This from Cancer Decisions--Dr. Ralph Moss's weekly newsletter:
DOES RESVERATROL ENHANCE THE EFFECTS OF RADIATION THERAPY?
Cancer patients are frequently told by their oncologists not to take antioxidants while undergoing chemotherapy or radiation therapy. Supposedly, antioxidants counteract the beneficial free radicals that are generated by conventional treatment, thereby interfering with its effectiveness. A small number of scientists have argued the opposite, suggesting that antioxidants do not generally interfere with cancer treatment but, rather, enhance its effectiveness while sparing normal cells from damage. It is one of the great dividing lines between conventional and CAM-oriented practitioners.
Recent research from the University of Rochester has contradicted the idea that antioxidants interfere and has added credibility to the idea that they enhance treatment effectiveness. It thus adds to a growing body of data, both experimental and clinical, that antioxidants should be used by cancer patients.
The Rochester research team was headed by Paul Okunieff, MD. He is chief of Radiation Oncology at the James P. Wilmot Cancer Center at the University of Rochester Medical Center. A graduate of Massachusetts Institute of Technology and Harvard University Medical School, he currently supervises high dose brachytherapy, 3D treatment planning, and stereotactic radiosurgery at the University of Rochester. Dr. Okunieff has won many awards, including the Davey Memorial Award for Outstanding Contributions to Cancer Research, and is the Radiation Therapy Committee Chair of the Southwest Oncology Group (SWOG). He is the author of over 150 PubMed listed articles, the latest of which was published in the March edition of the journal, Advances in Experimental Medicine and Biology (Sun 2008).
Prof. Okunieff and his colleagues studied the effect of resveratrol, a natural antioxidant that is found in grape skins, grape juice and red wine. He found that resveratrol can help destroy pancreatic cancer cells by entering the mitochondria, which are the cell's energy powerhouses, and crippling their function. Resveratrol combined with radiation caused programmed cell death, or apoptosis.
Where's the Interference?
According to a release from the University of Rochester: "[S]ome physicians are concerned antioxidants might end up protecting tumors. Okunieff's study showed there is little evidence to support that fear. In fact, the research suggests resveratrol not only reaches its intended target, injuring the nexus of malignant cells, but at the same time protects normal tissue from the harmful effects of radiation." According to Prof. Okunieff, "Resveratrol seems to have a therapeutic gain by making tumor cells more sensitive to radiation and making normal tissue less sensitive."
In this experiment, researchers treated all the pancreatic cancer cells with radiation, but some of the cells also were give a relatively high dose of 50 mg/ml of resveratrol. The researchers then evaluated the mitochondrial function of the cells. Although resveratrol is commonly classified as an antioxidant, this compound actually triggered the production of reactive oxygen species (ROS) in cancer cells. These free radicals probably then caused programmed cell death seen in the affected cells. Resveratrol actually had a more destructive effect on the mitochondrial membranes than radiation alone.
"While additional studies are needed," said Prof. Okuneiff, "this research indicates that resveratrol has a promising future as part of the treatment for cancer." According to Prof. Okunieff, although red wine consumption during chemotherapy or radiation treatment has not been well studied, it is not strictly contraindicated. That is to say, if a patient already drinks red wine moderately, most physicians would not tell that patient to give it up during treatment. Perhaps a better choice, said Okunieff, would be to drink as much red or purple grape juice as desired.
It is unclear whether it is a good idea for cancer patients who are undergoing treatment to take alcoholic beverages. Alcohol itself promotes the growth of certain forms of cancer. But while non-alcoholic grape juice does indeed contain some resveratrol, is there enough to generate a therapeutic effect? No one seems to know, beyond saying that one would have to take a lot of grape juice every day to have any effect at all.
That leaves the option of resveratrol supplements. Even one vehemently anti-alternative medicine Web site, quackwatch.org, concedes that taking resveratrol supplements is "certainly safer than heavy consumption of red wine." Perhaps a good choice would be to take capsules containing resveratrol. Consumerlab.com has rated the purity and potency of 14 such products. While two of them failed to come up to their stated amounts, most did. Consumerlab.com also ranked the products based on the price paid and amount of resveratrol found (or correctly claimed) in each product. Some of these capsules provided as little as 2.2 mg of resveratrol, which is almost certainly too little to make a difference. Others provided 250 mg, which is probably too much. The most dependable and economical sources were Resveratrol 100 from Jarrow, which cost 20¢ per 100 mg capsule, and Country Life Resveratrol Plus Antioxidants, which came to a similar 21¢ per 100 mg capsule. Anything in the 20¢ to 25¢ range per 100 mg capsule seems like a good deal.
Skeptics will of course say that Prof. Okunieff's paper was merely a laboratory potency study, not a clinical trial, and therefore doesn't prove that any particular dose of resveratrol is effective. That is true, but then almost all the data that claims to show that antioxidants are to be shunned during chemo- and radiation therapy is also derived from laboratory data. As my recent Cancer Decisions® report on this topic made clear, almost all the human clinical data that exists shows a positive interaction of radiation and/or chemotherapy and antioxidants. Prof. Okunieff's latest study adds to that impression of benefit, not harm.