title: Protection against oral and gastrointestinal diseases: importance of dietary nitrate intake, oral nitrate reduction and enterosalivary nitrate circulation.
abstract: Over the last 20 years, dietary nitrate has been implicated in the formation of methemoglobin and carcinogenic nitrosamines in humans. This has led to restrictions of nitrate and nitrite levels in food and drinking water. However, there is no epidemiological evidence for an increased risk of gastric and intestinal cancer in population groups with high dietary vegetable or nitrate intake. A reevaluation of our currently very negative perception of dietary nitrates comes from recent research into the metabolism and enterosalivary circulation of nitrate in mammals. These studies showed that nitrate is converted to nitrite in the oral cavity that then "fuels" an important mammalian resistance mechanism against infectious diseases. Moreover, there is now evidence that the conversion of nitrate into oxides of nitrogen prevents the formation carcinogenic nitrosamines.
authors.affiliation: Department of Plant & Soil Science, University of Aberdeen, Scotland, U.K.
authors.forename: C
authors.initials: C
authors.lastname: Duncan
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: R
authors.initials: R
authors.lastname: Dykhuizen
authors.forename: R
authors.initials: R
authors.lastname: Frazer
authors.forename: P
authors.initials: P
authors.lastname: Johnston
authors.forename: G
authors.initials: G
authors.lastname: MacKnight
authors.forename: L
authors.initials: L
authors.lastname: Smith
authors.forename: K
authors.initials: K
authors.lastname: Lamza
authors.forename: H
authors.initials: H
authors.lastname: McKenzie
authors.forename: L
authors.initials: L
authors.lastname: Batt
authors.forename: D
authors.initials: D
authors.lastname: Kelly
authors.forename: M
authors.initials: M
authors.lastname: Golden
authors.forename: N
authors.initials: N
authors.lastname: Benjamin
authors.forename: C
authors.initials: C
authors.lastname: Leifert
mesh_terms: D000818:Animals; D004032:Diet; D005767:Gastrointestinal Diseases / Q000517:prevention & control*; D006801:Humans; D009059:Mouth Diseases / Q000517:prevention & control*; D009566:Nitrates / Q000378:metabolism* / Q000627:therapeutic use*; D012463:Saliva / Q000378:metabolism*
chemical_list: D009566:Nitrates