Liquid Leucine May be Better Than Dietary Sources for Increasing Blood Concentration Levels
Leucine is an amino acid that is essential for building muscle. A recent study suggests that blood concentration levels of leucine may be higher when it’s taken in a liquid supplement than when it comes from a meal, even if the amount of leucine is the same.
Participants in the study included 10 healthy Japanese men with an average age of 25 who followed four interventions, with a one-week washout period between each intervention:
- 2 grams of leucine with 200 grams of water;
- a mixed meal with 2.15 grams of leucine;
- 2 grams of leucine immediately following a meal;
- 2 grams of leucine 180 minutes after a meal.
All of the meals on testing days were Japanese-style, including egg, fish, and milk for protein, as well as rice and vegetables. The researchers drew blood on testing days to analyze changes in plasma concentrations of leucine.
At the conclusion of the study, the researchers found that the maximum levels of leucine in the blood were lower when the participants ingested leucine immediately after their meal (205 µM), even when they’d ingested double the amount of leucine. They also noted that plasma concentrations of leucine were highest when it was taken as a liquid supplement 180 minutes after a meal (481 µM).
Researchers from Ritsumeikan University in Japan led the study. It was published on October 18, 2018, in Nutrients.
Leucine is an essential amino acid that stimulates skeletal muscle protein synthesis, which begins the muscle building process. Foods rich in leucine include soybeans, lentils, beef, peanuts, salmon, eggs and milk.