Branched Chain Amino Acids (BCAAs) get the majority of the attention in the sports supplement market. They’re right up there with creatine, pre-workout, protein powder, and meal replacement shakes as one of the more popular supp options. More recently, however, EAAs (Essential Amino Acids) have joined the amino acid club, with claims that they’re more complete and effective. If you’re supplementing with BCAAs, do you also need EAAs? Do you swap one for the other? Or do you even need either?
To learn the difference between BCAA and EAAs, the growing controversy around BCAA supplements, and the best way to get the benefits of EAAs, we dug through the research. We also spoke to Ben Esgro, MS, RD, who co-founded the supplement company Denovo Nutrition. Here’s what you need to know about BCAAs Vs. EAAs
BCAAs Vs. EAAs Video
Former BarBend Editor Nick English outlines everything you need to know about these two like supplements in this video:
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Editor’s note: The content on BarBend is meant to be informative in nature, but it should not be taken as medical advice. The opinions and articles on this site are not intended for use as diagnosis, prevention, and/or treatment of health problems. It’s always a good idea to talk to your doctor before beginning a new fitness, nutritional, and/or supplement routine. None of these supplements are meant to treat or cure any disease. If you feel you may be deficient in a particular nutrient or nutrients, please seek out a medical professional.
What Are BCAAs and EAAs?
You probably know that getting enough protein is critical to building and maintaining lean muscle mass. But did you know that it’s really the 20 amino acids in the protein that does the job? These organic compounds serve as building blocks for new tissue and cells. They are also vital for several other physiological processes, including manufacturing hormones and regulating immune function.
Of the 20 amino acids that make up most proteins, nine are essential to humans. These essential amino acids, or EAAs, get their name because the body cannot manufacture them itself. EAAs must be consumed through food. The nine EAAs are phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine. Most people get the recommended daily dose of EAAs through protein sources like meat, fish, dairy, and eggs, but EAA supplements are also available. And they’re increasingly being marketed to athletes as an alternative to BCAAs to boost workouts (more on why in the next sections).
That leads us to where branched-chain amino acids fit in the mix. BCAAs, as they’re commonly called, are made up of three EAAs: leucine, isoleucine, and valine. So, BCAA supplements contain EAAs, but just three. Also, BCAAs are often grouped because they have a slightly different chemical structure. Their side chain is branched, which allows them to be broken down in muscle tissue instead of the liver.
“Actually, ingesting BCAAs orally is very similar to having an injection of them. That’s how rapidly they’re absorbed,” explains Esgro. “Most things go to the liver first before circulating the body. BCAAs are unique in that they bypass the liver and can go directly to muscles. They can actually be oxidized in muscle for energy.”
Due to their rapid absorption rate, BCAAs have become popular among bodybuilders as low-carb, high-protein fuel to push through a few extra reps and stimulate protein synthesis while training on an empty stomach.
To be clear, EAA supplements are simply a complete version of BCAAs. They offer up all nine EAAs, as opposed to just three, and are thought to be more effective for building muscles and recovering from tough workouts. (More on that below.)
The Pros and Cons of BCAAs
Most people get BCAAs in a pre-workout supplement to give them some energy during fasted workouts and help support muscle building. BCAAs can also be used as a post-workout recovery drink to reduce muscle soreness and further support strength gains. Leucine, in particular, has a close link to muscle protein synthesis, which is a process that switches on genes responsible for muscle gain. (1) Some studies do support these claims. For instance, one 2017 study found that BCAAs increased muscle protein synthesis by 22%. (2)
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However, as BCAAs have been researched more widely, many studies suggest that their effects are limited and that supplementing with all nine EAAs may produce more impactful results. The likely exception is that isolated BCAAs do appear useful for helping to reduce muscle soreness. (3)(4)(5)
“A lot of things in supplements start on a great idea or a great hunch and sometimes fall apart with research,” says Esgro. “And that seems to be the case with BCAAs.”
One study from Robert Wolfe went so far as to say that BCAAs are so incomplete that they’re catabolic — meaning they’ll make your body pull amino acids from elsewhere in the body. (6)
“Whenever you’re making new proteins, you need all the amino acids available to convert into new proteins,” says Esgro. “And one of the problems with BCAAs, if you only have the three of them, you have a limiting source of amino acids. If the rest aren’t available through diet, you may pull them from somewhere else, or the protein synthetic process will stop. But knowing enough about physiology, it’s not going to shrivel you up to pull aminos from your body. I fail to see, practically, how that would cause an issue. I think that’s more something for academics to argue over than for gym-goers to argue over.”
