Los Angeles Times
March 9, 2010
Newborn mice who receive their mother's milk experience a biological process that boosts their metabolism, possibly lowering the risk of obesity and diabetes in adulthood, according to a new study.
Breast-feeding confers several protective benefits in human babies. Some research suggests, for example, that breast-fed babies have a lower risk of obesity and diabetes later in life. The new study sheds light on a little-known process that takes place just after birth in mice. Researchers in Spain found that suckling the mother's milk prompts the newborn's liver to produce a molecule that then turns on heat-generating brown fat. That process helps the baby's body adapt to a lower environmental temperature than it experienced inside the mother's womb.
The protein that is released in response to suckling, called FGF21, also appears to be important in regulating metabolism. In the study, researchers injected the protein into fasting newborn mice and found that the treatment prompted heat generation within brown fat and boosted body temperature. These brown fat cells burned more energy and glucose. Recent studies in humans have found that greater activity in brown fat appears to protect against obesity.
"There are many evidences that alterations of dietary, genetic, environmental, or other origin in the metabolic performance during the fetal and early neonatal life can make an individual prone to develop diabetes and obesity in adulthood," the lead author of the study, Francesc Villarroya, of the University of Barcelona, said in a news release. "It will be important to know whether any disturbance in this naturally occurring event (the burst of FGF21) may have negative consequences in adulthood."
Researchers still don't know yet if this process observed in mice is similar in human newborns. The study is published in the journal Cell Metabolism.
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