BfR 2022 — Nickel dietary intake via food based on the BfR MEAL Study (Germany)
The German Federal Institute for Risk Assessment (BfR) conducted a total diet study (TDS) on nickel in food as part of the first German MEAL Study, analyzing 356 foods grouped into 19 main food categories and measuring Ni concentrations in 840 pools purchased nationwide between December 2016 and May 2019. The study found that the food groups “Legumes, nuts, oil seeds and spices” and “Coffee, cocoa and tea” carry the highest mean nickel concentrations at 1,583 µg/kg and 1,488 µg/kg respectively, with cocoa powder the single highest item at 11,050 µg/kg, followed by cashew nuts at 5,350 µg/kg. Dietary nickel intake for German adults and adolescents averages 11% of the EFSA-derived TDI of 13 µg/kg BW/day, while children average 42% of the TDI, with fewer than 5% of highly exposed children (ages 0.5–5 years) exceeding the TDI. This report provides the most geographically specific German-population nickel exposure baseline, lower than EFSA’s pan-European estimates for the same population when using German consumption data paired with pan-European occurrence data.
Key numbers
Nickel concentrations by major food group (mean, upper bound, µg/kg):
- Grains and grain-based products: mean 359 µg/kg, range min 20 – max 1,975 (chia seeds highest within group)
- Vegetables and vegetable products: mean 84 µg/kg, range min 17 – max 340 (vegetable crisps)
- Starchy roots/tubers: mean 50 µg/kg, range min 23 – max 100 (fried potatoes/potato chips, UB)
- Legumes, nuts, oil seeds and spices: mean 1,583 µg/kg, range min 60 – max 5,350 (cashew nuts)
- Fruit and fruit products: mean 112 µg/kg, range min 16 – max 1,080 (dried fruits)
- Meat and meat products: mean 27 µg/kg, range min 16 – max 60 (liver sausage, poultry)
- Fish and seafood: mean 30 µg/kg, range min 16 – max 165 (shellfish)
- Milk and dairy products: mean 48 µg/kg, range min 6 – max 295 (ice cream)
- Eggs and egg products: mean 17 µg/kg
- Sugar, confectionery and water-based sweet desserts: mean 601 µg/kg, range min 30 – max 2,800 (semisweet/dark chocolate)
- Animal and vegetable fats and oils: mean 65 µg/kg, range min 30 – max 100 (corn/sunflower oil); all samples <LOQ (100 µg/kg)
- Fruit and vegetable juices and nectars: mean 21 µg/kg, range min 20 – max 27 (multi-vitamin fruit juice)
- Water and water-based beverages: mean 18 µg/kg, range min 3 – max 44 (energy drinks)
- Coffee, cocoa, tea and infusions: mean 1,488 µg/kg, range min 13 – max 11,050 (cocoa powder)
- Alcoholic beverages: mean 19 µg/kg, range min 6 – max 48 (red wine mLB / spirits UB)
- Food products for infants and toddlers: mean 185 µg/kg, range min 20 – max 1,040 (porridge/millet powder)
- Vegan/vegetarian products: mean 386 µg/kg, range min 48 – max 1,000 (soy protein extrudate)
- Composite dishes: mean 53 µg/kg, range min 20 – max 220 (lentil/pea/bean soup)
- Sauces and condiments: mean 111 µg/kg, range min 10 – max 565 (soy sauce)
Top 10 individual foods by nickel concentration (µg/kg, UB):
- Cocoa powder: 11,050
- Cashew nuts: 5,350
- Sunflower seeds: 4,750
- Walnuts: 4,300
- Semisweet/dark chocolate: 2,800
- Beverage powder (total): 2,150
- Hazelnuts: 2,000
- Hazelnut spread: 2,000
- Chia seeds: 1,975
- Pumpkin seeds: 1,850
Dietary exposure estimates:
- Adults and adolescents (N=13,926): mean UB 1.6 µg/kg BW/day; P50 1.4 µg/kg BW/day; P95 3.2 µg/kg BW/day. TDI exhaustion: mean 12%, P50 11%, P95 24%.
