- People following a gluten-free diet (GFD) bioaccumulate significantly higher levels of lead, arsenic, mercury, and cadmium than people not on a GFD.
- Editorial applauds the study, advises against routine heavy-metal testing, and suggests those who do not require a GFD “carefully should weigh the negative consequences...against any perceived benefits.”
Why this matters
- GFDs are growing in popularity even among people not diagnosed with a gluten-related disease.
- Such diets can lack fiber and micronutrients and contain excess salt, sugar, and fat.
- Rice and fish, often consumed in larger amounts in GFDs, are contaminated with heavy metals.
- 115 participants followed GFD (11 with celiac disease [CD]).
- Univariate analysis (GFD vs not):
- Mercury: 1.37 vs 0.93 mcg/L (P=.008);
- Lead: 1.42 vs 1.13 mcg/L (P=.007);
- Cadmium: 0.42 vs 0.34 mcg/L (P=.03); and
- Arsenic: 15.15 vs 8.38 mcg/L (P=.002).
- Multivariate analyses remained significant.
- Population-based, cross-sectional study, National Health and Nutrition Examination Survey (NHANES) data, 2009-2012 (n=11,354 adults).
- Blood samples tested for serologic CD; participants asked about CD, GFD.
- Researchers adjusted for confounders, including fish consumption (for mercury).
- Endpoints: lead, mercury, cadmium levels in blood (n=11,354); urinary arsenic (subset, n=3933).
- Funding: CDC.
- Few people were following GFD.
- Long-term clinical significance unknown.