By: Lauren Kolacki
Oolong tea extract has ‘great potential’ in the prevention of breast cancer, scientists believe because it was shown to stop tumors from growing at a lab at St. Louis University.
Laboratory tests showed the Chinese tea, used for centuries for its supposed health benefits, stopped the growth of breast cancer cells. Researchers found the extract hampered the DNA of the cancer cells, inhibiting the growth and progression of tumors.
Green tea showed similar promise, the scientists said. However, black and dark tea had little effect on the cells.
Scientists at St Louis University, Missouri, also analyzed the rates of breast cancer and deaths from the disease across China.
Their analysis found regions with high oolong tea consumption had generally lower rates of the disease.
The team now says the tea offers promise as a non-toxic approach to prevent breast cancer, which one in eight women will develop in their lifetime.
Researchers, led by Dr. Chunfa Huang, examined the effect of oolong tea extract on six breast cancer cell lines. “Green and oolong tea extracts prohibited breast cancer cell growth in all six breast cancer cell lines,” Dr. Huang says.
The team said, “From our results, oolong tea, much like green tea, plays a role in inhibiting breast cancer cell growth, proliferation and tumor progression.”
Oolong tea originates from China. Any tea that has been oxidized between eight and 85 percent (semi oxidized) can be considered an oolong tea. Tea oxidation is one of many steps in the production of oolong tea. As soon as you pluck a tealeaf, it starts to oxidize. Black teas are fully oxidized whereas green teas are hardly oxidized at all. Oolong, also known as ‘black dragon tea’ falls into the middle.
A cup would contain caffeine, vitamins, minerals, amino acids and beneficial tea polyphenol antioxidants, according to USDA Food Composition Databases.
These properties all have potential for health benefits including weight loss, brain function, heart health and diabetes prevention. But their efficacy in tea needs more research.
Oolong tea is mostly produced in China, where people have been using it for its supposed medicinal purposes for a historic period of time. Therefore, the scientists also looked at 2014 data from the Chinese and Fujian province cancer registry annual report. They found that the incidence of breast cancer in the Fujian province was 35 percent lower than the national average.
Those who drank the most oolong tea had a 25 percent lower incidence compared to the average Fujian, and 50 percent lower than the national average.
They also appeared to have a lower mortality rate – the death rate of high consumers of oolong tea in Fijian was 68 percent lower than the national average, according to the findings published in the journal Anticancer Research.
“It is clear that more study is needed,” Dr. Huang said. “The lower incidence and mortality in regions with higher oolong tea consumption indicate that oolong tea has great potential for its anti-cancer properties.”
More than 250,000 women in the U.S. were diagnosed with breast cancer in 2018, and around 41,000 die from the illness each year. Prevention and early diagnosis are key to improving future health prospects.