Ginseng: Another scientific study gives the thumbs down.
Meanwhile, the news about another popular supplement - ginseng - is not nearly as positive. Preparations of ginseng, which are supposed to be formulated using the roots of a plant called Panax ginseng, have been used in China for thousands of years in the treatment of a variety of different ailments. Many herbalists and Chinese doctors believe that ginseng provides individuals with resistance to a variety of different stressors, including physical and mental challenges.
Although ginseng contains some chemicals which probably have an impact on human physiology (most notably the 'ginsenosides,' which are known chemically as glycosylated steroids - steroids with ring-like sugar structures attached), the exact mechanism by which ginseng might influence human performance is unknown. One popular idea is that ginseng increases the production of cortisol, a key 'anti-stress' hormone released by the adrenal glands. Another theory is that ginseng might enhance the ability of muscles to extract oxygen from the blood.
However, research examining the effects of ginseng on physical capacity has produced very conflicting results. As Mel Williams points out in his fine new book, The Ergogenics Edge (published by Human Kinetics Publishers), many of the pro-ginseng studies were carried out in the 1960s and 1970s - and were pretty deeply flawed. Sometimes the findings were not even subjected to statistical analysis, and often there was no control or placebo group and no double-blind protocol (researchers frequently knew which subjects were getting ginseng, and the subjects themselves occasionally knew, too, raising the possibility that a 'placebo effect' boosted their performances). More recent, properly performed ginseng research has unearthed few benefits associated with use of the herb.
To find out whether ginseng really has any ergogenic effects, scientists at Wayne State University in Detroit recently divided 36 healthy men into three different groups. Placebo-group members received no ginseng during the eight-week study. Men in a second group ingested 200 mg of a standardized Panax ginseng preparation per day (in which 100 mg of the preparation was equivalent to 500 mg of Panax ginseng root), and a third group's members took in a very high dose - 400 mg of ginseng daily (the clinically recommended amount is 200 mg per day). Before and after the eight-week period, the subjects were assessed for oxygen consumption, respiratory exchange ratio, ventilation, blood-lactate concentration, heart rate, and perceived exertion during both submaximal and maximal exercise on a stationary bicycle. The study was carried out in double-blind manner ('No Ergogenic Effects of Ginseng (Panax ginseng C. A. Meyer) during Graded Maximal Aerobic Exercise,' Journal of the American Dietetic Association, vol. 97, pp. 1110-1115, 1997).
Well, the research showed that ginseng did absolutely nowt. There was no effect on oxygen consumption, lactate production, perceived effort, or anything else, and it mattered not whether the exercise was maximal or submaximal. Ginseng simply did not boost physical capacity, nor did it make exercise feel easier (some scientists have speculated that ginseng's main effect is actually on the nervous system). This same Wayne State research group has also shown that ginseng does not increase the work capacities of healthy young women (see 'Failure of Chronic Ginseng Supplementation to Affect Work Performance and Energy Metabolism in Healthy Adult Females,' Nutritional Research, vol. 16, pp. 1295-1305, 1996).
The subjects in the Wayne State study were not well-trained, and some ginseng proponents have argued that ginseng's true benefits become apparent only in highly fit people. However, surely the millions of Chinese who have taken ginseng for their ailments over the past two millenia were not all world-class athletes, and in fact the scientific evidence suggests that - if anything - ginseng might work better in persons who are not very fit ('Effects of a Standardized Ginseng Extract Combined with Dimethylaminoethanol Bitartrate, Vitamins, Minerals, and Trace Elements on Physical Performance during Exercise,' Clinical Therapeutics, vol. 13, pp. 373-382, 1991).
Can ginseng help you recover better from tough workouts - or improve your performances? Well, ginseng has been around for thousands of years, so it must be able to do something. And it's important to bear in mind that most of the scientific probes which have attempted to 'root out' ginseng's true actions have lasted only eight to 12 weeks, perhaps not long enough for ginseng's actual merits to emerge. Still, there is very little solid evidence to suggest that ginseng could enhance athletic performance by even a millisecond.
