ANSWER
D‐Glucurono‐γ‐lactone (glucuronolactone) is the γ‐lactone of glucuronic acid. It is a normal human metabolite and formed from glucose and glucuronic acid. It seems to be found naturally occurring substance produced in small amounts within the body (Ivy et al., 2009; Meyer, 2008).
Studies of Glucuronolactone benefits
Uses of Glucuronolactone as an ingredient outside of the food and beverage industry includes as a performance enhancer and recovery aid. Several studies have demonstrated that a pre-exercise, energy supplement (containing caffeine with taurine, glucuronolactone, creatine, and amino acids) can delay fatigue and improve the quality of resistance exercise. Taurine and glucuronolactone are often combined with caffeine to form an ‘energy matrix’ in many energy drinks (Gonzalez et al., 2011).
According to Gonzalez et al. (2011), a pre-workout energy supplement was given to subjects to consume 10 minutes prior to a bout of resistance exercise, consisting of 26 g of a powder containing an energy matrix (2.05 g of taurine, glucuronolactone and caffeine), a proprietary amino acid matrix (7.9 g of Lleucine, L-isoleucine, L-valine, L-arginine and L-glutamine), 5 g of di-creatine citrate, and 2.5 g of β-alanine and mixing it with 500 ml of water. The greater volume of training augmented both the growth hormone and insulin response to exercise, indicating that consumption of this pre-exercise energy supplement enhanced the anabolic response to the training session.
Another study was performed by Red Bull Energy Drink (ED; 2.0 g taurine, 1.2 g glucuronolactone, 160 mg caffeine, 54 g carbohydrate, 40 mg niacin, 10 mg pantothenic acid, 10 mg vitamin B6, and 10 μg vitamin B12) 40 minutes before a simulated cycling time trial. It was found out that consuming 500 ml of the ED 40 min before a 1-hr cycling time trial improved performance (Ivy et al., 2009).
References
Gonzalez, A. M., Walsh, A. L., Ratamess, N. A., Kang, J. & Hoffman, J. R. (2011). Effect of a pre-workout energy supplement on acute multi-joint resistance exercise. Journal of Sports Science and Medicine, 10, 261-266.
Ivy, J. L., Kammer, L., Ding, Z., Wang. B., Bernard, J. R., Liao, Y. H. & Hwang, J. (2009). Improved Cycling Time-trial Performance after ingestion of a Caffeine Energy Drink, International Journal of Sport Nutrition and Exercise Metabolism, 19(1), 61-78.
Meyer, K. (2008). The label can give (imaginary) wings: The Placebo Effect of Energy Drinks. Hamburg, Germany: Diplomica Verlag.