NICHD Studies May Help Women, With Their Doctors, Reduce Risk of Diabetes During Pregnancy
A series of studies by an NICHD researcher suggests that women who maintain a healthy diet and exercise before they become pregnant are less likely to develop gestational diabetes mellitus, a type of diabetes that occurs only in pregnant women.
While the studies do not establish a cause-and-effect relationship, they do show strong associations between certain types of foods and the likelihood of developing gestational diabetes during pregnancy. The information could help women of childbearing age and their doctors plan a diet that reduces gestational diabetes risk.
What is gestational diabetes? If a pregnant woman develops diabetes, but she didn’t have it before becoming pregnant, she has gestational diabetes. If not treated, gestational diabetes can cause problems for mothers and babies, some of them serious.
Cuilin Zhang, M.D., Ph.D., M.P.H., an investigator in the Epidemiology Branch within the NICHD Division of Intramural Population Health Research, studied the diets of a group of women before they became pregnant and then followed them during their pregnancies to track the incidence of gestational diabetes. Here are some of the key findings from her research:
- Increased dietary fiber reduced risk. Women who ate a diet low in fiber had twice the risk of developing gestational diabetes. (The fiber was measured by consumption of cereal, fruits, and vegetables.) An increase of 10 grams per day in total fiber intake reduced the risk of gestational diabetes by 26%.1
- Drinking sugar-sweetened cola increased risk. Women who drank five or more servings of sugar-sweetened cola per week had a higher risk of gestational diabetes when they became pregnant. Drinking other types of sugar-sweetened beverages or drinking diet beverages did not increase risk for gestational diabetes.2
- Meat and gestational diabetes:
- Eating red meat and processed meats increased risk. Women who ate a diet high in red meat and processed meats before pregnancy had a higher risk of gestational diabetes.3
- Eating animal fats and cholesterol increased risk. Women who consumed more animal fats and cholesterol before pregnancy had greater risk of gestational diabetes. Other dietary fats did not increase risk.4
- Replacing animal protein with protein from nuts lowered risk. Eating more animal protein, particularly red meat, was associated with higher risk of gestational diabetes. Substituting vegetable protein for animal protein lowered the risk by 51%.5
- Animal proteins and fats in a low-carbohydrate, high-protein diet increased risk. Women on a low-carbohydrate, high-protein diet had a greater risk of developing gestational diabetes when their dietary protein and fat came from animal sources. Women on the same type of diet had no higher risk of gestational diabetes when their protein and fat intake was from vegetable sources.6
- Heme iron (iron from animal sources) intake increased risk. Women with high levels of heme iron intake had increased risk of gestational diabetes. Iron from non-animal sources (non-heme iron) and iron from supplements did not increase the risk of gestational diabetes.7
But diet wasn’t the only pre-pregnancy factor related to gestational diabetes: exercise also lowered risk. Women who exercised more before they became pregnant had a lower risk of gestational diabetes; the more intense the exercise, the lower the risk. For example, walking at a brisk pace was associated with a lower risk than walking at a leisurely pace.8
NICHD researchers will continue to investigate gestational diabetes, seeking strategies to prevent the disease, to help improve outcomes for mothers and their babies.
For more information about gestational diabetes, select one of the following links:
Originally Posted: August 21, 2014
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- Zhang, C., Liu, S., Solomon, C. G., & Hu, F. B. (2006). Dietary fiber intake, dietary glycemic load, and the risk for gestational diabetes mellitus. Diabetes Care, 29(10), 2223–2230. PMID: 17003297 [top]
- Chen, L., Hu, F. B., Yeung, E., Willett, W., & Zhang, C. (2009). Prospective study of pre-gravid sugar-sweetened beverage consumption and the risk of gestational diabetes mellitus. Diabetes Care, 32(12), 2236–2241. PMID: 19940226 [top]
- Zhang, C., Schulze, M. B., Solomon, C. G., & Hu, F. B. (2006). A prospective study of dietary patterns, meat intake and the risk of gestational diabetes mellitus. Diabetologia, 49(11), 2604–2613. PMID: 16957814 [top]
- Bowers, K., Tobias, D. K., Yeung, E., Hu, F. B., & Zhang, C. (2012). A prospective study of prepregnancy dietary fat intake and risk of gestational diabetes. The American Journal of Clinical Nutrition, 95(2), 446–453. PMID: 22218158 [top]
- Bao, W., Bowers, K., Tobias, D. K., Hu, F. B., & Zhang, C. (2013). Prepregnancy dietary protein intake, major dietary protein sources, and the risk of gestational diabetes mellitus: A prospective cohort study. Diabetes Care, 36(7), 2001–2008. PMID: 23378620 [top]
- Bao, W., Bowers, K., Tobias, D. K., Olsen, S. F., Chavarro, J., Vaag, A., Kiely, M., & Zhang, C. (2014). Prepregnancy low-carbohydrate dietary pattern and risk of gestational diabetes mellitus: A prospective cohort study. The American Journal of Clinical Nutrition, 99(6), 1378–1384. PMID: 24717341 [top]
- Bowers, K., Yeung, E., Williams, M. A., Qi, L., Tobias, D. K., Hu, F. B., & Zhang, C. (2011). A prospective study of prepregnancy dietary iron intake and risk for gestational diabetes mellitus. Diabetes Care, 34(7), 1557–1563. PMID: 21709294 [top]
- Zhang, C., Solomon, C. G., Manson, J. E., & Hu, F. B. (2006). Physical activity before and during pregnancy and risk of gestational diabetes mellitus: A meta-analysis. Archives of Internal Medicine, 166(5), 543–548. PMID: 16534041 [top]