- What is oolong tea
What is oolong tea
Oolong tea is a traditional Chinese tea (Camellia sinensis) produced through a process including withering the plant under strong sun and oxidation before curling and twisting 1). The name oolong tea came into the English language from the Chinese name (wūlóng chá), meaning “black dragon tea”. In Chinese, oolong teas are also known as qingcha or “dark green teas”.
Most oolong teas, involve unique tea plant cultivars that are exclusively used for particular varieties. The degree of oxidation can range from 8–85%, depending on the variety and production style. Oolong is especially popular in south China and Chinese expatriates in Southeast Asia 2). The manufacture of oolong tea involves repeating stages to achieve the desired amount of bruising and browning of leaves. Withering, rolling, shaping, and firing are similar to black tea, but much more attention to timing and temperature is necessary 3).
Different styles of oolong tea can vary widely in flavor. They can be sweet and fruity with honey aromas, or woody and thick with roasted aromas, or green and fresh with complex aromas, all depending on the horticulture and style of production. Several types of oolong tea, including those produced in the Wuyi Mountains of northern Fujian, such as Da Hong Pao, are among the most famous Chinese teas. Different varieties of oolong are processed differently, but the leaves are usually formed into one of two distinct styles. Some are rolled into long curly leaves, while others are ‘wrap-curled’ into small beads, each with a tail. The former style is the more traditional.
Does oolong tea have caffeine
Yes. Oolong tea has 16 mg of caffeine per 100 gram of oolong tea leafs. However, the caffeine content in Oolong tea will vary based on environmental factors, farming practices and the tea’s specific growth habitat when the tea leaf is plucked and the production processes.
Moreover, to put Oolong tea caffeine content into perspective, we have included a table below to show you the typical caffeine content in popular beverages. Drink sizes are in fluid ounces (oz.) and milliliters (mL). Caffeine is shown in milligrams (mg).
Keep in mind that the actual caffeine content of a cup of coffee or tea can vary considerably because of factors such as origin, processing and preparation method, including brewing time. So use these numbers as a guide.
The Dietary Guidelines for Americans 4) recommends that women who are pregnant and those who are breast-feeding check with their health care providers for advice concerning caffeine.
The Dietary Guidelines for Americans doesn’t include guidelines for safe caffeine consumption for children. However, the American Academy of Pediatrics takes the position that stimulant-containing energy drinks have no place in the diets of children or adolescents.
Table 1. Caffeine content for coffee, tea, soda and more 5)
|Beverages||Size in oz. (mL)||Caffeine (mg)|
|Brewed, decaf||8 (237)||2-5|
|Espresso, decaf||1 (30)||0|
|Instant, decaf||8 (237)||2|
|Latte or mocha||8 (237)||63-126|
|Brewed black||8 (237)||25-48|
|Brewed black, decaf||8 (237)||2-5|
|Brewed green||8 (237)||25-29|
|Ready-to-drink, bottled||8 (237)||5-40|
|Citrus (most brands)||8 (237)||0|
|Root beer (most brands)||8 (237)||0|
|Energy drink||8 (237)||27-164|
|Energy shot||1 (30)||40-100|
Oolong tea caffeine and nutrition facts
Table 2. Oolong tea (brewed) caffeine and nutrition facts
|Nutrient||Unit||Value per 100 g|
|Total lipid (fat)||g||0.00|
|Carbohydrate, by difference||g||0.15|
|Fiber, total dietary||g||0.0|
|Vitamin C, total ascorbic acid||mg||0.0|
|Vitamin A, RAE||µg||0|
|Vitamin A, IU||IU||0|
|Vitamin E (alpha-tocopherol)||mg||0.00|
|Vitamin D (D2 + D3)||µg||0.0|
|Vitamin K (phylloquinone)||µg||0.0|
|Fatty acids, total saturated||g||0.000|
|Fatty acids, total monounsaturated||g||0.000|
|Fatty acids, total polyunsaturated||g||0.000|
Oolong tea health benefits
After water, coffee and tea are the two most commonly consumed beverages on the planet. They are brimming with antioxidants, flavonoids, and other biologically active substances that may be good for health.
