Chemicals with Anti-Aging Potentials

Provides information on chemicals with anti-aging potentials. Effectiveness; Risks involved in using the chemical.

By Peter Doskoch, published on December 01, 1996 - last reviewed on August 04, 2009

Every few months, it seems, another supplement--most often a hormone--ishailed as the latest breakthrough for extending our lives. Though you may know their names, you may not know why many experts are so optimistic about their anti-aging potential--and why others remain skeptical. To help sort out the hope from the hype, here's the scientific scoop on the most widely touted ways to stay young.

DHEA

Another of the 100-plus hormones pumped out by the adrenal glands, DHEA is converted into estrogen or testosterone as the need arises.

Reasons to take it: Studies confirm that DHEA extends life--if you're a rat. In humans, the hormone promotes feelings of well-being, spurs production of some types of immune cells, and may enhance libido.

Causes for concern: Rats produce little DHEA of their own, so some experts question the hormone's ability to prolong life in humans. Some users report minor side effects such as acne and extra body hair.

Bottom line: DHEA's long-term benefits and risks are unknown. Only three studies--none lasting more than a year--have been published on DHEA's effects on people. To be safe, Ray Sahelian, M.D., author of DHEA: A PracticalGuide, suggests starting with 5 milligrams daily and inching the dosage upward if desired. Don't exceed 50 milligrams a day.

PREGNENOLONE

How do our bodies make DHEA? From pregnenolone. That's why John Morley, M.D., professor of geriatrics at Washington University in St. Louis, calls pregnenolone "the mother steroid hormone," predicting that in the next century pregnenolone replacement therapy will be as common as estrogen replacement is today.

Reasons to take it: As the precursor of DHEA, pregnenolone should, in theory, have many of the same effects. Even tiny doses of the hormone boost memory in rats. It also helps some types of arthritis.

Causes for concern: Few pregnenolone studies have been done since the 1950s, when the hormone was briefly used to treat rheumatoid arthritis. And pregnenolone's effects on longevity--not just in people but in any living creature--remain unknown.

Bottom line: A hormone to watch, but even Dr. Morley admits there's too little evidence to recommend pregnenolone right now.

CALORIE RESTRICTION

If you eat less, you may live longer.

Reason to try it: Mice fed a third less than they would eat on their own live up to twice as long--a finding that's been replicated in fish, spiders, and fruit flies. Now it's being tested in rhesus monkeys; early results are encouraging.

Cause for concern: Does the brain suffer when the body "diets" for 80 years? No one knows, but calorie-deprived rats actually learn to run mazes faster than their well-fed counterparts.

Bottom line: Probably works--for those who can stomach a lifetime of nouvelle-sized portions.

MELATONIN

Manufactured by the brain's pineal gland, melatonin became the hormone du jour after a 1995 Newsweek cover story extolled its virtues. The hormone's prowess at promoting sleep is well established. But its role in retarding aging remains unclear.

Reasons to take it: Melatonin levels peak during our twenties and gradually decline. When the pineal glands of adolescent mice were transplanted into old rodents, their average life span increased by a third. Melatonin is also a potent antioxidant (see below) and kills some cancer cells.

Causes for concern: Gen Xers beware--melatonin reduces longevity in young rants, so people might be unwise to use it regularly before hitting age 40. The effects of long-term use are unknown.

Bottom line: In the short term melatonin appears safe. But so far there's no evidence it extends human life. For a good night's sleep, take 0.3 to 9 milligrams about an hour before bedtime.

GROWTH HORMONE

A product of the brain's pituitary gland, growth hormone is most abundant during childhood, when it stimulates the development of bones, muscles, and organs. As a supplement, it may be most notable for its price tag: $1,000 a month for thrice-weekly injections.

Reasons to take it: Yet another hormone found in increasingly short supply as we age. In a 19909 study, growth hormone increased muscle mass and strength in a small sample of men over the age of 60, while reducing their body fat and cholesterol levels.

Causes for concern: More recent studies haven't detected any increases in adults' strength or muscle mass. The hormone's side effects include joint pain and fluid retention, and it can exacerbate diabetes.

Bottom line: Probably doesn't extend life. And there's already a safer, cheaper way to preserve bone and muscle: exercise. Some experts think growth hormone might make sense for the frail elderly if prices drop and lower doses prove effective.

ANTIOXIDANTS

While oxygen fuels our every activity, it also contributes to the formation of free radicals--highly reactive compounds that play molecular bumper cars within a cell and wreak havoc with every collision. Many experts believe the resulting damage is the key cause of aging. Antioxidants--both our body's natural supply and those we get from our diet--mop up free radicals before they do further harm.