We've all seen it: large, muscular women with the jawline of Clint Eastwood. The cause is usually steroid use. Well, apparently, rats experience a similar jaw-growing phenomenon with juice use. Nandrolone, also known as Deca-Durabolin, was given to juvenile and adult rats. All were monitored weekly. The researchers took X-rays of the rats' little heads and found that the mandible, or lower-jaw bone, grew more than in non-Deca-treated rats. And, of course, the Deca-treated rats were bigger. The moral of the story: Anabolic steroids truly are anabolic'not just in skeletal muscle but perhaps in certain bones too.
Creatine upregulates myogenic regulatory factors. Let's get one thing straight: Weight gain from creatine supplementation is not just water. If someone tells you that, run the other way faster than a booty-shake from Shakira. If you want to read some cutting-edge creatine research, check out the work of Dr. Willoughby at Texas Christian University in Fort Worth (more affectionately known as Cow Town). He found that subjects who resistance trained for 12 weeks while taking six grams of creatine per day got an increase in total body mass, fat-free mass, thigh volume, muscle strength and so on. Yawn. We know that from the umpteen other studies on creatine. But he also found that muscle CK mRNA expression (M-CK'muscle creatine kinase isozyme), as well as myogenin and myogenic regulatory factor-4 (MRF-4) mRNA and protein expression, increased significantly. His past work has shown that myofibrillar protein content increases. The author concludes, 'When combined with heavy resistance training, creatine supplementation increases M-CK mRNA expression, likely due to concomitant increases in the expression of myogenin and MRF-4. Therefore, increases in myogenin and MRF-4 mRNA and protein may play a role in increasing myosin heavy chain expression, already shown to occur with creatine supplementation.'
Ah, you're scratching your head. What does that mean? Well, creatine supplementation combined with resistance training affects a certain subset of genes that regulate how proteins are made in muscle. That means creatine not only increases muscle energy stores (vis-'-vis increasing total creatine content and improving phosphocreatine resynthesis) but also affects muscle protein at the most basic level'the gene.
Leucine, I'm home. Leucine may be the key amino acid that drives muscle protein synthesis. Acute leucine feeding has been shown to alleviate defects in postfeeding muscle protein metabolism in old rats. A group of French scientists gave adult (nine months) and old (21 months) rats a semiliquid diet that contained 18.2 grams of protein per 100 grams protein standard diet for one month. The rats had access to that food for eight hours per day. Then each group got either alanine (control) or leucine for one hour per day, with access to the regular chow mix the remaining seven hours per day. The second phase lasted 10 days. On day 10 the rats got either no food (postabsorptive) or the supplemented meal for one hour. Blood levels of leucine were twice as high after the leucine-supplemented meal than after the control meal. The researchers found that in the postabsorptive state, muscle protein synthesis was enhanced in the adult rats but not the old ones. The leucine meal restored that stimulation in old rats. According to the investigators, 'The beneficial effect of leucine supplementation on postprandial muscle protein anabolism persists for at least 10 days.'
What does that research mean? It certainly points to the critical importance of the essential amino acids. Also, it suggests that certain amino acids are more essential than others. Perhaps adding three to five grams of leucine to a postworkout drink mix or protein powder is warranted for bodybuilders and other strength and power athletes.
Taurine better than creatine? You're thinking I'm off my rocker to suggest that taurine might perform better than creatine'and you're probably right. But some work done at the University of Bari in Italy showed the remarkable effectiveness of taurine. Researchers administered taurine or creatine'10 percent of their rodent chow'to mice that had a kind of muscle disease similar to muscular dystrophy, for one to two months, to reduce the muscle degeneration. Or they administered insulin-like growth factor 1 (IGF-1) to help stimulate regeneration of the afflicted muscles. They rated the substances in this order: taurine > creatine > IGF-1 counteracted the exercise-induced weakness. We're talking diseased muscle here'and in mice no less. But it would be interesting to see if taking taurine after very strenuous exercise helps promote muscle recovery and function.
Lemon-Ade. When you look at the variety of colors in the plant world, it seems that the plant foods we eat that are rich in color'carrots, peppers, oranges and so on'contain a variety of healthful nutrients. Take the lemon. Although we associate the word lemon with a yellow, bitter-tasting fruit or a used-car rip-off, there may some hidden nutritional secrets in that yellow orb. A study done at the Miyagi Agricultural College in Japan looked at a specific flavonoid in the lemon. Past research has shown that flavonoids, health-promoting compounds found in more than 4,000 fruits and vegetables, may inhibit the growth of human cancer cells and carry a variety of other health benefits.
In the lemon there's a flavonoid called eriocitrin (eriodictyol 7-O-rutinoside for you chemistry geeks). After giving it to rats prior to exercise, researchers have seen a reduction in markers of oxidative stress in the animals. For instance, eriocitrin maintained the levels of reduced glutathione after exercise. That would indicate that eriocitrin is effective in combating the potentially harmful effects of free radicals generated by exercise, thus protecting your cells' membranes.
Perhaps eriocitrin should be added to the long list of classic antioxidants, such as vitamins C, E, lipoic acid and beta-carotene.
Gebhardt, A., and Pancherz, H. (2003). The effect of anabolic steroids on mandibular growth. Am J Orthod Dentofacial Orthop. 123:435-40.
Willoughby, D.S., and Rosene, J.M. (2003). Effects of oral creatine and resistance training on myogenic regulatory factor expression. Med Sci Sports Exerc. 35:923-29.
Rieu, I., et al. (2003). Leucine-supplemented meal feeding for 10 days beneficially affects postprandial muscle protein synthesis in old rats. J Nutr. 133:1198-205.
De Luca, A., et al. (2003). Enhanced dystrophic progression in mdx mice by exercise and beneficial effects of taurine and insulin-like growth factor-1. J Pharmacol Exp Ther. 304:453-63.
Minato, K., et al. (2003). Lemon flavonoid, eriocitrin, suppresses exercise-induced oxidative damage in rat liver. Life Science. 72:1609-16.
Editor's note: Jose Antonio, Ph.D., CSCS, earned his doctorate at the University of Texas Southwestern Medical Center. He is a co-editor (with Jeffrey R. Stout, Ph.D.) of and contributor to Sports Supplements (Lippincott Williams & Wilkins), Sports Supplement Encyclopedia (Nutricia), Supplements for Strength-Power Athletes (Human Kinetics) and Supplements for Endurance Athletes (Human Kinetics). For more information visit www.supplementbooks.com. IM