While it’s doubtful that taking BCAAs will actually cause muscle loss, the experts and research tend to suggest that BCAA supplements may be a waste of calories and money.
Do EAAs Work Better Than BCAAs?
With the benefits of BCAAs being called into question, many people are turning to EAA supplements instead. According to Esgro, the more complete amino acid profile is likely better for the muscles.
“BCAAs are not better for exercise; they don’t produce a better protein synthetic response,” says Esgro. “When you compare both [EAAs and BCAAs], you get a better protein synthesis response from EAAs, and the protein synthetic response lasts longer.”
The research here is admittedly limited, but there are a few studies that back up his claim. A 2016 randomized controlled trial found EAAs worked better at stimulating muscle protein synthesis than both BCAAs and leucine alone (even though the researchers concluded the effect is still largely attributable to BCAAs). A 2018 study in the journal Frontiers in Physiology showed that pre-workout EAA supplementation delayed the onset of muscle fatigue and improved the quality of resistance training sessions. (7)(8)
That said, EAAs are likely most beneficial to people who don’t regularly hit the recommended daily dose of protein. That’s especially true for vegetarians or vegans who don’t consume complete protein sources and older adults who require more EAAs to stave off age-related muscle loss.
Are EAA Supplements Necessary?
All nine EAAs are necessary to build muscle, and research does show that supplementing with these aminos before a workout can support muscle building. However, McMasters University researchers compared the effects of low-dose whey supplements with leucine or EAAs versus complete whey protein. They found that all three could stimulate muscle protein synthesis immediately after exercise, but only the complete whey could sustain MPS for three to five hours afterward. (9)
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It seems that EAAs bound in food sources are armed with additional nutrients, like immunoglobulins, casein, and glucose, which work to spike insulin levels (an anabolic hormone that stops muscle breakdown and promotes muscle growth), increase energy production, and further support training goals. There’s just more in food than isolated amino acids.
“It seems ingesting glucose alongside some source of amino acids will improve protein synthetic response,” notes Esgro, who tiers the “what’s best to have before a workout” options like this:
- Whole foods
- Whey protein
In short, if you’re eating the recommended dose of complete protein daily, you’re likely already getting all the BCAAs and EAAs that you need. If you want an extra helping hand, whey protein or any other protein powder may be a cheaper, more effective means of getting an ample dose of EAAs.
As is often the conclusion to sports nutrition articles, the take-home is that your total calories, protein intake, and workouts matter the most regarding how your body looks and performs. Supplements — as the name implies — can help “supplement” your results if everything else is on point.
It’s worth experimenting with your options — whey, EAAs, BCAAs, food, nothing — and seeing how you feel when you work out. Provided your calories and protein are in check, whichever of these choices that results in you cranking out an extra few reps is the one that’ll make the difference.
- Phillips, SM et al. The impact of protein quality on the promotion of resistance exercise-induced changes in muscle mass. Nutr Metab (Lond) . 2016 Sep 29;13:64.
- Jackman SR, et al. Branched-Chain Amino Acid Ingestion Stimulates Muscle Myofibrillar Protein Synthesis following Resistance Exercise in Humans. Front Physiol. 2017 Jun 7;8:390.
- VanDusseldorp TA, et al. Effect of Branched-Chain Amino Acid Supplementation on Recovery Following Acute Eccentric Exercise. Nutrients. 2018 Oct 1;10(10):1389.
- Fedewa MV et al. Effect of branched-Chain Amino Acid Supplementation on Muscle Soreness following Exercise: A Meta-Analysis. Int J Vitam Nutr Res. 2019 Nov;89(5-6):348-356.
- Howatson, G et al. Exercise-induced muscle damage is reduced in resistance-trained males by branched chain amino acids: a randomized, double-blind, placebo controlled study. J Int Soc Sports Nutr . 2012 Jul 12;9:20.
- Wolfe, RR et al. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? J Int Soc Sports Nutr . 2017 Aug 22;14:30.
- 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.
- Negro M, et al. Essential Amino Acids (EAA) Mixture Supplementation: Effects of an Acute Administration Protocol on Myoelectric Manifestations of Fatigue in the Biceps Brachii After Resistance Exercise. Front Physiol. 2018;9:1140.
- Churchward-Venne TA, et al. 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. J Physiol. 2012 Jun 1;590(11):2751-65.
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