Since the American public became aware of the cancer-fighting properties of green tea, its sales have increased dramatically in the United States. Clinical research has not devoted as much attention to the preventive benefits of oolong tea, but a study published in a 2007 issue of the "International Journal of Molecular Sciences" indicates that oolong does have antioxidant properties, and that the right infusion time and water temperature can enhance its antioxidant content.
Significance
Green tea has a long history in the healing traditions of China and India, but its popularity in Western culture has been relatively recent, according to the National Library of Medicine. Since the discovery of antioxidants--naturally occurring substances that protect cells against the genetic alterations caused by toxic compounds--and their high concentration in green tea, this beverage has surpassed both black and oolong tea in American sales. Green tea is rich in polyphenols, plant-based antioxidants that may prevent a wide range of cancers, lower cholesterol and blood glucose levels, promote liver health and reduce gastrointestinal inflammation, according to the University of Maryland Medical Center, or UMMC.
Antioxidant Content
Green tea and oolong tea both come from the leaves of the same plant: the Camellia sinensis. Oolong tea leaves are partially fermented, while green tea leaves are not fermented. Fermentation reduces the concentration of antioxidant compounds, or polyphenols, in oolong tea. Although both forms of tea are rich in antioxidant compounds, the concentration of polyphenols is higher in green tea, according to the UMMC.
Green Tea Benefits
The UMMC recommends drinking two to three cups of green tea each day, for a total of 240 to 320 mg of polyphenols, to reap the benefits of its antioxidant compounds. The polyphenols in green tea may help destroy malignant cells and slow or prevent the formation of tumors. Drinking green tea may reduce the effects of free radicals, harmful compounds that can damage healthy cells and cause cancer, heart disease or premature aging.
Oolong Tea Benefits
A study published in a 2007 issue of the "International Journal of Molecular Sciences" reported that the antioxidant activity of oolong tea was increased when the tea was infused for three minutes at 100 degrees Celsius, or 212 degrees Fahrenheit. These results suggest that steeping oolong tea in boiling water for three minutes may enhance the cancer-fighting benefits of the tea. The study emphasizes that oolong tea is rich in polyphenols that may help prevent cancer and heart disease and reduce the effects of aging.
Considerations
In addition to antioxidant compounds, both oolong tea and green tea contain caffeine, which may cause side effects such as irritability, insomnia or heart palpitations. The longer tea leaves are fermented, the more caffeine the tea contains. Because green tea leaves are not fermented, their caffeine content--about 26 mg per 6-oz. cup--is lower than either oolong or black tea. Consult your health care provider before taking green tea for medicinal purposes if you have a heart condition, kidney disease or chronic anxiety.
References
- University of Maryland Medical Center: Green Tea
- "International Journal of Molecular Sciences"; Polyphenolic Profile and Antioxidant Activities of Oolong Tea Infusion under Various Steeping Conditions; Xinguo Su, Ph.D., et al.; 2007
- MayoClinic.com: Caffeine Content for Coffee, Tea, Soda and More
- National Library of Medicine: Tempest in a Teapot: Tea & Politics & Health, Green Tea's Medical Resurgence
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