By Dale Mayerson and Karen Thompson

Food Hypersensitivity is an adverse reaction to food and can occur as a result of food allergy (allergic food hypersensitivity), food intolerance (non-allergic food hypersensitivity) or chemical sensitivity.  There has been a dramatic rise in the incidence of food hypersensitivity in many industrialized countries over the past 20 years.  Food-induced anaphylaxis remains a leading cause for emergency medical treatment and has become a major health concerns in many countries.

When residents move into long term care homes, they are asked about their food allergies along with their food likes and dislikes. Unfortunately, it is difficult to prove or disprove that a resident has a given food allergy without either medical testing or developing an elimination diet. It is important to address and manage any reported allergies and intolerances even though many times a stated allergy may not be a true allergy, but simply an aversion or dislike

Food Allergies

A true food allergy results in a response of the immune system, usually to the protein of the food, which can range from a mild to severe reaction. Mild reactions can affect the eyes, skin, lungs, such as a rash or sneezing, but can also be more problematic, such as hives or vomiting. The most severe reaction is anaphylaxis, which can include extreme drop in blood pressure that affects the organ systems, swelling of the airway and death.

The immune system works by protecting the body and removing harmful elements, such as bacteria and other foreign particles. In an allergic reaction, this particle is called an antigen. The body mistakenly identifies a harmless food substance as a harmful antigen and produces antibodies to attack it, causing an array of allergic reactions. Common allergens include milk, eggs, shellfish, nuts, wheat, peanuts, soybeans and chocolate. More recently, mustard has been added to the list of possible food allergies.

Food Intolerances/Sensitivities

A food intolerance is different than a true food allergy. A food intolerance causes a reaction that does not trigger the immune system. Most symptoms affect the digestive system, with symptoms of nausea, vomiting, abdominal pain and diarrhea. Unlike a food allergy, food intolerance requires a larger portion of an offending food and a longer time (hours or days) to elicit an adverse reaction.

The most common food intolerance is to lactose, the sugar found in milk.  In this case, the body does not produce enough of the enzyme lactase, which is needed to split the lactose molecule so it can be absorbed from the digestive tract into the blood. If the enzyme is not available, the lactose cannot be split and the build-up of lactose causes abdominal pain and diarrhea.

Chemical sensitivity is an adverse reaction to a chemical that either occurs naturally in or is added to a food.  Such chemicals include caffeine in tea, coffee or chocolate, tyramine in aged cheese, monosodium glutamate (MSG), sulphites, and other additives in processed foods.  These can cause heart palpitations and/or headache. Reactions to food sensitivities, as well as food allergies, will vary with the individual.

Nutrition Care

Determining residents’ food allergies, intolerances and nutritional or chemical sensitivities is the first step in managing them.  Nutrition care staff ensure they are noted in the resident’s medical chart and on the diet list and high risk intolerances are noted as such and documented accordingly.  It is prudent to obtain information from previous caregivers/homes and to create a communication plan for all staff.  Strategies should be developed based on the inherent risk associated with the allergy or intolerance; this can include the use of identification/signage for the resident to alert staff, assessing seating assignments in the dining room, individualizing of snacks and meals.  Home and Nursing Administrators should be made aware of high risk situations and the strategies that have been implemented to manage the risk.

For a true allergy, only a trace of a food can cause a reaction.  It is important to practice good hygiene to avoid the risk of cross-contamination while food is being prepared.  It is also essential to read labels of purchased foods to be sure that the allergen is not in the product.  Some residents may have negative reactions to food flavourings or food colours that are widely used.  Sauces, salad dressings and other bottled products need to be checked if these are concerns.

Residents who are allergic to very common foods that are widely used, such as milk, wheat or eggs, may need to have an individualized menu developed for meal and snacks.

Any allergy that can affect a whole food group needs to be closely monitored to avoid a vitamin or mineral deficiency.   Substitutes can be used that provide similar nutrition, for example, fortified soya milk is a reasonable substitute for cow’s milk, since it has comparable protein. Almond milk and rice milk do not contain equivalent protein and therefore would not be the best substitutes. Rice cakes or corn tortillas can be used in place of bread for wheat allergies.

All employees are trained in management of allergies and keep watch for possible hazardous foods in order to keep residents safe. In case of an allergic reaction, there would be an investigation to track what the resident ate. Since residents may have access to a tuck shop, or may have a treat that a family member (or another resident’s family member) brought into the home, there are several aspects that this investigation would need to take.

The goal is to keep residents safe and enjoying their food, both for their physical well-being and for their quality of life.

Dale Mayerson, BSc, RD, CDE, and Karen Thompson, BA Sc, RD are Registered Dietitians with extensive experience in Long-term care.  They are co-authors of “Menu Planning in Long Term Care and Retirement Homes:  A Comprehensive Guide” and have participated for many years on the Ontario Long Term Care Action Group, an advocacy group of Dietitians in Canada