New research from scientists at the University of Auckland’s Liggins Institute has revealed that a pregnant mother can be putting her unborn child at risk by drinking as little as three glasses of juice a day or eating five apples. They have linked sugars such as fructose and impaired foetal development.
The team writes that pregnant women need to be aware of everything they are eating, and moderate not only their consumption of foods that are fatty but also those that are high in fructose. They note that too much fructose cause liver problems. Sugars should be limited from processed bread, cake, fizzy drinks and lollies. Senior research fellow Deborah Sloboda said, “Pregnant women are now eating low-fat milk and low-fat yoghurt. But less attention is paid to fructose content.”
For the study the team fed laboratory rats with fructose during pregnancy and lactation. They noted that the offspring from these rats had higher levels of hormones, which could negatively affect the way the body breaks food down. Dr Sloboda said the finding was significant because of the implications for human offspring adding, “The dose of fructose that we used is moderate, and equivalent to regular consumption in New Zealand - 50g to 80g a day - so for that reason, it has good relevance to the general population.” They note that while 50g of fructose is not excessive for an adult, an unborn child may not be able to cope with its pregnant mother consuming that amount. Dr Sloboda said that although only 10 days old, the rats' livers seemed to convert the fructose into fat. This led to a high concentration of insulin and impairment of liver function. High levels of insulin are linked to type 2 diabetes and obesity.
Too much fructose has been blamed as a contributor to the obesity epidemic, because unlike glucose, the body does not detect when it has had enough. Dr Sloboda said the effects of high-fat diets on offspring had been studied in detail, but very little was known about a high sugar intake.
Worst was that the rats bodies did not display signs of excess fructose intake. “There were no grave outward signs of changes… They didn’t put on excess weight or excess fat. The only change we did see was in their insulin levels… It could be that consuming fructose during pregnancy didn’t give the mother any particular indicators ... so women may be unaware that their diet could be compromising the development of their foetus,” said Dr Sloboda.
The study’s also found that at birth, female babies were more vulnerable to impaired development from a sugar-rich diet. The investigators observed that the females had lighter placentas, which supply nutrients to the foetus. Mark Vickers, co author of the study is now following the post-natal development of babies whose mothers have had a sugar-rich diet, to ascertain if there are persistent changes in adults.
The Liggins study was funded by the National Research Centre for Growth and Development, and was published in the journal Endocrinology.
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