The children of women who take fish oil supplement during pregnancy gain healthy weight more quickly for the first six years of their lives, according to a new study.
Researchers at Copenhagen University found that when their mothers took the pills during the later stages of pregnancy, their children had higher body mass indexes (BMI), but for those first years, they gained no more body fat than other children.
Studies in animals have shown that supplementing the diet with fish oil during pregnancy affects the development of fat cells.
But while trials in humans have shown pregnant women with a higher intake of fish oil give birth to higher birth weight babies, the impact on children later in life has been unclear – until now.
The children of women who take fish oil supplements during pregnancy continue to gain more healthy weight than other babies for their first six years of life, a new study suggests
Study co-author Dr Hans Bisgaard of Copenhagen University said: ‘Diet during pregnancy and infancy is an important determinant for children’s development and health.
‘In particular, intake of fish containing n-3 long chain polyunsaturated fatty acids (LCPUFA) is important for adequate development.’
These chains of fatty acids are crucial to the way a baby’s brain develops, both in the womb and during the first few months of life during breastfeeding.
For adults, some studies have suggested that fatty acids from fish may also help protect the brain from Alzheimer’s disease.
A number of previous studies have shown that taking fish oil supplements during pregnancy and breast feeding seems to be protective of babies’ birth weights.
‘However, the long term effect on anthropometry’ – or the way the body’s proportions grow – ‘during childhood is uncertain,’ said Dr Bisgaard.
So researchers based in Britain and Denmark set out to examine the effect of taking fish oil supplements during pregnancy on the growth and body composition of children later in life.
The trial involved 736 pregnant women who received either fish oil or olive oil daily from week 24 of pregnancy week until one week after birth.
Height, weight, head and waist measurements were assessed 11 times from birth to age six and adjusted for age and sex.
The findings, published in the British Medical Journal (BMJ), revealed a sustained higher BMI from 12 months old to six years of age.
Body composition was assessed using dual-energy X-ray absorptiometry (DXA) scans at 3.5 and six years of age.
The scans showed that the higher BMI was not the result of a higher fat percentage, but reflected a proportional increase in lean mass, bone mass, and fat mass, suggesting that the fish oil supplementation had a general growth stimulating effect.
At six years of age, DXA scans showed children whose mothers had taken fish oil supplements while pregnant had a 395g higher total mass, 280.7g higher lean mass, 10.3g higher bone mineral content and 116.3g higher fat mass compared with children of mothers who took the control oil.
Dr Bisgaard said: ‘The body composition at age six in children given fish oil supplementation was characterised by a proportional increase in lean, bone, and fat mass suggesting a general growth stimulating effect.
He concluded: ‘Fish oil supplementation from the 24th week of pregnancy led to a higher BMI in the offspring from 0 to six years of age but not an increased risk of obesity at age six.
‘The body composition at age six years in children given fish oil supplementation was characterised by a proportional increase in lean, bone, and fat mass suggesting a general growth stimulating effect of n-3 long chain polyunsaturated fatty acid.’