Fish oil during pregnancy reduces risk of child asthma – University of Copenhagen

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02 January 2017

Fish oil during pregnancy reduces risk of child asthma

Childhood asthma

Supplementing your diet with fish oil during pregnancy may benefit your unborn child. A new study from the University of Copenhagen shows that children whose mothers consumed fish oil during the last trimester of pregnancy have a significantly reduced risk of developing asthma.

Children are at much lower risk of developing asthma if their mothers consumed fish oil during pregnancy. This is the finding of a new study conducted by Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) under the Faculty of Health and Medical Sciences at the University of Copenhagen. The researchers have followed a group of pregnant women and their children since 2010, and the results are unequivocal: The number of children suffering from asthma was reduced by one-third among those whose mothers consumed fish oil during the last trimester, says Clinical Professor and Head of COPSAC, Hans Bisgaard.

"Fish oil contains long-chained fatty acids and high levels of these acids help to reduce the risk of child asthma. The effect is most visible among women with an already low level of the fatty acids, but all women who consumed fish oil in the last trimester of their pregnancy reduced the risk of their children developing asthma by at least 32 per cent. Consuming more fish oil than you need has no adverse effects. I therefore recommend that all women eat fish oil during the last trimester of their pregnancy," he states.

Asthma is the most common chronic disease among children. 20 per cent of all young children have asthma symptoms, and it is the most common cause of hospitalisation, doctor's visits and prescription medicine among children. The new findings are therefore not only important to the individual mothers and their children, but could also help cut public healthcare spending, emphasises Hans Bisgaard.

Fish oil need is hereditary
Back in 2010, researchers divided 736 women who were about to enter the last trimester of their pregnancy into two groups. One group was given a dose of fish oil every day during the third trimester, while the other group was given one dose of olive oil. The women were not told whether they had been given olive oil or fish oil until the children were three years old. Today, five years on, it is clear that the fish oil has significantly reduced the risk of developing asthma. The reason lies in the immune system, explains Hans Bisgaard.

"The long-chained fatty acids found in fish oil are important to the immune system. If the cell membrane does not contain a sufficient amount of fatty acids, it cannot produce antibodies, which increases the risk of developing asthma. Our ability to absorb these fatty acids is genetically determined which means that some people absorb them better than others. People who absorb the fatty acids less well need a larger dose," he says.

The findings are important in terms of preventing asthma in children, but according to Hans Bisgaard they may also help prevent other diseases. Asthma is a chronic inflammatory disease like diabetes, arthritis and intestinal diseases. Previous studies have shown that procedures that increase the risk of asthma, such as caesarean section, also increased the risk of developing other chronic inflammatory diseases later in life. Consequently, Hans Bisgaard's theory is that anything which may reduce the risk of asthma may also reduce the risk of developing other diseases. However, this link has not been proven.

The study 'Fish Oil-Derived Fatty Acids in Pregnancy and Wheeze and Asthma in Offspring' has  just been published in the scientific journal New England Journal of Medicine and can be read here.

Hans Bisgaard, Clinical Professor and Head of COPSAC, email:, tel: +45 39 77 73 63 / mobile: +45 26 80 30 90