What Is Leucine?

Leucine is an amino acid that is regularly taken as a supplement. It is essential to the body, meaning that it cannot be produced and is needed to survive. Hence, leucine must be provided through food intake or supplements.

Leucine is a branched chain amino acid (BCAA). The other two BCAAs are valine and isoleucine, with leucine the most promising of the three when used as a body building supplement.

Leucine increases energy and protein (therefore, muscle) production, which is a clear indication of its use as a bodybuilding supplement .

Similarly to many other amino acids, leucine is found in many foods that are high in protein. Examples include meats (such as fish, chicken, and turkey), dairy products (such as yogurt and cheese), and soybeans. Other foods like eggs, nuts, seeds, and fruit also contain leucine, but to a lesser extent.

Leucine can be classified in:

• L-leucine is the natural version of the amino acid, is found in the proteins of the body, and is the main form used as a supplement.
• D-leucine is the mirror image of L-leucine, which is created in the laboratory and is also used as a supplement.

Health Benefits of Leucine

1) Leucine Is Used to Increase Energy Production

Leucine Increases Energy
But, Leucine Also Decreases Energy
2) Leucine Supplementation Improves Muscles

Leucine Improves Muscle Recovery
Leucine Decreases Muscle Wasting
3) Leucine Supplementation Increases the Amount of Protein
4) Leucine Supplementation May Increase Strength

5) Leucine Supplementation May Increase Longevity
6) Leucine Supplementation Reduces the Risk of Hardening of the Arteries                (Atherosclerosis)
7) Leucine Supplementation May Help with Obesity

Leucine Side Effects

1) Leucine Supplementation May Decrease Serotonin

The blood-brain barrier competes for the absorption into the brain of branch chained amino acids (BCAA) and aromatic amino acids (ArAA), which are the precursors of serotonin. This competition decreases serotonin production.

Leucine absorption into the brain is influenced by diet; carbohydrate-rich, protein-poor diets increase BCAAs and decrease ArAAs in the brain, while a carbohydrate-poor, protein-rich diet does the opposite.

2) Excessive Leucine Supplementation Leads to Brain Damage and Liver Disease

The recommended dosage of leucine for everyday people is 50 mg/kgd, but for those who want to bolster their workouts, the dosage should not go over 500 mg/kgd. Overdose can lead to increased blood ammonia levels; therefore, brain damage and liver disease.

Contraindications of Leucine Supplementation

Leucine supplementation lowers glucose levels, which can lead to unhealthy levels in people with:

• Hypoglycemia (low blood sugar)
• Diabetes, in those who take blood sugar-lowering medication