- Children (N=732, ages 6 months–<5 years): mean UB 6.2 µg/kg BW/day; P50 5.5 µg/kg BW/day; P95 10.8 µg/kg BW/day. TDI exhaustion: mean 47%, P50 42%, P95 82%.
- Children aged 1–<2 years exhibit the highest exposure: P50 5.8 µg/kg BW/day; P95 11.0 µg/kg BW/day (84% TDI exhaustion at P95).
- Highly exposed children exceeding TDI: 2% of children ages 0.5–5 years in both mLB and UB scenarios (<5% in EFSA 2020 comparison).
Largest contributors to adult nickel exposure (% of total, UB): Grains and grain-based products 24%; Coffee, cocoa and tea 20%; Water and water-based beverages 11%; Composite dishes 7%; Sugar/confectionery/sweet desserts 7%; Fruit and fruit products 6%; Milk and dairy products 5%.
Largest contributors to children’s nickel exposure (% of total, UB): Grains and grain-based products 28%; Sugar/confectionery/sweet desserts 12%; Milk and dairy products 10%; Food products for infants and toddlers 9%; Composite dishes 8%; Fruit and fruit products 8%; Coffee/cocoa/tea 7%.
EFSA TDI reference point: 13 µg/kg BW/day, derived from BMDL10 of 1.3 mg Ni/kg BW/day from rat developmental toxicity studies, with uncertainty factor of 100 (EFSA 2020).
Methods (brief)
Total diet study design: 356 foods representing >90% of German food consumption, purchased in four regions nationwide between December 2016 and May 2019. Foods prepared as ready-to-eat per typical German household practice, then pooled (15–20 individual items per pool) and homogenized. Nickel analyzed in 840 total pools. 23% of pools showed non-quantifiable nickel concentrations (mLB approach). LOD and LOQ varied by food category (for example, drinking water LOD 0.3 µg/kg; LOQ 1 µg/kg; most other foods LOD 6–30 µg/kg; LOQ 20–100 µg/kg). Results presented as modified lower bound (mLB, values below LOD set to 0; values between LOD and LOQ set to LOD) and upper bound (UB, values below LOD set to LOD; values below LOQ set to LOQ). Consumption data: adults from NVS II (2005–2006; n=13,926 aged 14–80); children from VELS study (2001–2002; n=732 aged 6 months–<5 years). Organic vs. conventional production showed only minor differences in nickel concentration; report bases results on conventional/non-specific production.
Key limitations: consumption data from 2005–2006 (adults) and 2001–2002 (children) may not reflect current dietary patterns; 24-hour recall method may underestimate intake from rarely consumed high-nickel foods; MEAL drinking water had relatively high Ni at 3 µg/kg (mean UB), which may overestimate exposure from water-prepared foods such as tea, coffee, and infant formula in regions with lower-Ni tap water.
Implications
Certification: Nickel is in the HMT&C analyte vocabulary. This report establishes that cocoa powder (11,050 µg/kg), cashews (5,350 µg/kg), sunflower seeds (4,750 µg/kg), walnuts (4,300 µg/kg), and dark chocolate (2,800 µg/kg) are the dominant nickel-concentrated ingredients in the food supply. Any HMT&C product category containing these ingredients will have nickel as a primary concern. The data support a framework where a 20% TDI contribution threshold for a single food triggers a nickel control specification.
Courses: The BfR MEAL Study is the definitive German total diet study for nickel and provides the concentration data for estimating nickel exposure from processed foods and snacks. Children’s exposure substantially exceeds adults’ on a body-weight basis, and grains are the dominant pathway at population scale even though coffee, cocoa, and nuts carry higher concentrations per kg.
App: Cocoa powder, cashews, sunflower seeds, walnuts, hazelnut spread, and dark chocolate should carry high nickel flags in the ingredient risk model. Soy-based products (soy milk, soy protein extrudate) are high-exposure drivers for the small fraction of the population consuming them frequently. Infant formula prepared with high-nickel water should trigger an exposure note.
Microbiome: Not addressed in this report.