Coenzyme Q10 (CoQ10), a nutrient that occurs naturally in every cell in the body, improved blood-vessel function and increased peak exercise capacity in those with heart disease, in two new studies.
In a coronary artery disease (CAD) study, researchers recruited 33 men and five women with an average age of 55, who had CAD and whose hearts pumped blood normally, to take 300 mg of CoQ10 in three 100 mg doses per day or a placebo for one month. Doctors measured the activity of an important antioxidant enzyme, superoxide dismutase or SOD, on blood vessel walls, which declines in CAD. They found that those who had taken CoQ10 had a 29% increase in SOD activity compared to 4% for placebo. Scientists also measured the ability of the arteries to relax (dilate), the ability of the heart to deliver oxygen and the capacity of the cells to absorb oxygen, and found that, in all three measures, those who had taken CoQ10 had significantly greater improvement compared to placebo. Doctors noted that participants who began with the lowest SOD activity improved remarkably.
In chronic heart failure (CHF), the heart is damaged and may not fill with or pump enough blood. In this study, researchers recruited 20 men and three women, average age 59, who had CHF, to participate in four, four-week double-blind phases taking: 1) 300 mg of CoQ10 in three 100 mg doses per day without exercise, 2) the same CoQ10 dose with supervised exercise training, 3) a placebo without exercise, or 4) a placebo with supervised exercise training. Doctors measured the capacity of the cells to absorb oxygen and the ability of the arteries to dilate and found that compared to placebo, the CoQ10 group increased by 9% and 38% respectively. Scientists also tracked an index that measures the ability of the left ventricle of the heart to pump blood, which improved 12%.