A recent research has found that intake of cruciferous vegetables with a high content of isothiocyanates may offer a protective benefit against bladder cancer.
Isothiocyanates (ITC) are compounds found in cruciferous vegetables such as broccoli, cauliflower, kale, turnips, collards, Brussels sprouts, cabbage, radish, turnip and watercress.
They apply their anti-oxidant effect through down regulation of cytochrome p450 enzyme levels and provoke apoptosis by triggering Phase II detoxifying enzymes. Experimental data has recommended that these compounds may protect against the origins of bladder cancer.
In the May 15th issue of the International Journal of Cancer, Zhao and colleagues from the Departments of Epidemiology and Urology at the M.D. Anderson Cancer Center report on an epidemiological study assessing the connection between ITC consumption and bladder cancer risk.
The group included 697 patients with recently diagnosed bladder cancer and 708 healthy controls matched by age, sex, and race. The participants were asked to complete a dietary questionnaire, following which the intake of ITCs was compared with bladder cancer risk and with the expression of genetic polymorphisms for the arylamine N-acetyltransferases 2 (NAT) and glutathione S-transferase genes.
Average ITC intake per day was considerably lower in bladder cancer patients than in controls (0.23 vs. 0.33, p < 0.001). High ITC intake was linked to 29% lower risk of bladder cancer (odds ratio = 0.71, 95% CI 0.57 to 0.89). This anti-cancer effect was seen more frequently in men, in patients age 64 or older, and in smokers.
NAT2 slow acetylators displayed an augmented risk of bladder cancer in Caucasians compared with rapid acetylators (OR = 1.31, 95% CI 1.02 to 1.69). The decrease in bladder cancer risk associated with ITC intake was not associated to NAT2, GSTM1, or GSTT1 genotype expression.
This well-conducted study for the first time exhibits that eating cruciferous vegetables with a high content of isothiocyanates such as broccoli, cauliflower, kale, turnips, collards, Brussels sprouts, cabbage, radish, turnip and watercress is associated with a decreased risk of bladder cancer.