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 they improve performance. 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 necessary 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 from food. 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'd all love to think there's a quick fix. But if it looks too easy, it probably is.
Reviewed by: Steven Dowshen, MD
Date reviewed: April 2007