Childhood allergy rates have increased significantly over the last few decades now affecting 1 in 10 children! This has led to a lot of research into how we can prevent allergies in babies. 

We can take steps to minimise the risk of allergies in babies during pregnancy, breastfeeding and through the way we introduce solids to babies when they are ready to eat. Read on to learn more about what research has shown to be some of the key strategies for preventing allergies in babies.

Allergen exposure during pregnancy & breastfeeding

We can make a start on minimising the risk of allergies in babies during pregnancy and while breastfeeding.

A few decades ago, mainstream advice was to avoid potential allergy-causing foods during pregnancy and breastfeeding. What is emerging from the evidence now is that actually, the opposite seems to be true if we want to reduce the risk of allergies in babies.

  • Avoiding particular foods during pregnancy has not been shown to help reduce infant allergies. In fact, eating a variety of allergens including peanuts, milk and wheat has been shown to reduce the incidence of food allergies, asthma and eczema in children (Fujimura et al., 2019). 
  • The position is similar for breastfeeding. For example, breastfeeding mothers who regularly ate peanuts (and introduced peanuts as a food to their baby before 12 months) had the lowest incidence of peanut allergy in their children compared to those who avoided peanuts while breastfeeding or delayed introducing peanuts as a food (Pitt et al., 2018).

Foods consumed by the mother can flavour amniotic fluid surrounding the foetus and later on, breast milk (Spahn et al., 2019). Potentially, it seems that consuming certain foods is also helping to expose and desensitise babies to possible allergies.

So, unless the mother has a food allergy herself, there is no reason to cut out allergenic foods during pregnancy. 

The only exception is if the food is one that shouldn’t be consumed during pregnancy for safety reasons e.g. raw fish or fish high in mercury such as swordfish, are not safe seafood options during pregnancy.

Enjoy a wide variety of foods during pregnancy and breastfeeding to expose baby to lots of different flavours! Read more about what to eat during pregnancy and what to eat during breastfeeding.

Introducing Solids is KEY for preventing childhood allergies


One of the most scary things about introducing solids to babies is the possibility of an allergic reaction. But, even though this can be frightening, the key to minimising food allergies in babies is this early exposure to food!

The most common food allergens should be introduced before one year of age. 

Allergens should be introduced usually between 6 and 12 months of age, if you begin to introduce solids at 6 months. The key foods to introduce are:

  • egg
  • peanut
  • tree nuts (e.g. almonds, hazelnuts, walnuts)
  • sesame
  • cow’s milk
  • fish
  • shellfish (e.g. prawns)
  • wheat
  • soy

Once you have established that your baby can safely eat an allergenic food, try to offer it regularly to maintain their tolerance. The Australasian Society of Clinical Immunology and Allergy recommends to offer your baby these foods around twice a week.

A helpful Australian government-backed website on introducing allergens to babies is Prevent Allergies, which includes suggestions on how to introduce these foods in an age-appropriate way, safe for baby to chew and swallow. 

If you have concerns about your baby, speak to your child’s doctor and/or paediatrician. They may recommend you work with a paediatric dietitian to help plan baby’s first foods.

Can probiotics help prevent allergies in babies?


There is a lot of exciting research being published on the potential effects of probiotics. Probiotics are live microorganisms that can be found in fermented foods like yoghurt and sauerkraut, as well as being available in supplement form. 

The term “probiotics” actually refers to a huge variety of microorganisms, and they all have different potential effects! Each strain of probiotics is unique, so when we look at the research we need to look at the exact strain that was tested and the effective dosage and period of time required to see a benefit, too.

When it comes to preventing allergies in babies, a few particular strains of probiotics have shown some possible benefits.

  • Lactobacillus rhamnosus GG (“LGG”) – this strain has been discussed before in another blog post. Studies show that long term supplementation of children with LGG (for the first 2 years of life) may improve tolerance of cow’s milk in children who have a diagnosed cows milk protein allergy (Tan-Lim & Esteban-Ipac, 2018). 
  • There have also been a number of studies that have looked at whether supplementing with LGG can help to prevent infant eczema. Some studies have shown a significant reduction in the incidence of eczema when LGG supplementation began in the third trimester of pregnancy. However, other studies have shown only a minor or no difference, so it’s not guaranteed to prevent eczema in all children (Szajewska & Horvath, 2018). 
  • Lactobacillus rhamnosus HN001 (“LHN001”) – supplementing with LHN001 in the mother from 35 weeks’ pregnancy to 6 months postpartum while breastfeeding, plus supplementing the child from 0-2 years of age, may prevent the onset of eczema throughout childhood (Wickens et al., 2018).

Can Vitamin D play a role in allergy prevention?


An adequate level of vitamin D may play a role in the prevention of childhood allergies. Research conducted in Australia showed that low vitamin D levels in parents and in babies have both been associated with higher rates of food allergies (Allen et al., 2013), and given 1 in 4 adults are vitamin D deficient this could be affecting you and your future bub!

Vitamin D is important to the regulation of our immune system. When we don’t have enough vitamin D, our immune system may respond differently, including having an increased incidence of allergic reactions.

We get most of our vitamin D from the sun – “it’s the sunshine vitamin”. A small amount can be found in some foods including egg yolks and fish. Mushrooms left in the sun can also provide vitamin D, as they absorb the sunlight for us! 

If you are trying to conceive, pregnant or breastfeeding, it’s important to have your vitamin D levels checked. 

For some people, a vitamin D supplement may help achieve optimal vitamin D levels for mother and baby. However, start with getting your levels checked and then the appropriate supplementation can be discussed with a dietitian.

Fish Oil to Prevent Allergies in Babies?


A number of studies have looked at whether fish oil during pregnancy, breastfeeding and infancy has been able to prevent allergies in babies. 

Fish oil is rich in the omega-3 fats eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In most of the research into fish oil and allergies, participants were given a high-dose EPA/DHA fish oil supplement. 

So far the research has not produced consistent results, with some studies showing a possible benefit and others showing no effect. For the studies that have shown positive effects, EPA/DHA supplementation has reduced the incidence of eczema and sensitisation to specific foods, particularly egg (Ciaccio & Girdhar, 2014; Garcia-Larsen et al., 2018).

While we are yet to see consistent results for the prevention of allergies, fish oil also provides other benefits during pregnancy and breastfeeding – especially good amounts of DHA, which supports the development of the baby’s brain, eyes and nervous system.

If you enjoy seafood, try to incorporate 2-3 servings of fish into your meals each week, including oily fish like salmon, sardines, trout and tuna.

An EPA/DHA supplement may also be suitable. Learn more about omega 3s, fertility and pregnancy in my blog post here!


  1. Eat a varied diet during pregnancy and breastfeeding, do not avoid foods unless there is another reason to do so e.g. mother has an allergy, or food safety reasons.
  2. Introduce the key allergenic foods to your baby (in an age-appropriate way) between 6 months and 12 months of age. Maintain exposure to allergenic foods by regularly offering them to your baby.
  3. Maintain healthy vitamin D levels during preconception, pregnancy, breastfeeding and in baby.
  4. Consider a probiotic supplement with the strains LGG and/or LHN001.
  5. Enjoy 2-3 meals that include fish each week (especially oily fish) and/or consider taking a fish oil supplement (an EPA/DHA supplement).

If you want to put in place an action plan to minimise the risk of allergies, as a pregnancy and early life dietitian I can help from pregnancy all the way through to infanthood. Schedule a FREE 15 minute discovery call with us today!

This article was co-written by nutritionist Monique Cormack. You can find Monique on Instagram or connect with her on Linkedin.

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