You've seen the ads: "Natural herbs melt pounds away - without diet or
exercise!" or "Amazing new discovery boosts athletic performance!" They usually
claim that a doctor has discovered a new dietary supplement, a miracle substance
that will make you thinner, stronger, smarter, or better at whatever you do.
Best of all, you're told, this supplement works without any real effort - all
you have to do is send in your money and swallow what they send you.
Having trouble believing these ads? You're right to be skeptical. There's
little evidence that dietary supplements have the effects that they claim - and
there is evidence that some supplements can cause serious damage to a user's
health, especially when that user is a teen.
What Are Dietary Supplements? Dietary
supplements are products that include vitamins, minerals, amino acids, herbs, or
botanicals (plants) - or any concentration, extract, or combination of these -
as part of their ingredients. You can purchase dietary supplements in pill, gel
capsule, liquid, or powder forms.
How safe are they? In many cases, no one really knows. The U.S. Food and Drug
Administration (FDA), which normally checks out the safety of foods and
medicines before they come on the market, does not check on the safety of
dietary supplements before they're sold. The FDA has to wait until it receives
reports of problems caused by supplements before it can investigate and ban a
dietary supplement. This is what happened with the herb ephedra (also called ma
huang or herbal fen-phen) in 2003 when the FDA pulled the supplement from the
U.S. market after it was linked to the death of a well-known baseball player.
This means that if you take an untested supplement, you are serving as the
manufacturer's unpaid guinea pig and risking your own health.
Can Supplements Make Me a Better Athlete? Some athletes take dietary supplements believing that these improve
their performances.
However, claims for these improvements are often exaggerated or not based on
scientific evidence.
And some supplements may be hazardous to teens. Anabolic steroids, manmade hormones
similar to the male hormone testosterone, are unsafe and illegal. That's because
the large quantities of these steroids that are found in the supplements can
have devastating side effects on the body, including heart damage, kidney
damage, and bone problems. Studies also show that steroids may be addictive, and that even small doses
can interfere with growth in teens.
Because sports supplements like creatine are unregulated,
there is no standard dose. So users have no way of knowing what levels, if any,
are safe, especially for teens who are still growing. The same goes for
androstenedione, the supplement that gained attention because
professional baseball player Mark McGwire used it. Research suggests that this
hormone supplement may lead to health problems such as acne, gynecomastia (breast enlargement in
guys), and heart problems.
Some people think that
taking amino acid powders is helpful for increasing their muscle mass, but these
powders don't actually have any special muscle-building effects. Amino acids are
the building blocks of protein. Although it's scientifically true that they're
required to build muscle (along with enough exercise), the human body can easily
get all the amino acids it needs from the protein in food. So, if you work out
properly and eat a balanced diet with enough protein, taking amino acid
supplements won't actually do anything for you - except maybe empty your wallet.
Energy bars are also often used as a dietary supplement. These high-calorie,
fortified treats should be used with caution, though. They may serve a purpose
for athletes who burn lots of calories in high-intensity activities, like
competitive cycling. But for most people they can add unwanted calories to the
diet, and they're not particularly filling as a meal replacement.
Can Supplements Help Me Lose Weight? If you'd like to lose a few pounds, you might be tempted to try some
of the many herbal weight-loss products available today. But none of these
herbal remedies work - and some (like ephedra, the banned weight-loss supplement
mentioned above) can have serious side effects.
Herbs like chickweed, ginseng, kelp, and bee pollen, often included in diet
aids, do nothing to promote weight loss - and some
can be harmful or deadly in large doses. The only safe and effective way to take
off excess pounds remains healthy eating and exercise. If you are concerned
about your weight, talk to a doctor or dietitian. He or she can help you get to
a healthy weight.
What About Vitamin and Mineral Supplements? The best way to get your daily dose of vitamins and minerals
is by eating a balanced diet that follows the Food Guide Pyramid. Although there's
usually nothing wrong with a teen taking a basic multivitamin, if you're eating
well, you probably don't need one. If you do choose to take a multivitamin,
stick with a basic supplement and avoid brands that contain higher doses than
100% of the RDA for any vitamin or mineral. Some vitamins can build up in the
human system and cause problems when taken in excess amounts.
Talk to your doctor about additional vitamin and mineral supplements. If you
can't eat dairy products for example, you might need a calcium supplement.
Vegetarians might want
to take vitamin B12 (a vitamin that is found mainly in food that comes from
animals and may be missing in a vegetarian diet). Teens whose doctors have put
them on weight-loss diets of less than 1,200 calories a day or teens with food
allergies should also discuss vitamin and mineral needs with their
doctors.
Supplement Warning Signals Check with
your doctor before you take any dietary supplement, including vitamins and
minerals. If your doctor starts you on a supplement, watch for warning signals
that could indicate problems: stomach discomfort, pain, headache, rashes, or
even vague symptoms like tiredness, dizziness, or lethargy.
Because it's not always clear what goes into some supplements, people with
food allergies should be particularly wary. Some supplements contain ingredients
from shellfish and other potential allergens, and you just don't know how you'll
react to them.
When it comes to supplements, be a skeptical consumer. We all love to look
for the quick fix. But if it looks too easy, it probably is.
Reviewed by: Steven Dowshen, MD, and Jessica Donze
Black, RD, CDE, MPH Date reviewed:
August 2004
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