Impact of High‐Flavanol and High‐Theobromine Chocolate Consumption on Blood Glucose Homeostasis in Women at Risk of Preeclampsia: a Double Blind Randomized Clinical Trial

Abstract

Preeclampsia (PE) is characterized by generalized endothelial dysfunction and impaired maternal tissue perfusion, and insulin resistance is a prominent feature of this disease. A history of PE has also been associated with higher fasting glucose concentrations and higher risk of type 2 diabetes later in life. Despite controversy among previous studies, flavanol‐rich chocolate consumption during pregnancy could have beneficial effects on the risk of PE. Theobromine, a major constituent of dark chocolate, also possesses vasodilatation properties. To our knowledge, no study has investigated the effect of flavanol‐rich chocolate consumption on blood glucose homeostasis in pregnant women at risk of PE.ObjectiveTo assess the impact of high‐flavanol and high‐theobromine chocolate consumption on fasting glucose and insulin concentrations in pregnant women at risk of PE.MethodsA single‐center randomized controlled trial was conducted in women with singleton pregnancy between 11 and 14 weeks gestation. Uterine artery Doppler was performed and women with bilateral diastolic notches and either a uterine artery pulsatility index (PI) >95th percentile on one side and/or bilateral PI>50th percentile were considered as potentially eligible for randomization. A total of 131 pregnant women were randomly assigned to either high‐flavanol, high theobromine (HFHT) or low‐flavanol, low‐theobromine (LFLT) chocolate groups. Women had to consume a total of 30 g of chocolate on a daily basis for 12 weeks. Fasting blood samples and anthropometric variables were measured at baseline and at 12 weeks.ResultsNo significant group by time interaction was found in fasting glucose and insulin concentrations after 12 weeks of chocolate consumption. A significant time effect was observed in fasting insulin concentrations in both HFHT and LFLT chocolate groups (p<0.0001), with similar increases in fasting insulin concentrations at 12 weeks. A significant time effect was observed in fasting glucose in the LFLT chocolate group only (p= 0.002), with a significant decrease of 4.9% in fasting glucose concentrations at 12 weeks. A significant group by time interaction was noted for body weight (p=0.03), with a greater weight gain in the HFHT group.ConclusionOur results suggest that HFHT chocolate consumption during pregnancy in women at risk of PE does not conduct to more beneficial effect on fasting glucose concentrations compared to LFLT chocolate.Support or Funding InformationThis research project was supported by Canadian Institute of Health Research by the Jeanne and Jean‐Louis Lévesque Perinatal Research Chair at Laval University.