http://www.newscientist.com/news/news.jsp?id=ns99992994
Grandad's diet affects descendants' health 14:01 31 October 02 NewScientist.com news service The amount of food a boy eats in the years before puberty influences his grandchildren's risk of diabetes, a small Swedish study suggests. Researchers looked at 303 people, born either in 1890, 1905 or 1920, and the harvest data for the region where they lived. They found that males in areas with a surfeit of food were four times more likely to have grandchildren who died of diabetes mellitus than those who suffered famine in childhood. "Overeating in the 'slow-growth' period before puberty affects the likelihood of the second generation having diabetes," says lead researcher Gunnar Kaati at Umea University, Sweden. "But we don't know exactly why." The researchers acknowledge that more research is needed to replicate and explain their results. "But very little attention has been paid to this kind of inheritance, and it is an important subject to look at," Kaati told New Scientist. Similar effects have been shown in sons and daughters before, but if confirmed, the study would be the first evidence of the effect in grandchildren says geneticist Laurence Hurst at Bath University, UK. Environmental factors can affect genes by altering the methylation of DNA bases. This changes the expression of the genes concerned. The impact of the nutritional conditions experienced by a child could be passed on to subsequent generations in this way. In the study, only the paternal grandfather appeared to influence the health of their descendants, although male and female grandchildren were affected equally. This suggests imprinted genes - whose expression is determined by which parent they were inherited from - may be involved, says Marcus Pembrey at the Institute of Child Health, London, UK. "For example, insulin growth factor 2, which is involved in diabetes, is silenced when transmitted by the mother and active when transmitted by the father," he told New Scientist. _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
