Advice for preventing infant & child food allergies

Paediatric Dietitian, Jennifer Douglas sheds some light on infant and child food allergies and what can be done to prevent them.

Food allergies can occur in infants, children, and adults. Most of us will know a friend or a friend's child that has a food allergy. In New Zealand, around 1 in 10 infants under the age of one year, around 4-8% of school-age children and 2-4% of adults will be affected. The incidence of food allergies has increased over the past few decades and there are a number of reasons for this. 

Prevention of food allergies has been researched extensively over the last 10 years, but there is still much more to learn in terms of what could be done to reduce it in the western world. So, let's take a look at what food allergies actually are and what (if anything) can be done to prevent them.

WHAT ARE THE RISK FACTORS FOR FOOD ALLERGIES?

Food allergies can occur for any infant or child, with some starting later in adulthood. Some factors that increase the risk of food allergies are:

+  Eczema

+  Family history (eg sibling or parent) of food allergy, eczema, asthma or hayfever

WHAT ARE THE COMMON ALLERGEN FOODS?

The most common foods that cause an allergic reaction are cow’s milk, soy, egg, peanut, treenuts, sesame, wheat, fish and seafood, but your child can be allergic to any food.

WHAT ARE THE SYMPTOMS OR SIGNS OF FOOD ALLERGIES?

Food allergies occur when the body’s immune system sees a food as a threat and builds IgE antibodies against that food. Food allergy reactions normally occur within 30 minutes to 2 hours after ingestion of the food with varying signs and symptoms presenting.

MILD REACTION SIGNS

Mild to moderate reactions to look out for may include any one of the following:

+  Swelling of face, lips or eyes

+  Hives or welts on the skin

+  Tingling mouth

+  Abdominal pain

+  Vomiting

SEVERE REACTION SIGNS

Severe signs (including signs of anaphylaxis) to look out for may include any one of the following:

+  Difficult or noisy breathing

+  Swelling of the tongue

+  Swelling or tightness in the throat

+  Wheeze or persistent cough

+  Difficulty talking or hoarse voice

+  Persistent dizziness or collapse

+  Becoming pale and floppy

If your infant or child shows any of these symptoms, contact medical services immediately for help, and/or take them to your local emergency department.

HOW ARE FOOD ALLERGIES MANAGED?

Managing food allergies involves avoidance of the allergen food/s. It is possible that your child may tolerate some versions of that food allergen, such as the baked version, and in these cases they may continue to have this form of the food allergen within the diet. Your doctor will work in with your family to identify a time when or if the food allergen can be reintroduced into the diet again. Most children with cow’s milk, soy, and egg allergens will outgrow the allergy by the time they are at school. However, fish, seafood, and nut allergies are more likely to extend into adulthood. It is important that children who are avoiding whole food groups because of allergy symptoms have their growth and nutritional intake monitored regularly by a dietitian.

WHAT SHOULD I DO IN PREGNANCY TO PREVENT ALLERGIES DEVELOPING?

During pregnancy it is important to have a diverse diet that is high in fibre from wholegrains, fruit, and vegetables. There is no evidence to support avoidance of any allergen foods during pregnancy and pregnant woman should enjoy a wide variety of all foods. There is some evidence that a diet containing omega-3 fatty acids from oily fish eaten three times weekly may reduce the risk of eczema, but more research is needed in this area. There are also studies showing that taking probiotics during pregnancy may reduce the risk of eczema in infants, but other studies have shown no associated benefit, so the jury is still out on this one.

WHAT SHOULD I DO WHEN BREASTFEEDING TO PREVENT ALLERGIES DEVELOPING?

It is recommended by the Ministry of Health to exclusively breastfeed your baby until they are around six months of age, and to continue to breastfeed for up to two years or longer. If your baby is not breastfed, a commercial infant formula is the only suitable alternative to breast milk in the first year of life. There is no evidence to suggest that the use of hypoallergenic, hydrolysed, goat, or sheep formulas have a role in prevention of allergies. Breastfeeding has not been shown to directly reduce the risk of food allergies but has benefits for both mothers and babies, including lower incidence of respiratory infections. There is also no evidence to suggest that a breastfeeding mother's avoidance of food allergens will lower the risk of food allergies – avoidance may even increase the risk. There is some evidence to suggest that breastfeeding alongside allergen introduction can help reduce the risk. If your baby has a known food allergy, it is important to work with your doctor about whether the food allergen can continue in a breastfeeding mother’s diet, as in some cases it can.

WHEN SHOULD I INTRODUCE SOLIDS TO MY BABY?

In New Zealand it is recommended by the Ministry of Health that around six months of age (and not before 4 months), when your baby is showing signs of readiness, is the best time to introduce complementary foods.

WHEN SHOULD I INTRODUCE ALLERGENS TO MY BABY AND HOW?

There is very strong evidence from studies to show that introducing food allergens to your infant from between the ages of 6-12 months reduces the risk of food allergies. This is the number one thing you can do to help reduce the risk. These recommendations are also for infants at higher risk of food allergy (eg those with a sibling or parent with a food allergy). Once an allergen has been introduced to your infant, it is recommended that you continue to give the allergen regularly (eg twice weekly) to maintain tolerance.

