Effects of Oral Antioxidant Cocktail on Vascular Function and Blood Flow in Cardiovascular Disease Patients

Cardiovascular disease (CVD) is one of the leading causes of death in the United States. CVD is attributed to a combination of major risk factors including hypertension, dyslipidemia, obesity, poor diet, low physical activity levels, and vascular endothelial cell dysfunction.

The vascular endothelial cells (VECs) have significant control over vascular homeostatic regulation. In the case of mechanical and chemical stimuli, VECs can release vasoactive substances to regulate vascular tone, cell adhesion, and vascular smooth muscle cell (VSMC) proliferation. When the endothelium is damaged and becomes dysfunctional, atherosclerotic changes take place that can contribute to the development of CVD and atherosclerosis.

Endothelial dysfunction has been partially attributed to high levels of reactive oxygen species (ROS) causing significant oxidative stress (OS). OS is defined as an imbalance between the rate of ROS production and the rate of ROS clearance by the antioxidant defense system, with insufficient clearance leading to oxidative damage of the vasculature. High levels of OS have been shown to negatively affect the vascular endothelium by increasing VSMC proliferation and inflammation, which may result in vascular remodeling. Increased OS also attenuates the bioavailability of nitric oxide, a potent vasodilator, and can further exacerbate the structural and functional changes of the vascular endothelium that are associated with the development of CVD.

When the vascular endothelium becomes dysfunctional (partially due to OS), blood flow and vascular tone regulation become impaired, which then negatively affects O2 transport. Without proper blood flow and O2 transport, exercise capacity becomes attenuated. This is a major concern for CVD patients, because exercise is an effective non-pharmacological therapeutic treatment for many of the CVD risk factors including obesity, dyslipidemia, hypertension, and metabolic syndrome. Therefore, improvement of the antioxidant defense system could alleviate high OS, and improve vasodilatory capacity of blood vessels, blood flow and O2 transport, and by extension, can increase exercise capacity. This would make exercise a more viable treatment option for CVD patients.

The antioxidant defense system contains numerous enzymatic and non-enzymatic antioxidants, including catalase, superoxide dismutase, glutathione peroxidase, vitamins A, E, and C, along with glutathione, ubiquinone, and flavanoids. The antioxidant defense system has been found to be attenuated in CVD patients, particularly in those with peripheral arterial disease. However, as ROS production increases, this antioxidant defense system can be overwhelmed, leading to OS and damage to the tissues. Antioxidant capacity may be improved through supplementation in order to provide better OS clearance in the body, which could then result in better blood flow and O2 delivery to the muscles and other organs in the body.