Prostate Cancer Alert: A New Risk Factor for Men’s Health Identified.

Prostate cancer, apart from skin cancer, is the most prevalent cancer among males in America. As per the American Cancer Society’s projections for 2023, approximately 288,300 fresh cases of prostate cancer and 34,700 deaths from the disease are expected in the United States.

The number of diagnoses decreased considerably between 2007 and 2014, coinciding with a decline in screening due to revised screening guidelines.

However, since 2014, the overall incidence rate has risen by 3% annually, with advanced-stage prostate cancer increasing by about 5% per year.

According to a new study, it is possible that the nitrate that is consumed throughout the course of an adult’s lifetime from the drinking of tap water and bottled water might be a risk factor for prostate cancer. This is especially true in cases of aggressive tumors and in younger men.

This is the finding of a research project that was carried out in Spain and directed by the Barcelona Institute for Global Health (ISGlobal), which is a center that is supported by the “la Caixa” Foundation. Environmental Health Perspectives has published the results.

The study’s objective was to determine if drinking waterborne nitrate and trihalomethanes (THMs) increased the chance of developing prostate cancer. Nitrate and trihalomethanes (THMs) are two of the pollutants that are found in drinking water.

Rainfall washes agricultural fertilizers and intensive animal farming dung into aquifers and rivers, where the nitrate in the water originates from.

Nitrate, as explained by ISGlobal researcher Cristina Villanueva, “is a compound that is a part of nature, but we have altered its natural cycle.”

Researchers in the latest research investigated the link between chronic exposure to nitrite and an increased risk of developing cancer later in life.

THMs, or trihalomethanes, are chemical molecules produced as a byproduct of disinfecting water, often using chlorine.

THMs may also be breathed in and absorbed via the skin when taking a shower, swimming in a pool, 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 team of researchers headed by ISGlobal examined 697 instances of prostate cancer treated in Spanish hospitals between 2008 and 2013 (including 97 severe tumors) and a control group of 927 men aged 38 to 85 who had not been diagnosed with cancer.

Each participant’s lifetime exposure to nitrate and trihalomethanes was assessed by looking at factors such as where they had lived and the kind (tap water, bottled water, or, in some instances, well water) and quantity of water they had consumed since turning 18.

Available data from municipal or concessionary company drinking water quality controls, bottled water analysis of the most frequently sold brands, and measurements performed in various Spanish sites supplied by groundwater were used to generate estimates.

The results demonstrated that there was a stronger link between nitrate consumption and prostate cancer. In comparison to individuals with lower nitrate intakes, those with greater waterborne nitrate consumption (lifetime average of more than 14 mg per day) were 1.6 times more likely to get low- or medium-grade prostate cancer and approximately 3 times more likely to develop an aggressive prostate tumor (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,” adds lead author Carolina Donat-Vargas. “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 researchers pointed out that this study just offers preliminary evidence of the link, which has to be validated by more investigation.

Hence, there is still more work to be done before a causal link can be established.

“Being exposed to nitrates through drinking water does not mean that you are going to develop prostate cancer,” comments Donat-Vargas. “Our hope is that this study, and others, will encourage a review of the levels of nitrate that are allowed in water, in order to ensure that there is no risk to human health.”

Even though drinking water with THMs in it was not linked to prostate cancer, THM levels in tap water were linked to the growth of these tumors. This suggests that inhalation and skin exposure may play a big role in total exposure.

To come to firm conclusions, more research is needed to figure out how many ways people are exposed to THMs and how much.

The participants also filled out a food frequency questionnaire, which gave information about each person’s diet. The relationship between ingested nitrate and prostate cancer was only seen in males who consumed less fiber, fruit and vegetables, and vitamin C, which was a startling conclusion of the research.

According to Donat-Vargas, “antioxidants, vitamins, and polyphenols in fruits and vegetables may inhibit the formation of nitrosamines—compounds with tcarcinogenic potential—in the stomach.

“Moreover, vitamin C has shown significant anti-tumour activity. And fibre, for its part, benefits the intestinal bacteria, which protect against food-derived toxicants, including nitrosamines.” 

Higher nitrate consumption multiplied the risk of prostate cancer in individuals with lower fiber intakes (11 g/day) by a ratio of 2.3. Nevertheless, among individuals with greater intakes of fibre (>11 g/day), higher nitrate consumption was not associated with an increased chance of prostate cancer.

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 guarantee more stringent management of this natural resource.

To lower nitrate levels, the study’s authors suggest “putting an end to the indiscriminate use of fertilisers and pesticides” and promoting diets that put the health of the planet first by reducing the amount of animal-based foods, especially meat, that people eat.

Source: 10.1289/EHP11391

Image Credit: Getty