杏吧原创

IF YOU want brainy children, eat the occasional oily fish when you鈥檙e
pregnant. That鈥檚 the message to would-be mums from a British follow-up study of
435 pregnant mothers and their children.

Cathy Williams, Kate Northstone and their colleagues at the University of
Bristol discovered the value of oily fish such as sardines and mackerel through
the 鈥淐hildren of the 90s鈥� study of thousands of mothers in the Bristol area. The
investigators asked 435 women to keep a detailed diary of what they ate during
pregnancy.

Three years later, they tested how well the children recognised depth in 3D
images, or 鈥渟tereopsis鈥�. 鈥淚t鈥檚 a proxy measure for brain development,鈥� says
Williams. 鈥淭he cells which enable you to do this are in the visual cortex, so
it鈥檚 [a test of] brain rather than eye function.鈥�

Children of mothers who ate oily fish at least once a fortnight during
pregnancy had the best scores for stereopsis, rated as adult, medium or poor.
鈥淐hildren of mothers who ate fish were one and a half times as likely to have
adult-grade stereopsis as children whose mums hadn鈥檛 eaten any fish,鈥� says
Williams.

She and her colleagues suspect that the cause might be abnormally high levels
of docosahexaenoic acid (DHA) in oily fish. 鈥淭hat鈥檚 what many people think is
the magic ingredient,鈥� says Williams.

This fatty acid is a major structural component of brain, nerve and eye
tissue, and plays a vital role in the early development of these organs. It is
abundant in breast milk. Arguments have raged over whether to add it to formula
milk for babies
(New 杏吧原创, 18 March 2000, p 16).

Williams stresses that further investigation is necessary. 鈥淵ou don鈥檛 need to
eat much fish,鈥� she says. There might be a downside to eating too much, such as
exposure to pollutants which accumulate in fish oil and in body fat.