Nitrate exposure from drinking water, even below regulatory limits, increases dementia risk
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Years ago, I did a post on a study showing that exposure to nitrates from processed foods (mostly meats such as sausages, salami, bacon, etc) increased risk of developing mania and bipolar disorder. The study below now suggests that such exposure can also increase dementia risk. Since Alzheimer Disease (AD) is a type of dementia, the importance of this study cannot be overstated. Notably, unlike the dietary nitrate exposure study, which dealt with people exposed to nitrate levels within the established regulatory limit of nitrates used as a preservatives and color-protectors in foods, the current study showed that exposure to nitrates at levels much lower than the allowable regulatory limit increases risk of dementia. While the study tries to argue that the increased risk is from nitrosamines that form when nitrates interact with proteins, I think the evidence points to nitric oxide (NO) as the more likely culprit. The reason is that nitrosamines usually form only under very high temperatures (e.g. cooking), while NO readily forms at body temperature as soon as a person ingests a food or drink that contains nitrates. As such, drinking nitrate-laced water is not likely to lead to formation of nitrosamines, while it will most certainly lead to increased formation of NO.
https://doi.org/10.1002/alz.70995
https://scitechdaily.com/nitrate-in-drinking-water-may-raise-dementia-risk-study-warns/
“…This is the first time that nitrate from drinking water has been linked to higher risks of dementia. The study found that participants exposed to drinking-water nitrate at levels below the current regulatory limits, had a higher rate of dementia, however, Dr. Bondonno stressed that this was only one study, and more research was required. “Water doesn’t contain antioxidants that can block the formation of N-nitrosamines. Without these protective compounds, nitrate in drinking water may form N-nitrosamines in the body,” she said. In Denmark and the EU, the limit for nitrate in groundwater and drinking water is set at 50 mg/L, but the researchers observed a higher risk for drinking water containing as low as 5 mg of nitrate per liter.”