miércoles, 17 de agosto de 2011

NLM Director's Comments Transcript - Dietary Supplements Reform: MedlinePlus

FULL-TEXT ►NLM Director's Comments Transcript - Dietary Supplements Reform: MedlinePlus: "Dietary supplement reform should focus on reducing product contaminants, removing false marketing claims, as well as providing more evidence about the clinical efficacy of the vitamins, minerals and herbs intended to enhance one's diet, suggests an editorial recently published in the Journal of the American Medical Association.

The editorial notes a 2010 U.S. Government Accountability Office (GAO) report found trace amounts of at least one contaminant, such as lead, arsenic, mercury, and assorted pesticides, in 37 of the 40 dietary supplement products the GAO tested.

The editorial adds there can be legally defensible differences between the technical description of a diet supplement's clinical efficacy and its marketing language.

The editorial's author, Bryan Denham Ph.D., a social scientist at Clemson University, writes (and we quote): 'as long as (diet supplement) products do not claim to treat, prevent, or cure specific diseases, they can enter and remain in the marketplace' (end of quote).

Moreover, Denham notes the marketing latitude that is currently provided to manufacturers can be used to advance the impression that a dietary supplement is more effective than medicines that have been tested in rigorous clinical trials to treat a disease or condition.

Denham writes and we quote: 'among the most egregious marketing efforts were claims that garlic could be taken in place of high blood pressure medication and that Ginkgo biloba could be used to treat Alzheimer disease, depression, and impotence' (end of quote).

Denham emphasizes the burden of proof and evidentiary standards of clinical efficacy and safety required of dietary supplement manufacturers are sometimes the reverse of drug and medical product firms. While drug and medical product firms must demonstrate a product's safety and clinical efficacy to the U.S. Food and Drug Administration (FDA), Denham explains the FDA or the U.S. Drug Enforcement Agency must demonstrate a dietary supplement is unsafe, includes a controlled substance, or does not contain ingredients listed on the product's label to take it off the market.

Denham finds these relaxed standards can foster an inconsistent use of clinical evidence by food supplement manufacturers.

For example, Denham writes (and we quote): 'it is safe to assume that supplement manufacturers will not make an announcement each time a study finds no relationship between a dietary supplement and a health condition' (end of quote). Yet, when a null hypothesis is rejected (or clinical efficacy is statistically significant), he notes the existing law permits manufacturers to promote these findings, which he writes (and we quote): 'is a practice with which they appear comfortable' (end of quote).

Denham suggests dietary supplement regulations need a more informed debate by health care professionals, the public, and the U.S. Congress. He urges physicians to support future efforts to improve or reform the 1994 Dietary Supplement Health and Education Act because adults and children with serious medical conditions (and we quote) 'may be relying on products with no medicinal value' (end of quote).

In fairness, Denham adds the Dietary Supplement Health and Education Act provides some regulatory authority and the history of dietary supplements suggests they are rarely a threat to public health.

MedlinePlus.gov's dietary supplements health topic page explains dietary supplements include vitamins, minerals, herbs, and other substances intended to enhance your diet. They are available over-the-counter in pills, capsules, powders, and liquids.

While Denham provides examples where marketing claims eclipse evidence, MedlinePlus.gov's dietary supplements health topic page notes that evidence sometimes buttresses the clinical efficacy of dietary supplements, such as taking folic acid during pregnancy.

To help you discern applicable evidence, MedlinePlus.gov provides information about many supplements within the 'herbs and supplements' link available in the 'overviews' section. Each entry contains a page of helpful information.

To take a dietary supplement safely, MedlinePlus.gov's dietary supplements health topic page additionally suggests you should:

* Tell your doctor about any dietary supplements you take
* Do not take a larger dose than the label recommends
* Stop taking it if you experience side effects
* Consult trustworthy information about the supplement.

MedlinePlus.gov's dietary supplements health topic page provides links to three websites with reliable information about dietary supplements. These links are available in the 'start here' section.

MedlinePlus.gov's dietary supplements health topic page also contains research summaries, which are available in the 'research' section. Links to the latest pertinent journal research articles are available in the 'journal articles' section. Information about related clinical trials in your area is available in the 'clinical trials' section.

To find MedlinePlus.gov's dietary supplements health topic page, type 'dietary supplements' in the search box on MedlinePlus.gov's home page. Then, click on 'Dietary supplements (National Library of Medicine).'

Before I go, this reminder……. MedlinePlus.gov is authoritative,….. free…. does not accept advertising …and is written to help you.

To find MedlinePlus.gov, just type in 'MedlinePlus.gov' in any web browser, such as Firefox, Safari, Netscape, or Explorer.

We encourage you to use MedlinePlus and please recommend it to your friends. MedlinePlus is available in English and Spanish.

Your comments about this or any of our podcasts are always welcome. We welcome suggestions about future topics too!

Please email Dr. Lindberg anytime at: NLMDirector@nlm.nih.gov

That's NLMDirector (one word) @nlm.nih.gov

A written transcript of recent podcasts is available. Just click on the 'Director's comments' link on MedlinePlus' home page.

The National Library of Medicine is one of 27 institutes and centers within the National Institutes of Health. The National Institutes of Health is part of the U.S. Department of Health and Human Services.

A disclaimer –the information presented in this program should not replace the medical advice of your physician. You should not use this information to diagnose or treat any disease without first consulting with your physician or other health care provider.

It was nice to be with you….

Dr. Lindberg returns in the future.

To our readers:

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