Following a diet low in nickel can improve these symptoms, but can be challenging. First, there is a lot of conflicting advice regarding the nickel content of foods [Pizzutelli2011]. This may be due to the natural variations in nickel content caused by the nickel content of the soil where they were grown, how a sample was processed, or how a food sample was cooked. Second, keeping track of one's nickel intake is a chore. It is not easy to compute how much nickel is in a serving of a food because nickel concentrations are traditionally reported in mg/kg. Also, counting micrograms, like counting calories, is not a sustainable diet plan.
To address the ease of use issue, American doctors Dr. Mislankar and Dr. Zirwas proposed a simple "Low-Nickel Diet Scoring System" using data from the United States FDA [Mislankar2013]. In this system, nickel concentration [Ni] is converted from mg/kg to µg/serving by using the FDA approved serving sizes, doubled since actual portion sizes have been increasing in the United States [Young2002]. A food is assigned 0 points if it has less than 1 µg/serving, 1 point if 1 ≤ [Ni] < 10 µg/serving, 2 points if 10 ≤ [Ni] < 20 µg/serving, and so on up to 10 points if 90 ≤ [Ni] < 100 µg/serving. Foods with more than 100 µg/serving are to be avoided entirely, and nickel consumption is limited to 15 points or 150 µg/day.
In our extension of the low nickel diet scoring system, we use a collection of nickel content data from many sources around the world (over 70 sources to date, including national studies and research papers) to compute a weighted average so that the most geographically relevant samples are given priority. This reflects the potential local variations in food sources, manufacturing and food preparation methods. We use Health Canada's serving sizes to get the nickel per serving, and the points are assigned as in [Mislankar2013]. The food scores are presented on colour-coded Score Sheets using a traffic light system (green, yellow, red) to make the low (1 point), moderate (2 points) and high (3 or more points) nickel foods easy to recognize.
Score Sheets have been made for various locations around the world, and one from a global perspective (where the data isn’t weighted by location). Choose the Score Sheet for the location closest to you. All of the sheets are also available within the Excel workbook so that you can customize them if you feel so inclined. Don't forget to sign up for update notifications.
NOTE: This diet is intended for individuals with a diagnosed nickel allergy. If you have not been patch tested or had a blood test to diagnose your nickel allergy, please do so before starting this diet. It is not a weight loss diet and must not be entered into lightly.
The goal is to limit your daily points to 15. Pay close attention to serving sizes. We recommend using a kitchen scale until you get used to estimating serving sizes. In the Score Sheets, blue foods are essentially free, green foods cost 1 point, yellow foods 2 points, and red foods 3 or more points. You're more likely to win (eat more) if you stick to the blue and green foods. Red foods should typically be avoided to increase the variety of food that you eat and maximize the nutrition your body needs to heal. Aim to get at least 5 servings of fruits and vegetables each day! After 4-6 months, try to slowly reintroduce moderate nickel foods.
An asterisk (*) beside a food's label means that there is only one measurement available for this food. Be suspicious of these because there is often a wide variation in nickel content and this single measurement could be on the very low or very high side of the average. Beside the average score, the range of scores is given in brackets to give you an indication of how high a score can get, but be aware that the likelihood of a sample having the highest value is generally small. See Nickel in Foods for an analysis of the trends in nickel content by food group.
The Excel workbook contains macros that generate Score Sheets based on location. The first sheet contains notes and information on how to use it. The "Main" sheet contains the data. The "Settings" sheet is where the desired location is defined with a latitude and longitude and some customizations can be set. The Score Sheets above were generated with Level 2 granularity, but you can generate a higher-level view by choosing Level 1. You can choose to ignore cooked and canned foods, but be aware this won't work for Level 1 granularity because cooked and canned are sometimes combined into a single food label.
The GenerateAnalysisSheet macro will generate two new sheets with the results for the current settings, one for all foods, and one for foods marked as "Favourites" in the last column of the "Main" sheet. These are not the printable sheets, but can be pasted into a word processing program for pretty formatting. If you want to auto-generate it as a pretty-printable sheet, you have to add your location to the "Weights" sheet, sort the list alphabetically by the Data Label column, and then add the row index of the location you want to the array rowArr in the GenerateAllSheets macro. Running GenerateAllSheets should create the printable Score Sheet.
If you need a custom location and you can’t work with Excel, or the sheets and macros look like spaghetti, send us a note. We're happy to help.
