What if a baby’s developing brain determines their future risk for obesity during the crucial period soon before delivery and in the first few days afterward?
Previous studies have revealed that human genes linked to obesity can predict whether a person will struggle to maintain a healthy weight in the long run. According to Robert Waterland, PhD, professor of pediatrics-nutrition at Baylor College of Medicine in Houston, Texas, researchers have been looking for associations between genetic variations and body mass index (BMI) for decades. The issue, he argues, is that the genetic connections discovered thus far do not account for weight increase and who is more at risk.
Could there thus be more to the rise in obesity prevalence than just genes and lifestyle choices?
Waterland and his team examined the idea that environmental factors, such as stress and inadequate nutrition, during a crucial period of brain development may affect the risk of obesity in their recent study, which was published in Science Advances.
The arcuate nucleus of the hypothalamus, which controls the body’s energy balance between food intake, physical activity, and metabolism, was the focus of the research team, which was directed by Harry MacKay, PhD, a postdoctoral associate in pediatrics-nutrition at Baylor.
The arcuate nucleus undergoes considerable growth in the first few weeks of life in mice, which will later determine how well the body perceives when it is hungry and when it has enough food. This extensive growth occurs during a crucial period when brains are most susceptible to programming.
The researchers concentrated on epigenetics and sought to identify the genes that would and would not be used by various cell types. The sites targeted for epigenetic maturation in the mouse arcuate nucleus corresponded highly with human genomic regions linked to BMI, which was a big surprise to the researchers when they compared their epigenetic data from mice to human data.
Waterland notes that although the study did not address the timing of the epigenetic modifications in humans, past studies have demonstrated that they occur in people earlier than in mice.
According to him, the same epigenetic process that has been observed in early postnatal mice also happens in late foetal development in humans.
If so, the very high frequency of maternal obesity in the U.S. and many other wealthy countries across the world “is a big, enormous problem,” which may be impacting the health of newborns.
Some people may feel destined to become obese if future weight issues start before birth or during the first few weeks of life. However, Waterland notes that because it’s exceedingly challenging to change your genetics, the prior research’s emphasis on genetics wasn’t particularly hopeful either.
We can at least look for methods to enhance this in the future, he argues, “if we understand how environment influences development.”
It’s too soon to say whether obesity is actually a neurodevelopment disorder, but if preliminary research like this one keeps accumulating evidence, Waterland says, public health initiatives to stop the global obesity epidemic could put more of an emphasis on healthy weight gain, prenatal nutrition, and stress management.