CHICAGO (AP) The first scientific tests of some popular alternative-medicine products hint that American ginseng might lessen cancer fatigue and that flaxseed might slow the growth of prostate tumors.
But a big study proved shark cartilage worthless against lung cancer, and doctors said people should not take it.
The research was reported yesterday at an American Society of Clinical Oncology conference.
The ginseng and flaxseed studies are small and preliminary, and specialists warned against making too much of them because the substances tested are not the same as what consumers find on store shelves. Americans spend millions on these products, which are not approved by the federal Food and Drug Administration, even though no good studies confirm the benefits they tout.
“One of the most common things patients ask me is about these things they have snookered away in their purses” and medicine chests, said Dr. Bruce Cheson, a cancer specialist at Georgetown University Hospital. “They’ll come in with big bags of this stuff.”
Some “natural” remedies such as laetrile or high doses of vitamin C proved not helpful and even harmful for cancer patients once they were scientifically studied, he noted. Some keep chemotherapy from working as it should.
“Just because it is a vitamin or a leafy green does not ensure it does not have some harmful effects,” Dr. Cheson said.
Debra Barton, a research nurse at the Mayo Clinic in Rochester, Minn., tested powdered, four-year-old Wisconsin ginseng root, which is different from Asian ginseng and other varieties commonly sold, to treat the extreme tiredness that most people suffer from cancer or its treatment.
She randomly assigned 282 persons with breast, lung, colon and other forms of cancer to take either 750, 1,000 or 2,000 milligrams of ginseng or dummy capsules daily for eight weeks. One-fourth of those on the two highest doses said their fatigue was moderately or much less, compared with only 10 percent of those on the low dose or dummy pills.
The flaxseed study aimed to fight prostate cancer, not treat a side effect. The edible seed has been used for hundreds of years in cereals and breads and is high in beneficial omega-3 fatty acids and in lignan, a substance that can affect hormone levels and perhaps squelch their cancer-promoting effects.
Four groups of about 40 men who were scheduled to have their prostates removed three weeks later were assigned to get either 30 grams of powdered flaxseed, a low-fat diet, both or neither until their surgery.
After the men’s prostates were removed, researchers found that tumors grew 30 percent to 40 percent slower in the two groups taking flaxseed, based on how quickly cells were multiplying. Low-fat diets had no effect, said Wendy Demark-Wahnefried of Duke University Medical Center, who led the study.
The shark-cartilege study followed up on some small studies that suggested the substance might extend survival of people with advanced cases of non-small cell lung cancer, the most common form of the disease. Dr. Charles Lu of the University of Texas cancer center in Houston tested Neovastat, a shark cartilage liquid extract that a Canadian pharmaceutical company was trying to develop.
All 379 persons in the study were given standard chemotherapy and radiation. Half also were given shark cartilage twice a day. After about four years there was no difference in survival, which averaged 15 months for both groups.
Please read our comment policy before commenting.