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Food Safety Focus (112th Issue,November 2015) – Food Incident Highlight

Leftover Vegetables Not For Infants

Does food especially vegetables left overnight in the fridge cause cancer due to the accumulation of nitrite? For most people, eating leftover vegetables would not significantly increase the risk of cancer. Yet, caution should be taken when feeding infants with vegetables.

Vegetables naturally contain nitrate and nitrite. Some processed foods such as cured meats also contain nitrate and nitrite as food additives. Nitrate and nitrite themselves are not carcinogenic to humans. However, nitrite might react with amines to form carcinogenic nitrosamines in the stomach. On the other hand, vegetables are known to have protective effects against the risk of cancer.

Infants are at risk because nitrite might accumulate in leftover vegetables due to bacteria contamination. High level of nitrite may cause methaemoglobinaemia (commonly known as blue baby syndrome, a rare condition under which haemoglobin is unable to carry oxygen to body tissues) in infants due to the immaturity of their digestive systems and methaemoglobin reductase systems. It is most desirable to prepare infant food especially vegetables just before consumption.