Natural selections specifically for the guys

Certain products have become popular among men for specific health concerns, such as enhanced athletic performance and improved prostate health. Experts are particularly enthusiastic about the possible health benefits of selenium and lycopene for men. However, consumers beware: Studies have shown that the quality of various dietary supplement products can sometimes be inferior.

Selenium

THE promising antioxidant selenium is abundant in most Americans’ diets -- it’s found in most plant foods and nuts as well as animal products and seafood. The essential mineral is crucial for immune and thyroid function, sperm development and activating certain enzymes. Supplements are taken to prevent and treat cancer, particularly prostate, lung and colon cancer. They’re also taken for immune function and heart health.

Research has produced enough evidence in favor of selenium’s anti-cancer properties that the National Cancer Institute is sponsoring a prostate cancer prevention study involving more than 30,000 men. Most cancer-related studies involved doses of up to 200 micrograms per day; the FDA recommends getting 70 micrograms in a regular diet.

According to one study, men with low selenium intake had four times the risk of developing prostate cancer compared with those who got enough of the mineral. In a separate study, men randomly selected to take 200 milligrams of selenium a day developed prostate cancer at a far lower rate than men who did not take the supplement.

Long-term high doses can cause nausea, bad breath, dizziness, weakness or cold-like symptoms.

Saw palmetto

THE small, dark berries of the most common palm in the United States were widely popular for treating prostate conditions a century ago -- and they’re a favorite remedy today too. The berries of the shrub-like palm tree contain fatty acids and sterols, cholesterol-like compounds found in plants. Studies suggest the berries’ fatty acids may block the prostate-enlarging effects of high levels of testosterone and other hormones.

Today, saw palmetto is most often taken to treat chronic prostate inflammation or benign prostatic hyperplasia (BPH), an enlargement of the prostate gland that’s common in older men and can create difficulty in urinating. Saw palmetto supplements are also sometimes taken to reverse hair loss, prevent cancer and improve sex drive.

Saw palmetto supplements come in pill and liquid form; look for products that contain at least 80% fatty acids, the active ingredients in the palm’s fruits. (A 2003 scientific review of saw palmetto products found that several didn’t contain the listed ingredients or contained levels of fatty acids too low to be effective. Price was no indication of quality.) The recommended dosage is 1 to 2 grams a day, less if using oil extract. It can take up to six weeks to become effective.

Saw palmetto is one of the best-studied supplements on the market. Studies show that saw palmetto can help relieve symptoms associated with BPH -- including middle-of-the-night urination and difficulty emptying the bladder -- on par with prescription drugs. Unlike prescription drugs, however, the supplement does not shrink an enlarged prostate. So far, there’s no good evidence that saw palmetto can be used to treat prostate cancer, cure urinary tract infections, promote hair growth or boost sex drive.

Side effects include minor gastrointestinal symptoms, such as diarrhea and constipation, in addition to headache, nausea and dizziness. Claims that it can lead to impotence haven’t been substantiated. Avoid taking saw palmetto while on blood thinning drugs or herbs, because it can magnify their effects.

Lycopene

LYCOPENE is a red carotenoid (or pigment) found in an array of microorganisms and plants -- including watermelon, tomatoes, guavas and pink grapefruits. Among all the carotenoids found in fruits and vegetables, lycopene appears to have the strongest antioxidant activity. The lycopene in processed tomato products is actually easier for the body to absorb than that found in whole, fresh tomatoes -- and combining tomato products, such as tomato sauce, with olive oil helps the body absorb even more.

Lycopene is most widely touted as a way to protect against cancer, particularly prostate cancer. It’s also sometimes taken in attempts to fend off heart disease, asthma and age-related eye disease.

Recommended doses range from 5 to 30 milligrams a day. Most Americans get 25 milligrams a day, and at least half of this comes from processed tomato products. (A fresh tomato supplies between 8 and 40 milligrams of lycopene. A serving of tomato sauce can supply more than 100 milligrams.)

In a 1995 study of nearly 50,000 American men, those who ate the most tomato-based foods had the lowest risk of prostate cancer. Several other studies have linked increased tomato-product consumption with a lower risk of lung, stomach and prostate cancer, as well as heart disease. More rigorous lycopene-specific research suggests the supplement can help check the spread of prostate cancer.

Laboratory research suggests it may help prevent cancer by hampering cell growth, protecting against DNA damage or increasing activity of immune cells. (Experts caution, however, that studies haven’t confirmed a direct, causal relationship between low lycopene consumption and prostate cancer.) Evidence from some clinical trials suggests the pigment also may protect against exercise-induced asthma and age-related eye disease such as cataracts.

Creatine

USED by athletes from high school teams to the major leagues, creatine is a white, crystalline substance thought to build muscle and improve athletic ability. The substance, named for the Greek word for meat (kreas), is actually an amino acid necessary for muscle contraction. Most Americans get creatine naturally from animal-based foods, such as milk, eggs, fish, beef and poultry.

Creatine is taken most often to improve athletic performance, though the American College of Sports Medicine recommends against its use by people younger than 18. The substance has been banned by the NCAA. Sports medicine experts say 3 grams a day is sufficient to improve short-term exercise performance. Several studies have shown that creatine can boost short, sprint-type exercise performance but not endurance.

Other studies of creatine’s effectiveness in managing diseases that cause muscle weakness or failure have produced mixed results. A recent, small study showed creatine supplements improved muscle strength and endurance in people weakened by chronic pulmonary obstructive disease. A study in people with the neuro-degenerative disease Huntington’s chorea showed no benefit. University of Maryland researchers are now investigating creatine’s usefulness in treating Parkinson’s disease.

DHEA

THE major hormone produced by the adrenal glands located above the kidneys, dehydroepiandrosterone is responsible for the development of male sexual characteristics. The body’s DHEA levels reach a peak in early adulthood, around age 20 to 25, and then decline -- leading some to believe that the supplement has anti-aging powers.

Men often take DHEA to build muscle or lose fat -- though studies haven’t shown it to do either. In one small study of impotent men, those who took the recommended dose of 50 milligrams of DHEA a day for six months showed significant improvement in sexual function and drive -- but this single study is far from conclusive. DHEA is also sometimes used to manage diabetes, treat depression, lupus, HIV infections, Alzheimer’s disease and osteoporosis.

There’s some evidence that DHEA supplements can slightly reduce the risk of heart disease in men, but it may also lead to unhealthy cholesterol levels, so it’s not recommended for improving heart health. Studies of DHEA’s effects on blood sugar levels have produced mixed results. The hormone hasn’t been shown to improve motor or cognitive function in people 60 and older.

DHEA supplements can elevate levels of testosterone, which could lead to an increased risk of certain cancers, particularly prostate. Avoid supplements that claim to contain DHEA precursors; many of these are compounds that can’t be converted to DHEA by the body. Doses of 300 milligrams or more cause acne, sweating and an increase in facial hair.