Leucine is a branch-chained amino acid, and the fourth most concentrated amino acid found in the musculoskeletal system. Each branch chained amino acid (leucine, isoleucine and valine) is a vital key to the effectiveness of the others. Leucine is known for enhancing endurance and increasing energy.
It also aids in the breakdown of proteins and is absorbed during exercise when energy is needed most. This amino acid is most effective in preventing muscle catabolism and muscle shrinking. During intense work outs leucine is quickly broken down and converted into glucose. This provides readily available energy and stops muscle breakdown.
Leucine has an effect on brain network connectivity and may influence areas responsible for cognitive and metabolic processing. It also acts as a metabolic precursor for fuel molecules, regulating neurotransmitter production, and influencing enzyme activity related to brain energy metabolism
Leucine is known as an essential amino acid, which means it cannot be produced by the body.
Deficiency of leucine
A lack of this amino acid can prevent the body from utilising protein efficiently as it is consumed. Deficiency may be caused by maple syrup urine disease (MSUD) which is the inability to metabolise leucine, isoleucine and valine. The disease is so named because urine from affected people smells like maple syrup.
Symptoms of leucine deficiency
- Dizziness
- Fatigue
- Headache
- Irritability
Highest sources of leucine in milligrams per 100 grams
- Spirulina (dried) 4947 mg
- Chlorella (dried) 4700 mg
- Whelks 3807 mg
- Pumpkin and squash seeds 2793 mg
- Calf’s liver 2507 mg
- Lamb’s liver 2497 mg
- Cheddar cheese 2385 mg
- Chicken 2328 mg
- Beef (lean mince) 2074 mg
- Tuna (tinned) 2073 mg
- Pheasant 2063 mg
- Caviar (fish roe) 1956 mg
- Quail 1938 mg
- Mackerel (tinned)1885 mg
- Cod 1865 mg
- Peanuts 1812 mg
- Salmon (Atlantic farmed) 1796 mg
- Black beans 1725 mg
- Rabbit 1698 mg
- Crayfish (farmed) and mussels 1676 mg
- Shrimp/prawns and sunflower seeds 1659 mg
- Venison 1645 mg
- Lobster 1627 mg
- Almonds 1488 mg
- Crab 1452 mg
- Turkey 1360 mg
- Sesame seeds 1358 mg
- Soya beans 1355 mg
- Lamb 1279 mg
- Flaxseeds 1235 mg
- Walnuts 1170 mg
- Brazil nuts 1155 mg
- Squid 1096 mg
- Eggs 1088 mg
- Pine nuts 991 mg
- Rye 980 mg
- Wheat 926 mg
- Quinoa 840 mg
- Brown rice 657 mg
NOTE: For daily requirements of leucine see>> Protein
NOTE: The intake of leucine must be balanced with foods containing the amino acids isoleucine and valine.
Related subjects
- A-Z of nutrients
- Mental health disorders
- Sports nutrition
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