Are There Heavy Metals in Canned Food?

The Short Answer

The answer is yes, but it depends on the food. Heavy metals in canned food come from two sources: leaching from the can itself (mostly tin, aluminum, and chemical linings) and contamination in the food (lead, cadmium, and arsenic from soil).

Acidic foods are the biggest leaching risk. Tomatoes, pineapples, and citrus can corrode the can lining, causing tin and iron to migrate into your food. A 2026 study found that canned tomato concentrate frequently exceeded safety limits for cadmium, while glass-jarred versions did not. For non-acidic foods like beans or corn, the risk of metal leaching is significantly lower.

Why This Matters

Bioaccumulation is the real threat. You won't get acute poisoning from one can of soup. But heavy metals like lead, cadmium, and mercury accumulate in your body over decades. Even "safe" regulatory limits often don't account for the cumulative effect of eating canned foods daily.

Acidic foods strip the lining. Manufacturers coat the inside of cans with plastic (often containing BPA or BPS) to prevent corrosion. Acidity breaks this barrier down. When the barrier fails, the food reacts directly with the metal can, pulling tin and aluminum into your meal.

The "Safe" Switch isn't always safe. Many brands switched to "BPA-Free" linings, but replaced them with BPS or acrylic resins, which have their own toxicity concerns. Glass and cartons remain the only truly inert options.

What's Actually In Canned Food

Here is where the metals typically come from in your pantry staples:

• Tin — Leaches from the can body. Most common in unlacquered cans or acidic foods (tomatoes) where the lining has degraded. High levels can cause stomach irritation.
• Lead — Found in the food (soil) or old solder. While lead soldering is banned in US cans, imported cans may still use it. Root vegetables (carrots, sweet potatoes) naturally absorb lead from soil.
• Cadmium — Soil contamination. A major issue for conventionally grown tomatoes and spinach. Canning concentrates the food (like tomato paste), effectively concentrating the cadmium.
• Mercury — Found in the fish. This is not from the can. Tuna accumulates mercury from the ocean. Canned tuna is a primary source of dietary mercury. Is Canned Fish Safe
• BPA/BPS — The lining itself. Not a metal, but a potent endocrine disruptor that leaches alongside metals when the lining degrades. Bpa In Canned Foods

What to Look For

Green Flags:

• Glass Jars — The gold standard. Glass is inert and does not leach metals.
• Tetra Paks (Cartons) — A safer alternative to metal cans. While they are lined with plastic/aluminum, the food contacts a safer layer than a corroding metal can.
• "Mercury Tested" — For fish, look for brands like Safe Catch that test individual fish, not just random batches.

Red Flags:

• Dented Cans — A dent breaks the internal plastic lining, allowing the food to touch the metal directly. Never buy a dented can.
• Acidic Foods in Cans — Avoid canned tomatoes, pineapple, and citrus. The acidity is a catalyst for leaching.
• "Industrial" Size Cans — Large #10 cans (used in food service) often have different lining standards and higher surface area for leaching.

The Best Options

Switching to glass or cartons for acidic foods is the single most effective change you can make.

The Bottom Line

1. Buy tomatoes in glass. It's the easiest swap. Brands like Jovial and Bionaturae use glass jars. Best Canned Tomatoes

2. Choose cartons for beans/broth. Tetra Paks (like Pomi or Pacific Foods) are lighter, safer, and have a lower carbon footprint than metal cans.

3. Don't panic about beans. Non-acidic foods (black beans, chickpeas) are much less likely to leach metals from cans. A quick rinse before cooking reduces sodium and potential residues.

FAQ

Does washing canned food remove heavy metals?

It helps with sodium, but not metals. Rinsing beans can remove about 40% of the sodium and some metallic taste from the canning liquid, but it cannot remove lead or cadmium that has been absorbed into the food's fibers during growth.

Are "BPA-Free" cans safe from heavy metals?

Not necessarily. "BPA-Free" refers to the lining chemical, not the metal can. If the lining is scratched, dented, or degraded by acidity, tin and aluminum can still leach into the food. Is Bpa Free Lining Safe

Is canned tuna high in lead?

It's mostly mercury. While trace lead can exist, mercury is the primary neurotoxin in tuna. Skipjack (light) tuna generally has less mercury than Albacore (white) tuna. For the safest option, choose brands that strictly test for mercury limits. Is Canned Fish Safe