Introduction:

Within the supplement industry, there are lots of companies who claim that their products are revolutionary and list benefits and promises as much as they can to build hype. BCAAs are one of these products that have built up hype among the fitness industry and claim to have multiple benefits. But is this really the case?

What are BCAAs?:

BCAA’s (Branched-chain amino acids) are 3 of the 9 essential amino acids. These three amino acids are called Isoleucine, Leucine & Valine.

Amino Acids are essentially the building blocks of protein and muscle. There are a total of 22 different amino acids with nine of them being classed as ‘essential amino acids’. Essential amino acids are those which our body cannot produce naturally. So, we have to ingest them through various different protein sources.

What do BCAAs do?

Research has shown (1) 3 of these 9 essential amino acids are particularly effective at increasing protein synthesis and can be viewed as the ‘more important’ amino acids for muscle growth. These 3 amino acids are what makeup BCAA’s.

The theory behind this is that increasing our intake of these 3 amino acids will theoretically stimulate more protein synthesis and lead to greater muscle growth.

How effective are BCAAs?

The concept behind BCAAs seems to be overlooked because, in order to achieve muscle protein synthesis, you need all 9 of the essential amino acids present, not just the 3 which are in BCAAs. Various studies (2) have shown that without all 9 essential amino acids, BCAAs are pretty much useless when taken alone. 

So theoretically, BCAAs actually don’t provide any benefit over any other protein source that does contain all 9 of the essential amino acids. 

Research so far seems to back this theory up through a study (3) that showed how whey protein actually produced more protein synthesis than even all 9 essential amino acids, not just the 3 that are in BCAAs.

This suggests that “whey protein ingestion improves protein synthesis through mechanisms that are beyond those associated with its essential amino acid content.”

Another study in 2017 (4) showed that BCAAs were about half as efficient as whey protein at producing protein synthesis.

This shows again that BCAAs are inferior to other whole sources of protein like whey protein. Meaning that it would be more beneficial and cheaper for you to use Whey instead. 

BCAAs when fasted:

Further to this, a study in 2017 (5) shockingly showed that BCAAs can actually decrease your protein synthesis when you are in a fasted state due to the fact that your body is breaking down the extra 6 essential amino acids from your muscles.

This same study showed that in fasted individuals, there was an increase in protein breakdown and that it can also interfere with the absorption of amino acids. Which is the exact opposite to the objective for why most people want to consume BCAAs.

Cases where BCAAs are useful:

BCAAs can be good however for Vegans who struggle to get their essential amino acids through non-meat alternatives. However, it would be a good idea to have BCAAs alongside another form of protein (e.g. Quinoa). To negate the negative effects of taking BCAAs alone. 

Links:

1. https://pubmed.ncbi.nlm.nih.gov/20528801/

2. https://pubmed.ncbi.nlm.nih.gov/24284442/

https://pubmed.ncbi.nlm.nih.gov/22451437/

3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2612691/

4. https://pubmed.ncbi.nlm.nih.gov/24257722/

https://pubmed.ncbi.nlm.nih.gov/28638350/

5. https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0184-9