allergies: how much peanut is too much peanut?

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.”finding that eliciting dose is crucial from a public health perspective as people who have peanut allergies can experience a wide range of effects. according to food allergy canada, an estimated two in 100 children in canada are affected by peanut allergies which can lead to an itchy, tingling mouth and hives or something as serious as food-induced anaphylaxis. anaphylaxis is a potentially life-threatening condition that requires a trip to the emergency room and treatment with a shot of epinephrine.“the amount of exposure is also important in determining risk,” said haber. “water is healthy, but if you drink enough of it, it could kill you. there has been a move to shift to labeling that is based on a combination of the inherent hazard of a substance and how much of it is in a product. this is being done in australia, new zealand and europe.”the researchers point out that the eliciting dose they found in the study may only be relevant to people living in the united states because of how diets and exposure to peanuts may vary internationally. other cultures use peanuts far more frequently or infrequently compared to the u.s., and those differences can affect how sensitive people are to them.peanuts are a member of the legume family, and not related to tree nuts. a person can be allergic to peanuts and not be allergic to tree nuts, or they can be allergic to both. lupin (or lupine) is a legume belonging to the same plant family as peanuts and some people are allergic to both of those as well. it is recommended for anyone with a peanut allergy to avoid products containing lupin until they have consulted with their allergist.don’t miss the latest on covid-19, reopening and life. subscribe to healthing’s daily newsletter covid life.