Study Links Nitrate Sources to Differing Dementia Risks
New research from Edith Cowan University and the Danish Cancer Research Institute suggests that the health effects of dietary nitrate may depend on where it comes from. The study followed more than 54,000 Danish adults for up to 27 years and examined links between nitrate and nitrite intake and dementia, including early-onset dementia.
Researchers found that higher nitrate intake from vegetables was associated with a lower risk of dementia. In contrast, higher exposure to nitrate and nitrite from animal products, processed meats, and drinking water was associated with a higher risk.
The study’s authors say the difference may relate to how nitrate is processed in the body. Vegetables contain vitamins and antioxidants that may help nitrate convert into nitric oxide, a compound involved in healthy blood vessel function. These same compounds may also reduce the formation of N-nitrosamines, substances that have been linked to cancer and may be harmful to the brain.
Animal-based foods do not contain the same mix of protective compounds. Some, including red and processed meats, also contain heme iron, which researchers say may promote N-nitrosamine formation.
The study also reported an association between nitrate in drinking water and increased dementia risk, even at levels below current European regulatory limits. Researchers emphasized that the individual increase in risk was small and that people should not stop drinking water. They said the findings may warrant further review of long-term, low-level nitrate exposure.
The researchers cautioned that the study was observational. It can identify associations but cannot prove that nitrate from any source directly causes or prevents dementia. Other diet, lifestyle, or health factors may have influenced the results.
Still, the findings add to ongoing research on diet and brain health. They suggest that nitrate source may be an important factor when assessing potential long-term health effects. Further studies, including laboratory research, will be needed to clarify the mechanisms involved.