Taurine supplementation improves the body’s insulin and glucose metabolism, physiologists from the State University of Campinas report in the Journal of Nutritional Biochemistry. In mice, taurine boosts the secretion of insulin and boosts the sensitivity of the insulin receptor in muscles. Taurine may be even more interesting for athletes than we already thought.
Taurine supplementation improves the body’s insulin and glucose metabolism, physiologists from the State University of Campinas report in the Journal of Nutritional Biochemistry. In mice, taurine boosts the secretion of insulin and boosts the sensitivity of the insulin receptor in muscles. Taurine may be even more interesting for athletes than we already thought.
At first sight it looks as though the Brazilian study is only of interest as a piece of fundamental research. The researchers gave their lab animals taurine in their food in such large quantities that the human equivalent would be an irresponsibly high amount: 20-22 g taurine per day. But the researchers also did experiments in which they examined the effects of much lower doses of taurine on the insulin metabolism.
The figure below shows the effect of intravenous administration of glucose on glucose levels. Black circles/squares: mice given exorbitant quantities of taurine in their food. White circles/squares: mice given feed containing no taurine.
In the figure on the left the mice were given a single intravenous dose of glucose; in the figure on the right the mice were given a single intravenous dose of taurine and glucose.
Mice that were given taurine in their food were better able to deal with glucose than the mice that were not given taurine. What worked even better was simultaneous administration of glucose and taurine.
The amount of taurine that the researchers administered together with the glucose was not so high. If you convert the amount for an adult man weighing 80 kg you’d get 1.6 g. The oral equivalent would not be more than twice this amount.
In a similar experiment the researchers examined the effect of taurine on the functioning of the insulin receptor. The researchers gave the mice insulin, taurine or a saline solution [Sal], and then monitored the activity of the insulin receptor. Below left: the effect on the insulin receptor in the muscles. Below right: the effect on the receptor in the liver.
The taurine dose was about the same as in the previously described experiment.
Taurine may well be an interesting substance for athletes wanting to pump more glucose into their muscles during training or competitions. Endurance athletes may perform better in this way and recover faster.
One problem is the timing. Taken orally, taurine is an extremely ‘slow’ nutrient in humans. If you take taurine it can take up to two hours for the compound to enter the bloodstream.
Taurine supplementation modulates glucose homeostasis and islet function.
Carneiro EM, Latorraca MQ, Araujo E, Beltrá M, Oliveras MJ, Navarro M, Berná G, Bedoya FJ, Velloso LA, Soria B, Martín F.
Abstract
Taurine is a conditionally essential amino acid for human that is involved in the control of glucose homeostasis; however, the mechanisms by which the amino acid affects blood glucose levels are unknown. Using an animal model, we have studied these mechanisms. Mice were supplemented with taurine for 30 d. Blood glucose homeostasis was assessed by intraperitoneal glucose tolerance tests (IPGTT). Islet cell function was determined by insulin secretion, cytosolic Ca2+ measurements and glucose metabolism from isolated islets. Islet cell gene expression and translocation was examined via immunohistochemistry and quantitative real-time polymerase chain reaction. Insulin signaling was studied by Western blot. Islets from taurine-supplemented mice had: (i) significantly higher insulin content, (ii) increased insulin secretion at stimulatory glucose concentrations, (iii) significantly displaced the dose-response curve for glucose-induced insulin release to the left, (iv) increased glucose metabolism at 5.6 and 11.1-mmol/L concentrations; (v) slowed cytosolic Ca2+ concentration ([Ca2+]i) oscillations in response to stimulatory glucose concentrations; (vi) increased insulin, sulfonylurea receptor-1, glucokinase, Glut-2, proconvertase and pancreas duodenum homeobox-1 (PDX-1) gene expression and (vii) increased PDX-1 expression in the nucleus. Moreover, taurine supplementation significantly increased both basal and insulin stimulated tyrosine phosphorylation of the insulin receptor in skeletal muscle and liver tissues. Finally, taurine supplemented mice showed an improved IPGTT. These results indicate that taurine controls glucose homeostasis by regulating the expression of genes required for glucose-stimulated insulin secretion. In addition, taurine enhances peripheral insulin sensitivity.
PMID: 18708284 [PubMed – indexed for MEDLINE]
