β-alanine

Supplements are all the rave for many people in the fitness and health world – yet, many supplements tend to be unsubstantiated by solid science. One of the more popular supplements to take is β-alanine, especially in the fitness industry. In this article, we will understand what β-alanine is, what it does (if anything), appropriate dosages for healthy populations, and the physiology behind its function (or lack thereof), as well as the safety of supplementation – let us get started.

What is β-Alanine?

β-alanine (Beta-alanine) is a naturally occurring, non-proteogenic amino acid that is synthesized in the liver [1][2]. This means that although the body can synthesize it, because the liver contains the appropriate molecules and enzymes, it can only be used for metabolic intermediates (moving from one molecule to another), as well as used in the walls of certain cells, but cannot be used for protein synthesis or any process that combines molecules for structure like muscle [3]. It is of similar structure to the non-essential amino acid alanine, but a slightly different confirmation [4].

Beta-alanine chemical structure. As you can see, it holds a nitrogenous base like other amino acids.

What is its function?

β-alanine has been said to increase the ability for our muscle to continue moderate to high intensity exercise, if that exercise extends around 1-4 minutes, and/or falls within a repetition range between 8-15 [1][4]. However, further evidence suggests that any exercise that would either A) be volitionally stopped due to acute pain from acidosis (aka, “the burn”), or B) muscular failure brought on by acidosis would benefit from β-alanine supplementation [5][6]. Essentially, while power output may be unaffected, the duration of a set intensity is improved by β-alanine.

How well does it work?

You will see, roughly, a 12-13% increase in the duration at which you maintain a particular high intensity [1][6].
 

Understanding the Physiology

This is, as usual, my favorite part of each one of my articles, because this is the moment in which we should be enlightened about how our body works, specific to the subject at hand – this will be no different.

To begin, when
β-alanine is consumed, it is absorbed into the blood stream where it is finally taken in by the muscle cells [8]. There, an enzyme by the name of carnosine synthase acts on the β-alanine molecule and the proteogenic amino acid histidine, and in combination, synthesizes the dipeptide carnosine [1][9]. It is this molecule, not β-alaninee, that has a physiologically significant role in helping the muscle withstand particular intense exercise for a short time longer [1][4][6]. Carnosine is found, in high majority, in muscle tissue, which is one clue as to its function [1][9]. Carnosine acts as a hydrogen buffer during intra-muscular acidotic conditions [1][6]. What does that mean?
 

So, when we are at rest, our body uses a variety of fuel sources such as glucose and fat. However, when our body is at varying degrees of physical stress via, for example, exercise, these fuel sources need to be supplied at a far more rapid rate to meet the demand for energy by the muscular locomotion. So, as intensity increases, the body uses more glucose (glycogen, to be specific) and less fat, because glucose is readily available. However, as intensity increases to a point that oxygen supply cannot meet muscular need, glucose metabolism switches from oxygen dependent glucose metabolism to oxygen independent glucose metabolism. In doing so, the body produces hydrogen ions, which drive the pH of the muscle down [15]. Lactate is eventually used as energy using another metabolic pathway, but hydrogen sticks around in the muscle cell, and this added hydrogen (if you remember from chemistry), as mentioned, decreases the pH of the muscle cells – so, what ends up happening? The muscle cell becomes acidic, and that acidity hurts (hence the “burn”). However, beyond the fact that acidity hurts, it also reduces the ability for the muscle cell to contract, and less ability to contract means – a decrease in performance (potentially, failure).

So, how does carnosine play into this? Well, our body has defense mechanisms by which to combat the sudden intra-muscular drop in pH (increased acidity) and those defense mechanisms try and increase the pH (decreased acidity) so that the muscle cell can work properly again. Carnosine happens to be one of those defensive systems. Carnosine buffers hydrogen by taking hydrogen across the cell wall via hydrogen dependent transporters [9][10][11][14]. Then, because of the decrease in hydrogen inside the muscle, the pH stays higher longer, leading to better enzymatic activity and better overall muscle cell functionality translating into better appreciable performance. Carnosine is then hydrolyzed by the high levels of serum carnosinase enzyme [9].

Carnosine is synthesized from Beta-alanine &

Histidine once it enters the muscle, and here it helps stave off acidosis/lactic acid build up in the muscle cell.

However, carnosine may also have antioxidant functionality through a couple different mechanisms. Carnosine seems to be able to neutralize superoxide and peroxyl radicals, as well as chelate (bind to) iron molecules to prevent them creating hydroxyl radicals [5][9]. Finally, carnosine may prove useful in decreasing glycation – an enzyme independent process in which a sugar molecule sticks to an amino group rendering both molecules less physiologically useful (this is a process common in diabetics); carnosine may have an affinity for sugars that may prevent other amino groups from attaching [5][9]. However, research on this is still needed in vivo as glycation possess a majority threat in circulation, and the effectiveness of carnosine breakdown in this glycated condition would be a huge factor on the usefulness of this characteristic.

Why not supplement with carnosine directly?

That does, then, bring about the question to why not supplement with carnosine directly, since it is the functional component and
β-alanine is simply the intermediate?

You could. Simply stated, muscle carnosine levels are equally saturated by carnosine supplementation as with
β-alanine supplementation [5][13].

