Sodium nitrite and bladder cancer in New England
What it found
In a study of 987 cases and 1,180 controls, higher nitrate in drinking water and nitrate and nitrite from processed meat were linked to bladder cancer.
The study was in people.
What they found
Studies in people
Drinking water nitrate
People with the highest average nitrate concentration in drinking water (above 2.07 mg/L) had a higher chance of bladder cancer than those with the lowest (0.21 mg/L or less). The link was similar for average daily nitrate intake from water.
Processed meat nitrate and nitrite
Higher intake of nitrate and nitrite from processed meat was linked to bladder cancer. The highest intake group had about 1.4 times the chance for nitrate and 1.5 times for nitrite compared with the lowest group.
Other dietary sources
There was no link between bladder cancer and overall nitrate or nitrite intake, or nitrite from animal or plant sources.
Red meat interaction
People with the highest drinking water nitrate and who ate more red meat or processed red meat had a higher chance of bladder cancer. The link was stronger than for either factor alone.
Vitamin C and smoking
Vitamin C intake and smoking did not change the link between drinking water nitrate and bladder cancer.
What the authors conclude
“Our results suggest the importance of both drinking water and dietary nitrate sources as risk factors for bladder cancer.”
Also in their conclusions
- They suggest that nitrate concentrations in drinking water below the current regulatory limit are associated with bladder cancer.
- They say the associations may be stronger among those with higher red or processed red meat consumption.
- They add that their study supports growing evidence of a link between nitrate and nitrite from processed meat and bladder cancer.
How it was done
N-nitroso compounds are thought to cause bladder cancer in humans. The authors wanted to see if nitrate and nitrite, which can form these compounds, are linked to bladder cancer.
They studied 987 people with bladder cancer and 1,180 without it in Maine, New Hampshire and Vermont. They estimated nitrate in drinking water from public supplies and private wells from 1970 onward, and nitrate and nitrite from diet using a food questionnaire.
What it can’t tell you
- This kind of study can show a link, but it cannot prove that nitrate or nitrite cause bladder cancer.
- The study relied on estimated nitrate levels and self-reported diet, which may not be exact.
- It only looked at water nitrate over the prior 30 years, so longer or earlier exposure could not be assessed.
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 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error