Important information for pregnancy
Is folic acid enough to prevent congenital malformations?
Folic acid is essential as a prenatal supplement to prevent neural tube defects such as spina bifida and anencephaly. However, folate prevents only about 70 percent of these defects. Research also points to another factor: sugar in the diet. A study done through the California Birth Defects Monitoring Program in Berkeley, California found that women who had a high glycemic index diet were twice as likely to have a pregnancy affected by a neural tube defect (NTD). The risk increased to 4 times as likely for obese women on a high glycemic diet.
Previous studies found that diabetes, prepregnancy obesity, high insulin, and high intake of sweets were associated with increased NTD risks. This study confirms a similar finding that glucose metabolism is involved in the development of congenital malformations.
High glycemix index foods are foods that are high in sugar, or break down into sugar quickly (such as cereals, pasta, potatoes, and white bread). Low glycemic index foods include whole grains, beans, fruits, and vegetables.
High glucose concentrations lead to oxidative stress and depletes the nutrient inositol. Interestingly, investigators are currently finding that inositol intake may prevent neural tube defects in women who had previously given birth to a child with NTDs even while on folic acid. Inositol also happens to have evidence in helping women with polycystic ovarian syndrome (PCOS), another condition associated with poor glucose and insulin metabolism. Perhaps inositol is the link with high glycemix index and neural tube development.
Reference: G. Shaw, T. Quach, et al. Neural tube defects associated with maternal periconceptional dietary intake of simple sugars and glycemic index. Am J Clin Nutr 2003;78:972–8