L-Leucine

L-Leucine is an essential amino acid and also categorized as a “Branched Chain” amino acid. The other branched chain amino acids are Valine and Isoleucine. These are referred to as branched chain due to the fact of their molecular arrangement is marked by branched points. Leucine is also identified by the abbreviation LEU or L and has a weight of 113.16.

Function- Leucine accounts for 8% of the total amount of amino acids of body proteins. In muscle leucine is the forth most concentrated amino acid. Number one is glutamic acid, 2nd is aspartic acid and 3rd is lysine. The concentration of valine and isoleucine are shortly after leucine. Although the structure of the branched chain amino acids (BCAAs) is similar they have different metabolic routes. The breakdown of leucine is entirely through fat pathways, valine is entirely through carbohydrate pathways and isoleucine is through both.

The branched chain amino acids (BCAAs) are the major fuel involved in anabolic reactions and produce significant energy under situations of stress. The branched chain group stimulates protein synthesis and decreases catabolism (cell breakdown). Leucine is the only amino acid that can substitute for glucose (blood sugar) under fasting conditions. There are many glucose producing amino acids, however, leucine is the most effective at maintaining proper blood sugar levels.

In disease conditions where there is muscle wasting, such as Lou Gehrig’s disease (ALS), the branched chain amino acids are especially useful. In patients with conditions such as surgery, trauma, fever, starvation and infections these amino acids are essential for aid in recovery.

Branched chain amino acids have shown to enhance muscle metabolism, decrease the breakdown of muscle from physical stress and is beneficial to oxidative metabolism during exercise. In the brain the branched chain amino acids (BCAAs) are necessary for the production of neuropeptides (chemical messengers) and neurotransmitters which are involved in pain relieving and calming effects.

Deficiency- Muscle wasting and impairment with neurotransmitters and neuropeptides are associated conditions involved with the metabolism of these. (Refer to neurotransmitter deficiency.) L-leucine should be strongly considered in blood sugar disorders and hypoglycemia.

Sources- Dietary sources include brown rice, beans, meat, nuts, soy flour, lima beans, chickpeas, pumpkin seeds and whole wheat.

Precautions- An excessively high intake of leucine may also contribute to pellagra (due to the decrease amount of nicotinamide, kynurinase and an incease activity of picolinate carboxylase), and may increase the amount of ammonia. These side effects would be avoided if a balance of amino acids and cofactors were taken. The inborn error of metabolism is ketoaciduria (Maple Urine Disease) in which keto acids are excreted. Maple syrup urine can produce convulsions, ataxia and coma in severe cases.
Requirements- There is no Recommended Dietary Allowances (RDA) listed. Individual needs may differ due to clinical conditions, biochemical individuality and absorption. All sources of nutrients should be consumed in their most natural state, in the form of a variety of foods or supplements when necessary. Free form amino acid supplements are immediately absorbed by the body and should be consumed with natural occurring cofactors for best results. Consulting with a physician that is properly trained in the natural healing sciences and amino acid therapy may be needed for optimum results.

Written by Jerome Rerucha D.C.

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