Nickel triggers more hypersensitive reactions than any other metal – up to 15% of the population, mostly women, suffers from some form of nickel allergy. Nickel is an exceptionally common metal. It may be found in dental restorations, orthopaedic prostheses, cosmetics, stainless steel cutlery, pots and pans, costume jewellery buttons and coins (including the Euro). Dermatologists have developed low nickel diets, mainly for the treatment of hand eczema, which aims to nickel-rich foods in the diet (e.g. cocoa, chocolate, broccoli, nuts). It may also be beneficial to supplement with vitamin C and iron. More details on low nickel diet can be found HERE.
Nickel in surgery
In a document on nitinol-containing devices (nickel and titanium alloy) , the US FDA writes: “Since there is no known lower limit on the amount of nickel that can elicit allergic reactions in some patients, we recommend that the risk of potential allergic reaction to nickel be mitigated through labelling for nitinol containing devices. Specifically, we recommend that the labelling include a warning for prolonged and permanent contacting devices.”
Stainless steel is an alloy that contains up to 8-13% nickel. Alloys used in surgery contain trace amounts of nickel also. Cobalt chromium contains a trace of nickel at under 1%, whilst titanium alloys contain under 0.05%. However nickel levels may rise in the body may be released from implanted devices at a faster rate (1) or through exposure to nickel containing surgical instruments (2).
Nickel content in food
(more than 0.5 mg/kg)
(less than 0.1 mg/kg)
|Pistachio nuts nuts
|As analysed by the Swedish Food Administration
Further information on dietary nickel
Please note that the information below is taken from various sources and may not reflect the situation in your country. For example, a clinic in the USA states that potatoes are high in nickel, while analysis by the Swedish Food Administration found only a low nickel content in potatoes. The discrepancy is most likely due to the mineral and metal content of the soil in which the vegetables are grown.
There is a very thorough website, Rebelytics which has analysed nickel in food data from multiple source and has produced a spreadsheet which should avoid these kind of discrepancies see HERE.
The major dietary source of nickel is from plant-based foods. Nickel-rich food items include nuts, beans, peas, grains and chocolate. Animal foods are low in nickel. Total daily dietary intakes of nickel vary depending on the amount of plant and animal foods consumed. Diets high in plant foods, such as the ones listed above, supply about 900 micrograms daily of nickel. Nickel intake in the United States ranges from 69 to 162 micrograms daily. A daily dietary requirement of 25 to 35 micrograms has been suggested.
Nickel may be found in prepared foods (tinned foods) at markedly higher concentrations than the safe threshold laid down for hypersensitive patients. Some foodstuffs cooked in stainless-steel utensils react with the metal and thus contain much more nickel than when enamel or aluminium saucepans are used. Among the natural organic acids, which may be responsible for dissolving stainless-steel, oxalic acid is the most active at equivalent concentrations.
Contact Dermatitis. 1979 Jan;5(1):43-5. Nickel in food: the role of stainless-steel utensils., Brun R.
The normal daily intake of nickel by American adults is about 0.3 to 0.6mg. About 1 to 10% of nickel in food is absorbed in the gastrointestinal tract and the remainder is excreted. The nickel content of food is partially determined by the components of the soil in which the food was grown, pesticides used on it and the equipment used in the handling of the food. Nickel in food may vary considerably from region to region. Certain foods are routinely high in nickel content. Legumes, nuts, grains, chocolate and certain canned fish are among the foods high in nickel. In summary, ingested nickel from food, beverages or cooking utensils can cause a flare of dermatitis is some individuals. Accordingly, motivated persons may see improvement if they can reduce their ingestion of nickel through dietary change.