Cinnamon has a long history of medicinal and culinary use, and is proposed to improve health by fighting infections, preventing cancer, and by reducing levels of blood sugar, cholesterol -- and blood pressure. In fact, an analysis of 3 research trials demonstrated that short-term administration of cinnamon significantly reduced blood pressure in people with prediabetes and diabetes.

On average, as little as one-half teaspoon of cinnamon a day was of benefit. But not all studies have shown this spice improves blood pressure, and evidence-based data on the dose, safety and effectiveness of cinnamon in the management of hypertension -- and other medical conditions -- is lacking.

The reason cinnamon may help blood pressure is not fully understood, although more than one mechanism of action appears to be involved. Cinnamon is also a source of antioxidants and has anti-inflammatory properties, which can also be involved in controlling hypertension. Cinnamon's potential role in managing weight and blood sugars may also be a mechanism for blood pressure improvement, since obesity and diabetes are linked to hypertension.

There are different varieties of cinnamon, and the type seems to matter. While cassia cinnamon, commonly used as a spice and the type found in cinnamon pills, is most popular, the more expensive and milder Ceylon cinnamon is more likely to be found in health food stores. Both types have been shown to promote health benefits, but cassia cinnamon may not be as safe in large doses because it contains relatively high concentrations of coumarin, a natural blood thinning agent which can also be toxic to the liver.

A complicating factor in cinnamon research is that scientists have used both cassia and Ceylon varieties in their trials, with different doses and varying cinnamon compounds -- making it challenging to interpret how cinnamon works and how it can be used to manag e health conditions. In fact, the National Center for Complementary and Integrative Health concludes that at present, there is not enough data to support using cinnamon to manage any health conditions. Warnings Spicing up your foods and beverages with cinnamon is a great way to add flavor, and may even benefit your health. But if you plan to take cinnamon pills or use more than 1 teaspoon of cinnamon in your daily diet, a conversation with your doctor is in order -- particularly if you are under a doctor's care for any medical condition. Cassia cinnamon contains large amounts of coumarin, and supplementation with this spice may not be safe if you are on a blood thinning agent or if you have liver disease.