Can microplastics from food and packaging make food allergies worse in children?
A mouse study found oral polypropylene microplastics made cow's milk allergy worse by shifting gut immune responses. Human allergy risk is still being studied.
What's actually in it
Polypropylene is a common plastic used in food containers and some infant feeding products. During formula prep or hot food storage, small plastic particles can get into food or drink.
The gut lining helps teach the immune system what is food and what is a threat. When that barrier is stressed, allergy responses can become stronger.
What the research says
A 2026 mouse study in Journal of Agricultural and Food Chemistry tested oral polypropylene microplastics in a cow's milk allergy model. The exposed mice had worse allergy symptoms, stronger antibody responses, and more gut barrier dysfunction.
The study also found immune changes. Polypropylene exposure pushed dendritic cells and T cells toward a Th2 allergy pattern and reduced regulatory T-cell responses that help build oral tolerance.
This was a mouse study, not proof that plastic containers cause food allergies in children. Still, it gives parents a practical step: use glass or stainless steel for formula prep, food storage, and reheating when possible.