Can heavy metals in breast milk come from a mother's diet and environment?

What's actually in it

Breast milk provides perfect nutrition for babies, but it can also contain heavy metals that a mother absorbs from food, water, and air. Lead from old paint and pipes, mercury from fish, cadmium from cigarette smoke and food, and arsenic from rice and water all end up in breast milk to some degree.

What the research says

A 2026 review in J Nutr examined the factors that determine heavy metal levels in human breast milk. The review found that maternal diet, smoking, occupation, and geographic location all affect how much metal ends up in the milk. Mothers who ate more fish had higher mercury levels. Those living in industrial areas had higher lead and cadmium.

The review emphasized that breastfeeding is still the best choice for infant nutrition despite these findings. The benefits of breast milk far outweigh the risks from trace metals. But reducing exposure is still worthwhile.

While breastfeeding, limit high-mercury fish like tuna, swordfish, and king mackerel. Filter your drinking water. Eat a varied diet rich in calcium and iron, which help block heavy metal absorption. Don't smoke.