http://www.medicalnewstoday.com/articles/242555.php

According to a study conducted by investigators at UC San Diego School of Medicine and VA San Diego Healthcare System (VASDHS), a flavonoid called epicatechin, found in dark chocolate, enhanced mitochondria structure in individuals with advanced heart failure and type 2 diabetes after 3 months. The study is published this week by the journal Clinical and Translational Science.

The researchers examined 5 extremely sick patients with major damage to skeletal muscle mitochondria. Mitochondria are structures that provide the energy a cell requires in order to move, divide, and contract. Both heart failure and type 2 diabetes impair these power cells, resulting in abnormalities in skeletal muscle. In individuals with diabetes and heart failure these abnormalities in the heart and skeletal muscle cause decreased functional capacity. Frequently, these patients report difficulty walking even short distances, shortness of breath, as well as lack of energy.

Each day for three months, study participants consumed dark chocolate bars and a beverage with a total epicatechin content of around 100 mg. The researchers conducted biopsies of skeletal muscle before and after the 3 month treatment. After treatment, the team examined alterations in mitochondria volume as well as the amount of cristae. Cristae are the internal compartments formed by the inner membrane of a mitochondrion. They are vital for the mitochondria to function efficiently and can be measured by electron microscopy.