Cancer and Herbal Supplements - Part2
For the most part, herbal remedies have not been subjected to scientific study, so toxicity and drug interactions remain unknown. However, there have been reports of cerebral hemorrhage, which means bleeding in the brain, and retinal hemorrhage, which means bleeding behind the eye, caused by the popular and heavily advertised herbal, ginkgo biloba. Ginkgo biloba has an effect on platelets, which is the clot-forming element in the blood. In addition, there have been reports about the presence of toxic heavy metals such as lead, arsenic, mercury, and copper in imported herbal supplements.
The situation with ginkgo is especially serious because aspirin also affects blood platelets, and combining the two blood-thinning agents may be responsible for this potentially serious side effect. Many elderly people are told by their doctors to take aspirin in order to keep their blood thin, thereby reducing the risk of stroke and cardiovascular events. Many of these same health-conscious men and women are also concerned about memory and mental alertness, so they take ginkgo to improve memory. However, they may not inform their physicians that they are taking the ginkgo, and therefore, a high-risk situation may develop when the two substances are combined.
You have probably heard about supplements used by bodybuilders and other sports enthusiasts. One such androgen (the hormones associated with masculine physical traits) supplement has anabolic steroidal action in the body and can cause such side effects as liver toxicity and testicular atrophy.
From time to time you will hear about a “breakthrough” study, and you may think that some simple element in food has been found to prevent or cure cancer. For example, you may have heard about lycopene, a chemical in tomatoes responsible for their red color. Based on a small study, it was believed that lycopene was protective against prostate cancer because the group receiving the lycopene showed tumor regression prior to prostate surgery. The problem with this study is that it included only twenty men, ten in the treatment group and ten in the control group (those who were given placebo, not the active lycopene product). In addition, long-term follow-up was absent. Androgen blockers—drugs that block male hormone production—show the same results as lycopene. What we may learn is that lycopene may be helpful in the treatment of prostate cancer, but like androgen-blocking drugs, it may not be a curative substance. It is important to understand the distinction between a substance that may have health benefits and one that may cure a disease.
Saw palmetto is another plant that receives considerable attention in the popular media. Studies have shown that it is effective in reducing symptoms of benign prostate enlargement, a condition many men develop as they age. Urinary frequency and burning are frequent symptoms, and some older men report that for the first time in adult life, they must get up at night to urinate. Saw palmetto has anti-androgenic effects, and in some men, these symptoms may be reduced in varying degrees. However, it is unfortunate that claims for saw palmetto have suggested that it may reduce the incidence of prostate cancer. This simply is not true. Current studies that evaluate the effectiveness of anti-androgenic substances have thus far failed to demonstrate ability to protect against prostate cancer.
Researchers are encouraging testing of these botanical substances using the same strict criteria required for pharmaceutical drugs. Clearly, there are potential benefits of some herbs and supplements. However, some have potentially serious side effects, while others may have significant interactions with prescription medications. Most importantly, let your doctor know about any herbs or supplements you currently take or wish to consider and have an honest discussion with him or her about the pros and the cons—and the unknown factors—that could affect your treatment.