Led by Paula Jakszyn at the University of Barcelona in Spain, the researchers set out to develop a food composition database of nitrates, nitrites, nitrosamines, heterocyclic amines (HA), and polycyclic aromatic hydrocarbons (PAH) in foods.
"An accurate assessment of dietary intake of such compounds is difficult, mainly because they are not naturally present in foods, and they are not included in standard food composition tables," said the researchers, reporting their findings in the August issue of the US Journal of Nutrition, (134:2011-2014, 2004).
Polycyclic aromatic hydrocarbons are a group of over 100 different chemicals that are formed during the incomplete burning of coal and oil, or other organic substances like tobacco or charbroiled meat. Consumers might be exposed to PAHs by eating grilled or charred meats, contaminated cereals, flour, bread, vegetables, fruits, meats as well as processed or pickled foods.
The researchers in Spain conducted a literature search of the nitrates, nitrites, nitrosamines, HA, and PAH compounds in foods from 1980 onwards using the Medline and EMBASE databases. The final database included 207 food items listing concentrations of nitrites, nitrates and nitrosamines, 297 food items giving concentrations of HAs, and 313 food items with listings for the concentrations of PAHs.
The database gives the name of the food, cooking method, preservation method, how thoroughly cooked, temperature and time, quantity, analytical method and sampling method, year of publication, author and country. In some cases different sources provided information concerning the same food item.
"This database will allow investigators to quantify dietary exposure to several potential carcinogens, and to analyse their relation to the risk of cancer," conclude the Spanish researchers.
But, they add that the potential limitations of the database are due to the 'quality of the information we could obtain through the Medline and EMBASE databases.'