Study: Effect of BCAA with sufficient protein intake

Geschatte leestijd: 10 minutenIt is unclear whether BCAAs have an effect when you already consume sufficient protein. They are faster than normal protein but slower than hydrolyzed protein. Regarding BCAA quantities, it seems that you already get enough BCAAs from normal protein intake. Studies examining the added value of BCAAs to a protein shake with [protein](https://www.fitsociety.nl/proteine/) and carbohydrates after the training show different results. Two studies see no added value, where a third one does. This difference is difficult to explain, making it challenging to draw a conclusion.

BCAA Absorption Rate

In part I, we saw that BCAAs are used to a greater extent in the muscles than other [amino acids](https://www.fitsociety.nl/aminozuren/) that have multiple other tasks. Since BCAAs do not need to be processed in the liver, they are also more readily available in the bloodstream than other amino acids or longer protein chains (“oligopeptides”) that need to be broken down first. However, this is not a reason to purchase BCAAs. The fastest way to get amino acids into the blood is by using hydrolyzed protein. These are proteins to which the enzymes have already been added that normally break down the long chain of amino acids into shorter chains and individual amino acids in the body. This has already partially occurred before you ingest the proteins, saving time once in the body. Especially chains of two and three amino acids, “di- and tripeptides,” are absorbed the fastest because they are absorbed via a separate transport system.

Di and tripeptides are more efficiently absorbed than free amino acids which in turn are better absorbed than oligopeptides. P.B. Frenhani, Faculdade de Medicina da Universidade Estadual Paulista

So, the fastest way to get amino acids into the blood is with hydrolyzed protein such as casein hydrolysate from DSM, PeptoPro, or whey hydrolysate such as Optipep.

Amount of BCAA in Protein

Even the faster, hydrolyzed proteins contain all twenty amino acids, including the BCAAs. So you might wonder what the added value of BCAAs is. If the absorption rate is not a reason, then the dosage per amino acid you consume remains. Consuming BCAAs can help maintain the balance of breakdown and synthesis of protein in the muscles by providing the amino acids leucine, valine, and isoleucine specifically, instead of a distribution over all 20 amino acids. For example, looking at the popular Whey Perfection by Optipep (under the label of Bodyenfitshop), we see the following amino acid profile [source: Bodyenfitshop]: **Amino acid profile per 100 grams of protein:** – Alanine 4788 mg – Arginine 2260 mg – Aspartic acid 10625 mg – Cysteine 2094 mg – Glutamine 16831 mg – Glycine 3025 mg – Histidine 1799 mg – Isoleucine* 5985 mg – Leucine* 10667 mg – Lysine* 8468 mg – Methionine* 2631 mg – Phenylalanine* 2782 mg – Proline 6732 mg – Serine 5194 mg – Threonine* 6958 mg – Tryptophan* 1068 mg – Tyrosine 3092 mg – Valine* 5003 mg Suppose you take a 30-gram shake after training. That would yield: – 3.2 grams of Leucine – 1.5 grams of Valine – Almost 1.8 grams of Isoleucine Manufacturers often recommend a dosage of 5 grams of BCAAs divided among the three different BCAAs, often in different ratios. The more favorable ratios are in favor of Leucine, the most anabolic of the three (see part III). A common ratio is 2-1-1 in favor of Leucine. So that’s 2.5 grams of leucine and 1.25 grams of valine and isoleucine, less than what you would get from your usual 30-gram whey scoop. Whey hydrolysate also contains higher amounts of BCAAs. Then two reasons may remain for wanting BCAAs alongside protein: 1. **Timing**: You want to consume BCAAs at a different time than the full protein. This might still make sense if you’re using regular whey or even slower protein and therefore don’t find them suitable for or during training (because of stomach discomfort and the energy it costs). However, if you’re using hydrolyzed protein, you can use it before or during training. 2. **BCAA quantity in protein is not sufficient and needs to be supplemented**: Maybe you don’t find those amounts of BCAAs in normal protein enough and want more. Then you should only wonder why manufacturers recommend dosages of 5 grams if this would not suffice. They only benefit from you using more and buying a new pot faster. The reason for the current dosages is that similar amounts were used in studies that have established a positive effect.

Added Value of BCAAs to Full Protein after Training?

According to some studies, adding the most important of the BCAAs, leucine, does not add anything to whey after training.

Our results indicate that the whey protein plus leucine in healthy young volunteers results in an anabolic response in muscle that is not greater than the previously reported response to whey protein alone. K.D. Tipton, University of Texas

Researchers from Maastricht University came to the same conclusion in 2008:

Co-ingestion of leucine with carbohydrate and protein following physical activity does not further elevate muscle protein fractional synthetic rate in elderly men when ample protein is ingested. R. Koopman, Maastricht University

Unexplained Difference in Maastricht University Studies?

