The Durk Pearson & Sandy Shaw®
Life Extension NewsTM
Volume 11 No.
3 • May 2008
Astaxanthin Promotes Fat Metabolism,
Rather Than Glucose Metabolism,
During Exercise Improving Endurance
Astaxanthin is a carotenoid (not used to create vitamin A in the human body) found in algae, fish, and birds. A new paper reports on the beneficial effects of astaxanthin on exercise performance.
As the authors explain, when exercise depends upon glucose as its fuel, the intramuscular pH decreases due to the production of lactic acid, which may impair muscular contractions. On the other hand, utilizing fats as fuel for exercise works well, because it can be continuously and efficiently obtained via aerobic metabolism. The authors propose that fat burning during exercise not only reduces muscle fat content but also improves endurance. The authors had shown, in an earlier work, that astaxanthin “accumulates in muscle tissue, as well as liver and kidney, after oral administration, and dietary astaxanthin attenuates muscle damage and inhibits peroxidation of DNA and lipids due to prolonged exercise.”
In their new study, the researchers examined the effects of astaxanthin on lipid metabolism in exercising mice. They also looked at the protective effect of astaxanthin on oxidative damage to carnitine palmitoyl transferase 1 (CPT 1), an enzyme located in the mitochondrial membrane that plays an important role in the importation of fatty acids for metabolism in the mitochondria.
The mice were divided into four groups: a resting control group, a resting control group receiving astaxanthin (0.02% by weight), a running training group, and a running training group treated with astaxanthin. After 4 weeks, they were tested. The authors found that fat utilization was significantly higher in the astaxanthin-supplemented group compared with the normal-diet group. At the same time, carbohydrate utilization was significantly lower. The increase in lactic acid by exercise and the use of glycogen were reduced by astaxanthin. Oxidative modification of CPT 1 by one of the lipid peroxides was increased by exercise, but the increase was reduced by astaxanthin. Moreover, the running time to exhaustion for the running trained mice was increased with astaxanthin.
The authors propose that the specific lipolytic effect caused by astaxanthin—facilitating utilization of lipids in muscle rather than promoting release from fat stores—“may be unique in astaxanthin not obtained in other antioxidants. In fact, vitamins C and E failed to increase aerobic performance.” They suggest that astaxanthin’s high antioxidant activity and its intracellular location may be responsible, at least in part, for this.
- Aoi et al. Astaxanthin improves muscle lipid metabolism in exercise via inhibitory effective of oxidative CPT 1 modification. Biochem Biophys Res Commun 366:892-7 (2008).