First and foremost, jarred commercial baby food carrots (and other jarred commercial baby food vegetables) have nitrates too! Even jarred organic carrot baby foods have nitrates. Commercial baby food companies will tell you that they SCREEN for nitrate levels, not that they remove nitrates. This means that they may buy veggies that are grown in a part of the country where the nitrate contamination of soil is lower, where the sun shines more or where Farmer's do not use high levels of nitrogen containing fertilizers. Nitrates are naturally occurring and thus cannot be removed!
Due to screening, commercial baby foods may contain a lower level of nitrates than homemade as parents do not have the ability to screen veggies for nitrates. Please keep in mind that baby food companies voluntarily screen for levels of nitrate and there is no Federal (U.S.) regulation or mandate requiring them to screen. You see, nitrates are naturally occuring in the vegetable itself and not even the folks at Gerber/Beechnut/Heinz et al. can remove nitrates.
So when we first hear of nitrates and carrots, “Blue Baby Syndrome” and homemade baby food, it is often with a bit of fear and trepidation that we proceed to make baby’s food. We wish to do the best for our babies and we certainly do not want to poison them! Let’s take a moment to look at the facts about nitrates, infants and making baby food.
"Around the age of three months, an increase in the amount of hydrochloric acid in a baby's stomach kills most of the bacteria that convert nitrate to nitrite. By the time a baby is six months old, its digestive system is fully developed, and none of the nitrate-converting bacteria remain. In older children and adults, nitrate is absorbed and excreted, and methemoglobinemia is no longer a concern." http://ohioline.osu.edu/b744/b744_2.html
Nitrates are naturally occurring nitrogen/oxygen compounds found in almost every vegetable that we eat and the soils they are grown in. Nitrates are also laboratory formulated and used in fertilizers. Nitrates are ingested either from vegetables or drinking water. Nitrates/nitrites have been found to be responsible for "Blue Baby Syndrome." Adults are not affected by nitrates or nitrites because their stomachs produce acids that fight the bacteria that help convert nitrates into nitrites. This conversion, and the resulting nitrite, is what allows for nitrate poisoning or “Blue Baby Syndrome.”
The name “Blue Baby Syndrome” stems from the fact that nitrites hinder proper oxygen transportation in the red blood cells. “Once in the blood, nitrite oxidizes iron in the hemoglobin of red blood cells to form methemoglobin, which lacks hemoglobin's oxygen-carrying ability.”1 Without proper oxygen saturation in the blood, the body’s cells become oxygen deprived and the skin takes on a blue or purple hue. This oxygen deprivation may lead to the slow asphyxiation of the person poisoned.
Symptoms are described as: "The most obvious symptom of nitrate poisoning is a bluish color of the skin, particularly around the eyes and mouth. This is called cyanosis. A baby with these symptoms should be taken to an emergency medical facility immediately. The doctor will take a blood sample to be sure the baby is suffering from nitrate poisoning. The blood sample of an affected baby is a chocolate brown instead of a healthy red. Nitrate poisoning can be treated, and in most cases the baby makes a full recovery. http://ohioline.osu.edu/b744/b744_2.html
The highest concentration of nitrates occurs in water, root vegetables and leafy vegetables such as spinach, lettuce and other greens. The concentration and amount of occurring nitrates will vary depending on the type of vegetable, the temperature that it is grown at, the sunlight exposure, soil moisture levels and the level of natural nitrogen in the soil.
Foods that tend to accumulate large amount of nitrate include: spinach, beets, cabbage, broccoli, and carrots. Root vegetables such as carrots, beets and broccoli all contain nitrates though at a much lower level than do the leafys. Leafy vegetables include spinach, cabbage or other greens like Kale. Studies done on spinach and nitrates in particular have shown that with improper storage and preparation, the nitrate levels may actually increase. Proper preparation and immediate use or storing via freezer method will help eliminate this risk in leafy vegetables.
As boiling vegetables in water will not eliminate nitrate concentration, and nitrates may in fact seep into the water used for cooking, it is best to not use that water as the liquid to make your puree. For some people, they find it may be best to stick to feeding baby jarred carrots, beets and other vegetables that may contain nitrates until baby reaches 8 months of age.
"Because the intake of naturally occurring nitrates from foods such as green beans, carrots, squash, spinach, and beets can be as high as or higher than that from well water, these foods should be avoided before 3 months of age, although there is no nutritional indication to add complementary foods to the diet of the healthy term infant before 6 months of age" http://pediatrics.aappublications.org/cgi/content/full/116/3/784
If you prefer to make your own homemade baby vegetables, an alternative is to choose organic produce. Organics do not use commercial nitrate fertilizers and thus the risk of nitrate contamination/concentration is minimized, but not eliminated. The AAP suggests a very cautious and conservative waiting period, 8 months or older, to make homemade leafy vegetables that may contain nitrates. While this sounds frightening, the fact is that nitrate poisoning comes from contaminated drinking/ground water before it ever comes from vegetables.
So who is most at risk? Babies under the age of 6 months old are most at risk and babies under the age of 3 months old even more so. Babies who are over the age of 6 months old have developed the stomach acids necessary to fight the bacteria that helps nitrate conversion and subsequent nitrate poisoning. Infants who are formula fed and live on farms or in highly agricultural areas may also be at greater risk. Nitrates used in farming, and the excess not taken in by the crop itself, easily run-off and may seep into water tables, contaminating water supplies.
As mentioned earlier, nitrate poisoning is very rare and when it does occur, it is typically traced back to ground water contamination – specifically from contaminated private wells.2 If you have any doubts or fears, please speak to your pediatrician!
1. Ziebarth A. (1991), NF91-49, Well Water, Nitrates and the "Blue Baby" Syndrome Methemoglobinemia; Lincoln, NE; University of Nebraska Cooperative Extension.
2. Illinois Department of Public Health, Division of Environmental Health
For More Information, visit these links:
Blue Babies and Nitrate-Contaminated Well Water [http://www.uwsp.edu/water/portage/undrstnd/blbaby.htm]
Drinking Water: Nitrate and Methemoglobinemia ("Blue Baby" Syndrome) http://www.ianr.unl.edu/pubs/water/g1369.htm
Infant Methemoglobinemia: The Role of Dietary Nitrate (RE0004)(AAP) (This is an Abstract of the Full PDF document) http://pediatrics.aappublications.org/cgi/content/full/116/3/784
Methemoglobinemia - Feeling Blue?
[http://www.mc.uky.edu/ahec/skyahec/methem-CE.htm]
Nitrates in Drinking Water
http://www.idph.state.il.us/envhealth/factsheets/NitrateFS.htm
How does Nitrate Affect Families?
http://ohioline.osu.edu/b744/b744_2.html
Nitrates, Infants & Well Water - AAP (2005)
http://www.aap.org/advocacy/releases/sept05wellwater.htm
Margaret Meade is the Owner/Editor of http://www.wholesomebabyfood.com and http://www.wholesometoddlerfood.com. She continues to make baby and toddler food, study nutrition and expand the website weekly. The goal of the website and her articles is to get parents to disengage from the myth that commercial baby foods are superior and magical. In doing so, parents may become less reliant on not-so-healthy pre-packaged foods as their children grow! It is so easy to make your own baby food and once you begin, good healthy eating habits will automatically flow!
