As babies transition from breast milk or formula to solids, parents must navigate a whole new world of food and nutrition. One important part of introducing new foods to infants involves those that contain allergens - which could be crucial to decrease the risk of your baby developing food allergies in later life.
However, it has been hypothesised that a higher intake of specific allergens - such as gluten - in early childhood could actually be associated with a higher risk of developing serious intolerances, like celiac disease autoimmunity (CDA) and celiac disease.
A recent study published in The American Journal of Clinical Nutrition looked into the theory and found that dietary patterns in the first two years of a child’s life were associated with the subsequent risk of CDA and celiac disease, independent of their gluten intake. The study analysed children who were genetically predisposed to developing the conditions.
It suggested that what we eat in early childhood could shape food intolerances and allergies in later life, although further research is needed to define just how much diets impact these risks.
Exploring the link between diet and allergies
Hannah Whittaker, a dietitian and specialist in milk protein allergies, tells Yahoo UK that introducing common allergen foods when babies are ready for weaning, which is usually around the six-month mark according to the NHS, is important for early nutrition.
She points to the LEAP (Learning Early About Peanut Allergy) and EAT (Enquiring About Tolerances) studies, published in 2015 and 2016 respectively, as research that shows how avoiding common allergen foods foods during early life "can actually heighten the risk of developing food allergies later on".
The LEAP study focused on the early introduction of peanuts to infants at high risk for peanut allergy and found that high-risk children who were exposed to peanuts early had a 81% reduction in the development of peanut allergy, compared to those who avoided peanuts altogether.
Meanwhile, the EAT study showed a reduced rate of food allergies among children introduced to six allergenic foods - milk, eggs, wheat, sesame, peanut and fish. The study has since encouraged more research into early allergen introduction and its impact on allergy development.
Whittaker says: "Delaying introducing common allergen foods past 12 months may increase the risk of developing an allergy to that specific food. It’s not only about decreasing the risk of allergies but also about enriching a baby's diet. Early introduction of a varied diet can set the stage for healthy eating habits later in life."
Common food allergens you should introduce to babies
Peanuts and tree nuts
Whittaker recommends introducing smooth nut butters mixed into your baby’s porridge to avoid a choking risk. "If given on a spoon, this should have water added again to reduce the risk of choking," she adds.
A hard-boiled egg can be a good way to start incorporating eggs into your baby’s diet. Whittaker explains that the protein in eggs goes through "denaturation" when heated, which "makes it less likely to cause an allergic reaction". Following this stage, you can start moving on to soft-boiled or scrambled eggs, given as either finger food or mashed.
Whittaker suggests introducing it as a breakfast cereal mixed with baby’s usual milk (breast or formula) or as slices of toast for finger food.
You can introduce soft flakes of fish, mashed or pureed, into your baby’s food.
For babies with a milk allergy, soy products may be used in place of cow’s milk. Whittaker warns children should be monitored when introduced to soy due to the risk of a "secondary allergy", and that soy allergies can stand alone from milk allergies.
"As a dietitian, I recommend leaving at least three days between the introduction of new foods to account for potential non-IgE (non-immunoglobulin E) reactions that may take up to 72 hours to show," she adds.
Importance of introducing allergens
While some parents may avoid introducing common allergen foods to their children due to fear or anxiety, this can have long-term implications for their health.
"A lack of early introduction of peanuts, eggs and wheat when weaning commences may increase the likelihood of the child’s immune system identifying these as foreign later in life, potentially leading to allergic reactions," Whittaker warns.
Family history can also play a role in a child’s likelihood of developing an allergy, she adds. Children with a parent or sibling with a history of conditions such as asthma, hay fever, eczema or food allergies are often considered at higher risk of developing food allergies themselves.
However, Whittaker says: "While family history is an important marker, it doesn't guarantee that a child will or will not develop allergies and allergens should be introduced as above."
More information about food allergies:
Do You Have a Food Allergy or Intolerance? We Asked a Biochemist How To Tell the Difference (Woman's World, 6-min read)
Study links good gut health to lower risk of food allergies (Women's Health, 3-min read)