Here's another reason why you should eat more fruits and vegetables, for a new study has revealed that nitrates found in them may protect stomach against gastric ulcers.
Food nitrates have long been linked to an increased cancer risk, however the new study from Uppsala University has suggested that nitrate-rich vegetables such as spinach, lettuce, radishes and beetroot have a positive affect on the stomach by activating the mucous membranes' own protective mechanisms, thus reducing the risk of problems such as gastric ulcers.
In the body, blood circulation transports nitrates to the salivary glands, where they are concentrated. When we have eaten nitrate-rich food our saliva thus contains large amounts of nitrates, which the bacteria of the oral cavity partially convert into nitrites.
When we swallow the nitrites they come into contact with acid gastric juice, and are then converted into the biologically active substance nitric oxide.
This results in our developing high levels of nitric oxide in the stomach after eating vegetables.
The study led by Joel Petersson of Uppsala University's Department of Medical Cell Biology showed that the nitric oxide that is formed in the stomach stimulates the protective mechanisms of the mucous membrane.
Two such important defence mechanisms are the stomach's constant renewal of the mucous layer that covers the mucous membrane and its maintenance of a stable blood flow in the mucous membrane.
The research conducted using animal models revealed that nitrate additives in food protect against both gastric ulcers and the minor damage that often occurs in the gastrointestinal tract as a result of ingestion of anti-inflammatory drugs.
For the study, the rats were given nitrate-rich feed. Some of them were also simultaneously given an antibacterial oral spray. When these rats were given anti-inflammatory drugs, damage to the mucous membrane only occurred in the ones that had received the oral spray.
"This shows how important our oral flora is. The fact that these bacteria are not just involved in our oral hygiene but also play an important role in the normal functions of the gastrointestinal tract is not entirely new," said Petersson.