Use or Avoid? Advice on Alternative Cancer Treatments

Source: Tufts University
February 14, 2003

People with cancer who are looking for more treatment options often turn to non-traditional alternatives such as herbal supplements, dietary modifications, and acupuncture. But 'different' isn't necessarily 'better,' and doctors are concerned that some of these treatments are long on promise and short on proven value. Researchers from Canada and the United States recently summarized what is known about the effectiveness and safety of several popular complementary and alternative medicines (CAM). Their analysis was published in a recent issue of Annals of Internal Medicine.

A look at the research

The scientists analyzed studies that examined alternative treatments commonly used by people with cancer. The studies that were conducted according to rigorous scientific standards were given the most credit. Studies that relied on less thorough investigations were used, but were given less weight. The authors evaluated both the effectiveness and safety of various treatments - macrobiotics diets, vitamins A, C, and E, soy, and shark cartilage - and determined whether they could be 'reasonably recommended', 'accepted', or if their use should be 'discouraged' by physicians.

Macrobiotic meals and soy
Proponents of a macrobiotic diet - a very low-fat diet that is based on a limited variety of whole grains, vegetables and fruit - claim that it can cure and prevent diseases, including cancer. The researchers could find no evidence that a macrobiotic diet has healing properties beyond the possible benefits of a diet that is high in fiber and low in fat. The traditional macrobiotic diet is deficient in many key nutrients and is not a good choice for patients already challenged by serious health concerns.

It's not yet clear if soy supplements - which contain concentrated doses of plant compounds called isoflavones - help or hurt those with hormone-dependent cancers like breast cancer. The authors feel that it is prudent at the moment, though, to advise women with breast cancer not to take soy supplements. These supplements might, however, be beneficial to men who have prostate cancer. (A large well-designed study of the effect of isoflavones on prostate cancer is currently underway.)

Vitamin Supplements
The authors advise people being treated for cancer not to take high doses of vitamin A, C, or E. Supplemental doses of antioxidants can interfere with the action of chemotherapy drugs, and vitamin E supplements can be harmful when used in combination with anticoagulant medications. Two large studies found that high doses of vitamin A may actually increase lung cancer incidence in high-risk groups.

Shark Cartilage
No scientific evidence supports the use of shark cartilage, despite the fact that is it a popular supplement advertised as a treatment for cancer. For most people, adverse effects appear to be minor. But those with a history of high calcium levels, pregnant women, children, and those with coronary artery disease and blood clotting disorders should not use shark cartilage.

Advice to consumers

It is crucial that your doctor be aware of any alternative or natural treatments you may be using - or thinking about trying - even if it is something that you have used safely in the past. A dietary supplement like vitamin E, for instance, makes good nutrition sense in some cases but can exacerbate medical problems if used during chemotherapy.

Consumers in the United States should also be aware that dietary supplements are not protected by the rigorous standards required of prescription drugs, and there is currently no way to guarantee that a supplement actually contains what its label says it contains.

Source

• Advising patients who seek complementary and alternative medical therapies for cancer. WA. Weiger, M. Smith, H. Boon,  et al., Ann Int Med, 2002, vol. 137, pp. 889--903

Related Links
Alternative Medicine
National Center for Complementary and Alternative Medicine
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