Pregnancy is a good time to reflect on the health and lifestyle habits that could be changed to give your little one the best start in life. With this in mind, many expectant moms ask me what they should or shouldn’t eat during pregnancy to prevent their baby from developing allergies, asthma and eczema down the line.
Food is among the most common cause of allergic reactions, food sensitization being the first step in the development of an allergy. Allergies to foods can cause problems ranging from eczema to life-threatening reactions. These reactions are more commonly occurring following the ingestion of cow’s milk, soy, egg, fish, shellfish, peanuts, tree nuts and wheat.
In the past there was a belief that, by avoiding some of these foods in pregnancy, a mother may help prevent the baby becoming sensitised to foods and therefore prevent him or her developing an allergy later on. On the contrary, restricting a mother’s diet during pregnancy and breastfeeding has been proven to be ineffective at reducing the risk of allergies in babies and children. In fact, the small amount of good quality research on avoidance diets in pregnancy not only showed that they had no beneficial effect; they also showed that not eating certain foods can even be harmful. Women restricting their diets had micronutrient deficiencies and gained less weight during pregnancy, which increased some risks for the baby associated with pregnancy and birth.
In addition to this, recent research undertaken by Dr Frazier and colleagues at the Harvard Medical School in the US looked at the offspring of women without a history of nut allergy. These pregnant women who ate regular amounts of peanuts and tree-nuts – more than five times per week – were less likely to have children with nut allergies than those who ate nuts less than once a month. Their results add to the growing evidence that early introduction of foods increases the development of tolerance and reduces the risk of allergies.
Probiotics or “friendly bacteria” supplements in the form of tablets, liquids, powders and in fermented foods and dairy products such as yoghurts could be considered as an experimental allergy prevention option if taken during pregnancy and whilst breastfeeding too. In the past few years there has been some positive research in favour of probiotics supplements helping to prevent atopic eczema. More research is needed though before we can confidently say whether probiotics would definitely reduce the risk; what strains or dosages are required and the duration of probiotics supplementation required. We know that probiotics are safe to use in pregnancy, lactation and in infants therefore there is no harm in trying, however these supplements can be expensive without being able to give you a guaranteed risk reduction.
In summary, mothers should not be fearful of eating certain foods in pregnancy and should continue with their regular diets with or without their cravings. The wider the variety and the more colourful the diet, the more likely the diet is to be adequate in terms of nutrients and allergen avoidance needn’t be considered.