"This study adds significantly to a growing body of evidence that CoQ10 supplementation may be an efficacious complementary method for improving cardiac function in heart failure patients," said Kevin Connolly, director of scientific affairs and product development, Jarrow Formulas.
The majority of research looking at the benefits of CoQ10 for health has focused on the cardiovascular diseases. The heart tissue contains the highest concentration of CoQ10 in the human body (about 132 nanomoles per gram), and there is evidence, said the researchers of the new study, that plasma CoQ10 levels decrease in patients with advanced chronic heart failure (CHF).
According to the Study on Heart failure Awareness and Perception in Europe (SHAPE), about 14m people in Europe suffer from chronic heart failure (CHF) with the number forecast to rise to 30 m by 2020. About 5m people suffer from the condition in the US.
To test if supplementation of the coenzyme could improve cardiocirculatory efficiency and endothelial function in patients with CHF, Romualdo Belardinelli from the Lancisi Heart Institute, Italy and her colleagues recruited 23 patients (20 men, average age 59) with stable CHF for a double-blind, placebo-controlled cross-over study.
Participants were randomly assigned to one of four four-week intervention groups: oral supplements of CoQ10 (100 mg three times per day, Q-absorb, Jarrow Formulas); CoQ10 plus supervised exercise training (ET) five times a week; placebo; or placebo plus ET.
The results, published on-line ahead of print in the European Heart Journal (doi:10.1093/eurheartj/ehl158), show that the heart's functional capacity improved significantly by nine per cent, as measured by the peak volume of oxygen consumed (VO2), for the CoQ10 compared to placebo. Similar results were observed for the CoQ10 plus exercise groups.
Blood flow also increased, as measured by endothelium-dependent dilation of the brachial artery (EDDBA) by 38 per cent after CoQ10 supplementation.
Supplementation with CoQ10 tripled plasma CoQ10 levels, and CoQ10 plus exercise further increased levels.
This result is important, said Connolly, because the formulation of CoQ10 is reported to play a key role in its bioavailability. Since the coenzyme is lipophilic (fat-loving) its absorption is enhanced in the presence of fats. However, when taken as a supplement apart from meals, the absorption of some formulations is lower.
Indeed, trials with CoQ10 supplements in powder and oil-suspension forms are reported to result in small or negligible responses in plasma CoQ10 concentrations.
The results of the new study, however, validated the delivery system behind the Q-absorb supplements, said Connelly.
The coenzyme is concentrated in the mitochondria - the 'power plants' of the cell - and plays a vital role in the production of chemical energy by participating in the production of adenosince triphosphate (ATP), the body's co-called 'energy currency'.
A role beyond the mitochondria is also acknowledged, with CoQ10 acting as a potent antioxidant, and it is this role that is proposed to be behind the benefits observed in this study, by reducing reactive oxygen species (ROS) levels, which results in increased levels of nitric oxide and widening of the blood vessels (vasodilation).
"Oral CoQ10 improves functional capacity, endothelial function, and left ventricle contractility in CHF without any side effects," concluded Belardinelli.
While the majority of research has focussed on the role of CoQ10 in cardiovascular health, the sphere of study is widening with studies emerging linking supplements of coenzyme to benefits for diabetes, cancer (breast, lung and prostate), male infertility, and kidney failure.