Alternative Cancer Therapies Go Mainstream
What it is: A powder or extract made from the connective tissue of sharks, which is purported to contain substances that can shrink tumors.
Summary: There is no solid evidence that shark cartilage fights cancer, and several studies that show it's worthless.
The evidence: According to research published in the November-December 1998 issue of the journal Anticancer Research, scientists in Taiwan identified potent substances in shark cartilage that can block the formation of blood vessels to tumors. A dose of 200 micrograms of shark cartilage extract given to mice was enough to suppress the growth of melanomas, the researchers reported. Unfortunately, those promising findings haven't been repeated by other scientists.
Dutch researchers found no evidence that shark cartilage slowed the growth or reduced the size of tumors in mice, according to a report in the journal Acta Oncologia in 1998. What's more, research published in the Journal of Clinical Oncology in November 1998, found no evidence of tumor regression in any of 47 patients given shark cartilage. More clinical trials are under way.
Side effects and cautions: In the Journal of Clinical Oncology report, five patients had to be taken off shark cartilage treatment because they experienced nausea, vomiting, or constipation. Many cancer doctors worry that patients will use this unproven treatment in lieu of standard therapy. Environmentalists worry that the use of shark cartilage could endanger shark populations.
The Gonzalez Protocol
What it is: A complicated regimen that includes taking oral pancreatic enzymes, coffee enemas, and more than 150 pills daily, including vitamins, minerals, papaya extract, and animal glandular extracts. It is purported to treat pancreatic cancer.
Summary: One very small study shows promise. This approach requires strict physician supervision.
The evidence: In a preliminary study of just 11 patients, Nicholas Gonzalez, MD, reported that five patients survived more than two years on the regimen -- nearly three times longer than most patients with this rapidly fatal form of cancer. Pancreatic enzymes are believed by some researchers to have cancer-killing properties, although the evidence is far from complete. The NIH is conducting a five-year clinical study of the Gonzalez protocol.
Side effects and cautions: The Gonzalez protocol is a very demanding regimen which should only be undertaken under a doctor's strict supervision, because of the potentially toxic effects of combining many different supplements.
What they are: Megadoses of vitamins or minerals that are purported to prevent the formation or growth of cancer cells. Key nutrients under investigation are vitamin E and selenium.
Summary: Preliminary findings show real promise. Be sure to check with your doctor about dosage.
The evidence: In findings published in the May 1998 issue of the British Journal of Urology, 974 men with prostate cancer were given either 200 micrograms of selenium supplements or placebo pills daily for a period of about 4.5 years. Men in the supplement group had a 63% reduction in the incidence of new prostate tumors. They were also significantly less likely to die from all forms of cancer within the 6.5 years that researchers tracked them. Three large randomized trials funded by the National Cancer Institute found that taking vitamin E and selenium significantly lowered lung cancer risk.
Side effects and cautions: At high doses, selenium can be extremely toxic. Ingesting vitamin E at doses higher than 1,000 IUs can thin the blood and cause internal bleeding. Experts caution against taking very high doses of either of these supplements without consulting a doctor.