A new study from a group of researchers at the National Institute of Child Health and Human Development at Harvard University says women who eat the most potatoes have a higher risk on contracting gestational diabetes, according to a story on mashable.com.

Gestational diabetes is caused by high blood sugar levels in women during pregnancy and strikes about four percent of women.  Those with a history of type 2 diabetes in their family line, along with women who are overweight,  over 25,  and women of certain races already have a higher risk factor.  Scientists are unclear as to the exact cause of the disease, but changes in the hormonal system has an impact on insulin production, causing disruptions in the regulation of blood sugar.

The study involved some 15,000 women over the course of 10 years, looking at the dietary records of the women in the Nurse’s Health Study.  The participants recorded their diets, and during the period, 854 women developed gestational diabetes.

After factoring the data for age and parity, the findings show that women who ate the most potatoes had the higher risk of developing gestational diabetes, but the good news was that substituting legumes or whole grain foods instead of potatoes twice per week offset the risk.  Those substitutions in the women’s diets were associated with a 9-12 percent lower risk of gestational diabetes.

The reason may be the fact that potatoes have a high glycemic index, which in turn makes the blood sugar spike, effecting the production of insulin.  Vegetables and legumes with a lower glycemic index could lower that spike, when eaten in the place of potatoes.

The researchers are not ruling out the consumption of potatoes in your diet, but like everything else, they just need to be eaten in moderation.  Potatoes are rich in nutrients and contain beneficial vitamins and minerals.  The preparation of the potatoes, such as substituting baked for fried potatoes or potato chips should be considered as well.

The findings of the study were published in the British Medical Journal.