Nitrate and nitrite from water and food linked to bladder cancer
What it found
Higher levels of nitrate in drinking water and more nitrate and nitrite from processed meat were linked to more bladder cancer in people.
The link with water nitrate was stronger among those who ate more red meat.
What they found
Studies in people
Nitrate in drinking water
People whose drinking water had nitrate above 2.07 mg/L had about 50 percent more bladder cancer than those at or below 0.21 mg/L. This was seen in people across three US states.
Nitrate and nitrite from meat
Getting the most nitrate or nitrite from processed meat was linked to 40 to 50 percent more bladder cancer compared to getting the least. Nitrate and nitrite from other foods showed no such link in these people.
Combined with red meat
People with high water nitrate who also ate more red meat had over twice the bladder cancer risk. Those eating more processed red meat had over three times the risk compared to people low in both.
Vitamin C and smoking
Taking in vitamin C or being a smoker did not change the link between water nitrate and bladder cancer in this group of people.
What the authors conclude
- They say their results point to both drinking water and food as sources of nitrate that matter for bladder cancer risk.
- They note that the link with water nitrate was found at levels below the current US limit of 10 mg/L.
- The authors suggest the connection with water nitrate may be stronger for people who eat more red or processed red meat.
How it was done
Scientists think that nitrate and nitrite can turn into compounds inside the body that may cause bladder cancer. They wanted to see if getting these chemicals from drinking water or food was tied to the disease.
They studied 1,213 people with bladder cancer and 1,418 without it living in Maine, New Hampshire and Vermont. They estimated how much nitrate each person got from tap water and private wells from 1970 until diagnosis. They also used food questionnaires to measure nitrate and nitrite from diet over the previous five years.
What it can’t tell you
- This study looked back at past habits and exposures, so it can only show a link rather than prove that nitrate or nitrite caused the cancer.
- Scientists do not yet know if the same links would appear in places outside northern New England.
Who paid
- Funding
- Funded by NCI NIH HHS; Intramural NIH HHS (from the PubMed record).
- Conflicts
- Conflicts of Interest: None declared
- Authors work at
- National Cancer Institute, MD; University of Maryland School of Medicine, MD; Virginia Commonwealth University, VA
The paper
- Title
- Ingested Nitrate and Nitrite and Bladder Cancer in Northern New England
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Barry KH, Jones RR, Cantor KP, et al (2020). Ingested Nitrate and Nitrite and Bladder Cancer in Northern New England. Epidemiology (Cambridge, Mass.). doi:10.1097/EDE.0000000000001112Free full textPubMed 31577632DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error