A mother's stress during pregnancy and breast-feeding may prompt changes in her infant's genes that increase the child's risk of obesity later in life, according to a new study in mice.
When mice in the study were put under stress during pregnancy, their offspring grew faster after weaning than did the offspring of non-stressed mice. After two months, the offspring of stressed mice developed belly fat and prediabetes, a condition characterized by abnormally high blood sugar levels.
The researchers think the mother's stress causes changes in the way neuropeptide Y, a brain neurotransmitter, behaves. Neuropeptide Y stimulates appetite and can induce the formation and growth of fat cells. Stress may cause modifications of the offspring's genes that increase the activity of neuropeptide Y, and in turn, increase the number of fat cells in the body.
The number of fat cells a person has before they reach their teen years is a major determinant of his or her risk for obesity, said study researcher Ruijun Han, of the University of Minnesota Medical School's Department of Integrative Biology and Physiology. "So intervention during pregnancy and childhood might be an efficient way to prevent adult obesity," Han said.
However, more work needs to be done to see if stress produces the same effects in humans.
Only female offspring in the study appeared affected by the mother's stress in pregnancy. The researchers aren't sure why this is, but it may be because fatty tissue is more important for females in producing offspring later, Han said.
The study will be presented this week at the Experimental Biology 2011 meeting in Washington, D.C.
Pass it on: Stress during pregnancy may put the child at risk for obesity later in life.
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