When a woman is pregnant, it's often said that she is eating for two. While that may be true, what matters more than the quantity of food is quality. New research from the University of Illinois shows that mothers who have a diet that is high in fat during pregnancy could be increasing the risk of diabetes and other health problems in their children.
The research also showed that while a poor diet in pregnancy does increase risk, that risk can be mitigated if the child's diet is improved later in life. This is due to epigenetics, which are changes that impact gene expression. While each person inherits their particular DNA sequence, changes in lifestyle like a healthier diet or an exercise regimen can offset some of the negative consequences of inherited genes. Air quality in the environment, better food choices and regular physical activity are all ways to reverse DNA damage.
Laura Moody, a doctoral student in the Division of Nutritional Sciences at the University and co-author on the research explained, "Traditional genetics says that you inherit a sequence from your parents. Epigenetics says you can inherit these other changes to the DNA, as well," Moody explains. "This is where the whole maternal programming of metabolism—the epigenome—comes into play. We wanted to show these changes are easily altered, even after this critical period. You can still change that epigenome later in life. The message is not that the high-fat diet is itself bad, but rather you always have the opportunity to change it later. It's not like you are doomed by what your mom or dad did in early in life."
In the research, Moody and co-author Yuan-Xiang Pan, a professor in the Department of Food Science and Human Nutrition looked at rats who, during pregnancy and lactation, were given a diet that was composed of 45% fat. Once the pups were weaned half of the rats stayed on the high-fat diet, and the rest were fed a food with only 16% total fat.
After sequencing the whole genome of the rats to look for differences in gene expression the team found that there were specific differences in how the rats metabolized fat in the liver. DNA methylation is a process where cells control gene expression. In the rats that had been switched to the lower fat diet, the gene expression in the liver that controlled fat metabolism and inflammation was distinctly different from the patterns of gene expression in the rats on the fattier diet. The study results confirmed that DNA methylation is affected by dietary changes.
While the lower fat diet undoubtedly resulted in changes to the rats like lower body weight and BMI, the epigenetic changes were the most interesting. Diseases like diabetes and some forms of cancer have been shown to have metabolic pathways that lead to a person developing them. Showing that specific genes don't have to result in a poor outcome was the most significant part of the research.
Moving forward, the goal of any future research will be to see if these epigenetic changes can be used for intervention in preventing disease and assessing risk so that patients can make changes in their lives to offset any DNA damage done earlier in life. The video below has some information on a healthy pregnancy diet, but it's never too late to make dietary changes to offset any genetic factors.