Cooking methods can make a difference to the amount of nickel in the finished product. Nickel is leached from some stainless steel [Kuligowski1992, Kamerud2013, Bassioni2015] and aluminum [Lomolino2016, Papuc2017] cookware in amounts significant to those who are sensitized. There are also reports of ceramic pans leaching nickel [Lomolino2016, Papuc2017]. Acidity, heat and exposure time all contribute to the amount of nickel that leaches out. For baking and cooking in the oven, glass is probably the safest option. Parchment paper can be used to line existing pans (which also makes for easier clean-up). For recipes that normally wrap foods in aluminum foil, parchment paper can be creatively applied.
Look for "18/0" stainless steel cutlery (the 0 indicates the nickel content). Ceramic kitchen knives are also available, although they are not as durable as steel. In a pinch, plastic cutlery will do.
To minimize the nickel content in coffee, water can be boiled in a Pyrex measuring cup in a microwave, and the coffee made with a metal-free coffee maker such as the AeroPress. Similarly, water for tea can be microwaved in a mug (or the water and teabag heated simultaneously) instead of heated in a kettle .
To speed up the healing process, you'll want to deal with all other sources of inflammation, including foods to which you have experienced sensitivities in the past. If a food is low in nickel according to the data but your gut tells you it's a problem (maybe literally), exclude it from your diet. After you have improved, try reintroducing these foods and the moderate nickel foods that you've been missing, one at a time and very slowly. Use a food journal to track your response.
Histamine intolerance [Maintz2007] is known to be an issue for some SNAS sufferers, and some low-nickel foods are naturally high in histamine. A low histamine diet can be very helpful. It should be noted that there is a substantial amount if variation in the histamine content of foods and in the recommendations of various low-histamine diets [SanMauroMartin2016], and not all histamine-inducing foods affect everyone in the same way, so some trial and error will be needed.
Sweating is an excellent way to rid the body of excess nickel [Hohnadel1973]. Sweat also contains histamine and various immunoglobulins [Forstrom1975]. Saunas, hot baths and exercise will increase sweat production. It is important to wash the sweat off so that the skin doesn't react to the nickel.
It is common for multiple allergies to coexist with a nickel allergy. Nickel allergies have been found to coexist with another metal 40% of the time; palladium, cobalt and gold were most often paired with nickel [Tu2011]. If you haven't had a complete set of metal allergy testing (patch tests or blood tests), consult your doctor. Allergies to chemicals such as methylisothiazolinone and formaldehyde have also been observed, anecdotally.
Nickel is a common element in dental alloys, and is always present in trace amounts, even when they are labelled nickel-free [Ortiz2011]. Dental metals are a continuous oral source of nickel through galvanic corrosion, particularly when metals with different properties coexist [Nogi1989, Anusavice2012, Ciszewski2007, Taher2003, Lee2015]. Pairing nickel with titanium nearly doubles the corrosion rate [Taher2003, Lee2015]. Corrosion can increase with surface area and pitting [Zohdi2012], and saliva properties [Nogi1989, Zohdi2012], and flouride can impair the corrosion resistance of some alloys [Zohdi2012].
Probiotics have been shown to be beneficial for the healing of the gut and skin. L. reuteri was helpful in the treatment of SNAS [Randazzo2014], and a combination of L. reuteri and L. rhamnosus improved atopic dermatitis in another study [Rosenfeldt2003]. Some probiotic strains raise or lower histamine levels; more research is needed in this area.
Dietary supplements have been shown to be a hidden source of nickel [VanDerVoet2008, Li2015, PonceDeLeon2002, Adolfo2016, Avula2010]. Although iron is said to interfere with nickel uptake, the supplements themselves contain high levels of nickel [Cardoso2017, Li2015] and accidental overdose is easy and very dangerous. Only take iron supplements if you have been instructed to do so by a medical professional. In one study, vitamin A supplementation was shown to lower blood levels of nickel [Patar2011], but vitamin A toxicity can cause liver damage so care should be taken not to exceed established safety limits. Where practical, choose food sources of nutrients over supplements. The exception is vitamin C, which reduces the uptake of nickel when taken with food [Solomons1982].
Following a low nickel diet is challenging, but is worthwhile for SNAS. In one large study, 80% of patients on a low nickel diet for 4 weeks had a complete or near-complete recovery from dermatitis symptoms [Antico2015]. In a smaller study focussing on gatrointestinal symptoms, patients on a low nickel diet for 3 months showed a significant decrease in symtpoms [Rizzi2017]. Other helpful advice can be found at The Reluctant Health Nut. If you're on Facebook, the Low Nickel Diet - Eating Well with Nickel Allergy/SNAS group is a good support system.