Coenzyme Q10 (CoQ10) has had quite a journey as a nutritional ingredient. Isolated from beef heart in the 1950s, CoQ10 took part in a spate positive health studies in the 1980s and beyond, and enjoyed a surge in popularity in the health food segment in the 1990s. Along the way, it helped win a Nobel Prize (Peter Mitchell, 1977). Today, it has a place among cardiologist Stephen Sinatra’s “Awesome Foursome” and finds itself a sought-after ingredient in many different formulations, from supplements to functional foods.
The benefits of CoQ10 start with its role in ATP (energy) synthesis in the mitochondria and continue to its antioxidant actions in cell membranes. In healthy people, the body makes sufficient CoQ10 to reap these benefits, but in people with impaired CoQ10 synthesis—genetic defects, nutritional deficiency, drug side effects/interactions, etc.—supplementation is necessary. CoQ10 production in the body also diminishes with age, so seniors may have additional need for supplementation.
This vitamin-like nutrient has also proven useful in cases of a weakened heart, which uses more energy than other organs, including congestive heart failure (CHF). In fact, Sinatra lists potential cardio health uses such as ventricular arrhythmia, hypertension, cardiotoxicity, unstable angina and LDL oxidation.
Beyond matters of the heart, CoQ10 and/or a deficiency of the nutrient have been indicated in cancer, diabetes, chronic fatigue syndrome and various brain-health problems such as headaches.
CoQ10 is a ubiquinone found in every cell in the body. In its reduced, active-antioxidant form, ubiquinol, CoQ10 is actually the most powerful lipid-soluble antioxidant known, according to Thomas H. Schrier, national sales manager at Kaneka Nutrients L.P. “It’s capable of regenerating vitamin C and vitamin E,” he said. “And, the electrons donated by ubiquinol neutralize free radicals produced in the cell, as well as those coming from the environment.”
However, Robin Koon, president of Best Formulations, stated CoQ10 is not one of the body’s primary antioxidant sources, noting vitamin C and others play a much larger role. “When circulating through the bloodstream (before being absorbed inside individual cells), it is bound to low-density lipoprotein (LDL) in a reduced state, and can have some minor antioxidant effects,” he said. “This is due to CoQ10’s redox properties.”
The extent of its antioxidant impact may still be debated, but the importance of CoQ10’s ubiquinol form has found solid footing.
Steve Holtby, president and CEO of Soft Gel Technologies Inc., explained CoQ10 can exist in three states: the fully oxidized ubiquinone form (CoQ10); the partially reduced free radical semiquinone intermediate (CoQ10H); and the fully reduced ubiquinol form (CoQ10H2). “The body must first convert CoQ10 to ubiquinol,” he said, adding it is the dominant form of CoQ10 in human blood and the liver (more than 80 percent). “Without ubiquinol to carry electrons through the mitochondria, cellular energy cannot be produced.” He further explained it is this conversion to ubiquinol that declines as we age.
CoQ10 is sold in two finished product forms, oxidized (ubiquinone) and reduced (ubiquinol), according to Koon. “Regardless of which form is ingested, it is the total absorption of that dose that really matters,” he said, noting better absorption means a higher blood level and better bioavailability. The initial powder manufactured is the oxidized form, because it is stable, he explained, noting the reduced form is unstable. “When initially absorbed in the intestinal tract, the oxidized form is converted to the reduce form (via an enzyme, CoQ reductase), then placed into circulation. When the reduced form is absorbed, it does not need to utilize an enzyme to be reduced. In the bloodstream, it remains 98 percent in the reduced form, before being absorbed into the cells. Inside the cells, the ratio of reduced to oxidized CoQ10 is the same (50:50). Both forms are absorbed, but there is much variation between dosage forms and products in the marketplace.”
Schrier explained it another way, saying the ubiquinone-to-ubiquinol conversion is actually referred to as a Redox cycle, and the two chemicals are called a Redox pair. “They are constantly cycling back and forth in cells as the mitochondria use its electrons to generate ATP,” he said, adding ubiquinone is an electron acceptor. “Ubiquinol is the electron donor, thus referred to as the active antioxidant form, capable of actively donating those electrons for the two aforementioned roles.”
