Dietary intakes of nitrate, nitrite and NDMA in the Finnish mobile clinic health examination survey

Abstract

Concern about potential health hazards of nitrate, nitrite and N-nitroso compounds necessitates calculations of exposures to these compounds and their distribution in normal populations. This study describes dietary intake of nitrate (NO3-), nitrite (NO2-) and N-nitrosodimethylamine (NDMA) among 5304 adult men and 4750 women, who participated in the Finnish Mobile Clinic Health Examination Survey in 1967-72. Food consumption data for each individual over the preceding year were collected by a dietary history interview. Intakes of nitrate, nitrite and NDMA from vegetables, fruits, cheese, meat and fish products were calculated using available values mainly derived from Finland and other countries in northern Europe. Nitrate and nitrite from drinking water were not included in the study. Mean daily dietary intake of nitrate was 77 mg, of nitrite 5.3 mg, and of NDMA 0.05 microgram respectively. Intake of NDMA from beer, estimated in a part of the study population, was 0.07 microgram per day. More than 90% of dietary nitrate was derived from vegetables, including potatoes. Nitrite was mainly provided by cured meat products. Cured meat products and smoked and salted fish were important food sources of NDMA. The total daily intake of nitrate was similar in men and women, whereas intakes of nitrite and NDMA were higher in men than in women. The diet of farmers was characterized by lower amounts of nitrate, nitrite and NDMA, whereas white collar workers and those employed in industry had higher intakes. Current smokers were exposed to higher dietary intakes of nitrate, nitrite and NDMA than non-smokers. Intakes of dietary nitrate, nitrite and NDMA estimated on an individual level are suggested to be useful in evaluating the health effects of these compounds in epidemiological studies.

Intake and food sources of nitrites and N-nitrosodimethylamine in Spain

“…On the other hand, foods with a high content of NDMA 11 , such as smoked or salted fish, are not important contributors to the total intake because they are consumed by a very low percentage of the EPIC -Spain population (0.30% and 3%, respectively). Different patterns of consumption have been found in studies published in Finland and France, in which smoked fish contributed 22 -25% to total intakes of NDMA 18,33 . The highest values of NDMA intake have been reported in Japan, due to high intakes of dried and smoked fish 34 .…”

Dietary intake of different types and characteristics of processed meat which might be associated with cancer risk – results from the 24-hour diet recalls in the European Prospective Investigation into Cancer and Nutrition (EPIC)

“…This raises the question whether information at the food level as an indicator of cured PM consumption is sufficient to describe exposure differences for nitrite/nitrate through PM consumption, because this approach assumes a similar NaNO 2 content in the ready-to-eat PM products in the different countries which might not be correct. In a Finnish study, conducted between 1966 and 1972, mean intake of nitrite was 5.3 mg day 21 , provided nearly exclusively by cured meats and PM 5,36 . However, another report from Finland calculated an average daily intake of 1.88 mg 33 .…”

Estimated dietary intake of nitrite and nitrate in Swedish children

“…Some studies have also reported the presence of nitrite in other foodstuffs, e.g. cereals, cheese and bread, but the content of nitrite in these food groups is often lower than the limit of detection (LOD) (Knight et al 1987;Dich et al 1996;Petersen & Stoltze 1999;Jakszyn et al 2006;Thomson et al 2007;Menard et al 2008;Griesenbeck et al 2009). …”

“…Furthermore, nitrate is found in cured meat, either through F o r P e e r R e v i e w O n l y being used as a food additive or formed from conversion of initially added nitrite. Nitrate is also present in limited amounts in other foodstuffs such as bread, cereals and dairy products (Dich et al 1996;Ysart et al 1999;Menard et al 2008;Griesenbeck et al 2009 The conversion of nitrate to nitrite in the body mainly takes place in the oral cavity, and it has been estimated that 5-7% of nitrate ingested is converted to nitrite by bacteria normally occurring in the mouth (Eisenbrand et al 1980;FAO/WHO 2003b 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 years, 713 school children aged 8-9 years and 956 school children aged 11-12 years, resulting in a total of 2259 children. The children aged 4 years were randomly selected from a register of families with children of this age, while the school children were randomly selected as whole school classes.…”