if you are someone sensitive to peanuts, you are used to checking the ingredients on packages. so when you see a warning that reads “may contain nuts” or “this product was made in a facility that may process nuts,” how concerned should you be?
researchers at the university of cincinnati college of medicine tried to answer that question by determining an “eliciting dose” — the amount of peanut — that would cause an allergic reaction in a certain percentage of peanut-sensitive people.
the study examined 481 patients in double-blind placebo-controlled studies who were exposed to increasing levels of peanut protein in a controlled setting until the patient had an allergic reaction.
the dose calculated to elicit an allergic reaction in one per cent of patients with peanut allergies was 0.052 milligrams of peanut protein, about the weight of a single grain of salt, said senior toxicologist lynne haber. the eliciting dose for five per cent of patients was calculated to be 0.49 milligrams of peanut protein, or about the weight of a single grain of sugar.
“risk is based on a combination of how inherently hazardous something is, and how much of that substance someone is exposed to,” said haber, an adjunct associate professor of environmental and public health sciences at the university of cincinnati college of medicine. “arsenic is more toxic than sodium chloride, also known as table salt, but if you’re not exposed to any arsenic, it does not pose any risk.”