Leucine
Bio-Activity Analysis
Leucine Content per 100g Protein Source
SCIENTIFIC DATA VISUALIZATION
Health Benefits & Sources
Why You Need It
- Triggers Muscle Growth: Acts as the primary signal to turn on muscle building pathways.
- Preserves Muscle Mass: Helps prevent muscle wasting (atrophy), especially during weight loss or aging.
- Regulates Blood Sugar: Improves insulin sensitivity, helping your body manage glucose levels effectively.
- Boosts Recovery: Reduces muscle soreness and fatigue after intense physical activity.
Deep Dive
Leucine is the most anabolic (building up) of all amino acids. When you eat protein, your body breaks it down into individual amino acids. Leucine specifically interacts with a complex inside your cells called mTOR (mechanistic target of rapamycin). Think of mTOR as the ignition key for a car; Leucine is the hand that turns the key. Without sufficient Leucine, the engine (your muscles) won't grow or repair itself efficiently, regardless of how much other protein you eat. This makes it critical for maintaining a healthy body composition.
Natural Food Sources
Leucine is found in protein-rich foods. Animal products are the most concentrated sources, but plant-based options are available.
| Food | Amount | % DV (based on 2g goal) |
|---|---|---|
| Chicken Breast (3 oz) | ~2,500 mg | 125% |
| Yellowfin Tuna (3 oz) | ~2,200 mg | 110% |
| Beef (3 oz) | ~2,100 mg | 105% |
| Eggs (1 large) | ~600 mg | 30% |
| Almonds (1 oz) | ~650 mg | 32% |
Supplementation
Dosage: The scientifically supported 'leucine threshold' for maximizing muscle protein synthesis is roughly 2.5 to 3 grams per serving. Taking less than this may not trigger the mTOR pathway effectively.
Who Should Take It:
- Older Adults: To combat age-related muscle loss (sarcopenia).
- Vegetarians/Vegans: If plant-based protein sources are low in this specific amino acid.
- Athletes: During cutting phases or intense training to preserve lean mass.
Top Food Sources
Frequently Asked Questions
Safety & Side Effects
Safety Profile: Leucine is generally recognized as safe (GRAS) by the FDA when consumed within normal dietary ranges.
Side Effects: Extremely high doses (over 10-15g at once) may cause fatigue, coordinated loss (ataxia), or insulin resistance over time. It can also increase blood ammonia levels.
Who Should Avoid: Individuals with ALS (Lou Gehrig's disease), Hartnup disease, or those with kidney or liver disease should consult a doctor before supplementing. It may also lower blood sugar, so diabetics using insulin should monitor levels closely.
Scientific References
- [1]Garlick, P. J. (2006). The role of leucine in the regulation of protein metabolism.
- [2]Layman, D. K. (2003). The role of leucine in muscle mass maintenance and weight loss.
- [3]Mero, A. (1999). Leucine supplementation and intensive training.