Could fish make our children smart?
3 October 2005
The supposed benefits of giving fish oil supplements to children to improve their brainpower is being investigated by scientists at the University of Bristol.
Some of the strongest evidence in favour of fish in the human diet comes from the Bristol families who are part of the Children of the 90s project. University researchers have been following 14 thousand children since before they were born.
The project is featured as part of an Horizon documentary on BBC 2 on Thursday October 6 which looks at the scientific evidence for what the fish oil omega 3 can and cannot do
Dr Cathy Williams, head of neuroscience at Children of the 90s and a consultant ophthalmologist at the Bristol Eye Hospital, appears in the programme. She says that the fatty acid Omega 3, found particularly in oily fish, is an essential part of the human brain, and forms an important part of our normal diet.
The scientists in Bristol have shown that women who eat fish regularly during pregnancy tend to have children with better vision, cognitive development and behaviour.
But the Bristol researchers say that doesn’t mean that fish oil supplements should be taken routinely by schoolchildren themselves. The only positive evidence so far comes from the diets of pregnant women, not of the children themselves.
The debate over Omega 3 all began some time ago at Oxford University when one man began to investigate the strange fat found in high quantities in oily fish.
Professor Hugh Sinclair put himself on an Eskimo diet – for 100 days he ate minced seal and whale blubber. In spite of eating half a kilo of fat a day, he lost weight. Sinclair thought his reeking meals were packed with omega-3, which he believed could protect us against heart disease.
Fifty years later wide ranging studies have vindicated his early intuition: omega-3, in high doses, can protect people who’ve had a heart attack from having another one.
Dr Williams says: “The Children of the 90s project in Bristol was the first to identify the associations between a prenatal diet rich in fish oil, and neurocognitive development in ordinary healthy children.
“First of all we found that found that mums-to-be who eat oily fish such as sardines and mackerel have children whose visual development is better. Those children reach the adult grade of depth perception sooner, a positive association which was also seen for breastfeeding.
“We’ve also found that women who ate fish regularly during pregnancy had children with better language and communication skills by the age of 18 months.
“We analysed the diets of 7,400 mothers and found that there was a subtle but consistent link between eating fish during pregnancy and children’s subsequent test scores, even after adjusting for other factors such as the age and education of the mother, whether she breastfed, and the quality of the home environment.
“The largest effect was seen in a test of the children’s understanding of words at the age of 15 months. Children whose mothers ate fish at least once a week scored 7 per cent higher than those whose mothers never ate fish.”
“There has been some debate – particularly in the United States - about the negative effects of eating too much fish because of the toxins which may be present. All our evidence tends to suggest that in moderation it is an essential part of the human diet, especially during the later stages of pregnancy when the baby’s brain is developing.
“So far all that we have found shows this effect in the mothers’ rather than the children’s diets. At this stage we have no evidence that giving your children fish oil supplements will make them brainier, but we will continue to look into this as the Children of the 90s grow up.”
The programme also features the West Country chef Mitchell Tonks, founder of the Fishworks restaurant in Bath and Bristol.
Horizon: Could fish make your child smart? First broadcast BBC2 9pm Thursday October 6, 2005.
- Williams et al: Stereoacuity at 3.5 years of age in children born full-term is associated with prenatal and postnatal dietary factors. American Journal of Clinical Nutrition
- Daniels et al. Fish intake during pregnancy and early cognitive development of offspring. Epidemiology
- Oily fish is the richest source of DHA, a fatty acid which is an important structural component of neuronal membranes found in the brain. DHA is also present in breast milk but not standard formula milks.
ALSPAC The Avon Longitudinal Study of Parents and Children (also known as Children of the 90s) is a unique ongoing research project based in the University of Bristol. It enrolled 14,000 mothers during pregnancy in 1991-2 and has followed most of the children and parents in minute detail ever since.