Methemoglobinemia and Consumption of Vegetables in Infants

Abstract

ABSTRACT. Objective. To assess clinical and epidemiologic data of 7 infants diagnosed with acquired methemoglobinemia at the pediatric emergency department between 1993 and 1998. All cases were attributed to the consumption of mixed vegetables.Methods. Medical records were reviewed to collect anamnestic data; history of food ingestion; and results of physical examination, pulse oximetry, gasometry, cooximetry, urinalysis, and outcome. Local health authorities provided information on nitrate concentration in running water and in vegetables of common consumption in the area.Results. The mean age of the patients was 8.14 months (range: 7-13). None of the infants was undernourished, had diarrhea, or was given any drug. Drinking water showed a nitrate concentration of 3 to 6 ppm. All were fed homemade purée of mixed vegetables, prepared in advance and kept in the refrigerator for 12 to 27 hours. Silver beets were a common ingredient. No case showed metabolic acidosis. Methemoglobin level ranged between 10% and 58%. Three cases had nitrituria. Silver beets in our area were the vegetables with the highest nitrate concentration (mean: 3200 mg/kg).Conclusions. Consumption of silver beets and incorrect storage of homemade purées of mixed vegetables were potential causes of methemoglobinemia in this series. The disease may occur in children older than 6 months of age. Nitrituria in a cyanotic infant may suggest the diagnosis of methemoglobinemia. Pediatrics 2001; 107:1024 -1028; methemoglobinemia, nitrates, nitrites, food analysis, infant food, food preservation.ABBREVIATIONS. Sao 2 , oxygen saturation; Hb, hemoglobin. M ethemoglobinemia is a rare cause of cyanosis in pediatric patients. Methemoglobin, a derivative of hemoglobin in which the iron component has been oxidized from the Fe 2ϩ to the Fe 3ϩ state, imparts a characteristic brownish color to blood and is unable to transport oxygen. 1,2 Under physiologic conditions, methemoglobin reduction is accomplished primarily by red cell reduced nicotinamide adenine dinucleotide reductase so efficiently that there is Ͻ1% of methemoglobin in the circulating blood. Hereditary methemoglobinemia is attributable either to deficiency of erythrocyte methemoglobin reductase or to the presence of one of the M hemoglobins. Acquired methemoglobinemia is induced by oxidizing agents, particularly chlorates and inorganic and organic nitrites, or by exposure to certain drugs or their metabolites.The most common sources of nitrate exposure are well water, which is mixed with infant formula, consumption of some vegetables with high nitrate concentration, administration of oxidant drugs, and the presence of diarrheal episodes. After ingestion, nitrates are converted to nitrites by fecal organisms, rapidly absorbed from the intestine by passive diffusion reaching the systemic circulation without undergoing first-pass metabolism in the liver (extrahepatic metabolism). Nitrites are potent oxidant agents of ferrohemoglobin. Infants younger than 6 months old are particularly susceptible to nitrate-...

Dynamics of nitrate and nitrite content during storage of home-made and small-scale industrially produced raw vegetable juices and their dietary intake

“…Nitrate has a low level of acute toxicity but may be transformed into nitrite, which may lead to the formation of carcinogenic nitrosoamines (Walker, 1990, Kolb et al 1997) and the clinical symptoms of methaemoglobinemia (WHO, 1995;Sanchez-Echaniz et al 2001;Santamaria, 2006). Infant methemoglobinemia has been shown to be a result of consumption of high doses of nitrates by the infant foods and drinking water (Ezeagu, 1996, Coss et al Thomson et al 2007).…”

A 5-Month-Old Infant with Diffuse Cyanosis and No Other Symptoms

“…6 Furthermore, infants have low stomach acid production and a higher intestinal Ph, which promotes the growth of gram-negative organisms that convert dietary nitrates to nitrites and induce methemoglobin formation. 10 The combination of food containing nitrate and immaturity or low levels of cytochrome b reductase with higher pH in stomach may be conducive to metemoglobinemia in infants. Although exogenous methemoglobinemia is mainly due to ingestion or exposure to oxidizing agents, such as toxic substances or drugs (among which the most common are local anesthetics such as lidocaine 11 ), another common cause is the ingestion of food (in particular, vegetables such as green beans, courgette, carrots, squash, spinach, and chards [ Figure 1]) or water (used in preparation of infant formula) containing high levels of nitrates.…”

Nitrate removal from water using UV-M/S2O4 2− advanced reduction process

“…Ingestion of large quantities of NO 3 -incapacitates the human's red blood cells as oxygen carriers leading to a fatal condition of methemoglobinemia, commonly referred to as ''Blue Baby Syndrome'' (Sanchez-Echaniz et al 2001;Greer and Shannon 2005). It can also have carcinogenic effects on humans (Preston-Martin et al 1996;George et al 2001;Volkmer et al 2005).…”