Antibiotics causing allergic reactions to fruits and vegetables

Sometimes it isn't the fruit or vegetable that triggers an allergic reaction — it's the antibiotic sprayed on it to keep it from rotting.

The most striking example is a published 2013 case report: a ten-year-old girl with a milk and penicillin allergy, asthma, and seasonal allergies suffered life-threatening anaphylaxis after eating a slice of blueberry pie. Nothing in the pie's ingredients should have endangered her. Investigators traced the culprit to streptomycin — an antibiotic sprayed on the blueberries to keep them free of fungi, bacteria, and algae.

Antibiotics such as streptomycin and oxytetracycline are used in US orchards, notably on apples and pears to fight fire blight. The European Union does not authorize streptomycin as a plant-protection product, so the practice differs by region.

Could agricultural antibiotic use be contributing to rising allergy rates? Some researchers have raised the hypothesis, but it is not established — antibiotic residues are one of many suspected environmental factors, and far from a proven primary cause. What is established is that residue exposure is possible in conventionally grown produce; organic standards in the US have moved to restrict antibiotic use on fruit crops.

The practical takeaway is modest: wash produce well, and if you have unexplained reactions to foods you should tolerate, consider that an agricultural chemical — not the food itself — may deserve a look.