The investigators long-term goal is to better understand novel interventions to promote cardiovascular health in humans. The goal of the proposed research is to investigate whether there is sex-specificity in the effects of dietary capsaicin on mechanisms regulating nitric oxide (NO) bioavailability, its effect on key markers of cardiovascular (CV) health, including BP, macro- and microvascular function, and arterial stiffness. This knowledge will provide critical insight into the effects of dietary capsaicin on CV health and will guide future trials.

Specific Aim 1: Determine the sex-specific effects of dietary capsaicin on central and peripheral blood pressure and arterial stiffness. The investigators hypothesize that dietary capsaicin intervention (6 week) will improve BP and arterial stiffness, likely in a sex-dependent manner. The investigators will measure heart rate variability and excretion of capsaicin and metabolites to ascertain bioavailability, and understand the mechanistic role of the autonomic nervous system, in capsaicin's effect on BP.

Specific Aim 2: Assess whether dietary capsaicin effects on vascular function is sex-specific. The investigators hypothesize that dietary capsaicin intervention (6 week) will improve NO bioavailability, through improved redox balance and lowered asymmetric dimethylarginine, thereby improving peripheral vascular function, likely in a sex-dependent manner.

Utilizing a double-blind, randomized, placebo-controlled, design the investigators will investigate whether there is sex-specificity in the effects of a 6-week dietary capsaicin intervention on nitric oxide (NO) bioavailability, BP, vascular function, and arterial stiffness.

Inclusion Criteria:

• relatively healthy (other than elevated blood pressure) non-smoking men and women over the age of 18 from the local community

Exclusion Criteria:

• Women who are without a period (not due to a birth control method, intrauterine device or menopause), are pregnant, attempting to conceive, or are breastfeeding will be excluded.
• uncontrolled hypertension
• Anyone with severe illness or compromised or suppressed immune system (e.g. taking immune suppressants, chronic viral infection or treatment).
• Any participants with excessive sensitivity to spicy foods or fiber (psyllium husk) will be excluded
• Participants with food allergies will be excluded
• Participants who have difficulty swallowing or swallowing pills may be excluded.
• Participants who suffer from heartburn, hiatal hernia, gastritis, or peptic ulcer disease may be excluded.

Only deidentified data may be shared with the sponsor or research community through appropriate data repositories.

The capsules will be placed into solid white color bottles, and labeled discreetly by a third party not directly involved with the research.