Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "
Less fat, more muscle - thanks to tryptophan supplementation?
You probably know L-tryptophan as an essential amino acid which helps you sleep better and lightens your mood. It seems that the same L-tryptophan might also improve body composition. An animal study published in Amino Acids by nutritionists from Nanchang University suggests this. We warn in advance that the Chinese publication raises significantly more questions than it answers.
During this period these rats gained a little weight than rats in a control group, which had been given no supplements.
One possible mechanism is that tryptophan induces the small intestine to absorb more amino acids, the Chinese believe. The rats' small intestine became longer as a result of supplementation [figure below]. But how extra tryptophan may speed up muscle protein synthesis is still not clear.
"We found that tryptophan supplementation affected lipid metabolism, leading to reduced fat deposition in the body of tryptophan supplemented group, compared with the control group", the researchers write. "Both acetoacetate and beta-hydroxybutyrate are products of fatty acid oxidation in liver, and the ratio of acetoacetate to hydroxybutyrate is an indicator of cytosolic and mitochondrial redox states."
"In this study, tryptophan supplementation increased the level of acetoacetate and decreased the level of beta-hydroxybutyrate in serum, thus elevated the ratio of acetoacetate to beta-hydroxybutyrate. The result suggested that tryptophan supplementation promoted the oxidation of fatty acid."
"So it would lead to a reduced availability of fatty acids for the synthesis of lipids, LDL and VLDL in the body. In support of this view, tryptophan supplementation decreased the serum concentrations of lipids, unsaturated lipids, LDL and VLDL in tryptophan supplemented group rats compared to the control group rats."