Preventing food allergies

Consultant dietitian Sarah Keogh discusses how there are steps that may delay or possibly prevent your child from developing them.

Food allergies can cause a range of problems, as a parent, it is important to know how you can help towards preventing or delaying your child from developing them.

We have seen an increase in food (and other) allergies in Ireland over the past 10 years, so it is no wonder parents are looking for ways to avoid this problem for their children.

So is there a way of preventing food allergies?

In the year 2000, the American Academy of Pediatrics (AAP) issued guidelines that suggested that women avoid peanuts during pregnancy and that babies from allergic families should have soy milk instead of cow’s milk in first few months of life. Many weaning books sprang up telling parents to avoid cow’s milk for the first year of life as well as eggs and fish, and many parents were carefully introducing one food, waiting five days and then introducing the next – a strategy that meant their baby would be about 20 years old by the time they tasted their first stew.

Did all or any of this advice make a difference? The answer is simply: no. In a review of the guidelines in 2013, the AAP said that following the guidelines did not appear to make any difference to the rates of food allergy. New research also suggests that restricting the foods given to babies may actually increase food allergy. So it appears parents were doing it wrong all over again…

The reality is that we are still only beginning to understand what causes food allergies in one child and not another and what we can do to make a difference. It seems that exposing a baby to a food at the correct time is the key to avoiding allergies but that the ‘correct time’ is different for different foods. So where to start?

Pregnancy

The main change in terms of foods and pregnancy is peanuts and other nuts. The Department of Health in Ireland states that women ‘may wish’ to avoid peanuts during pregnancy. Of course, many women do just that, but new research is finding that women who eat peanuts during pregnancy are less likely to have a baby who is allergic to peanuts.

Obviously, if you have a peanut allergy, you do need to avoid peanuts while you are pregnant. Interestingly, women who did have a peanut allergy and ate peanuts had babies who were more likely to have a peanut allergy. Although the official position on peanuts and pregnancy hasn’t changed, it does seem that eating peanuts during pregnancy may reduce peanut allergy.

The first four months – breast is best

All experts agree that the best way to avoid food allergies in babies is to breast feed them for at least the first four months. Do not add in any top-ups or any other food. Babies’ guts are very immature when they are born and babies who have cow’s milk or foods other than breast milk in the first four months are more likely to have food allergies. So if you can, breastfeed for at least the first four months.

In families where a parent or sibling has a food allergy or eczema, keeping babies away from cow’s milk or formulas based on whole cow’s milk for the first year may cut eczema by up to 50%. This means either breastfeeding for the first year and giving the baby weaning foods that do not include dairy or using a hydrolysed cow’s milk formula (speak to your paediatric dietitian for where to get this).

It is very important for parents to note that this restriction only seems to work where there is a history of food allergy in the family. Where there is no history, there is no need to avoid dairy for the first year and you can give your baby cheese and yoghurt and use milk in sauces, but not as their main drink as it is too low in iron.

Wait until baby is at least four months old before you start to wean

Weaning means giving the baby anything that is not breast milk or formula milk. Babies who have foods other than milk before four months seem to be more likely to develop food allergies. So even a taste of gravy from your plate or a nibble on a biscuit is a bad idea before four months. At the same time, you do need to start weaning by six months. It seems that the four to six months is the crucial window and that leaving it later than this can actually increase food allergies.

Apart from honey, there are no foods that you need to wait a year to give to babies. In fact, research now suggests that babies need to have gluten (found in wheat, rye and barley) between four and seven months to reduce the chances of coeliac disease. Before or after this time, the risk increases. For many other foods, it seems to be best to introduce them before one year rather than waiting, especially fish and nuts (as nut butters not in large pieces!). It is as though there is a window of opportunity to reduce food allergies and it runs up to about nine months of age. This is one of the reasons it is so important to have variety in your baby’s diet from very early on.

Should we wait five days between new foods?

No. Unless there is a strong history of food allergy, there is no need to wait such a long time between new foods. You might want to introduce one food at a time in the early days but you can soon mix them up and try lots of different foods and flavours. If you do suspect that your child has reacted to a food, contact your doctor or paediatric dietitian for advice.

It is worth remembering that kids can react to lots of different things and can even have reactions that look like food allergies that are really due to an underlying viral infection! For this reason always get advice before you cut out a food for good.