Dietary link to early puberty

The research links the onset of early puberty to how much or how little the mother ate while she was pregnant. Photo / The Aucklander

Eating too much or too little during pregnancy has been linked in an Auckland University paper to the early onset of puberty.

Studies at the university's Liggins Institute have shown a mother's diet before conception and during pregnancy and lactation affects her offspring's growth, age of puberty and later reproductive capacity in subtly differing ways.

The studies were done in rats, but one of the researchers, Dr Deborah Sloboda, said there were striking parallels with some human studies and observations.

Published online in a Public Library of Science journal, the paper shows that female rats were born smaller and entered puberty earlier if, during pregnancy, their mothers were fed either a high-fat diet or a diet low in energy. Comparisons were made with the female offspring of those fed a normal diet.

The research also found that prenatal nutrition did more to lower the age of puberty than any later changes to the diet of the offspring.

The paper says the age of first menstruation for humans declined dramatically in the last century - from age 17, to 12 in Europe, although the rate of decline is slowing.

"This fall is usually attributed to improvements in child health and nutrition since the early 19th century, when the age of menarche [start of menstruation] was highest.

"This led to the hypothesis that the age of menarche is directly linked to a critical degree of body fat; however, although prepubertal nutrition and the age of puberty are certainly associated in some way, this concept did not stand up to critical analysis of the data."

Dr Sloboda said the Liggins studies' findings were no cause for alarm.

"... our results highlight the potential for women to positively influence their children's future health by making sensible and balanced nutritional choices before and during pregnancy."

Other work by the Liggins has indicated that before birth a fetus uses cues derived from its mother's nutrition and health to predict whether it will be born into a world of famine or plenty. This sets its life-long patterns of growth, energy use and reproduction.

Auckland University of Technology professor of nutrition, Dr Elaine Rush, told the Science Media Centre that the Liggins paper emphasised the importance and potential for women to influence their children's future health.