Isothiocyantes among African Americans and Caucasions
Initial Award Abstract
Smokers have a much greater chance of developing lung cancer than non-smokers. What remains to be determined is why some smokers get lung cancer while the majority do not. Many studies of large populations have found that eating fruits and vegetables protects against lung cancer, however it is not known what part of fruits and vegetables is responsible. In the past it was thought that beta carotene protected against lung cancer, but results from large clinical trials showed that smokers who consumed large quantities of beta carotene had a greater chance of developing lung cancer than smokers who consumed lower amounts of beta carotene.
Recent studies of cruciferous vegetables such as cabbage and broccoli have been shown to protect against lung cancer. A substance found in broccoli called isothiocyanate (ITC), is thought to be responsible for the protection, because administering ITC to animals reduces the ability of substances known to produce cancer from creating tumors. We recently conducted a study among Shanghai Chinese where we found that Chinese who had large amounts of ITC in their urine had a lower chance of developing lung cancer than Chinese who had smaller amounts.
It is important to measure ITC in the urine because then we will have a more accurate way to determine how much ITC our study subjects consumed, rather than only relying on how well they reported what they ate. Measures of ITC in the urine also tell us about the specific action of ITC, and not other compounds such as beta-carotene.
We propose to measure ITC in the urine of both African Americans and Caucasians so that we can develop a baseline measure among healthy people of both ethnic groups. We plan to determine whether there might be differences between the two groups. We also would like to see if ITC level differs according to whether our subjects currently smoke, whether our subjects are men or women, whether our subjects are exposed to passive smoke, and according to genes that are known to influence the metabolism of ITC as well as the metabolism of carcinogens from cigarette smoke.
We collected urine specimens of lung cancer patients and healthy control subjects in the early 1990’s when we conducted a population study of African Americans and Caucasians in Los Angeles. A study sample of 599 healthy individuals who previously provided urine specimens, answered our study questionnaire, and completed a dietary questionnaire will be available to the current proposed research. We will send the urine specimens to the American Health Foundation in Valhalla, New York for measurement of ITC.
ITC may be a supplement people, especially smokers, can use to reduce their chances of developing lung cancer. However only a few studies have been conducted on ITC. With the present study we can further establish the role that ITC may play in protection from developing lung cancer. |
|Low level anti-Hu reactivity: A risk marker for small cell lung cancer?
|Periodical: Cancer Detection and Prevention
|Authors: Tsou, J.A.; Kazarian, M.; Patel, A.; Galler, J.S.; Laird-Offringa, I.A., Carpenter, C.L.;