Good news for exercising enthusiasts and chocolate lovers. A new study found that dark chocolate is helpful in reducing oxidative stress after exercise.
The study - conducted by a research team from Aberystwyth University in Wales, Loughborough University, the University of Newcastle in the UK and the Nestle Research Center in Lausanne, Switzerland - is published in the current issue of the European Journal of Nutrition. According to lead scientist, Glen Davison, “Dark chocolate was effective at blunting the exercise-induced increase in plasma total antioxidant status observed in the other trials, providing support for the idea that the elevated total antioxidant status on the dark chocolate trial has physiological significance.”
Study volunteers ate 100 grams of dark chocolate containing at least 70 percent cocoa solids, a control bar or nothing. After two hours, the group cycled for 2.5 hours using 60 percent of their maximal oxygen uptake levels. Compared to the study group, the dark chocolate group showed both an increase in antioxidants before the physical activity and reduced levels of F2-isoprostane an hour afterwards. Increased insulin levels were also noticed in the dark chocolate group, which signaled a better maintenance of plasma glucose concentration.
Reactive oxygen species (ROS) are naturally produced by oxygen-breathing organisms and overproduced by smoking, air pollution, excessive sun exposure and intense exercise, as well as aging. ROS are key for cell signaling and function, but overproduction can overload the body's antioxidant defenses and cause excess oxidation and stress, which is linked to serious health risks including cancer, Alzheimer's and cardiovascular disease.
Polyphenols found in chocolate showed an ability to decrease the oxidative stress from the study volunteers' high-intensity physical activity, which is similar to any physical stress on the body. They're also linked with other health benefits to the cardiovascular system, healthy skin and brain function.
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