Oolong tea is made from Camellia sinensis leaves -- the same type of tea leaves that are used to make green, white and black tea. The difference between oolong and the other teas is the amount of time the leaves are allowed to ferment, or oxidize, according to the Linus Pauling Institute. Oolong tea leaves are oxidized longer than the leaves used for green and white teas but less than the leaves used for black tea. Drinking tea regularly may benefit cardiovascular health and help control blood sugar.
Oolong and other teas contain polyphenols -- a type of plant-based compounds that generally have antioxidant properties. Flavonoids are a subclass of polyphenols and commonly associated with cardiovascular health benefits. Tea flavonoids may prevent oxidation of "bad" LDL cholesterol and increase "good" HDL cholesterol levels, according to Harvard Health Publications. This can help prevent formation of cholesterol plaques, improve artery function, lower blood pressure and help prevent heart disease. In a study of 1,500 adults, drinking between 4 and 20 ounces of green or oolong tea a day for a year resulted in a 46 percent lower risk of subsequently developing high blood pressure. The study was published in the July 26, 2004 issue of "Archives of Internal Medicine."
In addition to flavonoids, oolong tea contains other polyphenols that are not found in green or black tea and may help lower your blood sugar, according to Dr. David Shafer, a professor of medicine at the University of Texas at Tyler. In a study published in the June 2003 issue of "Diabetes Care," 20 participants with Type 2 diabetes drank 1.5 quarts of oolong tea per day for a month to test its health benefits. Compared to drinking plain water, drinking oolong tea produced 29 percent lower blood glucose levels.
Oolong tea contains a specific group of flavonoids called catechins. Catechins may, in some instances, slow the growth of cancer cells, according to the National Cancer Institute. Animal studies have shown catechins to be effective cancer-fighting agents. They are able to eliminate free radicals before they cause cell damage and reduce the size of chemically-induced tumors. Human studies, however, have shown opposing outcomes. Some studies show promising results where catechins in tea may help treat and prevent cancer, while others demonstrate no effectiveness. The National Cancer Institute cites these disparities as most likely the result of environmental, dietary and lifestyle differences among the subjects studied.
- Linus Pauling Institute: Tea
- Harvard Health Publications: Benefit of Drinking Green Tea - The Proof is In - Drinking Tea is Healthy, Says Harvard Women’s Health Watch
- University of Texas Health Sciences Center at Tyler: Oolong Tea - A Drink to Your Health?
- National Cancer Institute: Tea and Cancer Prevention - Strengths and Limits of the Evidence
- Archives of Internal Medicine: The Protective Effect of Habitual Tea Consumption on Hypertension
- Diabetes Care: Antihyperglycemic Effect of Oolong Tea in Type 2 Diabetes
- GREEN TEA image by Pafnuty Khlystun from Fotolia.com
This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.