19 Jun 2017 --- Although consumer exposure to nitrites and nitrates as food additives is generally within safe levels for all population groups, if all dietary sources of nitrites and nitrates are considered, the safe levels (ADIs) may be exceeded. This is according to a report by EFSA, following a re-evaluation of existing safe levels for nitrites and nitrates intentionally added to meat and other foods.

Sodium and potassium salts of nitrite and nitrate (E 249-252) are authorized as food additives in the EU. They are used in meat, fish and cheese products to hinder microbial growth, in particular, to protect against botulism, as well as to keep meat red and enhance its flavor. Many consumers view these with suspicion and are increasingly seeking out healthier products with labels that are cleaner, clearer and easier to understand. Nitrate is also found naturally in high concentrations in certain vegetables, and it can enter the food chain as an environmental contaminant – mainly in water.

Using a refined exposure assessment, experts estimated that consumer exposure to nitrate solely from food additives was less than 5% of the overall exposure to nitrate in food, and did not exceed the safe levels. However, if all sources of dietary nitrate are considered (food additive, natural presence in foods and environmental contaminants), the safe level may be exceeded for individuals of all age groups with medium to high exposure.

However, based on the available evidence, EFSA concluded that there was no need to change previously set safe levels for either substance, according to Professor Maged Younes, a member of EFSA’s Panel on Food Additives and Nutrient Sources Added to Food, and Chair of the Working Group tasked with the re-evaluation.

The current acceptable daily intake (ADI) for nitrates is 3.7 milligrams per kilogram of body weight per day (mg/kg bw/day). The safe level for nitrites was re-established at 0.07 mg/kg bw/day, close to the slightly more conservative existing ADI of 0.06 mg/kg bw/day.

For nitrites used as food additives, experts estimated exposure to be within safe levels for all population groups, except for highly exposed children, who might slightly exceed the ADI. Exposure from all dietary sources may exceed the ADI for infants, toddlers and children with medium exposure, and for highly exposed individuals of all age groups. Children are often more exposed to substances because of their higher food consumption levels relative to their body weight.

Nitrite is also linked to the formation of a group of compounds known as nitrosamines, some of which cause cancer. EFSA’s experts therefore also estimated their formation inside the body following the use of nitrites as food additives. They concluded that when nitrites are used at approved levels, their contribution to overall exposure to nitrosamines is of low concern for health.

Nitrite unintentionally present in meat products from other sources such as environmental contamination can also contribute to the formation of nitrosamines. EFSA’s experts concluded that these levels of nitrosamines might give rise to potential health concerns but that more research was needed to address uncertainties and knowledge gaps in this complex area.

Although the panel concluded that nitrites and nitrates added to food at permitted levels are safe for consumers in Europe, it pointed out that there are still some knowledge gaps to be filled by future research.

For this reason, the panel made several recommendations, including “additional studies to measure the excretion of nitrate into human saliva, its conversion to nitrites, and the resulting methaemoglobin formation; further studies on the levels of nitrosamines formed in different meat products based on known amounts of added nitrites/nitrates; large-scale epidemiological studies on nitrite, nitrate and nitrosamine intake and risk of certain cancer types.”