by on May 14, 2018

in Monthly

Introducing Allergenic Foods

I have always maintained that there is a common theme when it comes to discussing politics, religion and food: consensus is virtually impossible, but compromise is an option.

The current guidelines by Health Canada, the Canadian Pediatric Society and allergists on the matter of when to introduce foods which are known to cause allergies have been updated. These guidelines will surprise many doctors and parents. I predict it will take quite a bit of time before parents become comfortable to introduce peanuts, eggs and fish, for example, at an earlier age.

Peanut allergies have tripled since 1990 and it still remains one of the most common causes of significant food allergies. I shall never forget being at a conference twenty years ago where a dynamic presentation raised the possibility of a vaccine to prevent peanut allergies. Two decades later that vaccine does not exist and it is unclear if it ever will see the light.

Most allergenic reactions to food in Canada are caused by nine types of food substances also known as priority food allergens: peanuts, tree nuts (almonds, Brazil nuts, cashews, hazelnuts, pecans pistachio, and walnuts), sesame seeds, cow’s milk, eggs, fish, soy, wheat and sulphites.

Canadian Family Doctors will be getting updates via reminders and continued education projects in the days ahead as to the optimal timing of introducing allergenic foods. They will tell parents to introduce foods such as peanuts, eggs, fish and other nuts before the age of one year. (In the past parents were told to delay the introduction of allergenic foods)

Food allergies are relatively common, occurring in about 5% of children and the prevalence is gradually increasing. The reasons depend on who we ask to explain this phenomenon.

Allergist have long maintained that the later introduction of solids may actually increase food allergies and that the avoidance of allergenic foods may in fact make things worse.

The news guidelines required input from allergists, pediatricians and dietitians.

When guidelines are updated it is usually as a result of new research. In 2015 the LEAP trial changed almost everything. LEAP stands for Learning Early About Peanut Allergy. 640 infants with severe eczema, egg allergy or both were randomized to consume or avoid peanuts until 60 months of age.

The group who was told to avoid peanuts had peanut allergy prevalence of 35% and the group who told to consume peanuts had 10% prevalence rate. This data influenced the collective recommendations by nine international societies, advising against delaying the introduction of common food allergens.

But the story got even better. After the LEAP trial, another trial took place, known as the
LEAP-On trial. (Persistence of Oral Tolerance to Peanut) This trial demonstrated the durability of oral tolerance to peanuts achieved in the LEAP trial.

In addition, another trial known at the EAT study (Enquiring About Tolerance) confirmed that the early introduction of peanuts and eggs led to a lower incidence of food allergies.

In January 2017 the PETIT trial (Two-step Egg Introduction for Prevention of Egg Allergy in High-risk Infants With Eczema) answered the question if eggs can be introduced to infants with eczema. The authors concluded that the introduction of heated egg in a stepwise manner along with aggressive eczema treatment is safe and efficacious to prevent egg allergy in high risk infants.

One area of agreement relates to breastfeeding. Many international pediatric associations follow the guidelines of the WHO/UNICEF Baby-Friendly Initiative (BFI), which recommends exclusive breastfeeding for six months.

Should nursing moms be concerned about consuming peanuts? Experts claim that at this point there is no reason to tell such mothers to avoid peanuts. However, the later introduction of solids has led a number of experts to get concerned about risks for low iron levels.

For that reason, it is recommended that no later than six months these foods should be gradually introduced: eggs, fish, poultry, beef, lamb tofu and legumes (Legumes must be thoroughly cooked to reduce the content of toxic lectins. The lectin story has created a huge controversy which is best captures in a New York Times Bestselling book The Plant Paradox by Dr. Steven Gundry)

To see an allergist in Canada is not a simple and easy process. The wait times are as long as 6 to 9 months. Allergists are doing their best to respond to the vast majority of requests in a safe and timely manner, and yet many primary care doctors and pediatricians are expected to counsel parents about this important topic.

It should be interesting in the days ahead to see how the LEAP trial’s data and the latest guidelines will change behavior. Public Health Nurses, doctors and dieticians will have their work cut out in telling parents the opposite of what was told in the past, which is to not delay the introduction of allergenic foods to after one year.


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