Breastfeeding has many health benefits for children, such as reducing their risk of obesity and strengthening their immune system. However, new mothers who consume a high-fat diet while breastfeeding may undermine some of those advantages, according to new research at The University of Toledo.
When mouse moms ate a high-fat, high-calorie diet while nursing, their offspring developed obesity, early puberty, diabetes and fertility issues.Dr. Mengjie Wang, a PhD candidate in the Department of Physiology and Pharmacology, is the lead researcher of a team that used mice as a model to study the impact of excess calories during the breastfeeding stage on the offspring’s metabolism and reproduction.
“All over the world, puberty is starting earlier than it did in the past,” said Wang, who is earning her PhD at UT after graduating from medical school in China at Guangxi Medical University. “Childhood obesity, a common health issue, is one of the risk factors for early puberty. Previous evidence from animals has revealed that post-weaning overeating advances the timing of puberty, but we lack knowledge of how nutrition before weaning influences metabolism and reproduction.”
To determine how excess body fat alters the timing of puberty, Wang’s team gave female mice that are new mothers a high-fat diet from the date they gave birth and started breastfeeding until they weaned their offspring. A second group of mice that also were new mothers were given a regular diet. The onset of puberty was evaluated in the offspring after weaning, and fertility tests were done on the mice in adulthood, as well as an examination of their metabolic function.
“We found that excess calories during the breastfeeding phase can cause early obesity and early puberty and increases the risk of developing diabetes, metabolic dysfunction and subfertility during adulthood,” Wang said. “These results show that the breastfeeding phase is a critical window that influences when puberty happens.”
The study found that offspring of the mothers fed a high-fat diet while breastfeeding suffered from glucose intolerance and insulin insensitivity. They also had decreased litter sizes and impaired pregnancy rates.
“Human studies are needed to know whether these results apply to our species,” Wang said. “Still, I recommend that mothers consume a moderate and healthy diet while breastfeeding to protect their child’s long-term health.”
Wang said the research is significant in the clinical setting because doctors don’t always follow the same patients from puberty to adult life.
“Our findings can alert doctors and patients with early puberty that other health problems may arise after they become adults,” Wang said.