Fish Oil During Pregnancy Linked to Bigger, Healthier Children

Pregnant women who take fish oil supplements could boost their baby's growth up until the age of six, according to a study.

Consuming supplements of n-3 long-chain polyunsaturated fatty acids, a type of fish oil, was linked to children having both a higher lean mass and bone mass at the age of six in the study, published by the journal The BMJ.

Dr. Hans Bisgaard, Professor of Pediatrics at the Unviersity of Copenhagen and author of the study, told Newsweek: "The study proves that health and disease is programmed during pregnancy, and not only determined by genetics and post-natal exposures."

Researchers at the University of Copenhagen and the University of Bristol arrived at this conclusion by recruiting 736 women who were already taking part in a study exploring the risks of children developing asthma. In their randomized control study, the researchers assigned the participants either fish oil or olive oil. The women took the supplements from week 24 of their pregnancy until a week after they gave birth.

To determine whether taking fish oil during pregnancy affects a child's growth, the researchers documented the height, weight and waist measurements of the participants' offspring 11 times from birth to the age of six.

The team found the children of mothers who took fish oil had a higher BMI on average between the ages of one and six—but they didn't have a higher than average percentage of body fat. Lean, bone and fat mass all grew proportionality, suggesting fish oil stimulated growth overall.

Specifically, the children in the fish oil group had a 395g higher mass on average, 280.7g lean mass, 116.3g fat mass and 10.3g higher bone mineral content than the children whose mothers consumed the olive oil. The higher bone mineral content implied fish oil could give children healthier bones less prone to fragility later in life, the authors said.

This new work provides insight into the less understood associations between taking fish oil and the longer term benefits for children, the authors of the study hope.

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Currently, the U.S. Department of Health does not officially recommend pregnant women consume fish oil tablets. Pregnant women are, however, advised to take folic acid, iron, calcium, vitamin A and B12 supplements.

To help both expectant mothers and fetuses to stay healthy during pregnancy, the group recommends women eat plenty of foods packed with nutrients. These include fruit and vegetables to keep vitamins and minerals topped up; and whole-grains like oatmeal and whole-wheat bread for fiber and B vitamins. Fat-free and low-fat dairy products or fortified milks can provide calcium and vitamin D; while legumes, eggs, lean meats, between eight to 12 ounces of seafood, as well as unsalted nuts and seeds are advisable sources of protein. At the same time, fats that are solid at room temperature, like butter, and sugary sodas and foods should be avoided.

The Department of Health also warned against the attitude that pregnant women can "eat for two," and consume double the amount of calories. A wiser approach is regarding the saying as a reminder that a woman's diet is her fetus's main source of nutrients.

This article has been updated with comment from Professor Hans Bisgaard.