Michael Henson

Just tell us! Which one should we choose - EAAs or BCAAs

By Michael Henson on December 5th, 2018 Supplement Reviews & Advice

Just tell us! Which one should we choose - EAAs or BCAAs

Firstly I want to start by saying my boss was a bit wary of me writing this article based on the fact that Branched-Chain Amino Acid is one of our best selling sport supplements and have been for many years now. However, saying this Cardiff Sports Nutrition will always endeavour to give our customers the best and most up to date information regarding supplements.

Most of you have been unaware, but a subtle discussion has begun with two very passionate sides. This discussion isn’t about whether nootropics are better than pre-workouts, or which brand has the better whey protein, or even what protein bar tastes the best.

What we're referring to is the one the majority didn't even know was that different; BCAAs and Essential Amino Acids (EAAs).

Each claim to be the best but which one is truly better? Well, Cardiff Sports Nutrition is picking a side... kind of.

Let us start with explaining Amino Acids

Branched-chain amino acids (BCAAs) were given their name due to their unique branch-like structure. The BCAAs consist of three amino acids — leucine, isoleucine, and valine, which are a subcategory of the larger Essential Amino Acids (EAAs).

There are a total of nine EAAs, which consist of:

  • Histidine
  • Isoleucine — BCAA
  • Leucine — BCAA
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine — BCAA

Why are they called essential?

Essential basically means that the human body can't produce them on its own - it needs to get it from food (endogenously). In addition to the essential amino acids, there are also several other conditionally essential amino acids (arginine, cysteine, glutamine, etc) as well as nonessential amino acids, which can be generated by the body from other amino acids, carbohydrates, and fats.

Conditionally essential amino acids refer to the amino acids that the body can produce sufficient amounts of under normal conditions. However, during times of extreme stress (illness, injury, intense exercise), the body cannot keep up with demand and therefore the amino acids must be obtained through food or supplements.

Hang on... I've always been told BCAAs were the only amino acids needed?

BCAAs have been shown in studies to retain lean mass and lose body fat. However, this was based on an extreme scale where 50+ grams of BCAAs was taken while protein consumption was also kept low. In other words, all this study did was note that consuming a tremendous amount of BCAAs might reduce the amount of muscle loss while dieting, but in no way is it helping you gain mass.

What about BCAAs for recovery?

It's been said that BCAAs can help reduce muscle damage and promote recovery following intense training. However once again the study backing this up the subjects are not consuming adequate amounts of protein.

Why are BCAAs so popular then?

This comes down to one amino acid - leucine.

Leucine is the real star in everything as it activates mTOR, which is the enzyme responsible for cell growth. Isoleucine enhances glucose uptake and utilisation by muscles but is a much weaker stimulator of mTOR compared to leucine. As for valine, it has its benefits (it promotes glycogen synthesis), but the real star of the BCAAs (and the reason for their popularity) is leucine.

Many supplement brands have marketed the fact that the BCAAs can activate mTOR into the belief that they are all that’s needed to create muscle growth as I explained earlier this simply isn't true. BCAA supplementation can increase nitrogen levels in your muscles, which enables you to train for longer periods without losing muscle, and they can even help sustain glycogen stores, but neither of these is directly building muscle.

The truth is that in order to build muscle, your body must have all nine essential amino acids (EAAs) NOT just the three BCAAs.

If you’re only consuming the three BCAAs all day long, you’re limiting the rate of protein synthesis (since all 9 amino acids are required to actually construct protein). The BCAAs and EAAs compete for the same receptors in the body, so if you’re constantly slamming BCAAs, you’re “bottlenecking” the uptake of the other needed EAAs and ultimately stunting muscle repair and growth.

Related article - BCAAs what they are and what they do

Remember those studies that put the subjects on a protein deficit?

Basically, hitting your protein levels every day means you’re satisfying your BCAA requirement through your diet. Supplementing over that will not bring added muscle growth. 

Does this mean BCAAs are useless?

We’ll come right out and say a definite no; the BCAAs are not useless.

Remember, protein synthesis. Your body either has enough quantity of all the essential amino acids, including the three BCAA, to sustain protein synthesis or it doesn’t. If any of the amino acids are lacking, protein synthesis grinds to a halt, which means muscle growth does too. Additionally, protein synthesis relies on the BCAA to get started, as we’ve discussed when we talked about activating mTOR.

They also serve as nitrogen donors for other amino acids, such as alanine, glutamine, and glycine, and they are frequently used as biomarkers for monitoring diseases such as insulin resistance, type 2 diabetes, cancer, and cardiovascular disease.

Secondly, unlike the vast majority of amino acids which are oxidized in your liver, the three branched-chain amino acids are oxidized directly in skeletal muscle. This important characteristic of the three BCAA brings to light two other unique benefits they can offer.

  • Energy production, thus sparing your glycogen stores for later in the workout
  • Anti-catabolic actions, preventing muscle breakdown if training fasted

A few other key points worth noting about the two “lesser” BCAA in valine and isoleucine are in regards to their ability to prolong exercise performance. More specifically, valine and the essential amino acid tryptophan compete for uptake in the brain.

So, to say that BCAAs are useless or unnecessary is ridiculous.

So why choose Essential amino acids?

A very interesting piece of research compared EAA to BCAA and observed that consuming an EAA supplement post-workout promoted a significantly stronger anabolic response than BCAA. These findings were backed up in yet another study comparing the muscle protein synthesis response of BCAA vs whey protein (which contains all of the EAAs). To save you having to read the study CSN has concluded it for you.

“Taken together, these results demonstrate that BCAAs exhibit the capacity to stimulate myofibrillar-MPS, however, a full complement of EAA could be necessary to stimulate a maximal response of myofibrillar-MPS following resistance exercise…

Our data support the notion that BCAA ingestion alone does not maximally stimulate myofibrillar-MPS following exercise despite stimulation of translation initiation pathways. The lack of sufficient EAA appears to limit the response of myofibrillar-MPS following exercise. Thus, whereas our data clearly shows that BCAA ingestion activates cell-signalling pathways that result in increased myofibrillar-MPS, ingestion of BCAAs alone may not be the optimal nutritional regimen to stimulate a maximal MPS response to resistance exercise training.”

And if you are still clinging on to the fact you need BCAAs to help you grow (even if you are in a high protein diet) the latest “nail in the coffin” for BCAAs comes from a 2017 review that concluded:

“An extensive search of the literature has revealed no studies in human subjects in which the response of muscle protein synthesis to orally-ingested BCAAs alone was quantified and only two studies in which the effect of intravenously infused BCAAs alone was assessed. Both of these intravenous infusion studies found that BCAAs decreased muscle protein synthesis as well as protein breakdown, meaning a decrease in muscle protein turnover. The catabolic state in which the rate of muscle protein breakdown exceeded the rate of muscle protein synthesis persisted during BCAA infusion. We conclude that the claim that consumption of dietary BCAAs stimulates muscle protein synthesis or produces an anabolic response in human subjects is unwarranted.”


Related article - Muscle protein synthesis explained

So here it is - CSN recommends both BCAAs and EAAs

Basically, it depends on what you are buying them for.

If you’re faced with training fasted or using BCAAs, use BCAAs. They’ll improve your anabolic response to exercise and recovery, as well as reduce fatigue, pain sensation, muscle damage, and perceived effort during training. Check out CSN's best selling BCAAs

However, if you are really focused on building as much muscle as possible and really maximizing your body’s anabolic response, a whey protein shake or EAA supplement consume pre-workout might be the superior option. Check out CSN's best selling EAAs

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