Long-term exposure to nitrate in drinking water may be a risk factor for prostate cancer

Date:
March 8, 2023
Source:
Barcelona Institute for Global Health (ISGlobal)
Summary:
The nitrate ingested over the course of a person's adult lifetime
through the consumption of tap water and bottled water could be
a risk factor for prostate cancer, particularly in the case of
aggressive tumors and in younger men.


Facebook Twitter Pinterest LinkedIN Email
FULL STORY ==========================================================================
The nitrate ingested over the course of a person's adult lifetime through
the consumption of tap water and bottled water could be a risk factor
for prostate cancer, particularly in the case of aggressive tumours
and in younger men. This is the conclusion of a study conducted in
Spain and led by the Barcelona Institute for Global Health (ISGlobal),
a centre supported by the "la Caixa" Foundation. The findings have been published in Environmental Health Perspectives.


==========================================================================
The study also suggests that diet plays an important role. The researchers found that eating plenty of fibre, fruit/vegetables and vitamin C could
reduce the negative effect of nitrate in drinking water.

Ingestion of Waterborne Nitrate and Trihalomethanes The aim of the study
was to assess whether there was an association between the ingestion of waterborne nitrate and trihalomethanes (THMs) and the risk of prostate
cancer. Nitrate and THMs are two of the most common contaminants in
drinking water. The nitrate present in the water comes from agricultural fertilisers and manure from intensive livestock farming; it is washed into aquifers and rivers by rainfall. "Nitrate is a compound that is a part
of nature, but we have altered its natural cycle," explained Cristina Villanueva, an ISGlobal researcher specialised in water pollution. The
new study looked at whether long-term exposure to nitrite throughout
adulthood could lead to cancer.

THMs are by-products of water disinfection -- i.e. chemical compounds
formed after drinking water is disinfected, usually with chlorine. Unlike nitrate, for which the only route of entry is ingestion, THMs can also
be inhaled and absorbed through the skin while showering, swimming in
pools or washing dishes.

Long-term exposure to THMs has been associated with an increased risk
of bladder cancer, but evidence of the relationship between THMs and
other types of cancer is, to date, very limited.

Prostate Cancer and Long-Term Exposure to Nitrate and THMs in Drinking
Water To evaluate the possible association between prostate cancer and long-term exposure to nitrate and THMs in drinking water, a research
team led by ISGlobal studied 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 38-85 years who had not
been diagnosed with cancer at the time of the study. The average nitrate
and trihalomethanes to which each participant had been exposed since
the age of 18 was estimated based on where they had lived and the type
(tap water, bottled water or, in some cases, well water) and amount of
water they had drunk throughout their lives. Estimates were made on
the basis of available data from drinking water controls carried out
by municipalities or concessionary companies, from analyses of bottled
water of the most widely distributed brands, and from measurements taken
in different Spanish locations supplied by groundwater.

The findings showed that the higher the nitrate intake, the greater the association with prostate cancer. Participants with higher waterborne
nitrate ingestion (lifetime average of more than 14 mg per day) were 1.6
times more likely to develop low-grade or medium-grade prostate cancer
and nearly 3 times more likely to develop an aggressive prostate tumour
than participants with lower nitrate intakes (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."
Drinking Water Does Not Imply Getting Cancer The authors noted that this
study simply provides the first evidence of the association, which will
need to be confirmed through further research.

Therefore, there is still a long way to go before we can assert a
causal relationship. "Being exposed to nitrates through drinking
water does not mean that you are going to develop prostate cancer,"
commented 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." While the
ingestion of waterborne THMs was not associated with prostate cancer,
THM concentrations in residential tap water were associated with the development of these tumours, suggesting that inhalation and dermal
exposure may play a significant role in total exposure. Further studies properly quantifying exposure to THMs via multiple routes are needed to
draw firm conclusions.

Fibre, Fruit, Vegetables and Vitamin C to Prevent Prostate Cancer
Participants also completed a food frequency questionnaire, which provided individual dietary information. A striking finding of the study was that
the association between ingested nitrate and prostate cancer were only
observed in men with lower intakes of fibre, fruit/vegetables and vitamin
C. "Antioxidants, vitamins and polyphenols in fruits and vegetables may
inhibit the formation of nitrosamines -- compounds with carcinogenic
potential -- in the stomach," explained Donat-Vargas. "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." In participants with lower intakes
of fibre (<=11 g/day), higher nitrate intake increased the likelihood
of prostate cancer by a factor of 2.3. However, in those with higher
intakes of fibre (>11 g/day), higher nitrate intake was not associated
with an increased likelihood of prostate cancer.

The research team hopes that this study will help to raise awareness of
the potential environmental and human health impacts of pollutants in
water, and to persuade authorities to ensure more rigorous control of
this natural resource.

Among the measures proposed by the authors of the study to reduce nitrate levels are "putting an end to the indiscriminate use of fertilisers and pesticides," and encouraging the adoption of diets that prioritise the
health of the planet by reducing the consumption of animal-based foods, especially meat.

Prostate Cancer: The Most Common Cancer in Spanish Men Prostate cancer
appears to be on the rise worldwide. It is currently the most common
cancer in Spanish men, among whom it accounts for 22% of all tumours
diagnosed. However, its causes remain largely unknown, and it is one of
the few cancers for which the International Agency for Research on Cancer (IARC) has not identified a clear carcinogenic agent. The currently
recognised risk factors -- age, ethnicity and family history -- are non-modifiable. However, it is suspected that certain environmental
exposures may contribute to the development of prostate cancer,
especially in its advanced-stage and more aggressive forms. Therefore,
it is vitally important to continue exploring the environmental factors
that may contribute to the development of this cancer, so that action
can be taken to prevent it.

* RELATED_TOPICS
o Health_&_Medicine
# Men's_Health # Prostate_Cancer # Urology #
Prostate_Health
o Earth_&_Climate
# Water # Drought_Research # Environmental_Issues #
Pollution
* RELATED_TERMS
o Prostate_cancer o Stomach_cancer o Cholera o
Water_purification o Desalination o Hair o Esophageal_cancer
o Cancer

========================================================================== Story Source: Materials provided by Barcelona_Institute_for_Global_Health_(ISGlobal). Note: Content may be
edited for style and length.


========================================================================== Journal Reference:
1. Carolina Donat-Vargas, Manolis Kogevinas, Gemma Castan~o-Vinyals,
Beatriz
Pe'rez-Go'mez, Javier Llorca, Mercedes Vanaclocha-Espi',
Guillermo Fernandez-Tardon, Laura Costas, Nuria Aragone's,
Ine's Go'mez-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 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2023/03/230308112202.htm

--- up 1 year, 1 week, 2 days, 10 hours, 51 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)