Every year, it seems, some sort of fruit, vegetable, vitamin, herb, or other product of nature causes a stir over its reported potential to prevent, treat, or cure a disease. This year has been no exception.
Several weeks ago, MedPage Today joined in what has become the annual media frenzy at the American Society of Clinical Oncology meeting. Not surprisingly, one of the most widely circulated stories of the meeting centered on a study about using ginger to prevent or lessen chemotherapy-induced nausea. Lest you doubt the commotion the study created, I Googled the terms "ginger," "cancer," and "ASCO" and came up with more more than 250,000 hits.
Before I'm accused of being dismissive toward complementary and alternative medicine, let me say that the findings were based on a randomized, placebo-controlled clinical trial involving more than 600 patients. Studies of that type yield the highest level of evidence for or against an intervention, and the data came down squarely on the side of ginger.
Unfortunately, too many natural therapies that have too little supporting evidence get too much press. Case in point: Echinacea. How many people do you know who swear that echinacea prevents or shortens the duration of colds? The data swore otherwise.
A large, randomized clinical trial showed that the root of Echinacea angustifolia didn't do squat for colds.Yet, how many people still swear by the stuff?
The echinacea study was funded by the National Center for Complementary and Alternative Medicine (NCCAM), which I consider the NIH equivalent of the cable TV show "Mythbusters." NCCAM takes a rational, evidence-based approach to the evaluation of a treatment and lets the data fall wherever. Most of the time, "wherever" causes true believers to shout "Say it ain't so, Joe!"
Think about it. How many natural therapies have looked terrific in epidemiologic studies and anecdotal reports, only to fall flat in a controlled trial or otherwise not pass muster in an evidence-based test? I submit for your consideration:
- Selenium and vitamin E to prevent prostate cancer
- Beta carotene to prevent lung cancer and heart disease
- Vitamin E to prevent lung cancer
- St. John's wort for major depression
- Hormone replacement therapy to reduce cardiac risk in women
- Saw palmetto for benign prostatic hyperplasia
- Vitamin C to prevent the common cold
- Glucosamine/chondroitin sulfate for arthritis
- Anything that promises to improve sexual function
In the spirit of equal time, I freely admit that some natural therapies do survive the rigors of scientific evaluation. Calcium and vitamin D to prevent osteoporosis come to mind. I believe that acupuncture works for some conditions. However, I also believe that a large randomized controlled trial (RCT) trumps observational studies, anecdotes, and testimonials every time. Cranberry juice to prevent urinary tract infections? Looks promising but hasn't passed the RCT test.
According to NCCAM, about 40% of adults in the U.S. use complementary and alternative medicine, with or without their healthcare providers' knowledge. That's a lot of people. It also can mean a lot of money for the marketing-savvy among us. Did you ever see any pomegranate juice or yogurt at the supermarket before pomegranate was linked to health benefits involving heart disease and arthritis?
I didn't set out to bash natual therapies, although I admit that I come from the "If it looks too good to be true . . . " school of thought.
Primarily, I want to know what the rest of you think. What do you think when you hear about a fruit or vegetable or herb that might have some major health benefits? What do your patients think or say about it? What do you tell your patients?