Nitrates Might Benefit GI Tract

Nitrates, naturally occurring compounds also used to cure meat, have fallen into disfavor because of purported links to cancer. But many have pointed to the natural nitrate content in other foods, especially vegetables, and in human saliva as reasons to allay the fears. In addition a growing body of evidence links these compounds to health benefits, including recent work from Sweden (Nitrate, Nitrite and Nitric Oxide in Gastric Mucosal Defense) that says nitrates can help protect the stomach from damage.

Researcher Joel Petersson, in the Department of medical Cell Biology, Uppsala University, Uppsala, Sweden, proposes that consuming nitrate-rich vegetables, such as spinach, lettuce, radishes and beets, has a positive effect by activating the protective mechanisms of the stomachs mucous membranes, thus reducing the risk of developing gastric ulcers and associated problems.

He describes the conversion of nitrates into nitrites by oral bacteria and the subsequent transformation into nitric oxide in the stomach: After eating nitrate-rich food, saliva contains high level of nitrates, part of which oral bacteria partially convert into nitrites. When swallowed, the nitrites contact the acid gastric juice, and are converted into nitric oxide. This compound stimulates the protective mechanisms of the mucous membrane, widening the blood vessels and increasing the blood flow and regulating elimination of the important mucus. Together, these factors lead to a more protective, disease-resistant mucous membrane.

Using animal models, Petersson and colleagues have shown that nitrate additives in food protect against both gastric ulcers and the gastrointestinal damage that often occurs from ingesting anti-inflammatory drugs.

These sorts of drugs are very common in the event of pain and inflammation, Petersson explains. They have the major disadvantage of causing a large number of serious side effects in the form of bleeding and ulcers in the gastrointestinal tract. With the aid of a nitrate-rich diet you can thus avoid such damage.

The study also found that using an antibiotic oral spray killed the important bacteria in the mouth that normally convert nitrates into nitrites, so that the compound no longer had a protective effect on the mucous membrane.

This shows how important our oral flora is, says Petersson. 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.

Nitrates and nitrates have long been used for the meat-curing process, where they delay development of the bacterial toxin that causes botulism, develop the cured meat flavor and pinkish color, and slow rancidity and off-flavor development. They have been implicated as carcinogens, because of their ability to form nitrosamines, some of which are carcinogenic. However, many experts, including Petersson, believe the evidence that nitrite and nitrate pose a cancer risk is weak, especially given the preponderance of naturally occurring nitrates. An earlier study done at The University of Texas Health Science Center at Houston also found evidence that these compounds may help heart attack survival and recovery.