Fish oil taken during pregnancy reduces the risk of asthma in a child

Women who take fish oil during the third trimester of pregnancy can reduce the risk of developing asthma in their children by a third, suggests a new clinical study.

A study of scientists from Denmark

The dose of fish oil taken by women participating in the study was high, with a level of fatty acids that is 15-20 times greater than the average adult person receives from food. There were no significant side effects, according to lead researcher Dr. Hans Bisgard (he is a professor of pediatrics at the University of Copenhagen in Denmark). Nevertheless, the doctor did not give any general advice to pregnant women.

Bisgard said that, according to his personal interpretation of the results of the study, cod liver oil is a safe way to prevent some cases of asthma in children. But he also said that there are questions left for future research. The main of them - at what point of pregnancy is best to start taking fish oil, and what is its optimal dose.

The opinion of disinterested experts

Experts who were not involved in the study, called the results encouraging. They also agreed on the need for further research.

"It is possible that even a lower dose can be effective," said Dr. Jennifer Wu, who works as an obstetrician and gynecologist at the Lenox Hill Hospital in New York. She now advises pregnant women to talk with their doctors about whether they need more fatty acids that are contained in fish oil, namely DHA and EPA. Pregnant women should ask about the amount of fish they eat, and whether they should start using prenatal vitamins.

Features of the study

In a study published on December 29 last year in The New England Journal of Medicine, there is additional evidence that fish oil can help prevent asthma.

Laboratory studies suggest that DHA and EPA can make the airway less prone to inflammation, according to Dr. Christopher Ramsden, a researcher at the American National Institutes of Health. In an editorial published with the results of the study, Ramsden called it "very promising." Nevertheless, he writes that "the warning is justified."

Because the doses of fish oil that were used during the study were high (2.4 grams per day), scientists need to understand whether the treatment will have any negative long-term effects, "Ramsden said. During the study, the researchers asked 736 pregnant women to take either capsules of fish oil, or a placebo every day during the third trimester. The placebo capsules contained olive oil.

results

In the end, children born to women who took cod liver oil were about one-third less likely to develop asthma or persistent wheezing (this is a sign of asthma in young children). At the age of 5 years, 17 percent of children had these problems diagnosed, compared to almost a quarter of the children in the group whose mothers were taking placebo.

However, it turned out that some children received more benefits than others. Effects mainly manifested in one-third of babies whose mothers started with the lowest level of consumption of DHA and EPA.

The influence of genetics

Genetics also proved to be an important factor: supplements were more effective when mothers were carriers of a variant of the gene that causes lower levels of DHA and EPA in the blood. Nevertheless, significantly more children will benefit from the fact that their mothers used fish oil.

How the results depend on the location of the experiment

The study was conducted in Denmark, where fish consumption is relatively high, - noted the scientists. Even those women in Denmark who consume a small amount of fish, still eat it more than the average in many other countries. Therefore, a stronger effect should be expected if the child was born in those countries where the fish is not too familiar in the diet. But more research is needed to confirm this.

The results of genetic research can also slightly complicate the picture: the percentage of people with "bad" gene variants that cause lower levels of DHA and EPA will probably differ depending on the country of residence.

Dr. Jeffrey Bieler, the head physician of the Children's Hospital in Miami, agreed that it is necessary to conduct research on other groups of the population.

Why does asthma occur in children?

Bieler also noted that many factors affect the risk of developing asthma in a child, including family history and exposure to environmental hazards such as cigarette smoke. So do not expect that fish oil will become a magic tool, "he said.

Bieler recommends pregnant women to consult their doctors before using fish oil, and to make sure that any product they take is of high quality. Additives are medicines. And so the need for their use should be discussed with the doctor.