The steroid-like supplement DHEA (dehydroepiandrosterone) is often used as a
muscle builder by gym goers and has been touted as an anti-aging remedy --
although the Federal Trade Commission has cracked down on companies that have
made such claims.
The artificial hormone has been found to be helpful for some patients with
the autoimmune disease lupus.
While the function of DHEA in the brain remains unclear, there has been
increasing interest among scientists and the public about whether the hormone --
which peaks during a person's 20s -- plays a role in sustaining normal mental
abilities.
In addition, preliminary studies in mice have suggested that DHEA may boost
memory.
Now, Dr. Owen M. Wolkowitz, of the University of California San Francisco
School of Medicine, and associates report that DHEA "did not significantly
improve" mental function in a small group of patients with Alzheimer's disease.
In their investigation, the team of researchers evaluated the mental
abilities of 28 men and women with Alzheimer's disease who took 50 milligrams of
DHEA twice per day and similar group of 30 individuals who took a placebo. All
of the participants underwent mental ability tests prior to the study and again
at three and six months.
Along the way, many of the participants dropped out of the study for various
reasons. The authors note in their report that some of the patients may have
opted for "other effective and well tolerated" medications. In the end, 19
people in the DHEA group and 14 in the control group finished the study.
In general, the authors found that DHEA treatment compared to placebo "was
not associated with significant improvements in (mental) performance," according
to the report published in the journal Neurology.
Although a small improvement in mental functioning was seen after three
months in patients given DHEA compared to those in the control group, the
finding was not statistically significant. In other words, this finding may have
been due to chance.
"It's too early to tell, so people should not go out and try DHEA on their
own in hopes of stemming Alzheimer's disease, but they should be encouraged that
further research will be done on it," Wolkowitz told Reuters Health.
Those taking the hormone supplement were twice as likely than those taking a
placebo to report feelings of confusion, agitation and anxiety, although
Wolkowitz noted that these symptoms were fluctuating, and that more patients
dropped out of the placebo arm than the DHEA arm because of adverse effects.
"It remains to be determined in larger scale studies if DHEA has a useful
role in treating symptoms of AD (Alzheimer's disease)," the authors conclude.
The findings of the current study, in spite of its small size, provide a
useful estimate of DHEA effects on symptoms of Alzheimer's disease, according to
Drs. David Knopman of the Mayo Clinic in Rochester, Minnesota and Victor W.
Henderson of the University of Arkansas for Medical Sciences in Little Rock.
"DHEA alone seems unlikely to be superior to currently available
(anti-Alzheimer's disease drugs)," Knopman and Henderson write in an
accompanying editorial. The study excluded patients taking cholinesterase
inhibitors, which have been shown to help patients. This may have contributed to
the high dropout rate, according to Knopman and Henderson.
More studies are needed to solve the issue of whether or not DHEA is helpful
for Alzheimer's disease patients, they conclude.
Wolkowitz remains hopeful that DHEA may act synergistically with
cholinesterase, because "in animal studies, the two agents together increase the
viability of hippocampal cholinergic neurons, the neurons that make
acetylcholine."
"We saw a suggestion of an effect on cognition, but no overall general
benefit," Wolkowitz said. "I think its ultimate role will be as an augmentation
strategy for other drugs, such as cholinesterase inhibitors."
The study was funded by the National Institute on Aging and Neuroscience
Pharma Inc. of Montreal, which supplied the DHEA and the placebo capsules used
in the study.
