TSUKUBA, Japan — Want to lose weight but don’t have the time to exercise all day? A new study finds a nice cup of tea can help do it for you — while you sleep! Researchers from the University of Tsukuba in Japan say drinking oolong tea increases the breakdown of fat and continues to work even when a person is resting.
Professor Kumpei Tokuyama finds drinking two cups of oolong tea each day significantly stimulates fat burning processes in the body.
“Like all teas, oolong contains caffeine, which impacts energy metabolism by increasing our heart rate. However, studies suggest that tea consumption may also increase the breakdown of fat, independent of the effects of caffeine,” the senior study author explains in a university release. “We therefore wanted to examine the effects of oolong consumption versus caffeine alone on energy and fat metabolism among a group of healthy volunteers.”
What’s so different about oolong tea?
Although all types of tea come from the same plant, Camellia sinensis, their degree of oxidation determines what variety ends up in your cup. This chemical process is what turns tea leaves black. The degree of oxidation, which ranges from 8% to 85%, determines the color and taste of the tea. This can range from light to full-bodied, floral to grassy, and sweet to toasty.
Oolong tea, largely produced in China and Taiwan, falls between green and black tea in terms of oxidation and flavor. It’s characterized by a unique process that includes withering the plant under the strong sun and oxidizing before curling and twisting.
Health experts consider tea to be extremely health, especially green tea, but study authors say oolong has been more of a mystery until now. Like other types of tea, oolong tea contains several vitamins, minerals, and helpful antioxidants. A cup of brewed tea will also contain caffeine, about a third the amount in a cup of coffee.
Drinking oolong tea could have benefits for heart health, brain health, bone health, and dental health, and it may help with weight management, though more research, similar to this study, is needed in many of these areas.
Burning fat without losing any sleep
For this study, scientists tested a group of healthy volunteers drinking either oolong tea, pure caffeine, or a placebo for two weeks. The results reveal participants drinking oolong tea or caffeine increased their breakdown of fat by 20 percent compared to the control group. Researchers note that the effects of oolong tea keep going after the participant goes to sleep.
Surprisingly, neither tea nor caffeine causes an increase in energy expenditure. Study authors say this shows the group developed a tolerance to the caffeine present in both drinks over the two weeks.
Since caffeine typically affects sleep, and losing sleep can impact your metabolism, the study also examined each person’s sleep quality during the experiment. Despite caffeine’s reputation for keeping people awake, researchers discovered there was no difference in the sleep patterns of the test group or the placebo group. Therefore, the team believes drinking a cup of oolong tea won’t keep you up all night and may help burn off some of those extra holiday pounds.
“The stimulatory effects of oolong tea on fat breakdown during sleep could have real clinical relevance for controlling body weight. However, we need to determine whether the effects we observed in the 2-week study translate into actual body fat loss over a prolonged period. In addition, we want to trial a decaffeinated oolong tea to better distinguish the effects of caffeine from other components of tea, which will help us understand exactly how oolong helps with fat breakdown,” Prof. Tokuyama concludes.
The study appears in the journal Nutrients.
This article has been updated from its original publication on Jan. 8, 2021.