic mechanism that leads to muscle growth — but the total response will not be maximal because BCAA supplements do not provide other amino acids essential for the best response. A sufficient amount of the full complement of amino acids is necessary for maximum muscle building, following exercise. Athletes interested in enhancing muscle growth with training should not rely on these BCAA supplements alone.

Professor Kevin Tipton, Chair in Sport, Health and Exercise Sciences at the University of Stirling, Science Daily

Pleintjes voetbal kan erg leuk zijn, maar met drie man heb je nog steeds maar één team. Een beetje gek als er 17 man langs de kant staat te smeken om mee te mogen spelen.

References

1. Sarah R. Jackman, Oliver C. Witard, Andrew Philp, Gareth A. Wallis, Keith Baar, Kevin D. Tipton. Branched-Chain Amino Acid Ingestion Stimulates Muscle Myofibrillar Protein Synthesis following Resistance Exercise in Humans. Frontiers in Physiology, 2017; 8 DOI: 10.3389/fphys.2017.00390
2. Witard, O. C., Jackman, S. R., Breen, L., Smith, K., Selby, A., and Tipton, K. D. (2014). Myofibrillar muscle protein synthesis rates subsequent to a meal in response to increasing doses of whey protein at rest and after resistance exercise. Am. J. Clin. Nutr. 99, 86–95. doi: 10.3945/ajcn.112.055517
3. Churchward-Venne, T. A., Breen, L., Di Donato, D. M., Hector, A. J., Mitchell, C. J., Moore, D. R., et al. (2014). Leucine supplementation of a low-protein mixed macronutrient beverage enhances myofibrillar protein synthesis in young men: a double-blind, randomized trial. Am. J. Clin. Nutr.99, 276–286. doi: 10.3945/ajcn.113.068775
4. Hagenfeldt, L., and Wahren, J. (1980). Experimental studies on the metabolic effects of branched chain amino acids. Acta Chir. Scand. Suppl. 498, 88–92.
5. Nair, K. S., Matthews, D. E., Welle, S. L., and Braiman, T. (1992). Effect of leucine on amino acid and glucose metabolism in humans. Metab. Clin. Exp. 41, 643–648. doi: 10.1016/0026-0495(92)90057-H
6. Tipton, K. D., Elliott, T. A., Ferrando, A. A., Aarsland, A. A., and Wolfe, R. R. (2009). Stimulation of muscle anabolism by resistance exercise and ingestion of leucine plus protein. Appl. Physiol. Nutr. Metab. 34, 151–161. doi: 10.1139/H09-006
7. Borgenvik, M., Apro, W., and Blomstrand, E. (2012). Intake of branched-chain amino acids influences the levels of MAFbx mRNA and MuRF-1 total protein in resting and exercising human muscle. Am. J. Physiol. Endocrinol. Metab. 302, E510–E521. doi: 10.1152/ajpendo.00353.2011
8. Wilkinson, D. J., Hossain, T., Hill, D. S., Phillips, B. E., Crossland, H., Williams, J., et al. (2013). Effects of leucine and its metabolite β-hydroxy-β-methylbutyrate on human skeletal muscle protein metabolism. J. Physiol. 591, 2911–2923. doi: 10.1113/jphysiol.2013.253203