Reduced blood supply during heart or blood vessel surgery can deprive tissues of oxygen. When blood supply returns to this tissue, the tissue can become damaged.

There is evidence that taking CoQ10 by mouth for a week before heart bypass surgery or blood vessel surgery might help to reduce tissue damage.

However, not all research agrees with this finding.

Taking a combination of nutrients including CoQ10 was associated with quicker recovery after bypass and heart valve surgeries, according to a 2011 randomized, controlled trial of 117 patients.

Chemotherapy has a lot of short-term side effects but there are long-term effects — including heart damage — that can occur years later as well.

Such cancer treatment can weaken the heart muscle (a condition called cardiomyopathy), cause heartbeat irregularities, and increase heart attack risk.

Fortunately, not all chemotherapy drugs have these potential side effects.

Researchers are looking at CoQ10 as a way to help mitigate long-term cancer treatment side effects.

One study showed that CoQ10 may help to reduce the toxic effects on the heart caused by daunorubicin and doxorubicin, two commonly used chemotherapy medications.

Of course, cancer patients should always check with their oncologists before taking any type of supplements along with chemotherapy.