Nickel is toxic to the body in all but trace amounts—the body needs minute amounts to maintain strong immune function. However, nickel is responsible for more allergic reactions than all other metals combined, and it can have a negative impact on the immune system. Nickel toxicity depletes the body’s zinc stores, because nickel substitutes for zinc in important metabolic pathways that support immune function. This happens because nickel and zinc are approximate in size, weight, and positive charge. But that’s where the similarity ends.
Nickel is so toxic that it’s used to promote cancerous tumor growth in laboratory rats. Studies show that occupational exposure to nickel dust at refineries results in increased incidences of pulmonary and nasal cancer. Some of our patients have had cancers possibly linked to nickel toxicity. Stainless steel braces and bridges leech nickel into the oral cavity, contributing to the development of tumors.
Unbelievably, like mercury, the use of nickel in dental appliances has been declared safe by the ADA.
Nickel toxicity can contribute to a wide array of symptoms and conditions, including, but not limited to food allergies, inflammatory bowel disease, Crohn’s disease, ulcers, colitis, nausea, diarrhea, compromised digestion and immunity, cancer, lupus, arthritis, chronic fatigue, capillary damage, cognitive problems, muscle tremors, paralysis, malaise, insomnia, endometriosis, and cirrhosis of the liver.
Gerard Mullin, MD, PhD, a gastroenterologist with and one of the country’s leading Crohn’s disease researchers, states that nickel—as well as other metals—is a primary source of stress to the immune system, including the depletion of zinc and dysfunction of the mucosal barrier.
Most exposures to nickel are dental, dietary, or industrial. Common sources include:
- Auto exhaust
- Buckwheat, cabbage, herring, hydrogenated oils, legumes, kelp, oats, and oysters (nickel-containing foods can aggravate an existing toxicity)
- Dental bridges and root canals
- Industrial emissions
- Nickel-plated alloys
- Tobacco smoke
Nickel is used as a catalyst in the hydrogenation of vegetable oils, including corn oil, peanut oil, and cottonseed oil, as well as margarine. Grains may be stone-ground, but if stainless steel is used to grind them, the nickel in the stainless steel can contaminate the grains. Stainless-steel cookware can transfer some nickel to foods; acidic foods in particular can leech nickel from stainless steel. Frequent handling of coins, especially—you guessed it—nickels, is another source. While there are many ways to be exposed, those at the highest risk are workers in the metallurgy fields who are constantly exposed to metal dust and debris.