In October 2018 researchers from Japan published the results of their study to assess the effect of high-cocoa chocolate intake on arterial stiffness and fat oxidation during a 4-week period of light- to moderate-intensity exercise. A total of 32 individuals (24 men, 8 women; average age 21 years) were divided into two equal groups. The first group did not alter their normal diet or physical activity throughout the study period, whereas the second group consumed 20g/day high-cocoa chocolate for the 4-week period. Blood pressure, heart-ankle pulse wave velocity, cardio-ankle vascular index, body composition, and metabolic characteristics during exercise were assessed before and after the study period. Results showed that the 4- weeks of high-cocoa chocolate significantly reduced heart-ankle pulse wave velocity and cardio-ankle vascular index. However, blood pressure, weight, BMI, body fat, waist circumference, and metabolic characteristics during exercise did not significantly change in either group. The researchers therefore concluded that 4-weeks of high-cocoa chocolate consumption reduced arterial stiffness
Nishiwaki M et al. Effects of regular high-cocoa chocolate intake on arterial stiffness and metabolic characteristics during exercise. Nutrition. 2018 Oct 5;60:53-58.