Unfortunately, there is also a darker side to ginseng supplementation. In the Wayne State work, three of the subjects in the high-dose (400 mg per day) ginseng group developed nasty bouts of diarrhoea, and other reports have linked ginseng with high blood pressure, nervousness, and sleeplessness, encouraging the idea that ginseng may indeed have a stimulant effect.
However, ginseng itself may not always be the culprit underlying these disorders, since investigators have determined that some 'ginseng' products contain no ginseng at all! In 1994, Swedish researchers determined that six of the popular 'ginseng' products sold in the United States, Great Britain, and Sweden contained no measurable amounts of ginseng ('What Do Commercial Ginseng Preparations Contain?' The Lancet, vol. 344, p. 134, 1994).
Beware of ephedrine
If not ginseng, what is actually in some of these 'ginseng' formulations? The researchers found unidentifiable herbal material and - in one case - ephedrine, a powerful (and very dangerous) drug. The inclusion of ephedrine in a product is a very cynical move by a supplement maker, since the ephedrine will tend to make the product more popular - while increasing the health risk for the user. Ephedrine is a potent stimulant and a proven 'fat-burner,' but it may also increase the risk of heart attacks, seizures, and episodes of psychosis!
The perils of 'ginseng' ingestion hit home for a young Swedish athlete in 1993 when he tested positive for ephedrine, which is banned by both the IOC and IAAF. During the investigation which followed, the Swede revealed that he had been using a 'ginseng' preparation called 'Up Your Gas'. Subsequent analysis of 'Up Your Gas' at Huddinge Hospital in Stockholm revealed that the product contained no ginseng at all - but did contain a great deal of ephedrine.
To put it bluntly, there are commercial 'ginseng' preparations which probably don't contain ginsenosides - but may contain stuff which will get you banned from competition if you're a competitive athlete - and possibly damage your health. If you do decide to plunge into ginseng supplementation, make certain that you use a product which has been independently analyzed for its purity and ginseng content.
Of course, the same is true for other supplements. Take the case of melatonin, for example. Melatonin has been hugely popular for the past two years as a 'remedy' for day-time drowsiness, insomnia, depression, and jet lag. In effect, large numbers of people are self-medicating themselves with the stuff in hopes of improving their well-being. No matter that melatonin is actually a fairly potent hormone produced by the pineal gland in the brain: it is marketed as though it is a harmless dietary supplement - a sort of 'magic dust' which can improve health without producing any major problems. Unfortunately, a recent laboratory analysis revealed that four out of six different melatonin products found at health food shops contained unidentifiable impurities ('Melatonin,' The Medical Letter, vol. 37, p. 111, 1995). In addition, scientists investigating the compound noted that the melatonin bottles usually identified the distributor - but not the manufacturer - of the product. When the investigators asked the distributor for the name of the manufacturer, they were told it was 'proprietary information'!
Who can forget what happened in 1990, when the sale of a popular sports supplement - 'purified' L-tryptophan - was halted when it was determined that the L-tryptophan was not pure at all? An important Japanese manufacturer of L-tryptophan had started using a new micro-organism in its production process while simultaneously decreasing the amount of carbon it used to filter out impurities in its products. As a result, the L-tryptophan it exported to the United States contained a contaminant which caused more than 1500 cases of an illness called eosinophilia-myalgia syndrome - and 27 deaths ('Eosinophilia-Myalgia Syndrome,' The Physician and Sportsmedicine, vol. 19(2), pp. 81-86, 1991).
Getting back to the less dangerous world of Panax ginseng, what's the final word on it? Well, there's no strong evidence that it will improve your health or performances, and it's hard to know what you're actually getting when you buy it, but it's certainly good for the national economy, if not yours!
In the next few issues of Peak Performance, we'll tackle two other currently popular supplements - calcium pyruvate and St. John's wort.
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