As some of my patients know, I began my professional life as a registered pharmacist. Caring for women in my ob-gyn practice, I still answer many questions about substances available without a prescription that some people believe are medicines. Have you heard about these dietary supplements?
- Glucosamine and/or Chonodroitin Sulphate
- Omega-3 Fatty Acids (from fish oil)
- St. John’s Wort
- Saw Palmetto
They are a few of the many that Americans buy and consume trying to stay healthy. In fact, the National Center for Health Statistics tells us that more than half of us use some form of dietary supplement.
Dietary supplements are substances you eat or drink, hoping to improve your diet. The list of substances that the Food and Drug Administration (FDA) considers dietary supplements includes herbs, botanicals, amino acids, and certain other substances, along with common vitamins, minerals, and dietary fiber products.
You hear about the health benefits of these products from advertising and even from family or friends who use them. They often take up an entire aisle in your neighborhood pharmacy. But are they safe; are they effective, and are they worth your money? Let’s separate fact from fiction.
The most important fact you should remember about dietary supplements is that they should never be used as a substitute for a healthy diet.
are dietary supplements safe?
Dietary supplements are not approved by the government for safety and effectiveness before they go to market. They may contain ingredients that are harmful in excessive amounts. Some may interfere with other medicine you are taking—for example, St. John’s Wort may weaken prescription medications like birth control pills or anti-depressants. Most have not been tested in pregnant women, women who are breastfeeding, or children. Some contain ingredients that increase bleeding risk during surgery or could interfere with anesthesia. Therefore, NEVER take more than the recommended amount of a dietary supplement, NEVER use it to replace a medication your doctor prescribes, and ALWAYS keep your physician informed about what you are taking. Remember that “natural” does not always mean safe.
do they work?
From the FDA, “Unlike drugs, supplements are not intended to treat, diagnose, prevent, or cure diseases.” Nonetheless, the health benefits of some supplements are supported by scientific research. We prescribe prenatal vitamins containing folic acid to our obstetric patients because research shows a link between folic acid deficiency and certain birth defects. The body requires calcium and vitamin D to promote bone health. We recommend that our patients meet this need through a balanced diet. For our menopausal patients and for all women who do not get enough calcium and vitamin D in their diets, we can discuss whether you should consider a supplement.
Research has also shown that people who eat plenty of fruits and vegetables (rich in anti-oxidants) have lower risks of several diseases. But studies of the popular anti-oxidant supplements, beta-carotene, Vitamin C, and Vitamin E, have not provided strong evidence that taking the dietary supplement form of these nutrients protects against cancer, heart disease or cataracts. In fact, supplementing with high-doses of beta-carotene and vitamin E may actually increase some health risks. (Note: if you have age-related macular degeneration, ask your eye doctor whether anti-oxidant supplements are right for you.
are they worth their cost?
We have discussed that some dietary supplements do have health benefits, but the claims of many others are unproven. Weight-loss supplements fall into this category. Even worse, the FDA has identified a number of products, sold as dietary supplements for weight loss, that contain dangerous, illegal ingredients. People buy them on the Internet and even in some stores. You can find warnings about some of these products on the FDA website. http://www.fda.gov/Drugs/ResourcesForYou/Consumers/BuyingUsingMedicineSafely/MedicationHealthFraud/ucm234592.htm
We don’t sell weight loss products or other dietary supplements in our office, and we don’t suggest them to our patients in most cases. (I discussed some exceptions above). But if you are considering a dietary supplement, I recommend that you guard your health and your wallet. Beware of claims that sound too good to be true like “Melts Fat Away” or “I didn’t change my diet or exercise.” And again, keep us informed of what you are taking.
Update May 2, 2013
A new study released in March 2013 from the National Toxicology Laboratory has raised concerns about the herbal product ginkgo biloba. Millions of Americans take this supplement to improve memory or ward off dementia, although no real scientific evidence supports that it is effective. Now the government laboratory has reported that ginkgo biloba causes cancer in lab animals, including liver, thyroid, and nasal tumors. Read more about the ginkgo biloba study.