A mother's obesity - and its associated metabolic problems - can be inherited through mitochondrial DNA present in the unfertilised oocyte, or egg to offspring.
Pregnant women who eat high-fat, high-sugar diets may lead to an increased risk of type 2 diabetes and heart disease in multiple generations, even if their kids consume healthy diets, a new study has warned.
While other studies have linked a woman’s health in pregnancy to her child’s weight later in life, a mouse study at Washington University is the first to indicate that even before becoming pregnant, a woman’s obesity can cause genetic abnormalities that subsequently are passed through the female bloodline to at least three generations.
This increases the risk of obesity-related conditions such as type 2 diabetes and heart disease, researchers said.
“Our findings indicate that a mother’s obesity can impair the health of later generations,” said Kelle H Moley from Washington University.
The research shows that a mother’s obesity – and its associated metabolic problems – can be inherited through mitochondrial DNA present in the unfertilised oocyte, or egg.
Mitochondria often are referred to as the powerhouses of cells because they supply energy for metabolism and other biochemical processes. These cellular structures have their own sets of genes, inherited only from mothers, not fathers, researchers said.
“Our data are the first to show that pregnant mouse mothers with metabolic syndrome can transmit dysfunctional mitochondria through the female bloodline to three generations,” said Moley.
“Importantly, our study indicates oocytes – or mothers’ eggs – may carry information that programs mitochondrial dysfunction throughout the entire organism,” she said.
From six weeks prior to conception until weaning, researchers fed mice a high-fat, high-sugar diet comprised of about 60 per cent fat and 20 per cent sugar.
“This mimics more of the Western diet. Basically, it is like eating fast food every day,” said Moley.
Offspring then were fed a controlled diet of standard rodent chow, which is high in protein and low in fat and sugar.
Despite the healthy diet, the pups, grand pups and great-grand pups developed insulin resistance and other metabolic problems.
Researchers found abnormal mitochondria in muscle and skeletal tissue of the mice.
“It is important to note that in humans, in which the diets of children closely mirror those of their parents, the effects of maternal metabolic syndrome may be greater than in our mouse model,” said Moley.
The findings were published in the journal Cell Reports.