Monday 13 February 2017

What are rhodiola rosea's therapeutic uses?


Overview

The herb Rhodiola rosea has been used traditionally in Iceland, Norway, Sweden, Russia, and other European countries as a “tonic herb” said to fight fatigue, aid convalescence from illness, prevent infections, and enhance sexual function. In the twentieth century, Soviet physicians classified rhodiola as an adaptogen. This invented term refers to a hypothetical treatment described as follows: An adaptogen helps the body adapt to stresses of various kinds, whether heat, cold, exertion, trauma, sleep deprivation, toxic exposure, radiation, infection, or psychological stress. Furthermore, an adaptogen supposedly causes no side effects, treats a wide variety of illnesses, and helps return an organism toward balance no matter what may have gone wrong.



Perhaps the only indisputable example of an adaptogen is a healthful lifestyle. By eating right, exercising regularly, and generally living a life of balance and moderation, individuals can increase their physical fitness and ability to resist illnesses of all types. Multivitamin/multimineral supplements could offer similarly general benefits, at least in people whose diets are deficient in basic nutrients. Whether there are any herbs that offer adaptogenic benefits, however, remains unproven (and somewhat unlikely). Nonetheless, advocates of the adaptogen concept believe that rhodiola (as well as ginseng, ashwagandha, reishi, suma, and several other herbs) have this property.




Therapeutic Dosages

Rhodiola extracts are standardized to their content of salidroside (also called rhodioloside). A typical dosage of 170 to 185 milligrams (mg) daily supplies 4.5 mg of salidroside. When rhodiola is used as a one-time treatment, two to three times this dose is often used. Most published studies involved a single proprietary product. It is not clear that the results of these studies apply to products using different rhodiola sources or different methods of extraction.




Therapeutic Uses

Rhodiola is marketed as the new ginseng, said to fight fatigue, enhance mental function, increase general wellness, improve sports performance, and enhance sex drive in both men and women. A few double-blind studies involving a single proprietary product support the first two of these uses, finding that the use of a particular rhodiola extract by people in stressful, fatiguing circumstances may help maintain normal mental function.




Scientific Evidence

A double-blind, placebo-controlled study of fifty-six physicians on night duty evaluated the potential benefits of rhodiola for maintaining mental acuity. Participants received either placebo or rhodiola extract (170 mg daily) for a period of two weeks. The results showed that participants taking rhodiola retained a higher level of mental function as measured by tests, such as mental arithmetic.


Another double-blind, placebo-controlled study evaluated one-time use of the same rhodiola extract (at a dose of 370 mg or 555 mg) in 161 male military cadets undergoing sleep deprivation and stress. The results showed that rhodiola was more effective than placebo at fighting the effects of fatigue.


Finally, a third double-blind, placebo-controlled study examined the effects of a low dose of this rhodiola extract (100 mg daily for twenty days) in forty foreign students undergoing examinations (presumably a highly stressful situation). The results showed modest benefits on some measurements of fatigue and mental function, and no significant benefit on others. The study authors considered the outcome relatively unimpressive and blamed this on the dose chosen.


While these results may sound impressive overall, they were all performed in former Soviet republics, and studies from these sources must be viewed with caution. For reasons that are unclear, double-blind studies performed in the former Soviet Union (or China) almost always find the tested treatment effective. This consistent pattern of excessively positive results has made outside observers highly skeptical. For this reason, only if confirmation is obtained in a more reliable setting can rhodiola be considered to have real supporting evidence behind it.


One small double-blind trial performed in Belgium did find evidence that use of a different rhodiola extract at a dose of 200 mg one hour before endurance exercise may improve performance. However, another study failed to find benefit with a combination of cordyceps and rhodiola.


Weak evidence hints that rhodiola might be helpful for preventing altitude sickness and might aid in cancer chemotherapy (by protecting the liver). Rhodiola has also been studied as a treatment for depression. In a randomized trial, eighty-nine people with mild to moderate depression received rhodiola extract 340 mg, rhodiola extract 680 mg, or a placebo for six weeks. Those in both rhodiola groups experienced an improvement in most of their depression symptoms, whereas those in the placebo group experienced no such benefit.




Safety Issues

There are no known or suspected safety risks with rhodiola, and in clinical trials, no severe adverse effects have been reported. However, comprehensive safety studies have not been performed. Safety in young children, pregnant or nursing women, and people with severe liver or kidney disease has not been established.




Bibliography


Colson, S. N., et al. “Cordyceps sinensis- and Rhodiola rosea-Based Supplementation in Male Cyclists and Its Effect on Muscle Tissue Oxygen Saturation.” Journal of Strength and Conditioning Research 19 (2005): 358-363.



Darbinyan, V., et al. “Rhodiola rosea in Stress Induced Fatigue: A Double Blind Crossover Study of a Standardized Extract SHR-5 with a Repeated Low-Dose Regimen on the Mental Performance of Healthy Physicians During Night Duty.” Phytomedicine 7 (2000): 365-371.



De Bock, K., et al. “Acute Rhodiola rosea Intake Can Improve Endurance Exercise Performance.” International Journal of Sport Nutrition and Exercise Metabolism 14 (2004): 298-307.



Fintelmann, V., and J. Gruenwald. “Efficacy and Tolerability of a Rhodiola rosea Extract in Adults with Physical and Cognitive Deficiencies.” Advances in Therapy 24 (2007): 929-939.



Shevtsov, V. A., et al. “A Randomized Trial of Two Different Doses of a SHR-5 Rhodiola rosea Extract Versus Placebo and Control of Capacity for Mental Work.” Phytomedicine 10 (2003): 95-105.



Spasov, A. A., et al. “A Double-Blind, Placebo-Controlled Pilot Study of the Stimulating and Adaptogenic Effect of Rhodiola rosea SHR-5 Extract on the Fatigue of Students Caused by Stress During an Examination Period with a Repeated Low-Dose Regimen.” Phytomedicine 7 (2000): 85-89.



Wing, S. L., et al. “Lack of Effect of Rhodiola or Oxygenated Water Supplementation on Hypoxemia and Oxidative Stress.” Wilderness and Environmental Medicine 14 (2003): 9-16.

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