Higher levels of potato consumption before pregnancy were linked with increased risk of gestational diabetes in a prospective cohort study involving 15,632 women. Investigators also found that eating vegetables, legumes, or whole grain foods instead could decrease the risk.

Participants, from the Nurses’ Health Study II, did not have gestational diabetes or chronic diseases prior to becoming pregnant. Researchers looked at their eating habits over 4 years, and determined first-time gestational diabetes from self-reports of a physician diagnosis, later validated by medical records.

Among the results:

• Over 10 years there were 854 cases of gestational diabetes among 21,693 singleton pregnancies.

• After adjustment for certain variables, women who ate more potatoes before pregnancy had higher rates of developing gestational diabetes.

• Substituting 2 servings per week of potatoes with the aforementioned alternatives was significantly associated with a 9% to 12% lower risk of gestational diabetes.

Citation: Bao W, Tobias D, Hu F, Chavarro J, Zhang C. Pre-pregnancy potato consumption and risk of gestational diabetes mellitus: prospective cohort study. [Published online ahead of print January 12, 2016]. Br Med J. doi: dx.doi.org/10.1136/bmj.h6898.