Infants born to mothers with obesity face a higher risk of developing heart issues and diabetes in their adult years. This increased risk is attributed to damage in fetal development from the mother’s high-fat, high-calorie diet.
This insight comes from a pioneering study featured in the Journal of Physiology, revealing for the first time that maternal obesity impacts a vital thyroid hormone in the fetal heart, hindering its growth and development.
Eating a diet rich in fats and sugars during pregnancy also heightens the chance that the unborn child may become insulin resistant later in life, which could trigger diabetes and lead to heart disease. This occurs even if the baby is born at a healthy weight.
Researchers from the University of South Australia uncovered this connection by studying tissue samples from fetuses of pregnant baboons who were given a high-fat, high-energy diet at a biomedical research center in the United States. They contrasted these findings with those from fetuses of baboons maintained on a regular diet.
Melanie Bertossa, a PhD candidate at the University of South Australia and lead author of the study, emphasized the importance of these findings, marking a clear connection between an unhealthy high-saturated fat and sugar diet and poor heart health.
“There has been ongoing discussion about whether diets high in fats cause a hyper- or hypothyroid condition in the fetal heart. Our research suggests the latter,” Bertossa explains.
“Our results showed that a maternal diet high in fats and energy decreased levels of the active thyroid hormone T3, which normally signals the fetal heart to prepare for life outside the womb toward the end of pregnancy. Without this crucial signal, the fetal heart undergoes abnormal development.”
Bertossa points out that fatty and sugary diets can disrupt the molecular pathways related to insulin signaling and essential proteins for glucose absorption in the fetal heart. This may elevate the risk of cardiac insulin resistance, a precursor for diabetes in adults.
“Once you are born, you have all the heart cells you will ever possess. The heart does not generate enough new muscle cells after birth to mend any damage, so negative changes to these cells during pregnancy can have lasting effects throughout life.
“These enduring alterations could lead to a further decline in heart health as children transition into their teenage years and adulthood when the heart naturally ages.”
Senior author, Professor Janna Morrison, who is a Physiologist at UniSA, emphasizes that the research highlights the necessity of maintaining healthy nutrition for mothers before they conceive, not only for their health but also to ensure the well-being of their babies.
“We noticed poor cardiac outcomes in infants who had normal birth weights—a crucial observation that should influence future medical practices,” says Prof. Morrison.
“It is important to conduct cardiometabolic health screenings for all infants born to women with such dietary habits—beyond those born with atypically low or high weights—to identify risks for heart disease at an earlier stage.”
Prof. Morrison warns that if the trend of increased high-fat and sugary diets continues, it may lead to a rise in health issues like diabetes and heart disease, potentially shortening life expectancy in the years to come.
“With the current understanding of the detrimental impacts of obesity on health, we have the opportunity to alter this trajectory.”
The research team is in the process of conducting long-term studies on infants born to women on high-fat, high-energy diets to observe their health outcomes over the coming decades.
