Interpretive Summary: Hypertension is one of the leading risk factors of cardiovascular diseases. Factors that improve insulin often also improve hypertension. Cinnamon has been shown to improve insulin, cholesterol, triglycerides and related factors associated with cardiovascular diseases in humans and experimental animals. The purpose of the present study was to examine the effects of dietary cinnamon on blood pressure in a strain of rats with increased sensitivity to eating sucrose or sugar. Addition of cinnamon to the diets of rats consuming added sugar reduced the sugar-induced blood pressure to virtually the same level as that of rats not consuming sugar. The addition of cinnamon to the diet also decreased the blood pressure of rats not consuming sugar suggesting that cinnamon reduces more than just sugar-induced blood pressure elevations but perhaps a genetic component(s) of the elevated blood pressure as well. The effects of cinnamon improved with increasing amounts. Cinnamon is used for flavor and taste in food preparation, but cinnamon may have additional roles in the control of hypertension. It may be possible to aid in controlling hypertension by not only limiting the amounts of dietary substances that have negative effects but also the addition of beneficial ones, such as cinnamon, that have positive effects on hypertension. This work will be of importance to the scientific and medical communities but also to the millions of people who take drugs to control hypertension.

Technical Abstract:
Many agents (nutrients, nutraceuticals, and drugs) that favorably influence the insulin system by enhancing insulin sensitivity and/or reducing circulating insulin concentrations have been shown to lower blood pressure (BP). Recently, it was reported that cinnamon has the potential to favorably influence the glucose/insulin system. The purpose of the present study was to examine the effects of dietary cinnamon on blood pressure, and various glucose- and insulin-related parameters in spontaneously hypertensive rats (SHR) consuming diets with added sucrose. The latter is associated with insulin resistance and the elevation of BP. Addition to diets of cinnamon (8% w/w) reduced the systolic BP of rats eating sucrose to virtually the same levels as SHR consuming starch. The presence of cinnamon in the diet also decreased the systolic BP of SHR consuming starch, suggesting that cinnamon reduces more than just sucrose-induced BP elevations, perhaps a genetic component(s) of the elevated BP as well. The effects of cinnamon on systolic BP were dose-dependent. Cinnamon did not decrease the levels of blood glucose, but did lower circulating insulin concentrations. Aqueous extracts of cinnamon also decreased systolic BP and lowered the circulating levels of fructosamine. Cinnamon is used for flavor and taste in food preparation, but cinnamon may have additional roles in glucose metabolism and BP regulation. It may be possible to aid in BP regulation by not only limiting the amounts of dietary substances that have negative effects on BP and insulin function but also the addition of beneficial ones, such as cinnamon, that have positive effects on insulin function and BP.