© Provided by The Guardian
Photograph: Chris Radburn/PA
Children of women who were overweight or obese when pregnant have a higher risk of developing bowel cancer in later life, research suggests.
Obesity in women has previously been linked to health problems in their offspring. Among them, studies have suggested women who are overweight when trying to conceive are more likely to have a baby with serious birth defects.
Now researchers say adult offspring of women who were overweight or obese when pregnant have a greater risk of bowel cancer compared with offspring of mothers who were underweight or a healthy weight. The findings, they add, may help explain why incidence of bowel cancer is rising among younger people in Europe and other developed regions.
“Given population trends in maternal obesity, which has multiplied in prevalence by nearly six since the 1960s, we may see a growing burden of early-onset [bowel cancer] for decades to come,” the team write.
Writing in the journal Gut, researchers in the US report how they analysed data collected from women who received prenatal care between 1959 and 1966 in Oakland, California, with information obtained from their medical records in the six months before they became pregnant through to them giving birth.
The team then tracked the health of more than 18,000 of the offspring through to 2019, looking at cases of bowel cancer once they became adults.
The results reveal that 68 of the children developed bowel cancer as adults, with half of the diagnoses made before the individual reached 50 years old. About 20% of those who developed bowel cancer had a family history of the disease.
After taking into account race and ethnicity the team found adult offspring of women who were obese while pregnant had about a 2.5 times greater risk of developing bowel cancer compared with those of mothers who were underweight or a healthy weight, with a slightly smaller increase in risk seen for the adult offspring of women who were overweight while pregnant.
Being overweight or obese is known to increase the risk of bowel cancer, causing an estimated 11% of cases according to Cancer Research UK, while studies have found the children of obese parents are more likely to be obese than other children.
However, the US-based team say their work suggests influences in the womb may play an important role when it comes to the risk of bowel cancer.
Among possible mechanisms, the team suggest nutrients received in the womb may lead to lasting changes in appetite regulation, metabolism and the structure and function of body fat, while they also note maternal obesity has previously been linked to changes that affect several genes involved in energy metabolism in the child. Exposure to excess insulin or high maternal glucose levels may have an effect, they say.
However, the study has a number of limitations, including that it did not track the BMI of the offspring into adulthood, or take into account that parents and children often share a similar diet and may have a similar collection of gut microbes. The team were also unable to explore whether gestational diabetes in the women may have played a role.
© Photograph: Chris Radburn/PA
A person weighs themself on some bathroom scales
Keith Godfrey, a professor of epidemiology and human development at the University of Southampton who was not involved in the study, said it was difficult to provide definitive evidence for whether maternal obesity had lasting effects on the health of the offspring, not least as children of obese women “generally themselves experience influences after birth that make them more likely to gain more weight than is healthy”.
But, he said, a link between maternal obesity and bowel cancer risk in adult offspring was plausible.
“If the findings are confirmed they would add to an already strong case for supporting prospective parents to achieve a healthy weight before trying for a baby – this is in line with increasing recognition of the importance of preconception diet and lifestyle for the health and life chances of the offspring,” he said.
Source by www.msn.com