The last sentence is important: “When ample protein is ingested.” However, the same researchers from Maastricht saw the added value of BCAAs three years earlier:

In the CHO (carbohydrate) + PRO (protein) + Leu (leucine) trial, whole-body net protein balance was significantly greater compared with values observed in the CHO + PRO and CHO trials. R. Koopman, Maastricht University

This difference is unexplainable to me, although I have read both studies multiple times to find differences in the circumstances. Initially, I thought that in 2008, apparently more protein was ingested after training (“when ample protein is ingested”). In the 2008 study report, the researchers indeed explain this with the text:

However, the surplus value of additional leucine ingestion under normal living conditions, in which physical activity is followed by ample food intake, has not been assessed. Therefore, in the present study, we investigated the effect of carbohydrate (0·49 g/kg per h) and protein ( 0·24 g/kg per h) co-ingestion with or without additional leucine (0·058 g/kg per h) intake on whole-body protein balance after resistance exercise in elderly men during post-exercise recovery conditions when ample protein intake was ingested. R. Koopman, Maastricht University

In 2008, they used lower amounts of protein. However, the amounts mentioned are not lower than those used in the 2005 study (about 22 grams per hour for the protein trial and 25 grams per hour for the leucine trial). It’s a mystery to me.

Conclusion

In conclusion, if you consume enough protein, there doesn’t seem to be a significant added benefit to taking BCAAs, especially when using hydrolyzed proteins like whey hydrolysate or casein hydrolysate. The timing of BCAA consumption might play a role, but if you’re using hydrolyzed protein, this can be taken care of as well. Additionally, the evidence regarding the added value of BCAAs to a protein shake after training is inconclusive, with some studies showing no additional benefit while others do.

• Alanine 4788 mg
• Arginine 2260 mg
• Aspartic acid 10625 mg
• Cysteine 2094 mg
• Glutamine 16831 mg
• Glycine 3025 mg
• Histidine 1799 mg
• Isoleucine* 5985 mg
• Leucine* 10667 mg
• Lysine* 8468 mg
• Methionine* 2631
• Phenylalanine* 2782 mg
• Proline 6732 mg
• Serine 5194 mg
• Threonine* 6958 mg
• Tryptophan* 1068 mg
• Tyrosine 3092 mg
• Valine* 5003 mg

If you take a 30-gram shake after training, it will yield:

• 3.2 grams of Leucine
• 1.5 grams of Valine
• Almost 1.8 grams of Isoleucine

The recommended dosage of BCAAs by manufacturers is often 5 grams divided among the three different BCAAs, often in different ratios. The more favorable ratios are in favor of Leucine, the most anabolic of the three (see part III). A common ratio is therefore 2-1-1 in favor of Leucine. That’s 2.5 grams of leucine and 1.25 grams of valine and isoleucine. Less than what you would get from your usual 30-gram whey scoop. Whey hydrolysate also contains higher amounts of BCAAs. Then two reasons may remain for wanting BCAAs alongside protein:

1. Timing: You want to consume the BCAAs at a different time than the full protein. This might still make sense if you’re using regular whey or even slower protein and therefore don’t find them suitable for or during training (because of stomach discomfort and the energy it costs). However, if you’re using hydrolyzed protein, you can use it before or during training.
2. BCAA quantity in protein is not sufficient and needs to be supplemented: Maybe you don’t find those amounts of BCAAs in normal protein enough and want more. Then you should only wonder why manufacturers recommend dosages of 5 grams if this would not suffice. They only benefit from you using more and buying a new pot faster. The reason for the current dosages is that similar amounts were used in studies that have established a positive effect.

Added Value of BCAAs to Full Protein after Training?

According to some studies, adding the most important of the BCAAs, leucine, does not add anything to, for example, whey after training.

Our results indicate that the whey protein plus leucine in healthy young volunteers results in an anabolic response in muscle that is not greater than the previously reported response to whey protein alone. K.D. Tipton, University of Texas

Researchers from Maastricht University came to the same conclusion in 2008:

Co-ingestion of leucine with carbohydrate and protein following physical activity does not further elevate muscle protein fractional synthetic rate in elderly men when ample protein is ingested. R. Koopman, Maastricht University

Unexplained Difference in Maastricht University Studies?

