WEDNESDAY, March 29, 2023 (HealthDay News) -- Long-term waterborne-ingested nitrate is associated with an increased risk for prostate cancer, especially aggressive tumors, according to a study published online March 8 in Environmental Health Perspectives.
Carolina Donat-Vargas, Ph.D., from the Instituto de Salud Global de Barcelona in Spain, and colleagues examined the association between drinking-water exposure to nitrate and trihalomethanes (THMs) and prostate cancer in Spain. During 2008 to 2013, 697 hospital-based incident prostate cancer cases (97 aggressive tumors) and 927 population-based controls were included. To calculate waterborne ingestion, average nitrate and THM levels in drinking water were linked to lifetime water consumption.
The researchers found that waterborne-ingested nitrate >13.8 versus <5.5 mg/day was associated with odds ratios of 1.74 and 2.78 overall and for tumors with Gleason scores ≥8, respectively. Higher associations were seen in the youngest participants and those with lower intakes of fiber, fruit/vegetables, and vitamin C. There was no association seen for waterborne-ingested THMs with prostate cancer. Inverse and positive associations with prostate cancer were seen for residential tap water levels of brominated-THMs and chloroform, respectively.
"It has been suggested that aggressive prostate cancers, which are associated with a worse prognosis, have different underlying etiological causes than slow-growing tumors with an indolent course, and our findings confirm this possibility," Donat-Vargas said in a statement. "The risks associated with waterborne nitrate ingestion are already observed in people who consume water with nitrate levels below the maximum level allowed by European directives, which is 50 mg of nitrate per liter of water."