From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history

Leucine or L-leucine is a pyruvate family amino acid and a essential amino acids for humans.[1] Leucine is also available as a natural supplement, and in branched chain amino acid (BCAA) supplements.[2]

Purpose[edit | edit source]

Leucine is an important amino acid for protein synthesis, and for energy metabolism. Leucine also helps regulate blood sugar, grow and repair muscle and bone tissue, produces growth hormone, and supports wound healing.[3]

Leucine has a role as a plant metabolite, an E. coli (bacteria) metabolite, a human metabolite and others.[1]

Leucine is concentrated in muscle tissues in humans, and like other BCAAs (isoleucine and valine) it is mostly oxidized in skeletal muscles rather than the liver.[2][3]

Leucine, once catalyzed, contributes to ATP production, which is vital when moving from rest to exercise.[2]

Sources[edit | edit source]

Leucine is available in many different foods, so leucine deficiency is very rare. Good dietary sources of leucine include:

  • Salmon
  • Tuna
  • Brown rice
  • Corn
  • Eggs
  • Beans including garbanzo (chickpeas) and soy beans
  • Nuts, including pine nuts, almonds, brazil nuts, and pistachios
  • Unsweetened cocoa powder
  • Beef[4][5]

Evidence[edit | edit source]

Leucine helps prevents breakdown of muscle proteins after physical injury or severe stress, and it has been investigated for metabolic support.[3][2]

Leucine has been used to treat sarcopenia, which is the loss of lean skeletal muscle mass, in the elderly.[5]

ME/CFS[edit | edit source]

Costs and availability[edit | edit source]

Available over the counter as a dietary supplement.

Branch-Chain Amino Acids[edit | edit source]

Leucine is branched chain amino acid (BCAA) and found in BCAA supplements, along with isoleucine and valine.[2]

AXA1125[edit | edit source]

Leucine is one of a number of amino acids in AXA1125, which is undergoing clinical trials for a number of uses.

Risks and safety[edit | edit source]

See also[edit | edit source]

Learn more[edit | edit source]

References[edit | edit source]

  1. 1.0 1.1 PubChem. "Leucine". PubChem. Retrieved October 31, 2021.
  2. 2.0 2.1 2.2 2.3 2.4 van der Poll, MCG; Luiking, YC; Dejong, CHC; Soeters, PB (September 2, 2009). "Amino Acids". In Caballero, Benjamin (ed.). Guide to Nutritional Supplements. Oxford, UK: Academic Press. pp. 7–8. ISBN 978-0-12-375661-9.
  3. 3.0 3.1 3.2 "Leucine | NCI Thesaurus". National Cancer Institute. Retrieved November 1, 2021.
  4. "Top Foods High in Leucine". WebMD. Retrieved November 1, 2021.
  5. 5.0 5.1 Rondanelli, Mariangela; Nichetti, Mara; Peroni, Gabriella; Faliva, Milena Anna; Naso, Maurizio; Gasparri, Clara; Perna, Simone; Oberto, Letizia; Di Paolo, Enrica (2021). "Where to Find Leucine in Food and How to Feed Elderly With Sarcopenia in Order to Counteract Loss of Muscle Mass: Practical Advice". Frontiers in Nutrition. 7: 383. doi:10.3389/fnut.2020.622391. ISSN 2296-861X.