Consuming fish during pregnancy might be increasing the risk of obesity and rapid growth for the baby, suggests a new study published by JAMA Pediatrics.
Fish is widely claimed to be a healthy food. The nutrients it contains are known to promote fatty tissue growth and foetal neurodevelopment. But, too much of it might have a downside.
While previous research has shown that babies whose mothers would eat fish regularly would be less likely to be born premature, the effects might extend to the endocrine system in a negative way: the consumption of fish might increase exposure to organic pollutants that can disrupt the function of hormones; the pollutants are said to affect nuclear receptors leading to modifications in gene expression and consequently impacting on the metabolism of fats. This would, in turn, lead to an increased obesity risk.
Investigating these links further, the researchers of the new study analysed the association between fish consumption among pregnant women and the growth and weight of their children who were also followed until they reached 6 years of age. Based on data from 26,184 women, they found that 31% of the children grew rapidly from birth to 2 years old. 19.4% of them and 15.2% were found to be overweight or obese at 4 and 6 years old respectively. Is there a link between fish intake and the weight gain?
Babies whose mothers consumed fish more than thrice a week when pregnant had higher BMI at 2, 4 and 6 years of age as opposed to those whose mothers ate less fish. High intake of fish was also associated with higher overweight and obesity rates for 4- and 6-year-old children.
A link was also drawn between high fish consumption and faster growth from birth to 2 years of age.
Another finding is that the effects seem to be more pronounced in girls than in boys, though it is but a link deemed not conclusive by the authors themselves.
The researchers do point out other limitations: the fish types were not determined and distinguished nor was their origin and cooking methods. But, the scientists suggest that environmental pollutants contaminating fish might account for the link observed between high fish consumption and greater adiposity among the children.
The researchers also add that their findings support the US FDA recommendation for fish intake limit during pregnancy which is at three servings per week.