Fibromyalgia (FM) is a term given to musculoskeletal pain experienced in the body's soft, fibrous tissues. Its cause is unknown, and the pain is often accompanied by other symptoms including fatigue, sleep disorders, irritable bowel syndrome, headaches and others.
It is the second most common rheumatologic disorder in industrialized countries behind osteoarthritis, affecting more than 1.3 percent of Americans (3.7 million people).
DHEA (dehydroepiandrosterone) - a precursor to the hormone testosterone - occurs naturally in the blood of young people. Levels have been shown to peak between the ages of 20 and 30 years, but decrease progressively thereafter.
Dietary supplements containing DHEA (derived from a plant in the wild yam family) have been available in the US for more than 20 years. The anti-aging benefits are said to include aiding cognitive function, mood enhancement and stress disorders, as well as fighting viral infection and suppressing chronic inflammation.
Since FM sufferers tend to have low levels of DHEA, supplements are often used to help alleviate the symptoms.
The double-blind crossover study, published in the July issue of the Journal of Rheumatology (2005; 35; 1336-40) involved 52 postmenopausal women suffering from FM, who took either 50mg of DHEA or a placebo every day from three months. After a one-month wash-out period, those taking the placebo switched to the DHEA, and vice versa.
Each month the participants were assessed for well-being and pain, and levels of fatigue, cogitative function, sexuality, functional impairment, depression and anxiety were also assessed.
Although median DHEA sulfate blood levels tripled during the three months of DHEA supplementation, the researchers found no improvement in any of the outcome markers. Moreover, several side effects to DHEA supplementation, such as greasy hair, acne and increased body hair growth, were also observed.
Finckh's conclusion - that DHEA "does not improve quality of life, pain, fatigue, cognitive function, mood, or functional impairment in FM" - may not be welcomed by some members of the dietary supplements industry, who are seeking support for a campaign to keep DHEA available as a dietary supplement.
Although the researchers concede that higher doses of DHEA or supplementation over a longer period could yield positive results, they said that the 50mg per day dose is most commonly used in studies.
Finckh also expressed concern over the long-term use of DHEA, since it can covert to estrogen and may, therefore, be linked to an increased risk of breast cancer.
The scientist's misgivings are echoed by Senator Chuck Grassley, who introduced a bill in May that would make DHEA a federally-controlled substance. He called DHEA "an anabolic steroid that can be bought by anyone… that may cause a number of long term physical and psychological effects, including: heart disease, cancer, stroke, liver damage, severe acne, baldness, dramatic mood swings, aggression etc."But the National Nutritional Foods Association maintains that "anabolic steroid" is a misnomer.
"[DHEA] is a naturally occurring hormone that has a wide range of benefits, including maintaining muscle strength and strong bones, boosting immunity, and improving mood and sleep patterns," it said.
Indeed, some recent studies have strengthened the case in DHEA's favor. February's issue of the Archives of General Psychiatry published research that suggested that DHEA may be an effective alternative to traditional anti-depressants for sufferers of midlife-onset major or minor depression.
Its role in the prevention and treatment of metabolic syndrome, associated with abdominal obesity, was highlighted in a Washington University School of Medicine study in the Journal of the American Medical Association last year.
Nonetheless, more research into its long-term effects is certainly called for, including an investigation into a purported link with the build-up of cholesterol in the arteries, which raises the risk of heart disease.
Some scientists have also claimed that testosterone created from DHEA does not stay in the blood for long, but breaks down into other hormones associated with prostate gland growth.