Applied nutritional investigationEffects of long-term folate supplementation on metabolic status and regression of cervical intraepithelial neoplasia: AÂ randomized, double-blind, placebo-controlled trial

•The effects of folate supplementation on regression and metabolic status of patients with cervical intraepithelial neoplasia grade 1 (CIN1) were evaluated.•A randomized study divided patients with CIN1 into two groups and followed them for six months.•Folate supplementation among patients with CIN1 resulted in the regression of neoplasia.•Folate intake had beneficial effects on insulin resistance and oxidative stress in patients with CIN1.

ObjectiveThis study was conducted to determine the effects of long-term folate supplementation on regression and metabolic status of patients with cervical intraepithelial neoplasia grade 1 (CIN1).MethodsThis randomized, double-blind, placebo-controlled trial was performed among 58 women diagnosed with CIN1, ages 18 to 55 y old. Participants were randomly divided into two groups to receive 5 mg/d folate supplements (n = 29) or placebo (n = 29) for 6 mo. Fasting blood samples were taken at baseline and 6 mo after intervention to quantify related markers.ResultsA greater percentage of women in the folate group had regressed CIN1 (83.3 versus 52.0%, P = 0.019) than those in the placebo group. Long-term folate supplementation resulted in a significant decrease in serum insulin levels (−1.6 ± 6.2 versus +2.6 ± 6.9 μIU/mL, P = 0.018) and homeostatic model assessment-beta cell function (HOMA-B) (−13.0 ± 39.0 versus +11.2 ± 42.3, P = 0.028) compared with the placebo. Additionally, plasma glutathione (GSH) levels were significantly increased (+81.5 ± 264.1 versus −220.9 ± 342.5 μmol/L, P < 0.001) and malondialdehyde (MDA) levels were significantly reduced (−1.0 ± 1.1 versus +0.1 ± 1.6 μmol/L, P = 0.004) in the folate group compared to the placebo.ConclusionsTaken together, folate supplementation (5 mg/d) for 6 mo among women with CIN1 resulted in its regression as well as led to decreased serum insulin, HOMA-B, plasma MDA and increased plasma GSH levels; however, it did not affect other metabolic profiles.