It stands to reason that chubby mothers give birth to chubby babies. After all, they share food for the nine months before delivery. But what about chubby fathers passing on the health consequences of their bad eating habits?
Evidence that they do comes from an Australian study with rats showing that chubby fathers could be passing on diabetes to their offspring.
Male rats fed a high-fat diet and mated with healthy female rats went on to produce offspring that had trouble with blood-sugar levels even though the offspring were eating low-fat foods.
"I think what's really exciting about this work is what's novel about it," Margaret Morris said of the study she supervised at the University of New South Wales. "This is the first report of non-genetic, intergenerational transmission of metabolic consequences of a high-fat diet from father to offspring."
Father role ignored
Morris looked at fathers because their role has largely been ignored. After all, conventional thinking is that their role stops after they pass on the DNA in their sperm cells. Morris wanted to test this, believing that both mother and father play a role.
"There's no question that the role of the uterus during the development of the baby is important, but I think it's important to realise that the father can be having a non-genetic effect as well," she said.
The findings of the study, published in the US journal Nature, relate to rats but are very likely to hold true for humans as well.
Best to be in top physical shape
"If it's true in the human, it really underlines the necessity for both parents to be approaching pregnancy in the best possible physical shape," Morris said.
The critical aspect of the study - the non-genetic transmission - is something that is not a big surprise to Diabetes Australia chief executive Greg Johnson. That genes play a part in the passing on of diabetes is a certainty but the role of environmental factors are not well understood.
"There are things that people can do to help reduce their risk of developing type-2 diabetes," Johnson said. "Most of those modifiable things that they can do relate to eating a good healthy balanced diet and maintaining good physical activity and exercise and a healthy body weight."
But, of course, we knew that; what we did not know, and still do not know for sure, is that a healthy diet and keeping in shape has consequences for a man's offspring as well as for himself.
(Sapa, October 2010)
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