All tea – green, black and oolong, come from the same plant, Camellia sinensis. Green Tea is an anti-inflammatory and anti-cancer tool.
Green tea is made from unfermented leaves, black tea is made from fermented leaves and Oolong tea leaves are partially fermented. It’s the processing that makes the difference. While green tea has been studied the most, all of the teas have certain powerful anti-oxidants in common.
Oolong tea may rival green tea for its health benefits. The use of oolong tea dates back to almost 400 years in China. It is a partially fermented tea – the fermentation process is halted as soon as the tea leaves start to change their color.
Oolong tea is rich in antioxidants. It also contains important vitamins and minerals such as calcium, manganese, copper, selenium, and potassium, as well as Vitamin A, B, C, E and K. Additionally, it contains folic acid, niacin and other detoxifying alkaloids. The fermentation process adds numerous polyphenolic compounds – adding even more anti-inflammatory and anti-cancer value to the tea.
Oolong tea also contains caffeine, theophylline and theobromine all of which may stimulate the nervous system. It is possible to get decaffeinated oolong tea (as well as decaf green tea) if you are sensitive to caffeine.
Epigallocatechin gallate, (EGCG) is the catechin most present in tea and the catechin most studied for health benefits. EGCG is a powerful anti-oxidant with a high ORAC score and anti-inflammatory and anti-cancer characteristics. It has also been found to cause a higher production of regulatory T cells as we will see below.
Plant phenols are also known to have anti-allergenic effects. This study published in JAMA Dermatology noted a significant reduction of recalcitrant atopic dermatitis after drinking oolong tea for one month. Results were actually seen after 1 – 2 weeks in some patients.
An important study performed at Oregon State University (and other centers) found that green tea increased the number of regulatory T cells (T regs).
T regs are critically important for balance and regulation of the immune system so that it remains tolerant of harmless particles. When there are not enough T regs, or they do not function properly, the immune system can overreact, creating inflammation and leading to allergies and autoimmune conditions.
Emily Ho, an LPI principal investigator and associate professor in the OSU Department of Nutrition and Exercise Sciences said,
This appears to be a natural, plant-derived compound that can affect the number of regulatory T cells, and in the process improve immune function… when fully understood, this could provide an easy and safe way to help control autoimmune problems and address various diseases… and is of significant clinical importance for the suppression of autoimmune diseases(source)
In my experience, some people with autoimmunity react to green tea and should not have it. However, they may be able to tolerate oolong tea (or black tea), thereby gaining the health benefits inherent to these foods.
This study published in PLos One in 2013, showed that a newly discovered polyphenolic constituent of oolong tea called chafuroside B has a protective effect against UVB-induced DNA damage, cell death (apoptosis) and immuno-suppressing chemicals in cultured normal human skin cells (epidermal keratinocytes).
The researchers conclude,
Because oolong tea, which contains chafuroside B, could easily be consumed as a dietary supplement for skin photoprotection, these findings suggest that not only topical treatment but also routine consumption of chafuroside B in tea may provide a degree of protection against the harmful effects of solar UV radiation in humans. A study of the in vivo effects of chafuroside B seems warranted.
This could be the start of a more natural approach to skin care and skin protection from the sun. I can imagine myself catching some rays while drinking an iced oolong tea – can’t you?
There are literally hundreds of research papers that have been published regarding green, black and oolong tea and cancer prevention.