Avoiding peanuts during pregnancy is a common precaution that many expecting mothers take even though current public health recommendations show there is no need for this. New research just published in the Journal of Allergy and Clinical Immunology not only endorses the safety of eating nuts during pregnancy, but links peanut exposure to less allergies in kids.
Food allergies normally start in childhood with peanuts, cow’s milk, shellfish, wheat and eggs the most common food allergens (a substance which cause an allergic response). In utero exposure to nuts was thought to be a trigger for elevating allergy risk in children, but this idea has fallen out of favour due to the findings of recent research.
Recently, both the American Academy of Pediatrics and the UK Food Standards Agency have rescinded their advice that women should avoid eating nuts when pregnant if it was done to prevent possible future food allergies in their children. Nuts are also an okay food to consume during pregnancy according to Food Standards Australia and New Zealand.
Even with nuts during pregnancy given a green light from peak health bodies, there is still an understandable concern that many expectant mothers may still wish to avoid eating them.
To strengthen the safety profile of nuts, Danish researchers looked at the pregnancy diet and health outcomes of children born to 62,000 Danish mothers. The researchers had a good handle on the diet of the pregnant women as the food surveys included questions about nut consumption. They followed up the dietary surveys by tracking the health of the children at 18 months and 7 years after birth.
What the study found
The children of mothers who ate peanuts more than once per week during pregnancy surprisingly went on to develop less asthma (15% of children) at 18 months of age compared to children born to non-peanut eaters (17% of these children developed asthma). The difference was small, but grew larger to a 21% lower risk of developing asthma in children from mothers who ate peanuts when allowance was made for other risk factors that could explain the development of asthma.
Moving forward to 7 years of age, the difference in asthma rates were still stark with 34% less asthma seen in the children exposed to peanuts during pregnancy.
Looking at allergies as a whole, there were 20% less cases of those in children of mothers who were frequent peanut eaters. A similar trend of less allergic disease was also seen when consumption of tree nuts in general was looked at.
The study does have its limitations. Using an observational study design cannot prove that nuts lowered allergy risk. Other dietary factors linked to nut consumption such as a dietary pattern high in fruit, vegetables and legumes could be one explanation. Assessment of food consumption and reporting of allergy symptoms were both self-reported which introduces potential bias.
What it all means
The in utero environment is not a static one. Both maternal over and undernutrition during pregnancy are considered important factors in influencing later-life disease risk. The findings from this latest research make it appear unlikely that allergen exposure during pregnancy is a major driver of allergic disease risk in children. Recent changes to recommendations that pregnant women do not need to avoid nuts appear a sensible shift in policy.