Fish oil in pregnancy 'cuts child allergy risk'
1st March 2018 – Pregnant women who take fish oil supplements during the later stages of pregnancy and while breastfeeding may reduce the risk of childhood allergies, according to new research.
The study in the journal PLOS Medicine also found that taking probiotics during the same period may reduce the risk of childhood eczema.
Scientists from Imperial College London reviewed 433 studies involving 1.5 million people.
Omega-3 fatty acid
They found that a daily fish oil capsule taken from the 20th week of pregnancy, and during the first 3 to 4 months of breastfeeding, reduced the risk of egg allergy in offspring by 30%.
These capsules contained a standard dose of omega-3 fatty acids, which has been shown to have anti-inflammatory properties.
The researchers also found that taking a probiotic each day from 36 to 38 weeks of pregnancy, and during the first 3 to 6 months of breastfeeding, reduced the risk of childhood eczema by 22%.
Probiotic supplements, containing live bacteria that can boost the natural balance of bugs in the gut, were taken in capsule form, as most yoghurts do not contain enough probiotics to make a difference.
These probiotics mostly contained a bacterium called Lactobacillus rhamnosus.
The team, that was commissioned by the Food Standards Agency to conduct the study, found no evidence that avoiding potentially allergenic foods such as nuts, dairy products and eggs during pregnancy altered the risk of a child developing allergies or eczema.
Food allergies affect around 1 in 20 children in the UK. They happen when the body's immune system wrongly identifies them as a threat and mounts an inflammatory response against them. This can trigger symptoms, including swelling, vomiting, and wheezing.
Eczema is common among children, affecting around 1 in 5 UK children. It causes dry, cracked and itchy skin.
Although the causes of eczema are not fully known, allergies are more common in those who have eczema.
The researchers say more studies are needed to understand how fish oils and probiotics can reduce risk.
'Our diet plays an important role'
Dr Louisa James, lecturer in Immunology at Queen Mary University of London, comments in a statement: "Our diet and the microbes living in our gut play an important role in building and maintaining a healthy immune system.
"Determining how different dietary factors affect the way our immune system works is therefore essential, especially during the early stages of our development, when our immune system is learning how to recognise potential danger.
"The results of this study confirm that maternal diet can influence the development of allergies in early life and highlights the pressing need for more research in this area."
Seif Shaheen, professor of respiratory epidemiology at Queen Mary University of London, says: "More definitive answers on the possible role of maternal probiotic and fish oil supplementation in the prevention of childhood allergic disease can only come from further large trials, which follow up the children to school age.
"If such trials are big enough they may be able to identify particular subgroups of mothers and children who would benefit most from these interventions."