HMB (Beta Hydroxy-Beta-Methylbutyrate)
What does it do? HMB (beta hydroxy-beta-methylbutyrate) is a metabolite of the essential amino acid leucine (one of the branched-chain amino acids). As with other amino acid–related substances, HMB appears to play a role in the synthesis of protein—including the protein that builds new muscle tissue.
Animal research suggests that HMB may improve the growth of lean muscle tissue,
1 but only preliminary and limited research in humans supports the potential link between HMB and enhanced muscle building in athletes.2 One study involving twenty-eight individuals involved in a regular weight-lifting program found that supplements of 3 grams of HMB, compared to no supplements, contributed to greater gains of muscle over the seven-week-long study.3Where is it found? Small amounts of HMB are present in many foods of animal and plant origin, especially alfalfa and catfish. The amino acid leucine is metabolized into a compound called alpha-ketoisocaproate (KIC), which is then turned into HMB by the body. Dietary supplements of HMB are also available.
In what conditions might HMB be supportive?
Who is likely to be deficient? HMB is not an essential nutrient, and since the body creates HMB from leucine, any diet containing sufficient amounts of leucine (and the majority of diets do provide adequate amino acids) should lead to the satisfactory production of HMB. There is limited evidence that athletes may benefit from supplemental intake of HMB.
How much should I take? There is no need for most individuals to use HMB. For those involved in regular exercise who do choose to take this supplement, the research generally uses 3 grams of HMB per day in combination with resistive exercise, such as weight lifting.
Are there any side effects or interactions? No safety issues have been reported in the limited number of studies currently available.
References:
1. Nissen SL, Morrical D, Fuller JC. Effects of the leucine catabolite
beta-hydroxy-beta-methylbutyrate (HMB) on the growth and health of growing lambs. J
Animal Sci 1994;77:243.
2. Nissen S, Panton L, Wilhelm R, et al. Effect of beta-hydroxy-beta-methylbutyrate (HMB)
supplementation on strength and body composition of trained and untrained males undergoing
intense resistance training. FASEB J 1996;10:A287 (abstract).
3. Nissen S, Sharp R, Ray M, et al. Effect of leucine metabolite
beta-hydroxy-beta-methylbutyrate on muscle metabolism during resistive-exercise training. J
Appl Phys 1996;81:2095–104.
Copyright © 1998 Virtual Health, LLC
It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over-the-counter medication is also available. Consult your physician, nutritionally-oriented health care practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications.The information presented in HealthNotes Online is for informational purposes only.