what you need to know about isoleucine(L-isoleucine)

Isoleucine is one of the nine essential amino acids(EAAs) which means we cannot synthesize it and require dietary sources. Isoleucine is non-polar and aliphatic and have a four-carbon side chain emerging from the basic amino acid structure.

Isoleucine benefits

It may help how hemoglobin is created. This is the oxygen-carrying pigment inside of red blood cells. It might even help control blood sugar but Isoleucine does not promote glycogen synthesis. It might also boost energy and endurance. It’s also believed to help speed healing of injured muscles. Isoleucine is also believed to encourage muscle development and lean mass. Isoleucine also has a role in the detoxification of nitrogenous waste like ammonia, which is then excreted from the body by the kidneys. isoleucine induces muscle protein synthesis (more than valine, but much less than leucine). It is closely associated with the release of gluconeogenic precursors, such as alanine, from muscle.

The reason we are not confident in these claims is because there is not sufficient research behind isoleucine since most of the research is on BCAAs which is the combination of three important amino acids(leucine, isoleucine and valine).

Isoleucine supplementation

isoleucine from food products is bioactive, so doses of isoleucine supplements taken with meals can be lowered if your food is already high in isoleucine sources. Based on a research published by NIH in june 1999, There are now suggestions that the current recommended dietary intake(RDA) of leucine need to raise from 14 mg per kg bodyweight in a day to a minimum of 45 mg per kg bodyweight in a day for sedentary individuals, and more for strength and endurance athletes in order to promote whole body protein synthesis.

Consumption of BCAA (30 to 35% leucine) before or during endurance exercise may prevent or decrease the net rate of protein degradation, may improve both mental and physical performance and may have a sparing effect on muscle glycogen degradation and depletion of muscle glycogen stores. However, leucine supplementation (200 mg per kg bodyweight) 50 minutes before anaerobic running exercise had no effect on performance. During 5 weeks of strength and speed training, leucine supplementation of 50 mg per kg bodyweight in a day, supplementary to a daily protein intake of 1.26 g per kg bodyweight in a day, appeared to prevent the decrease in the serum leucine levels in power-trained athletes.

Natural sources of isoleucine

RDI(recommended daily intake)

Beef (Isoleucine per 100g is 1580mg or 113% RDI), poultry (Isoleucine per 100g is 1573mg or 112% RDI), pork (Isoleucine per 100g is 1468mg or 105% RDI), tuna(Isoleucine per 100g is 1378mg or 98% RDI), milk(Isoleucine
per 100m is 174mg or 12% RDI), lentils(Isoleucine per 100g is 390mg or 28% RDI), nuts and seeds(Isoleucine per 100g is 1265mg or 90% RDI)