Fried-Food Intake Prepregnancy Ups Gestational Diabetes Risk

Troy Brown, RN

October 16, 2014

Frequent consumption of fried foods before becoming pregnant increases a woman's risk for gestational diabetes, and that risk is even higher when those fried foods are eaten away from home, according to a recent study published online October 8 in Diabetologia.

Dr Wei Bao (Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, Maryland) and colleagues studied the association between prepregnancy fried-food intake and the risk for gestational diabetes mellitus.

"Gestational diabetes mellitus is not only associated with short-term [adverse] perinatal outcomes but also related to long-term metabolic risk in both mothers and their offspring. Thus, it is crucial to identify modifiable risk factors that may contribute to the prevention" of this condition, the authors write.

"Findings from this study and our previous work highlight the potential importance of prepregnancy diet and lifestyle in the prevention of gestational diabetes mellitus in pregnancy," coinvestigator Dr Cuilin Zhang (Eunice Kennedy Shriver National Institute of Child Health) told Medscape Medical News.

Therefore, physicians should "advise their patients who are planning for pregnancy to lower their intakes of fried food," Dr Zhang added.

Risk Independent of Body Mass Index

The research included 21,079 singleton pregnancies in 15,207 women who participated in the Nurses' Health Study II (NHSII), an ongoing prospective cohort study of 116,671 US nurses aged 25 to 44 years when it began in 1989.

Participants have completed a questionnaire every 2 years about disease outcomes and lifestyle behaviors, including smoking status and medication use. Every 4 years since 1991, NHSII researchers have obtained information about diet, including fried-food intake at home and away from home, with a validated food frequency questionnaire.

There were 847 incident gestational diabetes mellitus pregnancies recorded during 10 years of follow-up. The researchers adjusted for age, parity, and dietary and nondietary factors.

Among women who ate fried foods one to three times weekly, the risk ratio (RR) for gestational diabetes was 1.13, compared with women who ate fried foods less than once per week. For women who ate fried foods four to six and seven or more times per week, the RRs were 1.31 and 2.18, respectively (P for trend < .001).

Dr Zhang noted that, in epidemiological studies, frequent consumption of fried foods has been linked to a higher risk for overweight and obesity in Mediterranean cohorts, and both overweight and obesity are related to increased risk for gestational diabetes mellitus.

Nevertheless, the association remained even after the researchers additionally adjusted for body mass index (BMI), although it was moderately attenuated: the RRs for gestational diabetes were 1.06, 1.14, and 1.88 for those who ate fried foods one to three, four to six, and seven or more times per week, respectively, compared with those who ate fried foods less than once per week (P for trend = .01).

Food Fried Away From Home Is Greatest Risk

When the researchers analyzed fried-food intake at home and away from home separately, fried-food consumption away from home was significantly associated with gestational diabetes mellitus, but fried-food consumption at home was not.

"Frying deteriorates oils through the processes of oxidation and hydrogenation, leading to an increase in the absorption of oil degradation products by the foods being fried, a loss of unsaturated fatty acids such as linoleic and linolenic acids, and an increase in the corresponding trans-fatty acids such as translinoleic acids and translinolenic acids," the authors explain.

"[This] has been positively related to diabetes risk," Dr Zhang said.

Frying foods also causes significantly higher levels of dietary advanced glycation end products, which have been linked to insulin resistance, pancreatic beta-cell damage, and diabetes, in part because they stimulate oxidative stress and inflammation,.

"Intervention studies with a diet low in advanced glycation end products have shown significantly improved insulin sensitivity, reduced oxidant stress, and alleviated inflammation," the authors explain.

"The…deterioration of oils during frying is more profound when the oils are reused, a practice more common away from home than at home. This may partly explain why we observed a stronger association of gestational diabetes mellitus risk with fried foods consumed away from home than fried foods consumed at home," they conclude.

Still, they caution, further studies "are warranted to confirm our findings and to elucidate the underlying mechanisms."

The authors have disclosed no relevant financial relationships.

Diabetologia. Published online October 8, 2014. Article


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