The last sentence is important: “When ample protein is ingested.” The same researchers from Maastricht saw the added value of BCAAs three years earlier:

In the CHO (carbohydrate) + PRO (protein) + Leu (leucine) trial, whole-body net protein balance was significantly greater compared with values observed in the CHO + PRO and CHO trials. R. Koopman, Maastricht University

This difference is unexplainable to me, although I have read both studies multiple times to find differences in the circumstances. Initially, I thought that in 2008, apparently more protein was ingested after training (“when ample protein is ingested”). In the 2008 study report, the researchers indeed explain this with the text:

However, the surplus value of additional leucine ingestion under normal living conditions, in which physical activity is followed by ample food intake, has not been assessed. Therefore, in the present study, we investigated the effect of carbohydrate (0·49 g/kg per h) and protein (0·16 g/kg per h) ingestion with or without additional free leucine (0·03 g/kg per h) on muscle protein synthesis rates following physical activity in lean, elderly men (approximately 75 years old).

In other words, there simply wasn’t enough eating after training in 2005 for leucine to have an effect. However, in 2005, more was eaten after training than in 2008. In 2008, it was 0.16 grams per kilogram of body weight after training. So, nearly 13 grams for someone weighing 80 kg. In the 2005 study, however, this was 0.2 grams per kilogram of body weight. The difference is also not explained by the fact that one study involved young men and the other involved old men. In a 2006 study by the same researchers, this didn’t make a difference [8]. I recently asked the principal investigator for clarification on this matter and will incorporate any response into an update. Shortly after publication, I received a response from the researcher who now works for the University of Melbourne:

The big difference between the studies lies in the fact that the amount of leucine in the beverages, about 42 g in 6 hours in the 2005 paper and 14 g in the 2008 paper. I must also say that in the 2005 paper, the differences between CHO+PRO and CHO+PRO+Leu in FSR (protein synthesis) were not significant, so both studies actually show the same thing… additional leucine intake does not further increase protein synthesis when ample amount of protein is ingested. R. Koopman, University of Melbourne

In both cases (the 2005 and 2008 studies), there is no added value when sufficient protein is ingested. Moreover, the amounts of protein after training are still less than the minimum 20 to 30 grams that most people will take after their training, although it came close in 2005 (16 grams for someone weighing 80 kg). Furthermore, it was not investigated what happens if a good meal is eaten beforehand to increase glucose in the blood and reduce the need for breakdown. In both studies, training was done on an empty stomach after overnight fasting. Normally, you would only do this if you were “cutting” (see part III). Again, other articles on websites have also discussed the benefits of BCAAs, but almost never compared them to just taking sufficient whole protein. If you ask whether BCAAs help reduce muscle breakdown before, during, or after training, for example, the answer is ‘yes’. But that’s compared to nothing or taking a placebo. Like the study from Canada, which found that BCAAs reduce muscle fatigue and breakdown [9].

Furthermore, the increased intramuscular and arterial BCAA levels before and during exercise result in a suppression of endogenous muscle protein breakdown during exercise. D.A. McClean, University of Guelph

In this case, it involved five “healthy” young men, and it’s unknown if they were trained. More importantly, they also trained after overnight fasting. So, this is not a representative setup. If you train in the morning without eating, your body hasn’t received nutrients for 8 hours or more. The stress hormone cortisol is elevated upon waking up as a signal to eat, but as long as that food doesn’t come in, it causes additional breakdown of fats and protein in the muscles. Then, you train, which costs even more energy and further increases cortisol, and then you see if BCAAs limit this breakdown compared to… nothing. So, if you’re someone who habitually does strength training in the morning without eating anything, BCAAs will indeed reduce muscle breakdown. However, this is not recommended unless you are consciously trying to lower body fat. Even then, you may wonder if BCAAs are useful, but more on that in part III. In a Finnish study, men involved in athletics were given 50 mg of leucine per kilogram of body weight [10]. So, about 4 grams for someone weighing 80 kg. It is known from this study that the participants consumed 1.26 grams of protein per kilogram of body weight per day. This is, as Ronnie Coleman would say, “Nuthin’ but a peanut” for someone seriously trying to build muscle mass. Although opinions on this matter continue to change, it has been known in the bodybuilding community for more than half a century that you want to consume 2-3 grams of protein per kilogram of body weight per day. Almost two to three times as much. Moreover, this is spread throughout the day without any special intake around training as would normally be advised. So, it’s not surprising in the Finnish study that leucine led to less muscle breakdown than the placebo. If you are already well provided for in your basic diet and supplements throughout the day and also ensure the right amount and type of sugars and protein around your workout, you may wonder what BCAAs still add to this.

Added value of BCAAs during cutting

In the third and final part of this series, I will discuss the properties of the different BCAAs: leucine, valine, and isoleucine. Do you need them all in the same amount and why (not)? Additionally, I will address the value of BCAAs when trying to reduce body fat while attempting to retain as much muscle mass as possible (“cutting”).

References

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