SPANISH AGENCY FOR CONSUMER AFFAIRS, FOOD SAFETY AND NUTRITION RECOMMENDATIONS

In light of the conclusions of the EFSA on nitrates in vegetables, and the eating habits and paediatrician recommendations in Spain, the Spanish Agency for Food Safety and Nutrition makes the following recommendations for consumption with the aim of reducing exposure to nitrates in sensitive populations (babies and infants):

• As a precautionary measure, neither spinach nor chard should be included in baby food before the infant's first birthday. If these vegetables are included at an earlier stage, ensure that the spinach and/or chard content is not more than 20% of the total content of the baby food.
• Do not feed more than one portion of spinach and/or chard per day to children aged between 1 and 3 years old.
• Do not feed spinach and/or chard to children with gastrointestinal bacterial infections.
• Do not keep the cooked vegetables (whole or in pureed form) at room temperature. Store in a refrigerator if they are to be eaten the same day, and if not they should be frozen.

It should be noted that when the risks/benefits of exposure to nitrate due to the consumption of leafy vegetables are compared, the recognised beneficial effects from their consumption prevail. In any case, a varied and balanced diet is one of the bases of an adequate and healthy diet.

Nitrates

Nitrates are naturally found in vegetables, especially in green leafy vegetables, such as spinach and lettuce. The nitrate itself is relatively harmless. Its toxicity is determined by its reduction to nitrites in the human body which, in high concentrations may lead to methemoglobinemia, the most characteristic sign of which is cyanosis. This disease particularly affects babies and young children who are exposed to high concentrations of nitrates in diet, often called the “blue baby syndrome”.

Aware of this dietary risk, maximum limits for nitrates in lettuce and spinach, and in infant food have been established at community level (Regulation 1881/2006, of 19 December 2006, setting maximum levels for certain contaminants in foodstuffs). These limits are currently being reassessed based on the control data collected in recent years. In some cases it has been confirmed that, in spite of the application of codes of good farming practice, the maximum limits for nitrates are not met, especially in the case of fresh spinach.

The key for explaining this situation lies in the weather conditions, specifically light as a key factor in the cultivation of these vegetables. A high light intensity favours the metabolism of the plant fixing the nitrogen in organic nitrogen compounds, including amino acids, proteins, chlorophyll, etc., which reduces the nitrate content, so that any factor which reduces the light intensity or the speed of photosynthesis favours the build-up of the same in the plant. Consequently, winter crops have higher nitrate concentrations than summer crops and similarly crops grown in countries in northern Europe have higher levels than those grown in the south. For the same reason, crops grown in the open air have a lower nitrate content than those grown under glass.

Scientific Opinions

The Panel on Contaminants in the Food Chain of the EFSA published a statement on possible health risks for infants and young children from the presence of nitrates in leafy vegetables, such as spinach and lettuce. The statement supplements a scientific opinion on “nitrates in vegetables”, published by the same Panel in 2008, in which the risks and benefits of eating vegetables and leafy vegetables were compared.

The EFSA Panel concludes that nitrate levels in lettuce are not a health concern for children. In the case of spinach the situation is different; EFSA has studied two different exposure scenarios and has reached the following conclusions:

• Infants (babies from 3 to 12 months): It is unlikely that the consumption of spinach is likely to be a health concern, as considering that spinach forms part of the diet as one of the ingredients in pureed baby food for infants aged between 6 and 12 months old. However, the EFSA recognises that there would be a concern if more than one portion of infant food containing spinach is consumed per day (considering that spinach forms 50% of the contents of the infant food).
• Children aged 1 to 18 years: The EFSA studied three population groups of children (1-3, 4-6 and ≥7 years old), in which spinach may be eaten as a full portion, and established that the highest exposure to nitrates took place in the 1 to 3 year-old group. The absence of risk is not rejected for this group in extreme situations, or in situations in which a high intake of spinach is combined with the presence of high levels of nitrates in the same.

Lastly, the EFSA advises that the inappropriate storage of these cooked vegetables (preparation of pureed infant food one day in advance and storage at room temperature) can result in the in situ conversion of nitrates to nitrites, thereby increasing the potential to cause methemoglobinemia. In addition, children with bacterial infections of the gastrointestinal tract are more sensitive to nitrate, and the Panel recommended against feeding spinach to such children.

Other information of interest

The mean levels found in vegetables with a high level of consumption are:

As can be seen from the table, chard is the vegetable with the highest mean nitrate content, although the consumption of this vegetable in Europe is insignificant.

As regards the remaining vegetables, it should be noted that those with the highest consumption levels, i.e. potatoes, carrots, tomatoes, pepper, aubergine, courgette, cucumber, leek, etc. have very low levels of nitrates when compared to lettuce, spinach and chard. Only beetroot and celery have mean levels of more than 1000 mg/Kg, but their dietary contribution is minor.

Situation in Spain

The leafy vegetables consumed in Europe are mainly lettuce and spinach, and consequently the EFSA statement is only based on these. However, in Spain the consumption of chard is significant, and with in the EU is almost exclusive to Spain. At present there is no maximum limit for nitrates established for chard at European level.

The Spanish Association of Paediatrics (AEP) recommends the introduction of vegetables in purred form from the age of 6 months, avoiding spinach, cabbage and beetroot in the first months as these may be a cause of methemoglobinemia due to their nitrate content; they recommend these vegetables be introduced after the age of 12 months (Nutrition Protocols. AEP Protocols, 2002. Chapter 2).

The mean level of nitrates in chard in Spain is similar, although slightly higher, than that of spinach. However, the dietary consumption of chard in Spain is not insignificant, as revealed in consumer surveys (Model of the Spanish diet to determine consumer exposure to chemical substances. AESAN (2006)). For a mean consumption of chard with a mean content of nitrates, there is unlikely to be a health concern; however, as is the case of spinach, in cases of consumption of high levels of chard, there may be a risk.

Examples include: a pureed infant food containing 20% of chard as an ingredient, considering that these contain a mean level of nitrates, would suppose an input of 60% of the maximum reference intake used by the EFSA in their opinion. The nitrates from the other ingredients, although in lower quantities, would also have to be added to those from the chard.

Consequently, the recommendations for consumption applicable to spinach must be extended to chard given the significance of its consumption in our country. This considers that the composition of the pureed food is made up of different vegetables which also provide nitrates, although to a far lesser degree.