Inorganic Nitrate Supplementation on Cerebrovascular Aging and Arterial Stiffness Study

Prior treatment

• Currently taking medications that may affect cerebral blood flow (e.g. papaverine, indomethacin, acetazolamide, etc) or efficacy of beetroot juice (proton pump inhibitors)
• Current clinically abnormal thyroid function not adequately regulated by thyroid hormone supplementation or medication.
• Unwillingness to wash out from a vitamin or dietary supplement regime prior to enrollment and maintain throughout the duration of the study.
• Inability to fast or hold morning medications doses until after testing is complete.
• Currently enrolled in another study using an study medication, supplement, device or intervention.

Other illness

• Current or history of cardiovascular disease disease (heart attack, stroke, heart failure, cardiomyopathy or peripheral artery disease, heart angioplasty/stent or bypass surgery, valve replacement, carotid endarterectomy, heart transplant.
• Medical history of stroke or other neurological disorder or systemic illness that could potentially affect cognition or brain function (outside of a diagnosis of Mild Cognitive impairment, Alzheimer's Disease) or could affect their safety or comfort while undergoing the imaging or cardiovascular studies.
• Subjects with evidence of cardiovascular disease at baseline or during the exercise test (evidence of myocardial infarction, abnormal cardiac arrhythmia, myocardial ischemia, conduction delays, \>1mm S-T segment depression or elevation; \>3 beat ventricular tachycardia; atrial fibrillation) will be excluded from the study.
• Wilson's disease, hemochromatosis
• Medical history of chronic major psychiatric or current diagnosis of major psychiatric disease (other than dementia).
• Systemic illness or neurological disorder potentially affecting cognition or cerebral blood flow other than mild cognitive impairment
• Unable to provide informed consent due to cognitive impairment
• Allergic to beets
• Current tobacco user or history of tobacco use within the past 3 months (cigarettes, cigars, chewing tobacco, hookah, electronic cigarettes) or living with someone who smokes/has smoked in the past 3 months.
• Current diagnosis of insulin-dependent diabetes (Type I or insulin dependent Type II)
• Current diagnosis of chronic obstructive lung disease, cystic fibrosis, emphysema, chronic bronchitis
• History of renal failure, dialysis or kidney transplant
• Current diagnosis or history of liver disease or HIV/AIDS, or cancer (other than non-melanoma skin cancers).
• Current diagnosis or history of rheumatoid arthritis, systemic lupus erythematosus, Wegener's granulomatosis
• Uncontrolled intercurrent illness that would limit compliance with study requirements per investigator.

Other

• Individuals taking clonidine or other short-acting beta blocker
• Resting blood pressure \> 200/ 110 mmHg or systolic \<90 mmHg
• Vulnerable populations (prisoners, etc) will not be eligible.
• Inability to comply with experimental instructions.
• Hormone replacement use within the past 6 months

• Age 50-79 years
• Cognitively healthy, having mild cognitive impairment
• Able to undergo cardiovascular testing procedures including fasting overnight and holding selected morning medication doses.
• Ability to understand and willingness to sign a written informed consent document.
• Ability to lie comfortably for up to 90 minutes
• Women only: Post-menopausal