Nitrates are inorganic ions that occur naturally throughout the nitrogen cycle, according to the Agency for Toxic Substances and Disease Registry. The nitrates in the foods you consume may affect your health, although no consensus exists that definitively sets consumption limits. The frequency that you consume foods high in nitrates, the amount of nitrates in the food and whether you have certain diseases impacts whether the nitrates in foods you eat negatively affect you.
Occurrence
Nitrates form from the decomposition of nitrogen-rich waste present in either soil or water, and plants that come into contact with nitrate-rich soil or water often contain varying levels of nitrates. Additionally, food manufacturers often add nitrates to meats to increase the color and shelf life of foods. When farmer's add fertilizers with nitrates to crops, some of the nitrates move from the soil into the plants. Animal feces also contribute to nitrates in the soil, if the animals eat plants or feed high in nitrates. The New Hampshire Department of Environmental Services indicates that the the average nitrate intake from vegetables for an adult is between 75 and 100 mg a day.
Processed Meats
Many hot dogs, luncheon meat and sausage varieties contain nitrates, although some food manufacturers also produce processed meats with no added nitrates. A recent study featured in the May 2010 edition of the journal "Circulation" drew a correlation between processed meats high in nitrates and the risk of diabetes, stroke and heart disease. An earlier foundational study published in the March 1994 edition of "Cancer Causes and Control" focused on hot dog consumption, pregnant women and brain tumors in children. The researchers found a link between how often pregnant women consumed hot dogs and the incidence of brain tumors in their children, as well as a link between hot dog consumption and brain tumors in small children. The nitrates in hot dogs vary depending on the brand you purchase. If you choose to consume processed meat, limit your consumption to once or twice a month, or purchase nitrate-free varieties.
Vegetables
Vegetables can contain nitrates, and over 70 percent of the nitrates the average adult consumes comes from nitrates in natural foods, according to the Agency for Toxic Substances and Disease Registry of the Centers for Disease Control and Prevention. The agency indicates that nitrate-rich vegetables do not normally contribute dangerous levels of nitrates to the American diet. Any produce that comes in contact with either nitrate-rich fertilizer or animal feces contaminated with nitrates may contain nitrates. Root vegetables, such as potatoes or carrots, contain more nitrates than plants grown above the ground. Other vegetables often higher in nitrates include spinach, broccoli and cauliflower.
Water
Some water supplies can be contaminated with nitrates, according to the ATSDR. The agency indicates that about 1.2 percent of wells in small communities and 2.4 percent of wells on private land have unacceptable levels of nitrates in the water. Rural areas rich in agricultural farming abounds often have higher incidences of nitrate contamination than wells located away from agricultural areas. Infants who consume formula or baby food made with nitrate-rich water risk developing blue-baby syndrome, which can cause the infant to become very ill and die, if not recognized and treated promptly, according to Lynda Knobeloch, lead author of the study "Blue Babies and Nitrate-Contaminated Well Water," which was published in the July 2000 issue of "Environmental Health Perspectives."
References
- Centers for Disease Control and Prevention; Agency for Toxic Substances & Disease Registry; Nitrate/Nitrite Toxicity What Are Nitrate and Nitrite?; September 2007
- New Hampshire Department of Environmental Services; Nitrate and Nitrite: Health Information Summary; 2006
- "Cancer Causes and Control"; Cured and Broiled Meat Consumption in Relation to Childhood Cancer: Denver, Colorado (United States); S. Sarasua, et al.; March 1994
- "Circulation"; Red and Processed Meat Consumption and Risk of Incident Coronary Heart Disease, Stroke, and Diabetes Mellitus; Renata Micha, et al.; May 2010
- "Environmental Health Perspectives"; Blue Babies and Nitrate-Contaminated Well Water; Lynda Knobeloch, et al.; July 2000
