Obese women can pass on the weight problem to at least three generations, a new study found. In particular, even if the offspring eats healthier diets, obese women who consume high-sugar and high-fat diets can cause their descendants to become obese as well.
Previous studies showed a woman's health during pregnancy affects her unborn child's obesity risk in the future. A recent study conducted on mice showed that pre-pregnancy health can also cause genetic abnormalities that can be passed on to future generations through the mother's bloodline.
Apart from obesity, the abnormalities also increase the risk of developing weight-related health issues such as heart disease and type 2 diabetes. The new findings suggested that a woman's obesity, especially that of a mother's, can affect the health of future generations.
These genetic abnormalities can span generations through the unfertilized oocyte's (egg) mitochondrial DNA. Dubbed as the "powerhouse of the cells," the mitochondria is the one that supplies the energy needed for biochemical processes such as metabolism.
The mitochondria contain sets of genes that are exclusively inherited from the mother.
"Our study indicates oocytes - or mothers' eggs - may carry information that programs mitochondrial dysfunction throughout the entire organism," said Kelle H. Moley from Washington University.
In the study, researchers fed the mice participants with a diet that consisted of 60 percent fat and 20 percent sugar. The female mice's diet started from six weeks before they conceived.
The researchers maintained the high-sugar, high-fat diet until the offspring started weaning. Typically, the diet mimicked the Western diet among humans.
When the offspring started weaning, they were given a controlled diet that consisted of standard mice food, which is low-sugar, low-fat and high-protein.
However, despite the offspring's healthier diet, the descendants spanning three generations developed several metabolic issues including insulin resistance. When they examined the mice's skeletal and muscle tissue, they discovered abnormalities in the mitochondria.
"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," added Moley.
The new research published in the Cell Reports journal on June 16.
Obesity Rising
Earlier this month, a separate study found that obesity rates are rising among American women. A study published in the JAMA journal found that in 2013 to 2014, 40 percent of women and 35 percent of men were obese.
A trend analysis showed that from 2005 to 2014, the obesity rates among women in the United States have been significantly and steadily increasing.
