You might be consuming toxic metals without realizing it: beware of these foods

Found naturally in the environment but amplified by human activity, cadmium quietly enters the food chain. Invisible, with no taste or smell, it accumulates in the body over time, especially in kidney tissue. This insidious nature explains why the public often underestimates it.

The colder months can increase dietary exposure: higher consumption of winter root vegetables and leafy greens, grain-based dishes, and seafood during the holidays. If these habits repeat, they can add to a chronic background dose.

Cadmium moves from soil into plants, then into animals and onto our plates. Its main sources are local geology, industrial fallout, certain phosphate fertilizers, and the spreading of sludge. Soil acidity and low organic matter make it easier for roots to take it up.

The foods most affected fall into everyday categories:

• Grains and cereal products: wheat, rice, rye, buckwheat, breads and biscuits (levels depend on grain type and the soil where it was grown).
• Root vegetables: potatoes, carrots, beets, celeriac, parsnips (direct contact with soil).
• Leafy greens: spinach, lettuces, cabbages, chard (large exchange surface and rapid growth).
• Seafood: filter-feeding shellfish and crustaceans, with potentially high levels in internal organs or the “brown meat.”
• Other notable contributors: cocoa and chocolate, seaweed, certain wild mushrooms.

At low doses over the long term, cadmium primarily targets the kidneys (tubular damage, impaired reabsorption), then the liver and bones (demineralization, fragility, increased osteoporosis risk). It is classified as carcinogenic to humans (IARC Group 1), mainly by inhalation; chronic ingestion remains a concern because it accumulates.

Effects vary by age, nutritional status, and duration of exposure. A deficiency in iron, zinc, or calcium can increase intestinal absorption of cadmium. Symptoms appear late, which complicates prevention without upstream action.

• Children: growing bodies, relatively higher absorption, critical windows of developmental vulnerability.
• Pregnant women: important to avoid unnecessary buildup to protect the fetus.
• Older adults and people with kidney disease: long biological half-life, more fragile mineral reserves.

The first line of defense is diversification: rotate grain sources (rice, wheat, oats, corn), vary vegetables and origins, and favor local, certified brands that monitor levels. Avoid eating the same higher-risk food too often.

• Washing/Preparation: scrub and rinse vegetables thoroughly; peel roots when possible; remove outer leaves from lettuces and cabbages.
• Cooking: boiling and discarding the water can reduce some water-soluble contaminants; do not reuse cooking water from vegetables or rice. Rinsing rice first and cooking it in excess water lowers certain loads.
• Choosing seafood: moderate how often you eat higher-risk shellfish/crustaceans, remove the “brown meat” from crabs, and diversify with fish that bioaccumulate less.
• Offal: limit liver and especially kidneys from large animals, which are more likely to concentrate metals.
• Nutritional status: meet your iron, zinc, and calcium needs to reduce cadmium absorption.

Making informed choices, reading origin and supply-chain information, and alternating brands can limit cumulative exposure without sacrificing a balanced diet.

Intensive practices can increase contamination: use of phosphate fertilizers with naturally variable cadmium content, spreading of residues, industrial fallout. Soil acidification and erosion mobilize more metal, boosting its bioavailability to plants.

European rules set maximum levels for several food categories and regulate fertilizers placed on the market. While these frameworks have reduced some contamination spikes, gaps remain: heterogeneous soils, legacy pollution, and differences in enforcement across sectors and countries. Monitoring needs to stay regular and transparent, with better traceability of origins.

There are agronomic levers: choose low-cadmium fertilizer sources, correct pH (liming), enrich soils with organic matter, select cultivars that accumulate less, fine-tune input rates, and diversify rotations. Promoting responsible farming and agroecological approaches protects both soil fertility and public health over the long term.