Newborn mice that receive their mother's milk experience a biological process that boosts their metabolism, according to a new study, suggesting that breast-feeding confers some 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 in mice just after birth. Researchers in Spain found that suckling mother's milk prompts the newborn's liver to produce a molecule that turns on heat-generating brown fat. That helps the baby's body adapt to a lower environmental temperature than in the womb.
The protein released in response to suckling, called FGF21, also appears important in regulating metabolism. Researchers injected the protein into fasting newborn mice. The treatment prompted heat generation within brown fat and boosted body temperature. Recent studies in humans have found that greater activity in brown fat appears to protect against obesity.
The study is published in the journal Cell Metabolism.