The low-nickel diet: a four-week guide for systemic nickel allergy

A nickel allergy diagnosis usually arrives through your skin. A watch back, an earring, a jean stud, and a patch test confirms it. What comes next is contact avoidance, and for most people that is the end of it.

A smaller group keeps flaring without touching anything metal, and for them the cause turns out to be food. This guide is for that group.

Who this is for

Systemic nickel allergy syndrome, usually shortened to SNAS, describes people with a confirmed nickel contact allergy who also react to nickel in food. Beyond the skin, it shows up as gut symptoms, headaches, fatigue and widespread flares, which is why it takes so long to connect to eating.¹

Two conditions have to hold before a low-nickel diet makes sense. A patch test has confirmed nickel contact allergy, and symptoms persist or recur without an obvious contact source. Without the first, this is the wrong path entirely, and the foods involved are ones most people should be eating.

If that describes you, a dermatologist or allergist is the right person to confirm it. An oral nickel challenge under supervision is the closest thing to a definitive test.²

How dietary nickel works

Nickel is an element, so nothing destroys it. Cooking cannot remove it and neither can washing.

Plants take it up from soil, and how much reaches your plate depends on which part of the plant you eat. Seeds concentrate it, which puts nuts, pulses, cocoa, oats and wholegrains at the top. Leafy greens take up a fair amount, spinach especially. Animals do not concentrate it, so meat, fish, eggs and dairy sit low.

The amount in any single food matters less than the total across a day. Most people with SNAS have a threshold, and the diet is a way of finding yours.

The four-week reduction

The standard approach runs in two phases. The first lowers your intake, and the second, reintroduction, finds your threshold.

Weeks one to four: reduce. Build meals from the low-nickel list and remove the high-nickel foods. Keep everything else about your diet the same, because changing two things at once tells you nothing.

Three practical changes belong in this phase alongside the food. Stop cooking acidic dishes in stainless steel, because a tomato sauce simmered in a new pan picks up a measurable amount. Run the tap briefly before filling a kettle or glass, since water standing in pipes overnight carries more. And check your supplements, because multivitamins and some mineral supplements contain nickel directly.

Weeks five onward: reintroduce. Bring back one high-nickel food at a time, a normal portion, and wait at least three days before the next. Dietary nickel reactions are typically delayed by a day or more, so a two-day gap will mislead you.

Record the portion size as well as the food. The answer is usually something like "two squares of chocolate is fine and a bar is not", and you only see it if you wrote down which one you ate.

Journal your day in 30 seconds, find your triggers.

What to expect

Improvement during the reduction phase, where it happens, usually appears in weeks two to four. If four weeks produce no change at all, dietary nickel is probably not your problem and the restriction is not worth continuing.

Many people find their tolerance improves over months, so a threshold found in November may not be the threshold in March. It is worth retesting now and then.

The nutritional cost

The foods on the high-nickel list are oats, beans, lentils, nuts, wholegrains, spinach and cocoa. That is most of the plant protein and most of the fibre in an ordinary diet, and removing it without cause carries a real nutritional price.

So the diet is worth doing properly and worth stopping promptly if it does not help. A dietitian is useful here, particularly if you are vegetarian, because the overlap between high-nickel foods and plant protein is nearly total.

Check any food in seconds

The nickel checker grades any food in our database, and both food lists link every entry to its own page.

Where Triggerbites fits in

A low-nickel diet means keeping a daily total across everything you ate and comparing it with symptoms that arrive a day later. That is hard to keep up in a paper diary.

With Triggerbites you journal your day in plain words or by voice, in about 30 seconds: "porridge and a coffee for breakfast, a tuna sandwich on wholemeal and a Coke Zero for lunch, two squares of dark chocolate after dinner." The app grades every ingredient for nickel, adds up the day, and lines it up against how you felt, including reactions a day or two later.

During reintroduction it keeps the portion sizes you would otherwise forget. You can export the whole record as a PDF for your dermatologist or allergist.

Log your day in 30 seconds

Text, voice or photo. Log as you go, or recap it all in the evening.

Your food, broken down

Meals become ingredients and sensitivity profiles: histamine, salicylates, FODMAPs, allergens, and even the additives on packaged food.

Everything in the same journal

Symptoms, supplements, sleep, stress, exercise and mood, beside what you ate.

See what repeats over time

Patterns between what you eat and how you feel, including delayed reactions that show up days later.

Triggerbites Features

• Log your day in 30 seconds: Text, voice or photo. Log as you go, or recap it all in the evening.
• Your food, broken down: Meals become ingredients and sensitivity profiles: histamine, salicylates, FODMAPs, allergens, and even the additives on packaged food.
• Everything in the same journal: Symptoms, supplements, sleep, stress, exercise and mood, beside what you ate.
• See what repeats over time: Patterns between what you eat and how you feel, including delayed reactions that show up days later.

Common questions

What is systemic nickel allergy syndrome?

It describes people with a confirmed nickel contact allergy who also react to nickel in food. Symptoms go beyond skin and include gut problems, headaches, fatigue and widespread flares, which is why the food connection is so often missed.

How long does a low-nickel diet take to work?

Where it helps, improvement usually appears in weeks two to four, and the first few days rarely show it. If four weeks produce no change at all, dietary nickel is probably not the problem and the restriction is not worth continuing.

Do I need a diagnosis before trying a low-nickel diet?

Yes, ideally. Two things should hold first: a patch test confirming nickel contact allergy, and symptoms that persist without an obvious contact source. Without the contact allergy this is the wrong path, and the foods involved are ones most people should be eating.

What should I change besides food?

Three things. Stop cooking acidic dishes in stainless steel, because tomato sauce simmered in a new pan picks up a measurable amount. Run the tap briefly before filling a kettle, since standing water carries more. And check supplements, because multivitamins often contain nickel directly.

How do I reintroduce high-nickel foods?

One food at a time, a normal portion, with at least three days between each. Dietary nickel reactions are typically delayed by a day or more, so a shorter gap will mislead you. Record the portion size, because the answer is usually about quantity.

Is a low-nickel diet nutritionally safe?

It removes oats, beans, lentils, nuts, wholegrains and spinach, which is most of the plant protein and fibre in an ordinary diet. It is worth doing properly and stopping promptly if it does not help. A dietitian is genuinely useful here, especially if you are vegetarian.

Live, love, log. 🧡