Abstract
Inorganic nitrate and nitrite are plant nutrients, legally mandated additives to processed meats, and components of foods and dietary supplements associated with blood pressure-lowering and performance-enhancing effects. Controversy around dietary nitrate and nitrite consumption exists because of the potential for increased risk of certain cancers in adults and methemoglobinemia (ie, blue baby syndrome) in infants. However, more recent evidence suggests that dietary nitrate, as an exogenous source for endogenous nitric oxide production via the human nitrate-nitrite-nitric oxide pathway, exerts blood pressure-lowering effects and athletic performance-enhancing activities in humans. Nitrate and nitrite content in foods is lacking from nutrient databases, which limits the ability to study health-related epidemiological associations. Therefore, we estimated human nitrate and nitrite intakes from cultural meal patterns, foods, and dietary supplements in order to determine the potential exposure range from available foods. Examination of prototypical daily meal patterns from 4 cultures showed that meal patterns with the greatest nitrate and nitrite concentrations were those with an abundant amount of leafy greens and root vegetables, such as the Japanese and Chinese diet, whereas concentrations in the American and Indian diet were considerably lower. Furthermore, consumption of 1 serving of a nitrate-rich food or supplement can exceed the World Health Organization acceptable daily intake for nitrate (0-3.7 mg/kg body weight per day or 222 mg/d for a 60-kg adult). Given the potential health benefits and risks for dietary nitrate and nitrite intakes, there is a need for rational dietary guidance regarding nitrate- and nitrite-containing foods in order to achieve optimal cardiovascular health and athletic performance, while taking into account the potential negative health risks.