L-Carnitine Supports Blood Sugar Balancing

According to a new study, L-carnitine supports blood sugar balancing after glucose ingestion. L-carnitine is a naturally occurring compound synthesized in the body from the amino acids lysine and methionine. L-carnitine is involved in cellular energy production by chaperoning activated fatty acids into the mitochondria where they are utilized for synthesis of ATP.

Sixteen lean and overweight adult males participated in a submaximal predictive exercise test. The males were evaluated for fasting blood sugar and a 2-hour oral glucose tolerance test in which serial blood sugars are measured after ingesting a glucose drink, at the beginning of the study and after each 2-week supplementation period. Additionally, the subjects were assessed for insulin, non-esterified fatty acids, and total glucagon-like peptide-1, which is a hormone that stimulates insulin release from the pancreas. The subjects were supplemented with a placebo of 3 grams daily of glucose for 14 days followed by 3 grams daily of L-carnitine L-tartrate for 14 days.

The results showed that the 30-minute post-prandial (after glucose ingestion) glucose levels were lower in the lean subjects after L-carnitine supplementation compared to placebo. Plasma glucose was higher in the overweight subjects at 90-minutes post-prandial with L-carnitine supplementation and placebo. Beta cells, which are the cells in the pancreas that secrete insulin, had greater function with L-carnitine supplementation in the lean subjects. There was no change in non-esterified fatty acids and total glucagon-like peptide-1 with L-carnitine supplementation.

The study authors concluded that L-carnitine supplementation supports normal blood glucose metabolism during an oral glucose tolerance test, which is not influenced by glucagon-like peptide-1. The effect that L-carnitine had on glucose metabolism is different between lean and overweight subjects, suggesting that further investigation is required.

Reference:

Galloway SD, Craig TP, Cleland SJ. Effects of oral L: -carnitine supplementation on insulin sensitivity indices in response to glucose feeding in lean and overweight/obese males. Amino Acids. 2011 Jul;41(2):507-15.