Do heavy metals in vegetables vary by type, and which are safest?

What's actually in it

Vegetables absorb lead, cadmium, arsenic, mercury, and chromium from the soil they grow in. The amount varies wildly depending on the type of vegetable, where it was grown, and what contaminants are in the local soil and water. You can't wash heavy metals off because they're inside the plant tissue, not on the surface.

What the research says

A 2026 systematic review in Environ Monit Assess analyzed data from studies worldwide to map out which vegetables accumulate the most heavy metals and which pose the greatest dietary risk.

Leafy greens like spinach, lettuce, and kale had the highest metal concentrations. Their large surface area and fast growth mean they pull more metals from the soil. Root vegetables like carrots, potatoes, and beets were next, since they're in direct contact with contaminated soil.

Fruiting vegetables like tomatoes, peppers, and squash accumulated the least. The metals have to travel further through the plant to reach the fruit, and less gets through.

The review also found that vegetables from industrialized areas, near highways, or grown with contaminated irrigation water had the highest levels. Organic farming reduces pesticide residues but doesn't necessarily reduce heavy metal content, since the metals come from the soil itself.