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Skipping breakfast may mean your baby is a girl
Women on low-calorie diets or who skip
breakfast at the time of conception are more likely
to give birth to girls than
boys, British scientists said on Wednesday.
Women on low-calorie diets or who skip breakfast at the time of conception
are more likely to give birth to girls than boys, British scientists said on
Wednesday.
New research by the universities of Exeter and Oxford provides the first
evidence that a child's sex is associated with the mother's diet, and higher
energy intake is linked to males.
"This research may help to explain why in developed countries, where many
young women choose to have low-calorie diets, the proportion of boys born is
falling," said Fiona Mathews of the University of Exeter.
There has been a small but consistent decline, of about one per 1,000
births annually, in the proportion of boys being born in industrialized
countries over the past 40 years.
In humans, going without breakfast may be interpreted by the body as
signaling low food availability, since it depresses levels of blood sugar.
Although sex is genetically determined by fathers, it is known that high
levels of glucose encourage the growth and development of male embryos while
inhibiting female ones, although the exact mechanism is unclear.
Mathews and colleagues studied 740 first-time pregnant mothers in Britain
and found 56 percent of those in the group with the highest energy intake at
conception had sons, compared with 45 percent in the lowest group.
In evolutionary terms, this correlation may make sense.
Males' breeding potential is strongly influenced by fitness, while females
breed more consistently.
"If a mother has plentiful resources then it can make sense to invest in
producing a son because he is likely to produce more grandchildren than would a
daughter. However, in leaner times having a daughter is a safer bet," Mathews
said.
Some researchers have been sounding alarms for years over the change in sex
ratios in developed countries and have in the past blamed pollutants and
synthetic chemicals such as those found in some pesticides which disrupt human
hormones.
The latest findings were published in the journal Proceedings of the Royal
Society B: Biological Sciences.(Agencies)
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