EFSA balances the consumer risks from nitrate in vegetables with the benefits of a balanced diet high in vegetables and fruit
5 June 2008
EFSA’s Contaminants Panel (CONTAM) has assessed the risks and benefits to consumers from nitrates in vegetables and concluded that the beneficial effects of eating vegetables and fruit outweigh potential risk to human health from exposure to nitrate through vegetables. Fruit and vegetables are important components of a healthy and balanced diet, and, if consumed daily in sufficient amounts, could help to reduce the risk of certain diseases. The Panel said that the average consumer eating approximately 400g of mixed vegetables and fruit per daywould not exceed the Acceptable Daily Intake for nitrate (ADI). In estimating exposure, the Panel assumed that all of the 400g of fruit and vegetables eaten by consumers could potentially be vegetables which are substantially higher in nitrate content than fruit. The Panel said that a small part of the European Union population (2.5%), who are high consumers of green leafy vegetables, could exceed the Acceptable Daily Intake for nitrate.
EFSA was asked by the European Commission to deliver an opinion on the risks to consumers from nitrate in vegetables and to consider the balance between health risks and benefits in order to provide an up-to-date scientific basis to support risk managers in defining future strategies on nitrate in vegetables. EFSA’s CONTAM Panel was assisted by an expert working group which also included a member of EFSA’s Panel on dietetic products, nutrition and allergies(NDA). Epidemiological studies do not suggest that nitrate intake from diet or drinking water is associated with increased cancer risk. However, the human body changes nitrate into compounds, such as nitrite and nitric oxide which can have possible health implications.
Commenting on the opinion, Josef Schlatter, chair of EFSA’s Contaminants Panel, explained: “We assessed both the risk and benefits of exposure to nitrate from vegetables and concluded that the beneficial effects of vegetables prevail.”
The main dietary sources of nitrate are vegetables, preserved meat and drinking water but vegetables and fruit can represent over half or, as much as two thirds, of all nitrate intake. Nitrate is present in most vegetables to a varying degree but the critical driver for a high dietary exposure to nitrate is not the absolute amount of vegetables consumed but the type of vegetables (e.g. leafy vegetables) and the respective concentration of nitrate. Green leafy vegetables, such as spinach, lettuce and rucola have the highest nitrate content. Nitrate content of vegetables also varies in relation to other factors, such as the extent of use of nitrate fertilisers and the amount of sunlight to which vegetables are exposed (vegetables grown in North European countries tend to have higher nitrate content). According to the opinion, vegetarians and vegans who consume a high quantity of fruit and vegetables, are not considered likely to exceed the ADI, as their protein needs are normally covered by consumption of cereals, nuts and pulses which are low in nitrate.
Vegetables such as lettuce and spinach are already subject to EU regulation laying down maximum nitrate levels. In the group of leafy vegetables, rucola has the highest levels of nitrate based on information reported from Member States. For instance, consumers eating more than 47 grams of rucola per day might already exceed the ADI without taking into account any other sources of nitrate exposure. EFSA notes that consumption of rucola at this level on a daily basis is not likely to occur over a long period of time and therefore considers that exceeding the ADI on occasion would not represent a health concern.
The CONTAM Panel noted that further mitigation of nitrate intake may result from processing e.g. washing, peeling and/or cooking thus providing an extra safety margin for consumers.
 400 grams is based on WHO recommendations for vegetables and fruit consumption. The Panel carried out its risk assessment based on the assumption that all of the 400grams were vegetables, as is the case for some high consumers in some EU Member States.
 An Acceptable Daily Intake (ADI) for nitrate of 3.7 mg/kg b.w./day was established by the former Scientific Committee on Food and was reconfirmed by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 2002. The CONTAM Panel noted that there were no new data to alter this figure. The ADI is the amount of a specific substance in food that can be ingested orally over a lifetime without an appreciable health risk.
 The metabolites and reaction products of nitrate, e.g. nitrite, nitric oxide and N-nitroso compounds can lead to methaemoglobinaemia (resulting in a limited oxygen supply to the blood) and have potential cancer-causing properties.
 Commission Regulation (EC) No 1881/2006 fixes maximum nitrate levels in spinach and lettuce. Some countries (Belgium, France, Ireland, the Netherlands and the United Kingdom) were given a temporary derogation from these levels for one or more of these two vegetables until December 2008.