The ‘Growing up in New Zealand’ study identified that New Zealand babies by the age of 9 months of age have been introduced to a wide variety of foods. The most common first foods to be introduced were baby rice, fruit, and vegetables. These were followed later by meat, bread, toast, milk pudding, rice pudding, yoghurt or custard, and baby breakfast cereals.

Data on how New Zealand is doing with introducing allergen foods within the first year of life is not available yet, but in Australia (where education around early introduction is widespread) the rates from the ‘OzFits study’ show that over 90% of infants have had egg and peanut introduced within the first year of life.

DOES ECZEMA INCREASE THE RISK OF FOOD ALLERGIES?

Eczema in infants has been associated with increased risk of food allergy. Well-managed eczema is important to reduce the risk of skin sensitisation to food allergens. Eczema management involves a routine of creaming, ointments, possible bleach baths and wet wraps prescribed by your doctor or nurse practitioner. It is useful to keep your baby’s skin well moisturised and to avoid using soap that can dry out the skin. It is advisable to also avoid using baby creams containing food allergens, such as almond/peanut oils.

DO PROBIOTICS OR VITAMIN D HAVE A ROLE IN THE PREVENTION OF FOOD ALLERGIES?

There is limited evidence to suggest that probiotics reduce the risk of food allergies, but some studies do suggest that given in the last trimester of pregnancy and/or in the first 3 months of life, probiotics might reduce the risk of eczema.

There are some studies currently looking into the role of Vitamin D in relation to food allergies, but research in this area is limited. In New Zealand the recommendation is that pregnant woman and infants at risk of vitamin D deficiency (eg have darker skin, live in the southern regions of NZ, previous low vitamin D levels) may benefit from supplementation, especially over the winter months. Talk to your health provider about whether you or your baby need Vitamin D supplementation.

JENNY'S IDEAS FOR INTRODUCING ALLERGEN FOODS

Here are some simple ways to introduce common allergen foods into your child's diet in their first year – when they are ready for solids. 

Egg

◻️ Cooked egg in a muffin/pancake

◻️ Frittata

◻️ Hard boiled egg added to puree

◻️ Scrambled egg

◻️ Omelette

Peanut

◻️ Smooth peanut butter on toast

◻️ Smooth peanut butter added to puree, curry or stew

◻️ Finely ground peanut added to cereal, baking, yoghurt, or added to meatballs

Treenut

◻️ Smooth almond/cashew/brazil butter on toast, into cooking, or into puree

◻️ Finely ground almond, brazil, cashew, walnut etc added to cereal, baking, yoghurt or added to a crumble

◻️ Blitzing together treenuts that have been introduced into a powder is a great way to keep regular exposure to each treenut and this ‘nut powder’ can be used in baking or add to porridge/cereal

Cow’s milk protein

◻️ Unsweetened yoghurt

◻️ Grated, sliced, melted cheese added to meals

◻️ Cow’s milk with cereal or in baking

◻️ Cow’s milk made into a white/cheese sauce and added to cooked veggies/pasta. Cow’s milk should not be given as a drink until after 12 months of age as babies should have either breast milk or formula to drink for the first 12 months. However, cow’s milk can be added to foods

Sesame

◻️ Offering hummus as a spread or dip for cooked veggies as this contains tahini (sesame paste)

◻️ Thinly spread tahini on toast fingers, cooked veges, or add to puree

◻️ Sprinkle sesame on crumble or add to cereal

Wheat

◻️ Wheat-based cereal

◻️ Bread

◻️ Pasta either as a finger food or blitzed into puree/mash

◻️ Wheat flour added to sauces such as white/cheese sauce

Soy

◻️ Most commercial breads in NZ contain soy flour, so you can give toast/bread

◻️ Reduced salt soy sauce added to family meals

◻️ Tofu given as finger food or added to puree/mash

◻️ Soy milk added to cereal or into baking/cooking

Fish

◻️ Pan-fried fish, or baked fish (remove bones)

◻️ Canned (low salt) salmon/tuna added to pasta dishes or into veggie puree

◻️ Crumbed fish as small pieces

◻️ Fish added to curry and stews

Seafood

◻️ Prawns mashed into puree, or served with noodles/rice and veggies

◻️ Crab cakes

◻️ Scallops added to rice/noodle dishes and veggies, or served crumbed  

USEFUL RESOURCES

If you are concerned about your baby or child having a food allergy then have a chat with your healthcare provider.
Some other places to find information would be:

+  Nip Allergies in the Bub: preventallergies.org.au

+  ASCIA: allergy.org.au

+  Allergy NZ: allergy.org.nz/

+  Healthify NZ: healthify.nz

Jenny Douglas is a registered dietitian with around 20 years experience working with families and is a leading expert on baby and child nutrition. Co-author to the YUM cookbook with Nadia Lim, Jenny is also director of Jumpstart Nutrition – a company of dietitians working to improve nutrition for families. Jenny holds regular workshops around NZ and sees families in her Dunedin clinics or online. Visit jumpstartnutrition.co.nz for more information.