Interestingly, however, carnosine is not the limiting factor when it comes to its intramuscular benefit – rather, it is the availability of
β-alanine intramuscularly that limits the reaction to carnosine [1][9]. That means that endogenous (aka, within the body) production of β-alanine is not sufficient to maximize production of carnosine – this is, however, variable based on genetics and muscular development as some people do produce more than others [5]. This would suggest supplementation is likely necessary to see benefit.

Dosage?

β-alanine effective dosage is typically around 2-5g a day [4].
Carnosine, as we now know, is also effective and has been used, in study, at levels 4-6.4g a day [13]. I have not found any reputable clinical sites with carnosine recommendations, however.


Duration before effectiveness?

To begin seeing noticeable benefits, one should take
β-alanine for 3-4 weeks [1][5][13]. Likely, the same recommendation is true for carnosine.
 

Safety?

β-alanine is considered safe for healthy, adult populations [1][4]. The only side effect experienced is paraesthesia (aka, tingling), which is likely due to the fact that β-alanine may help excite nerves leading to the skin; this is not alarming considering some of the neural benefits closely tied to carnosine, as well as no evidence of it being harmful [1]. However, if the tingling does bother, the alternative is to take sustained release capsules of β-alanine or simply separating a single dose into multiple [1].

Aside from paraesthesia,
β-alanine does decrease taurine levels in cells rather substantially (due to a shared transporter into the cell), but there seems to be no physiological consequence from this occurrence [1]. Also, β-alanine has no long standing safety studies beyond one year of use, but again, the concern is low [1].

SUMMARY

There we have it. Beta-alanine does seem to help in maximizing performance at moderate to high intensity by increasing duration of activity slightly. It does this via the synthesis of carnosine in muscle, and supplementation is necessary to see results from Beta-alanine. Supplement with 2-5g a day, and after 3-4 weeks, you should see a benefit.

Writer: Nicolas Verhoeven

References

[1] Trexler, E. T., Smith-Ryan, A. E., Stout, J. R., Hoffman, J. R., Wilborn, C. D., Sale, C., … Antonio, J. (2015). International society of sports nutrition position stand: Beta-Alanine. Journal of the International Society of Sports Nutrition, 12(1). doi:10.1186/s12970-015-0090-y

[2] Beta-alanine metabolism. (n.d.). Retrieved from https://lsresearch.thomsonreuters.com/maps/804/

[3] non-proteinogenic amino acid (CHEBI:83820). (n.d.). Retrieved from http://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:83820

[4] BETA-ALANINE Supplement: Usage, Dosage, Side Effects & Benefits - Examine.com | Examine.com. (n.d.). Retrieved from https://examine.com/supplements/beta-alanine/

[5] Sale, C., Saunders, B., & Harris, R. C. (2009). Effect of beta-alanine supplementation on muscle carnosine concentrations and exercise performance. Amino Acids, 39(2), 321-333. doi:10.1007/s00726-009-0443-4

[6] Hobson, R. M., Saunders, B., Ball, G., Harris, R. C., & Sale, C. (2012). Effects of β-alanine supplementation on exercise performance: a meta-analysis. Amino Acids, 43(1), 25-37. doi:10.1007/s00726-011-1200-z

[7] Hill, C. A., Harris, R. C., Kim, H. J., Harris, B. D., Sale, C., Boobis, L. H., … Wise, J. A. (2006). Influence of β-alanine supplementation on skeletal muscle carnosine concentrations and high intensity cycling capacity. Amino Acids, 32(2), 225-233. doi:10.1007/s00726-006-0364-4

[8] Helms, E. R., Aragon, A. A., & Fitschen, P. J. (2014). Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition, 11(1), 20. doi:10.1186/1550-2783-11-20

[9] Derave, W., Everaert, I., Beeckman, S., & Baguet, A. (2010). Muscle Carnosine Metabolism and β-Alanine Supplementation in Relation to Exercise and Training. Sports Medicine, 40(3), 247-263. doi:10.2165/11530310-000000000-00000

[10] Caruso, J., Charles, J., Unruh, K., Giebel, R., Learmonth, L., & Potter, W. (2012). Ergogenic Effects of β-Alanine and Carnosine: Proposed Future Research to Quantify Their Efficacy. Nutrients, 4(12), 585-601. doi:10.3390/nu4070585

[11] Acid-Base Imbalances. (n.d.). Retrieved from http://www.mhhe.com/biosci/ap/saladin/student/olc/u-reading5.html

[12] Heisler, N. (2004). Buffering and H+ ion dynamics in muscle tissues. Respiratory Physiology & Neurobiology, 144(2-3), 161-172. doi:10.1016/j.resp.2004.06.019

[13] Harris, R. C., Tallon, M. J., Dunnett, M., Boobis, L., Coakley, J., Kim, H. J., … Wise, J. A. (2006). The absorption of orally supplied β-alanine and its effect on muscle carnosine synthesis in human vastus lateralis. Amino Acids, 30(3), 279-289. doi:10.1007/s00726-006-0299-9

[14] Culbertson, J. Y., Kreider, R. B., Greenwood, M., & Cooke, M. (2010). Effects of Beta-Alanine on Muscle Carnosine and Exercise Performance: A Review of the Current Literature. Nutrients, 2(1), 75-98. doi:10.3390/nu2010075

[15] Phypers, B., & Pierce, J. T. (2006). Lactate physiology in health and disease. Continuing Education in Anaesthesia, Critical Care & Pain, 6(3), 128-132. doi:10.1093/bjaceaccp/mkl018

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