Nickel Content of Food and Estimation of Dietary Intake

Overview

This Zeitschrift für Lebensmittel-Untersuchung und -Forschung review from the Danish National Food Institute and the Danish Toxicology Centre is the foundational primary-data source for nickel concentrations in foods and dietary nickel intake estimation. The authors compiled 2,221 food samples from the post-1969 literature (when AAS flame/flameless or PIXE methods began producing reliable Ni values) plus their own National Food Institute analyses, then modeled the Danish average diet (2,099 g/person/day exclusive of drinking water, 3,250 kcal). The headline number: 150 µg Ni/person/day from the Danish average diet, with drinking water adding another 16 µg/day. By replacing average-diet items with high-Ni foods, total intake can climb to 900 µg/day or more, well within the 600 to 5,600 µg single-dose range that provokes hand eczema flare in nickel-sensitive patients per oral challenge. The paper introduces the load factor F (ratio between percent of total Ni intake and percent of total consumption) as a way to identify which foods drive intake disproportionately to their dietary weight.

Key numbers

High-nickel foods not in the Danish average diet (µg/g, ordered by Ni content)

Selected average-diet items with notable Ni content (µg/g, weighted means)

The load factor F is the ratio between a food’s percent of total Ni intake and its percent of total consumption; F > 1 indicates a food contributes Ni disproportionately to its dietary weight. Oatmeal at F = 24 is the standout outlier in the Danish average diet.

Dietary intake summary

Sample-distribution caveats

Some foods are extensively measured (fish n=658, milk n=63, liver and kidney n=108) while others have fewer than 10 samples across the literature (cocoa, nuts, soya products). Mean values for low-n foods carry correspondingly wider uncertainty.

Methods (brief)

Literature search across Food Science and Technology Abstracts, Biological Abstracts, Chemical Abstracts, CAB, and Bulletin Signalétique, restricted to 1969-1982 (when AAS flame/flameless or PIXE methods produced reliable Ni values). Methods restricted to wet or dry digestion followed by AAS or PIXE; older methods excluded for specificity and interference concerns. The Danish average diet model was computerized from University of Aarhus statistical reports, supplemented with coffee/tea data, and used to compute Ni intake by multiplying mean food-content by consumption weight. The load factor F was derived per food item as percent-of-Ni-intake divided by percent-of-consumption.

Implications

• Certification: This is the foundational primary occurrence-data source for Ni in foods. Cocoa (9.8 µg/g), soy beans (5.2 µg/g), soy products (5.1 µg/g), walnuts (3.6 µg/g), peanuts (2.8 µg/g), oats (2.3 µg/g), bitter chocolate (1.9 µg/g), hazelnuts (1.8 µg/g), dried legumes (1.7 µg/g), and almonds (1.3 µg/g) are the priority commodities for HMTc Ni-threshold-setting. The load factor F flags oatmeal as the dominant per-gram contributor to dietary Ni in the average diet (F = 24). Whole-grain wheat, potatoes, and root vegetables also contribute meaningfully.
• Microbiome / clinical: Establishes the dietary Ni context for SNAS, low-Ni diet trials (Kaaber 1978, Veien 1993), and clinical-population studies. 150 µg/day Danish-average baseline is the comparator that the ~50 µg/day BraMa-Ni diet (Braga 2013) targets.
• App: The full mean-Ni-content table is the seed dataset for ingredient-page contamination_profile.Ni values. Body-prose synthesis should cite this paper as foundational and supplement with newer occurrence data (Pereira 2020, cereal-grains studies) where available.
• Courses: Standard older reference for Ni-occurrence-in-food. Cited by virtually every subsequent Ni-in-food paper.

Wiki pages updated on ingest

• Nickel
• Cocoa
• Chocolate
• soybean
• oats
• peanut
• walnut
• hazelnut
• Almond
• Legumes
• Wheat
• Rice
• potato
• Leafy Vegetables

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