Racial and Aging Effects of Acute Antioxidant Supplementation
Condition: Healthy
Study type: Interventional

Summary: 
      This research is,being done to better understand how antioxidants (vitamins C, E and Alpha
      Lipoic Acid) af,f,ect the heart,and arteries. For this study, we will obtain blood samples to
      measure oxidative stress markers (substances in the blood that are linked to oxidative
      stress), cholesterol, insulin and blood glucose (sugar), as well as measure how well the
      heart and arteries are working following supplementation with the antioxidants.

      Our central hypothesis is that acute antioxidant supplementation will improve arterial
      function at rest and during exercise in African Americans without an impact of age, whereas
      aging will modify these effects in Caucasians.
    

Detailed description: 
      The overall goal of this application is to investigate the effect of aging on how acute
      antioxidant supplementation affects decrements in arterial function observed in African
      Americans (AA). Additionally, this application will facilitate the applicant's emergence as
      an independent investigator in integrative clinical physiology. Oxidative stress (OS),
      contributes to hypertension, diabetes, heart failure, atherosclerosis, sepsis and aging.
      Increased OS leads to the development of endothelial dysfunction and subsequent development
      of cardiovascular disease through the inactivation of nitric oxide (NO) by superoxide (O2)
      and other free radicals. African Americans (AA) have increased OS and inflammation in vivo
      and in vitro, and have a lower serum concentration of most antioxidants. Endothelial cells of
      AAs have steady state NO/ O2/ONOO- balance that is close to redox state, which is a
      characteristic of endothelium impaired function disorders. Endothelium-derived NO is a
      vasodilator and inhibits monocyte adhesion and platelet activity and therefore is important
      in the maintenance of vascular homeostasis. These specific differences in OS could be a
      contributing mechanism to the high prevalence of cardiovascular disease, especially
      hypertension and heart failure, observed in AA. Aging causes increases in OS, endothelial
      dysfunction, and decreased arterial compliance, thus increasing the risk of cardiovascular
      disease. Acute supra-physiological dosages of antioxidants have been shown to transiently
      restore endothelial function in older adults and patients with coronary artery disease and
      hypertension by scavenging free radicals.However, it is unknown if acute antioxidant
      supplementation can diminish differences in vascular function between AA and Caucasians (CA).
      It is also unknown if acute antioxidant supplementation with known efficacy will
      differentially affect blood flow in AA vs CA during exercise.
    

Intervention name(s): Antioxidant; Placebo
Intervention type(s): Dietary Supplement; Other
Intervention description(s): Comparison of antioxidant supplementation with a placebo. Effects of race and age and race in repsonse to the supplementation will be evaluated.; Comparison of antioxidant supplementation with a placebo. Effects of race and age and race in repsonse to the supplementation will be evaluated.
Other intervention name(s): Vitamin E, Vitamin C, α-lipoic acid; No other names
Intervention MeSH terms: Vitamins; Vitamin E; Antioxidants
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Prevention
Keywords: antioxidants; Caucasians; healthy; African Americans; vascular; aging; racial differences