Nitrates in Drinking Water and Prostate Cancer: Latest Research Findings and Precautions

The incidence of prostate cancer is increasing around the world. In 2020, it is estimated that there will be about 1,414,259 new cases (accounting for 7.3% of all cancers in that year). According to the Ministry of Health and Welfare of Taiwan, prostate cancer The incidence rate ranks sixth among all cancers in Taiwan (7,115 cases per year). Compared with the United States, although the incidence rate of Chinese people is only 1/7 of that of the United States, the death rate is 1/3 of that of the United States, showing that Taiwan The mortality rate of the disease is relatively high, so it is necessary to step up health education. In addition to early detection and early treatment, further precautions should be taken to prevent its occurrence.

Prostate Cancer Causes Polynitrites and Nitrates May Also Affect

However, the cause of prostate cancer is still not fully understood. It is one of the few cancers for which the International Agency for Research on Cancer (IARC) has not clearly identified the carcinogenic agent. The currently known risk factors are: age, race and family history (including genetics). In addition to the well-known slow-growing indolent types of prostate cancer (Gleason score less than 8), there are actually aggressive and fatal types of prostate cancer. Prostate cancer (Gleason score greater than 8), but we still do not know the main reason for the difference. Of course, many more risk factors for prostate cancer have been proposed, such as smoking, unhealthy diet, overweight and lack of exercise, etc., as well as exposure to endocrine disrupting chemicals such as Agent Orange (Agent Orange; contains dioxins) and pesticides, among others, and just recently (2022) a link between nitrite and nitrate in food additives and prostate cancer was reported.

At present, nitrate in human drinking water mainly comes from fertilizers used in agricultural planting and manure produced by animal husbandry. They are easily washed into the aquifer of the soil and rivers by rainwater. Nitrate is a compound that is also It is a part of nature, but humans have changed its natural cycle and disrupted the balance of the environment. Therefore, the nitrate content in the water cycle around the world is gradually increasing, and the nitrate ingested by the human body is mainly through food and drinking water. When the ingested nitrate is reduced to nitrite for any reason, under the acidic conditions of the stomach, the nitrite may chemically react with amines or amides to form nitroso Compounds (e.g. nitrosamines, Group 2A carcinogens). Therefore, when the conditions in the body are likely to cause this type of reaction to occur, when more nitrates or nitrites are taken in, there is a chance to cause cancer to humans. At present, the epidemiological research on the relationship between nitrate exposure in drinking water and cancer in the scientific community is still limited, and further research is needed. In addition, when chlorine-containing disinfectants and their by-products in drinking water encounter ammonia (NH3+), they have the opportunity to combine with chlorine to form chloramines (Chloramines), and may also form carcinogenic nitrosamines. Therefore, scientists want to To understand the association between exposure to nitrates in drinking water and prostate cancer.

On March 8, 2023, Professor Cristina Villanueva, who specializes in water pollution research at the Barcelona Global Health Institute in Spain, published an article in the international journal “Environmental Health Perspectives” (Environmental Health Perspectives) Research Papers. The results showed that the higher the intake of nitrates in drinking water, the greater the association with prostate cancer. Participants with higher nitrate intake (lifetime average of more than 13.8 mg per day) had less aggressive prostate cancer compared to participants with lower nitrate intake (lifetime average of less than 5.5 mg per day) were 1.74 times more likely to develop highly aggressive prostate cancer, and were even more astonishingly nearly 2.78 times more likely to develop highly aggressive prostate cancer. shows that the total amount of nitrate a person consumes through drinking tap and bottled water in adulthood may be a risk factor for prostate cancer, especially for highly aggressive tumors.

The experiment was carried out in this way. From 2008 to 2013, a total of 1,624 men aged 38 to 85 were recruited in Spain, of which 697 were prostate cancer patients (97 cases were highly invasive), 927 Humans were the control group (without any cancer during the study). For each participant from the age of 18, the nitrate intake in drinking water needs to be calculated in detail, first of all, to know their residence history and the type of drinking water (tap water, bottled water, or well water), if it is tap water, then According to the control standards for nitrates in drinking water announced by the local municipal government or licensed companies, if it is bottled water, use the analysis data of the best-selling local brands; if it is well water, use the monitoring data of groundwater in different locations. Also, it is worth mentioning that among the participants in this study who had a lower fiber intake (≤11 g/day), higher nitrate intake was associated with an increased likelihood of developing prostate cancer 2.3 times. However, higher nitrate intake was not associated with increased prostate cancer among those with higher fiber intake (>11 g/day).

Eating more colorful fruits and vegetables can reduce the negative impact of nitrate in drinking water

Therefore, if you can eat more fiber, fruits, vegetables and vitamin C, you can reduce the negative impact of nitrates in drinking water, and just in March 2023, the latest research by scientists at the University of South Australia,Men who regularly eat colorful fruits and vegetables are less likely to be diagnosed with prostate cancer, further supporting this finding. Antioxidants, vitamin C, and polyphenols in fruits and vegetables can inhibit the chances of nitrosamines forming in the stomach, while also preventing food-derived toxic substances, including nitrosamines, since fiber helps the good bacteria in the gut. Because of this, Professor Lin Yijun from the Food Safety Institute of Yangming Jiaotong University explained at a press conference in 2022 that if the source of nitrate intake comes from vegetables and fruits, there is no need to worry, and it may even help the cardiovascular system. But it should be reminded that if you eat nitrite from processed red meat such as bacon, bacon or sausage, you should still eat less. Today’s research paper reminds everyone that if nitrate comes from drinking water, it may come from vegetables and fruits, so different considerations must be taken?

Carolina Donat-Vargas, lead author of the paper, further stated that the association between nitrate levels in drinking water and prostate cancer has also been observed in Europe, where current EU regulations are Nitrate per liter of water should not exceed 50 mg, and should be considered for reduction in the future. But she also emphasized that drinking water with high levels of nitrates does not mean that you will get cancer. This paper only provides the first evidence of this association, and more research is needed to confirm it in the future , so it is a long way to go before asserting causality, but the authors expect that this study and others will encourage governments to reduce the levels of nitrates allowed in drinking water to ensure there are no risks to human health.

Finally, it is expected that more research in the future will help to raise awareness of water pollutants and their potential impact on the environment and human health, and can influence governments to ensure stricter controls on the protection of this natural cycle, such as A green diet that prioritizes protecting the planet by ending the overuse of fertilizers and pesticides and encouraging less animal food consumption is king.

references

1. Carolina Donat-Vargas, Manolis Kogevinas, Gemma Castaño-Vinyals, Beatriz Pérez-Gómez, Javier Llorca, Mercedes Vanaclocha-Espí, Guillermo Fernandez-Tardon, Laura Costas, Nuria Aragonés, Inés Gómez-Acebo, Victor Moreno, Marina Pollan, Cristina M. Villanueva. Long-Term Exposure to Nitrate and Trihalomethanes in Drinking Water and Prostate Cancer: A Multicase–Control Study in Spain (MCC-Spain). Environmental Health Perspectives, 2023; 131 (3) DOI: 10.1289/EHP11391

2. Varinderpal S. Dhillon, Permal Deo, Michael Fenech. Plasma Micronutrient Profile of Prostate Cancer Cases Is Altered Relative to Healthy Controls—Results of a Pilot Study in South Australia. Cancers, 2022; 15 (1): 77 DOI: 10.3390/cancers15010077