Leucine supplement fights pre-diabetes in mice; human studies next
Joslin Diabetes research suggests adding the amino acid leucine to the diet might help fight metabolic syndrome that is the precursor to diabetes.
In the study, scientists fed leucine to the mice that had been on a high fat diet, providing twice the usual amount of the amino acid that comes from protein and found in lean meats such as fish, chicken, beef and pork. Other foods containing the essential nutrient include eggs, soybean, milk, asparagus, nuts and seeds.
Dietary leucine changes metabolic pathways that lead to metabolic disease
Adding leucine to the animal’s diet reduced blood sugar levels and the amount of fat in the liver. Insulin resistance and fatty liver are both are associated with metabolic syndrome.
Lead study author, C. Ronald Kahn, M.D., Head of the Joslin Section on Integrative Physiology and Metabolism and the Mary K. Iacocca Professor of Medicine at Harvard Medical School said, “The impact on the animals on the high-fat diet, even though it didn’t change how fat they got, was that their bodies were able to handle glucose better.”
Kahn said the mice were better able to process glucose, improving insulin sensitivity and shown by improved glucose sensitivity testing.
Their bodies responded to insulin better than they would have before they got the leucine. It improved their ability to metabolize sugar and fats. It markedly improved their pre-diabetic condition. Their metabolic syndrome also improved’, said Kahn.
Mice that ate a regular diet did not show any metabolic changes from taking leucine dietary supplements.
However, Kahn notes the study did show how small changes in the food environment can lead to big changes. Leucine is often taken by body builders to boost muscle mass.
The researchers chose leucine, which is a protein building block, and one of 22 synthesized in plants and microorganisms. In the body,based on past studies showing the possible benefits for fighting metabolic disease, performed in vitro.
The amino acid is used by muscle tissues to form sterols. High doses of the amino acid are toxic and can lead to neurologic problems and delirium.
The next step is to study the amino acid in humans. For now, Kahn explains it’s too soon to say whether humans would experience the same changes in pre-diabetes and metabolic syndrome from taking a supplement of leucine.
“Dietary Leucine - An Environmental Modifier of Insulin Resistance Acting on Multiple Levels of Metabolism”
Yazmin Macotela, et al