SLEUTHIT

Ingredient decoder

Peach

Peach is a birch-pollen cross-reactive food — its PR-10 Proteins protein resembles the birch allergen closely enough that pollen-allergic people can react to it.

Allergen family data

FamilyCategorySeverityMapping
PR-10 Proteinspollen_foodUsually mild (oral allergy syndrome)Curated mapping

Sources: SleuthIt curated dataset

Also appears as

Pru p 1Prunus persica

Cross-reactivity

strongBet v 1 (Birch PR-10)Mal d 1 (Apple PR-10)

~70% of birch pollen allergics react to raw apple

strongBet v 1 (Birch PR-10)Pru av 1 (Cherry PR-10)

~50% of birch allergics react to cherry

moderateBet v 1 (Birch PR-10)Api g 1 (Celery PR-10)

Birch-celery-mugwort-spice syndrome

Case notes

Peach is one of those ingredients that hides in plain sight because the label rarely uses the word. You may see Prunus persica in a botanical-sounding ingredient list, or Pru p 1 in allergy testing paperwork that a parent is trying to match up against a snack wrapper. Both names point to the same fruit, and neither reads like "peach" to someone scanning quickly in a grocery aisle.

The second reason it slips past is that peach sits in the PR-10 Proteins family, a group of pollen-related food proteins whose defining allergen is birch pollen's Bet v 1. Parents watching for a fruit reaction often aren't watching for a pollen-food connection at all, so the pattern looks random: one food in this family causes trouble, another doesn't. Reactions in this family are usually mild, described as oral allergy syndrome, which can make them easy to dismiss rather than log.

Because PR-10 proteins are heat-labile, processing matters more here than with most label reading. The same protein that's often destroyed during juice processing may persist in fresh or minimally processed products, so the form of the food can change the outcome more than the ingredient name suggests. Related PR-10 foods worth reading alongside peach include apple, where roughly 70% of birch-allergic people react to the raw fruit, cherry at around 50%, plus celery, carrot, hazelnut, and soybean's Gly m 4. Noting which form was eaten, not just which fruit, is what makes a record useful later.

Questions

Peach is a birch-pollen cross-reactive food — its PR-10 Proteins protein resembles the birch allergen closely enough that pollen-allergic people can react to it.

On the case

SleuthIt flags Peach automatically when you scan a label.

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