The study, published recently in the American Heart Association journal “Hypertension,” adds to a growing body of evidence that suggests that pharmaceutical grade nutritional supplements could play a very important role in preventing heart disease – the nation’s No.1 killer. It also resurrects the idea that oral antioxidants, which have been largely dismissed as ineffective in recent years, could reap measurable health benefits if properly targeted.
Lead author Matthew Rossman, a postdoctoral researcher in the department of integrative physiology, says that “this is the first clinical trial to assess the impact of a mitochondrial-specific antioxidant on vascular function in humans. It suggests that therapies like this may hold real promise for reducing the risk of age-related cardiovascular disease.”
For this study, Rossman and senior author Doug Seals, director of the Integrative Physiology of Aging Laboratory, recruited 20 healthy men and women, aged 60-79 from the Boulder area.
Half of the participants took 20 milligrams per day of a commercially available supplement called MitoQ. It’s made by chemically altering the naturally-occurring antioxidant Coenzyme Q10 to make it cling to the mitochondria inside cells. The other half took a placebo.
After a period of six weeks, the researchers assessed how well the lining of blood vessels, or the endothelium, functioned by measuring how much subjects’ arteries dilated with increased blood flow.
Then, after a two week period of taking nothing, the two groups switched, with the placebo group taking the supplement, and vice versa. The tests were repeated.
The researchers observed that when taking the supplement, dilation of subjects’ arteries improved by 42%, making their blood vessels, at least by that measure, look like those of someone 15-20 years younger. An improvement of that magnitude, if sustained, is associated with around a 13% reduction in heart disease, Rossman said. The study also showed that the improvement in dilation was due to a reduction in oxidative stress.
Those participants, who, under placebo conditions, had stiffer arteries – another indication of vascular dysfunction – supplementation was associated with reduced stiffness.
Shedding New Light on Antioxidants
Blood vessels grow stiff and have difficulty dilating with age largely as a result of oxidative stress – the excess production of metabolic byproducts called free radicals which can damage the endothelium and impair its functioning. When we are young, our bodies produce enough antioxidants to destroy those free radicals. However, as we age, the balance tips in the other direction, as mitochondria and other cellular processes produce excess free radicals and the body’s antioxidant defenses can’t keep up.
Oral antioxidant supplements such as vitamin C and vitamin E fell out of favor after a number of large studies found them to be ineffective.
This particular study breathes new life into the discredited theory that supplementing your diet with antioxidants can help to improve your health. It suggests that targeting a certain source – mitochondria – might be a much better way to decrease oxidative stress and improve cardiovascular health with aging.