Children of obese mothers have a greater risk of developing fatty liver disease in their 20s, according to researchers who say policymakers need to do more to tackle the promotion of poor-quality food and drink.
Non-alcoholic fatty liver disease (NAFLD) can be caused by obesity. If it progresses it can lead to serious health problems such as cirrhosis and liver cancer, while high levels of fat in the liver are also associated with a greater risk of type 2 diabetes and heart disease.
According to the NHS, up to a third of people in the UK have early stages of NAFLD, meaning they have small amounts of fat in their liver. If the condition is picked up it can be prevented from getting worse, and damage can even be reversed.
While age is a risk factor for NAFLD, researchers have previously warned of an epidemic of the condition in young people after finding that about 20% of 24-year-olds in England had fatty deposits on the liver, with half of those having a severe form of the condition.
Now the same team say influences in the womb may play a role in increasing the risk of developing NAFLD.
The researchers, whose results will be presented at the International Liver Congress 2021 convened by the European Association for the Study of the Liver, looked at liver scans from 2,961 participants born in England and enrolled in a longitudinal study called the Children of the 90s. For the majority of participants, information was also available on the body mass index (BMI) of their parents.
After taking into account factors such as maternal age, smoking in pregnancy and social class, the team found that obesity in mothers before pregnancy was associated with a three times greater risk of their children going on to have a fatty liver at the age of 24.
The team also found an increased risk associated with obese fathers, but this link was smaller than for mothers, suggesting that while the family environment or father’s health may play a role, there appears to be a particular influence occurring in the womb.
“What our study is saying is that maternal pre-pregnancy obesity is causing an early life effect to prime the [offsprings’] livers to develop fatty liver, making them vulnerable to environmental hits such as a hyper-calorific diet, or a western diet, which will increase their risk of developing more advanced liver disease,” said Dr Kushala Abeysekera, of the University of Bristol.
“We are not blaming mums for this,” Abeysekera said. Instead he noted that the research highlighted that the impact of the obesogenic environment can be passed down through generations, in addition to already known heritable genetic risk factors for NAFLD. The team note that the work builds on research in Australia that found a similar link when looking at offspring at 17 years of age.
“There is no easy solution to this,” Abeysekera added. But he said there were actions that could be taken, such as reducing special offers on unhealthy foods to make it easier for people to make healthier choices.
Chris Byrne, a professor of endocrinology and metabolism at the University of Southhampton who was not involved with the work, said the results chimed with other research, including in mice, and one possible explanation was that the cells’ powerhouses, known as mitochondria, might be involved since these are only inherited from the mother.
However, he cautioned that further work was needed to fully rule out shared parental environmental factors that may be behind the apparent link.
Vanessa Hebditch, of the British Liver Trust, said greater awareness of the risk factors of NAFLD was needed. “At the moment, the majority of patients with this serious disease are not picked up until a late stage when the liver is so severely damaged it is too late for effective intervention,” she said. “Any research such as this that sheds light on the causes and can potentially improve early detection in the future is important.”