(NaturalNews) An antioxidant specifically engineered to seek out the mitochondria within cells may help reverse the aging of arteries, according to a study conducted by researchers from the University of Colorado-Boulder and published in The Journal of Physiology.
The study was funded by a grant from the National Institute on Aging.
Blood vessels aged by free radicals
To keep the body healthy, blood vessels must be able to dilate and contract as needed. When dilation is required, the endothelium (a thin layer of cells lining the blood vessels) produces a chemical known as nitric oxide. Nitric oxide is highly vulnerable to destruction by free radicals, however -- particularly the free radical superoxide, which is actually produced by the body's own mitochondria. Superoxide also degrades one of the enzymes that functions as a precursor to nitric oxide, leading to even lower levels of the chemical and decreased dilation of blood vessels. This, in turn, increases the risk of heart disease.
Superoxide is necessary to maintain cellular function, but as the body ages, mitochondria begin to produce it in higher quantities. At the same time, levels of antioxidants in the body often decrease with age, which leads to even greater circulating levels of superoxide. Superoxide then begins to cause damage to the mitochondria themselves -- which induces the mitochondria to produce even more superoxide, leading to even lower blood levels of antioxidants and more cellular damage.
"You have this kind of balance, but with aging there is this shift," lead author Rachel Gioscia-Ryan said. "There become way more reactive oxygen species than your antioxidant defenses can handle."
Finding an antioxidant that works
Previous studies have attempted to use antioxidant supplements to lower superoxide levels and thereby improve vascular dilation, but none have been successful. The researchers in the current study hypothesized that most antioxidants do not reach mitochondria and therefore have a limited impact on superoxide.
In order to get around this problem, the researchers specifically engineered an antioxidant for affinity for mitochondria. This chemical, MitoQ, was formed by adding a mitochondria-binding molecule to coenzyme Q10 (also known as ubiquinone or CoQ10).
"The question is, 'Why aren't we all just taking a bunch of vitamin C?" Gioscia-Ryan said. "Scientists think that, taken orally, antioxidants like vitamin C aren't getting to the places where the reactive oxygen species are being made. MitoQ basically tracks right to the mitochondria."
When the researchers gave elderly mice a MitoQ supplement for four weeks, their arteries went from functioning at a level equivalent to a 70-to-80-year-old human to a level equivalent to a 25-to-35-year-old human. In addition, the mice's levels of nitric oxide increased, their levels of oxidative stress decreased and their mitochondrial health improved.
"One of the hallmarks of primary aging is endothelial dysfunction," Gioscia-Ryan said. "MitoQ completely restored endothelial function in the old mice. They looked like young mice."
Although tests into its function are still in preliminary stages, MitoQ can already be purchased as a dietary supplement and skin cream. CoQ10, the chemical used as the base for MitoQ, can also be purchased as a nutritional supplement.
CoQ10 is a substance naturally produced by the body to help enzymes carry out various functions -- including helping mitochondria produce adenosine triphosphate (ATP), the major cellular energy source. CoQ10 has also been linked, on its own, to prevention of cellular damage and improvements in high blood pressure. It is also being investigated for a number of other potential benefits, including fighting cancer, improving cognitive health, slowing the effects of aging, reducing diabetic neuropathy pain, lowering high cholesterol and improving heart health.