Numerous studies of CoQ10’s benefits to the circulatory system have been conducted during recent years, all showing a strong benefit to heart health.
Good for those with heart issues
A study in the European Heart Journal showed that CoQ10 strengthens the heart. The team studied 23 patients, average age 59 years, with moderate to severe heart failure. They were assigned four weeks each of oral CoQ10 supplements or inactive placebo pills with or without supervised exercise training five times per week. Supplementation with CoQ10 led to an improvement in peak exercise capacity and cardiac function without any side effects.
One study in the journal Evidence Based Integrative Medicine specifically points to CoQ10’s use in supporting healthy circulation.  Patients who took CoQ10 together with Pycnogenol (pine tree bark extract) benefited from the collaborative antioxidant effects. It provided antioxidant protection from cell-damaging free radicals and helped to maintain a healthy capillary circulatory system.
Regenerates vitamin E
In another study of its interactive benefits with other nutrients, CoQ10 was shown to interact with alpha-lipoic acid to regenerate oxidized vitamin E, which can help support healthy blood pressure levels and lipid metabolism. CoQ10 raises the body’s level of vitamin E, causing a cascade of other benefits. 
Protects against stress from exercise
Vigorous exercise, as well as environmental toxins, can generate free radicals in the body. CoQ10 helps neutralize these free radicals so you get all the benefits of exercise without the potentially damaging effects.
Prevents damage from high trans fat diet
The news keeps getting better. Based on research from India, CoQ10 may be useful to protect the heart for people who consume too much trans fat.  This is the bad fat found in candy bars, some breads and many processed foods.
Statin drugs may deplete CoQ10
Evidence suggests people who use statin drugs to treat high cholesterol levels may be simultaneously depleting their CoQ10 levels. Many cardiologists are now recommending CoQ10 to patients as an adjunct to traditional medical treatments.
CoQ10 levels decline with age
The concentration of CoQ10 in the body decreases as we age. This decrease in CoQ10 begins to take place around the age of 40. However, some research suggests levels begin to diminish as early as 20 years of age, with a slow but continuous decline thereafter.
Several factors contribute to the aging process, but many age-related conditions are associated with this decline in CoQ10 levels. You might think of fatigue, and reduced stamina and energy as unavoidable symptoms of aging.
However, these problems may be linked to diminished amounts of CoQ10, thereby warranting the consideration of CoQ10 supplementation.