Ubiquinol, the reduced and active form of coenzyme Q10, is well known for its critical function in the production of cellular energy. But it also plays a key role in heart health, based on its unique abilities. As a person ages, these functions can be compromised, increasing the need for Ubiquinol supplementation for both heart health and overall wellness.
Coenzyme Q10 (also known as ubiquinone) is naturally synthesized in the body. It is converted to Ubiquinol by the addition of two electrons in an enzymatic redox reaction. Ubiquinol is thus the reduced form of coenzyme Q10.
As the reduced form, Ubiquinol acts as an antioxidant. Further, as a polar molecule, it is one of the few antioxidants that works in the lipid parts of the body such as membranes and low-density lipoprotein (LDL) cholesterol. Vitamin E is the other main lipid-soluble antioxidant; however, it is not synthesized in the body and is obtained only through the diet or supplementation. Vitamin E also acts in the mitochondria. It is dependent on Ubiquinol to be recycled and therefore cannot act independently of it.1
Due to its great and constant need for energy, the heart muscle is known to contain a large number of mitochondria. As a lipid-soluble antioxidant that is located in the mitochondria, Ubiquinol plays a very important role in quenching the free radicals that are produced in abundance in the mitochondrial membrane as a by-product of the catabolism of food for energy. In this way, it protects the membrane and surrounding environment from damage.
A second cardiovascular benefit is the antioxidant role of Ubiquinol in the blood. LDL cholesterol is well known to be an aggravating factor in the formation of plaques in the artery. The first step in this process is the oxidation of the LDL molecule, which makes it sticky and causes its particles to adhere to one another and the endothelial walls of the vessels.2
Ubiquinol prevents the oxidation of LDL cholesterol (LDLox) and is more potent than vitamin E at accomplishing this. Ubiquinol has been shown to be ten times more concentrated in cell membranes than vitamin E.3 In addition, Ubiquinol is constantly regenerated through its role in the electron transport chain where it cycles from Coenzyme Q10 to the active antioxidant form.
Going beyond general biochemistry, in vitro studies show Ubiquinol does in fact prevent the oxidation of LDL cholesterol. In two separate studies, fresh LDL from human blood was exposed to oxygen in the presence of Ubiquinol. LDL was oxidized very slowly until Ubiquinol was quenched, only after which point the LDL was quickly oxidized to LDLox.3,4
Further, a meta-analysis of five human, randomized, controlled trials with a total of 194 patients showed Coenzyme Q10 supplementation was associated with significant improvement in blood vessel endothelial function in subjects with and without cardiovascular disease, as assessed peripherally by flow-mediated dilatation (FMD).5 Coenzyme Q10 supplementation has also been shown to have beneficial effects on vascular elasticity.6
As with many body functions, aging affects Ubiquinol. Preliminary studies have shown that Ubiquinol levels are significantly diminished by aging and conditions marked by high oxidative stress. In a human study, plasma was taken from 127 healthy male subjects ranging in age from 20-70 years old. The % coenzyme Q10 (a measure of the ratio of coenzyme Q10 and Ubiquinol) increased progressively and significantly with age when pooled for 20-year intervals, starting at age 40.7 A second human study showed that Ubiquinol supplementation (150 mg/d) could improve this ratio in older adults after two weeks.8 Similar human studies have shown that adding back Ubiquinol can attenuate decreases often found with chronic disease.9,10