Preventing allergies in pregnancy: fish oil and probiotics

Nutrition is an extremely important part of developing a healthy baby during pregnancy. Also, new evidence of the positive impact of supplements on a baby's development has emerged in recent years.

 

Can supplements prevent allergies in babies developing in the womb? We spoke to the highly experienced paediatric allergist, Dr Robert Boyle, to find out.
 

How much do supplements help in supporting the healthy development of a baby?

Women who take probiotics and fish oil tablets in later pregnancy may reduce their child's risk of food allergy and eczema.
 

As the leading lead author of the research from the Department of Medicine at Imperial College London, I helped assess over 400 studies involving 1.5 million people to find out how a pregnant woman's diet affects their baby's allergies and eczema.
 

As part of the study, we found that when pregnant women took a fish oil capsule daily, from 20 weeks pregnant, and during the first three to four months of breastfeeding, the babies risk of egg allergy in the child was reduced by 30%.
 

We found that taking a daily probiotic supplement from 36-38 weeks pregnant, and during the first three to six months of breastfeeding, could lower the risk of a child developing eczema by 22%.
 

Eczema and food allergies in children are a growing problem across the world.

We found no evidence that avoiding potentially allergenic foods such as dairy, nuts, and eggs during pregnancy made a difference to a child's eczema or allergy risk.
 

Eczema and food allergies in children are a growing problem. However, it has been suggested that what a woman eats during pregnancy may affect her baby's risk of developing eczema or allergies, until now, there has never been such a comprehensive analysis of the data.
 

Our research has suggested that probiotic and fish oil supplements may reduce a child's risk of developing an allergic condition. These findings need to be considered when guidelines for pregnant women are updated.
 

We also assessed a host of dietary factors during pregnancy, including fruit, vegetable and vitamin intake. However, we found no clear evidence that any of these affected allergy or eczema risk.
 

How else can we reduce the risk?

More research is now needed to understand how fish oils and probiotics may reduce allergy and eczema risk. Although allergies and eczema is on the rise, and it affects millions of children, we are still searching for the root causes of these conditions, and still investigating how to prevent it. This study has provided clues, which will need to be followed up.
 

Our team also assessed 28 trials of probiotic supplements during pregnancy, involving around 6,000 women. Probiotics contain live bacteria that can influence the natural balance of bugs in the gut. Previously research has linked a disruption in naturally-occurring bacteria to allergy risk.
 

In the research, probiotics were taken during pregnancy and breastfeeding as a capsule, drink or powder (most yoghurts do not contain enough probiotic). We found that they can reduce the risk of a child developing eczema - between the ages of six months to three years - by 22%.
 

This is the equivalent of 44 cases of eczema per 1000 children.
 

We also assessed around 19 trials of fish oil supplements during pregnancy. These trials involved around 15,000 people. These studies revealed a 30% reduction in risk of egg allergy by age one, which equates to a reduction of 31 cases of egg allergy per 1000 children. Egg allergy was tested with a skin prick test.
 

Can a peanut allergy be prevented?

In the studies using fish oil supplements, the capsules contained a standard dose of omega-3 fatty acids (Omega-6, was not found to have any effect on allergy risk when it comes to peanuts. Previous research suggests fish oils may prevent the immune system from over-reacting.

Most of the trials used supplements, although one involved eating oily fish, and a few others used non-fish oils, for example, nut oils. However, the Department of Health advises women to eat no more than two portions of oily fish a week. It's also recommended they avoid shark, marlin or swordfish as these contain high levels of mercury.
 

We found that taking fish oil supplements during pregnancy reduced the child's risk of peanut allergy by 38%. However, this is only based on two studies, and not as reliable as the egg allergy and eczema results.
 

What would you recommend for feeding during pregnancy?

Studies reveal some evidence for links between longer duration of breastfeeding and a reduced risk of eczema. Breastfeeding has also been linked with a lower risk of type one diabetes.
 

Findings from this study (funded by the Food Standards Agency) are being considered by the Government alongside the wider evidence base on infant feeding and introducing solid foods. As part of the cross-government review of complementary feeding, the benefits and risks associated with the timing of the introduction of allergenic foods are also being considered.
 

Parents and guardian should continue to follow the current Government advice to exclusively breastfeed for around the first six months of age. It is preferable that breastfeeding is continued after that. Solid foods should be introduced to the infant when they are around six months old. Pregnant women should also continue to follow government supplement and dietary advice.

For allergy testing, and to support the healthy development of a child, you may like to book an appointment with a leading paediatric allergist. Visit Dr Robert Boyle ’s profile today for more information on the services he offers as well as appointment availability.