What are maca's therapeutic uses?

Overview

Maca is a Peruvian root vegetable used as both food and medicine. It is sometimes called Peruvian ginseng, not because the plants have any botanical relationship, but because their traditional uses are somewhat similar. Traditionally, maca has been said to increase energy and stamina and to enhance both fertility and sex drive in men and women.

Therapeutic Dosages

The usual dose of maca is 500 to 1,000 milligrams (mg) three times a day.

Therapeutic Uses

Maca is widely marketed for improving male sexual function, female sexual function, and both male fertility and female fertility. However, at present there is no reliable evidence that it actually provides any benefits. Much of the evidence for maca comes from animal studies. In one study in rats, use of maca enhanced male sexual function. Animal studies have had mixed results regarding male and female fertility.

There are two published human trials on maca, performed by a single research
group. In one small twelve-week, double-blind, placebo-controlled study, use of
maca at 1,500 mg or 3,000 mg increased male libido. While this was an interesting
finding, the study did not report benefits in male sexual function, just in
desire. Since loss of sexual function (for example, impotence) is
a more common problem in men than loss of sexual desire, these results do not
justify the widespread claim that maca has been shown to act like a kind of herbal
Viagra.

Another small study found that four months of maca use increased sperm count
and sperm function. This study failed to use a control group, and for this reason,
its results are essentially meaningless. There have been no human trials on maca
for female fertility or female sexual function. Contrary to widespread reports,
maca does not appear to increase testosterone levels or, in fact, to
affect any male hormones.

Other animal studies hint that maca might offer benefits for prostate
enlargement, stress, diabetes, and high blood pressure. However, this evidence is
too weak to justify any claims regarding maca and these conditions. One human
trial evaluated a combination of maca and cat’s claw
for osteoarthritis, but because it failed to include a placebo group, its results
mean little.

Safety Issues

In the two reported human clinical trials, use of maca has not led to any serious adverse effects. However, this herb has not undergone comprehensive safety testing. Safety in young children, pregnant or nursing women, and people with severe liver or kidney disease has not been established.

Bibliography

Gonzales, G. F., et al. “Effect of Lepidium meyenii (Maca), a Root with Aphrodisiac and Fertility-Enhancing Properties, on Serum Reproductive Hormone Levels in Adult Healthy Men.” Journal of Endocrinology 176 (2003): 163-168.

_______.“Effect of Lepidium meyenii (Maca) on Sexual Desire and Its Absent Relationship with Serum Testosterone Levels in Adult Healthy Men.” Andrologia 34 (2002): 367.

_______.“Lepidium meyenii (Maca) Improved Semen Parameters in Adult Men.” Asian Journal of Andrology 3 (2002): 301-303.

Lopez-Fando, A., et al. “Lepidium peruvianum chacon Restores Homeostasis Impaired by Restraint Stress.” Phytotherapy Research 18 (2004): 471-474.

Mehta, K., et al. “Comparison of Glucosamine Sulfate and a Polyherbal Supplement for the Relief of Osteoarthritis of the Knee.” BMC Complementary and Alternative Medicine 7 (2007): 34.