Abstracted from CNN Interactive/AP News
Chemical in Tomatoes (Lycopene)
PHILADELPHIA (AP) -- Lycopene, the chemical which makes tomatoes red, may inhibit growth of prostate cancer, according to a report today at the annual meeting of the American Association of Cancer Research. In this pilot study, 33 men with localized prostate cancer were treated with 30 mg of lycopene extract daily (or nothing) for a month prior to radical prostatectomy. When the prostaate glands were analyzed pathologically, men treated with lycopene appeared to have less aggressive, lower stage tumors than the untreated men.
Levels of prostate specific antigen, a measure of tumor activity, also fell 20 percent between the start of treatment and surgery in the lycopene patients. They were unchanged in the comparison group. The study was performed on patients at the Karmanos Cancer Clinic in Detroit.
The results of this work appear to corroborate a study published in 1995 by Dr. Ed Giovannuci and others at Harvard Medical School. In the Giovannuci study, a semi-quantitative food questionnaire was administered to more than 47,000 men, who were then followed for 6 years. The incidence of prostate cancer among this cohort (N=812) demonstrated an inverse relationship to the intake of certain foodstuffs, particularly tomatoes and the lycopene content, especially. The 1995 conclusion was that "... lycopene or other compounds in tomatoes may reduce prostate cancer risk."
While these data are of interest, a practical application remains elusive. Dr.Omar Kucuk, principle author of the current work, warned that his study was small, and he cautioned against routine use of lycopene supplements without further evidence. Also, he emphasized that the amount of lycopene used in the study was found in about a pound of tomatoes, but because lycopene was not easily absorbed from raw tomatoes, it might take two or three pounds of tomatoes a day to actually raise blood levels as high as were seen in the study.
Another dietary supplement, saw palmetto extract, which is used throughout Europe to treat benign prostatic hyperplasia, has been studied extensively at USRF. Results of this study will be presented at the annual meeting of the American Urological Association, May, 1999 in Dallas, TX.