The Physiological Effects of Capsaicinoid Ingestion on Human Metabolism and Exercise Performance

Capsaicinoids (the active ingredient in hot peppers) have been shown to cause a moderate increase in energy expenditure (50 kcal/day) as well as reductions in appetite, energy intake, and (visceral) adiposity. As such, there is considerable interest in capsaicinoid for weight loss supplements. Of particular interest are the recent findings that free-fatty acids in the blood are elevated 2-2.5hrs post ingestion, yet changes in typical cardiovascular or sympathetic nervous tone indicators (heart rate, blood pressure) were unaffected, suggesting some of the negative consequences of other stimulants may be avoided. At present, however, more in depth investigations of the effects on endothelial function, vascular autonomic tone and inflammation are lacking.

The investigators seek to understand the effect of 3 months capsaicinoid ingestion on alterations in body composition, traditional cardiovascular risk factors and cardiovascular function

Hypotheses:

1. Continued use of capsaicinoids will alter resting metabolism substrate use, which will result in moderate (but clinically meaningful) alterations in body composition manifested as a decrease in adiposity. 2) Blood lipids will be unaffected by capsaicinoid use, as will brachial blood pressure. 3) Levels of systemic inflammation may increase slightly, and this could have an effect on vascular reactivity to hyperemic flow or baseline vascular tone. However, previous research suggests that these alterations will not be manifested in autonomic nervous tone assessed by changes in heart rate variability.