A high-fat, high-sugar diet during pregnancy can affect health outcomes for children, grandchildren, and great-grandchildren, researchers say.
The study is published in the journal Cell Reports and was led by Dr. Kelle H. Moley, from the Washington University School of Medicine in St. Louis, MO.
Obesity in pregnancy is common and can increase certain obstetrical risks. According to the Centers for Disease Control and Prevention (CDC), almost 60 percent of women begin pregnancy above a normal weight, and less than 30 percent of women gain weight during pregnancy within recommendations of the Institute of Medicine.
Furthermore, a 2008 study found that the prevalence of prepregnancy obesity increased by 69 percent over a 10-year period. It was 13 percent in 1993-1994, but by 2002-2003, it had skyrocketed to 22 percent.
"Our findings indicate that a mother's obesity can impair the health of later generations," says Dr. Moley. "This is particularly important because more than two thirds of reproductive-age women in the United States are overweight or obese."
The researchers note that although previous studies have linked a woman's pregnancy health to her child's weight in later life, their study is the first to show that prepregnancy obesity can result in genetic abnormalities that are passed through the female bloodline to three future generations, increasing risks for type 2 diabetes and heart disease.
Mothers' eggs carry information that programs dysfunction in offspring
To conduct their study, the researchers fed mice a high-fat, high-sugar diet that consisted of 60 percent fat and 20 percent sugar, which mimics a Western diet. "Basically, it's like eating fast food every day," explains Dr. Moley.
The offspring of the mice were then fed a controlled diet of standard rodent chow that is low in fat and sugar and high in protein.
Results showed that even though the offspring were fed a healthy diet, the pups, grand pups, and great-grand pups of the mothers developed insulin resistance and other metabolic problems.
Additionally, the researchers observed abnormal mitochondria in the muscle and skeletal tissue of the mice.
Mitochondria are typically described as the "powerhouses" of cells; they supply energy for metabolism and other biochemical functions. Furthermore, they have their own sets of genes that are inherited only from mothers and not fathers.
"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. Importantly, our study indicates oocytes - or mothers' eggs - may carry information that programs mitochondrial dysfunction throughout the entire organism."
Dr. Kelle H. Moley
The researchers add that the observed effects of maternal metabolic syndrome may be greater than in their mouse model since the diets of human children often closely mirror those of their parents.
Although more research is needed, Dr. Moley says eating healthfully is of vital importance and adds that "our diets have worsened, in large part due to processed foods and fast foods," fueling the current obesity crisis.