Differential effect of polyphenol-rich dark chocolate on biomarkers of glucose metabolism and cardiovascular risk factors in healthy, overweight and obese subjects: a randomized clinical trial

Abstract

The association between excess cortisol and various parameters of metabolic syndrome including hypertension, insulin resistance and dyslipidaemia is increasingly recognised. The present single-blind randomised placebo-controlled cross-over study compared the effect of polyphenol-rich dark chocolate (DC) on biomarkers of glucose metabolism, lipid profile, and blood pressure (BP) in females with BMI $ 25 kg m À2 (n ¼ 21) and females with BMI < 25 kg m À2 (n ¼ 21). Volunteers consumed 20 g of DC containing 500 mg polyphenols or a placebo DC with negligible polyphenol-content daily for 4 weeks, separated by a 2-week washout period. Systolic BP and diastolic BP decreased after 4 weeks of polyphenol-rich DC. Placebo raised fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and salivary cortisol, an effect that was significantly different from polyphenol-rich DC which had a negligible effect on fasting insulin, HOMA-IR and salivary cortisol. Females with BMI $ 25 kg m À2 responded less favourably to placebo than lean females and consequently had higher fasting insulin and HOMA-IR, in addition to a lower quantitative sensitivity check index (QUICKI) after ingestion of placebo compared to polyphenol-rich DC. No significant changes in lipid profile were observed. This study provides evidence for the metabolic benefits of consuming polyphenol-rich dark chocolate while demonstrating the possibility of adverse effects occurring with polyphenol-poor chocolate placebo. Methods DesignThe study used a single-blind randomised placebo-controlled cross-over design where each subject acted as their own control. Following a 1-week run-in phase, eligible subjects were randomly assigned to receive 20 g DC containing 500 mg polyphenols or

β-Glucan and Dark Chocolate: A Randomized Crossover Study on Short-Term Satiety and Energy Intake

“…In addition to fatty acid composition, the polyphenol content of cocoa can also be considered as an important factor [39]. There is evidence showing the positive effects of having cocoa flavanols as part of a diet on oxidative status [40] and glucose metabolism [23] and, as the current study indicates, although cocoa polyphenols may also play a role in conducting satiety responses, this hypothesis needs to be corroborated by future studies.…”

“…However, recent studies indicate that dark chocolate, which has a greater content of cocoa and lower content of sugar when compared to milk chocolate, is associated with a reduction in blood pressure, cardiovascular diseases, type 2 diabetes, fat deposition and mortality rates [19,20,21,22,23]. Sorensen and Astrup [24] have demonstrated the significant effect of dark chocolate on a greater satiety feeling, lower energy intake in prospective meal and reduced appetite for sugary snacks in comparison to milk chocolate consumption.…”

Effect of aerobic exercise on blood lipid and glucose in obese or overweight adults: A meta-analysis of randomised controlled trials

“…It has been reported that obesity or overweight is the risk factor of cardiovascular diseases [6,7]. Moreover, the blood lipid and glucose indexes are associated with cardiovascular diseases in population with obesity or overweight [8][9][10]. Thus, it is necessary to find a method for improving the lipid and glucose metabolism in obese and overweight people.…”

Nutritional composition and glycemic index analyses of vitamin A‐biofortified maize in healthy subjects

“…The presence of polyphenols in plant foods has been reported to interfere with the activities of some starch‐digesting enzymes such as glucosidases and maltase (Hanhineva et al., 2010). A number of intervention studies have reported considerable improvement in glycemic status in both rats and humans following supplementation with polyphenol‐rich diets (Abesundara, Matsui, & Matsumoto, 2004; Almoosawi, Tsang, Ostertag, Fyfe, & Al‐Dujaili, 2012). The HCl released as a by‐product in the metabolism of cyanogenic glycosides has been implicated in central nervous system dysfunction, respiratory failure, and cardiac arrest (D'Mello, 2000).…”