Washington, May 22 : The belief that DHEA supplements act as a preventive agent for many chronic diseases has been questioned by researchers who could not find any evidence of a beneficial effect of the supplements on cognitive function in healthy older adults in a new study.
And based on their study, they have said that DHEA supplements should not be recommended for enhancement of cognitive function or well-being in the general population.
DHEA is a naturally-occurring hormone in the human body, which acts as a precursor to male and female sex steroid hormones (androgens and estrogens). DHEA levels are highest between the ages of 20 and 30 and then decline with age. In fact, by age 70, they fall to just about 20 percent of what they were in young adulthood.
This first long-term study (1-year in length), focussed on 110 men and 115 women aged 55-85 and was aimed at examining the effects of supplementation in a healthy sample of older men and women.
All the participants received either daily 50 mg doses of DHEA or a similar looking placebo pill for 1 year. They were also given six cognitive function tests were and measures of depression, perceptions of physical and emotional health, life satisfaction and sexual function were recorded at the beginning of the study and again after 12 months.
"We found that, although youthful levels of DHEA were restored in the group on treatment, the DHEA supplements had no benefits for cognitive function in these healthy older adults," said Donna Kritz-Silverstein, lead author of the study.
In fact, there were also no differences seen between those taking DHEA and those taking placebo in any of quality-of-life measures.
However, the results of earlier research examining the effects of DHEA supplementation on cognitive function and quality-of-life had inconsistent results, with some showing positive effects and others showing no effect.
On the other hand, these trials used small sample sizes, were of short duration (generally 2 weeks to 4 months) and did not include older men and women who were at an age when memory loss and cognitive impairment become more apparent.
Besides, in this study, the participants were not selected for lower levels of DHEA unlike the participants in most of the previous studies. This implied that the results gave a clear idea of what would be found in the general population.
The study is published in Journal of the American Geriatrics Society.