U. ILLINOIS (US) — A woman who eats a high-fat diet while pregnant may be putting her unborn child at risk for developing diabetes, even if she is not obese or diabetic herself.
“We found that exposure to a high-fat diet before birth modifies gene expression in the livers of offspring so they are more likely to overproduce glucose, which can cause early insulin resistance and diabetes,” says Yuan-Xiang Pan, professor of nutrition at the University of Illinois. The high-fat diet that caused the changes was a typical Western diet containing 45 percent fat.
“In recent years, the American diet has shifted to include many high-energy, high-fat, cafeteria-type, and fast foods,” he says.
Because the epigenetic marks can be easily evaluated, Pan says the study, published in the Journal of Physiology, can offer doctors a diagnostic tool to screen newborns born with this propensity to help keep blood sugar in a normal range and give them their best chance of avoiding diabetes.
For the study, obesity-resistant rats were fed either a high-fat or a control diet from the first day of gestation. Because the animals were not obese before the study began, the scientists were able to determine that diet alone had produced these effects.
“At birth, offspring in the high-fat group had blood sugar levels that were twice as high as those in the control group, even though their mothers had normal levels,” says doctoral student Rita Strakovsky.
The high-fat offspring also had epigenetic modifications to genes that regulate glucose metabolism. One of these modifications, the acetylation of histones, acts by loosening the DNA, making it easier for the gene to be transcribed.
While the epigenetic marks cannot be erased easily, if people are aware of them and change diet and lifestyle to compensate for their predisposition, it may be possible to delay or even prevent the development of diabetes.
“We’d like to see if diet after birth could alleviate this problem that was programmed before birth,” Pan says.
Although the study points to using epigenetics as a diagnostic tool, Strakovsky stresses the importance of making dietary recommendations more available to prevent the problem.
“Obstetrics patients rarely see a dietitian unless they’re having medical problems like gestational diabetes or preeclampsia. Doctors now tend to focus on how much weight a woman should gain in a healthy pregnancy. Although healthy weight gain is extremely important, nutritional guidance could be invaluable for all pregnant women and their babies,” she says.
Pregnant women should consume a balanced diet low in saturated fats, found in fattier cuts of meat, fast foods, pastries, and desserts. But they should also consume appropriate amounts of healthy fats, including good sources of omega-3 and -6 fatty acids, which are important for unborn babies’ brain and neuron development.
Cold-water fish low in mercury, flaxseeds and flaxseed oil, soybean and cod liver oils, walnuts, winter squash, are good sources of omega-3 fatty acids. Eggs, corn oil, whole-grain bread, poultry, and sunflower seeds and oil provide omega-6 fatty acids.
“Until now we didn’t realize that a mother’s diet during pregnancy had a long-term effect on the metabolic pathways that affect her child’s glucose production,” Pan says.
“Now that we know this, we urge pregnant women to eat a balanced low-fat diet that follows government guidelines. Then a woman can prime her child for a healthy life instead of future medical struggles.”
More news from University of Illinois: http://www.aces.uiuc.edu/news/