Because of intense livestock husbandry and the use of agricultural fertilizers, nitrate is frequently discovered in tap water and bottled water. According to research published in Environmental Health Perspectives, consuming nitrate through water consumption throughout a lifetime may increase the risk of prostate cancer, particularly in younger men and those with aggressive tumours.
Particularly in the event of aggressive tumours and in younger men, the nitrate eaten throughout the course of an adult lifespan through the use of tap water and bottled water may be a risk factor for prostate cancer. The Barcelona Institute for Global Health (ISGlobal), a facility funded by the “la Caixa” Foundation, led a study that was carried out in Spain that came to this conclusion. Environmental Health Perspectives, a publication, released the results on March 8.
The research also hints at the significance of diet. According to the study, consuming a lot of fibre, fruit and vegetables, and vitamin C can lessen the harmful effects of nitrate in drinking water.
The study suggests that diet is an important element to take into account. According to the study’s findings, having a lot of fibre, fruits and vegetables, and vitamin C may lessen the negative effects of drinking water nitrate.
The study’s objective was to determine whether drinking waterborne nitrate and trihalomethanes (THMs) increased the risk of developing prostate cancer. Two of the most frequent pollutants in drinking water are nitrate and THMs. Rainfall washes agricultural fertilizers and intensive livestock farming dung into aquifers and rivers, where the nitrate in the water comes from. Although being a naturally occurring substance, nitrate has had its natural cycle changed, according to Cristina Villanueva, an ISGlobal researcher who specializes in water contamination. The latest research examined the possibility that adulthood’s prolonged exposure to nitrite can cause cancer.
THMs are chemical compounds created as a result of water disinfection, which is typically done using chlorine. THMs can be ingested, but they can also be inhaled and absorbed via the skin while taking a shower, swimming, or doing the dishes, unlike nitrate, which can only enter the body by ingestion. Long-term exposure to THMs has been linked to an increased risk of bladder cancer, but there is currently very little data to support a link between THMs and other cancers.
A research team led by ISGlobal examined 697 cases of prostate cancer in Spanish hospitals between 2008 and 2013 (including 97 aggressive tumours), as well as a control group made up of 927 men aged 38 to 85 who had not yet been diagnosed with cancer at the time of the study, in order to assess any potential associations between prostate cancer and long-term exposure to nitrate and THMs in drinking water. Based on where participants had resided, the kind (tap water, bottled water, or occasionally well water), and quantity of water they had consumed throughout their life, the average nitrate and trihalomethanes to which each person had been exposed since the age of 18 were estimated.
Calculations were generated on the basis of accessible data from drinking water controls carried out by municipalities or concessionary enterprises, from examinations of bottled water of the most frequently sold brands, and from measurements done in different Spanish areas supplied by groundwater.
The results demonstrated that there was a stronger correlation between nitrate intake and prostate cancer. In comparison to those with lower nitrate intakes, those with greater waterborne nitrate intakes (lifetime average of more than 14 mg per day) had a 1.6-fold increased risk of low- or medium-grade prostate cancer and a nearly 3-fold increased risk of aggressive prostate tumours (lifetime average of less than 6 mg per day).
“It has been suggested that aggressive prostate cancers, which are associated with a worse prognosis, have different underlying aetiological causes than slow-growing tumours with an indolent course, and our findings confirm this possibility,” explained ISGlobal researcher Carolina Donat-Vargas, lead author of the study. “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 litre of water.”
The authors pointed out that this study just offers preliminary evidence of the link, which needs to be confirmed by more studies. Consequently, there is still much work to be done before we can claim a causal connection. Donat-Vargas said that exposure to nitrates from drinking water does not guarantee that one would acquire prostate cancer. In order to assure that there is no harm to human health, “our hope is that this study and others will stimulate a reconsideration of the levels of nitrate that are allowed in the water.”
Although consumption of aquatic THMs was not linked to prostate cancer, THM concentrations in household tap water were linked to the growth of these tumours, indicating that cutaneous and inhalation exposure may be important contributors to overall exposure. To get definitive results, more research that accurately quantifies exposure to THMs through various routes is required.
Also, participants filled out a meal frequency survey, which revealed details about their unique diets. The relationship between ingested nitrate and prostate cancer was only seen in males who consumed less fibre, fruit and vegetables, and vitamin C, which was a startling conclusion of the study. According to Donat-Vargas, “antioxidants, vitamins, and polyphenols in fruits and vegetables may suppress the development of nitrosamines—compounds with the potential to cause cancer—in the stomach. “Vitamin C has also demonstrated notable anti-tumour action. Moreover, fibre helps the intestinal flora, which defends against toxins obtained from food, such as nitrosamines.
Higher nitrate intake raised the risk of prostate cancer by a ratio of 2.3 in those with lower fibre intakes (=11 g/day). Higher nitrate intake was not linked to an increased risk of prostate cancer in people who consumed more fibre (>11 g/day).
The research team expects that this study will contribute to increasing public awareness of the possible negative effects of water pollution on the environment and human health and will influence policymakers to ensure more stringent management of this natural resource. “Putting an end to the indiscriminate use of fertilizers and pesticides” and “encouraging the adoption of diets that emphasize the health of the earth by lowering the consumption of animal-based foods, especially meat” are two actions the study’s authors suggest as ways to lower nitrate levels.