Research suggests that drinking at least three cups of either black or green tea per day reduces the risk of stroke 7) and cancer 8), 9).
The key to tea: Antioxidants
Polyphenols are likely the key component to what makes tea a healthy drink. These chemical compounds act as antioxidants, which fight against free radicals in the body. Free radicals can alter DNA by stealing its electrons, and this mutated DNA can increase LDL “bad” cholesterol or alter cell membrane traffic – both harmful to our health. Though green tea is often considered higher in polyphenols than black or oolong (red) teas, studies show that – with the exception of decaffeinated tea – all teas have about the same levels of these chemicals, albeit in different proportions.
While the antioxidant action of tea is promising, some research suggests that the protein and possibly the fat in milk may reduce the antioxidant capacity of tea 10). Flavonoids, the antioxidant component in tea, are known to bind to proteins and “de-activate,” so this theory makes scientific sense 11).
One study that analyzed the effects of adding skimmed, semi-skimmed, and whole milk to tea concluded that skimmed milk significantly reduced the antioxidant capacity of tea. The fattier milks also reduced the antioxidant capacity of tea, but to a lesser degree 12). Overall, it’s important to keep in mind that tea – even tea with milk – is a healthy drink. To reap the full antioxidant benefits of tea, however, it may be best to skip the milk.
Three big benefits of tea:
1. Reduced risk of cardiovascular disease
Polyphenols, the antioxidants abundant in tea, have been shown to reduce the risk of death due to cardiovascular disease (8), including stroke. (9,10) In one study of 77,000 Japanese men and women, green tea and oolong tea consumption was linked with lower risk of death from cardiovascular disease. (11) Other large-scale studies show that black tea also contributes to heart health 13), with research suggesting that drinking at least three cups of either black or green tea per day appears to reduce the risk of stroke by 21 percent. The study also stated that drinking tea may be one of the most significant changes a person can make to reduce his or her risk of stroke 14).
2. Protection from cancer
Research shows benefits for a variety of types of cancer, including ovarian and digestive system cancers 15). Green tea might also have a positive effect in reducing risk of breast, prostate, and endometrial cancers, though more evidence is needed 16).
3. Reduced risk of high blood pressure
In a study of green and oolong tea consumption, regular consumption for one year reduced the risk of developing hypertension 17). Long-term regular consumption of black tea has also been shown to lower blood pressure 18).
Be wary of weight-loss claims. Some advertisements claim that tea can speed weight loss, but research on the effects of green tea and fat reduction have shown little promise of weight loss benefits 19). Moreover, it’s best to skip any so-called “diet” teas that may contain potentially harmful substances such as laxatives.
Beware the bottle. Avoid purchasing expensive bottled teas or teas in coffee shops that contain added sweeteners. To enjoy the maximum benefits of drinking tea, consider brewing your own at home. You can serve it hot, or make a pitcher of home-brewed iced tea during warmer months.
Though further research is needed to confirm the benefits, recent studies show that tea holds promise in preventing cardiovascular disease, cancer, and hypertension – and that there are no serious risks associated with drinking it. So pick a color and pour a cup to maximize the health benefits.
References [ + ]
|1.||↵||Zhongguo Chajing pp222-234, pp419-412, & pp271-282, chief editor: Chen Zhongmao, publisher: Shanghai Wenhua Chubanshe (Shanghai Cultural Publishers) 1991.|
|2.||↵||Joseph Needham, Science and Civilization in China vol 6 part V 40f Tea Processing and Utilization, pp535-550 Origin and processing of oolong tea.|
|3.||↵||Donaldson, Babette (2014-01-01). The Everything Healthy Tea Book: Discover the Healing Benefits of Tea. “F+W Media, Inc.”. ISBN 9781440574597.|
|5.||↵||Caffeine content for coffee, tea, soda and more. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20049372|
|6.||↵||United States Department of Agriculture Agricultural Research Service. National Nutrient Database for Standard Reference Release 28. https://ndb.nal.usda.gov/ndb/search/list|
|7, 13, 14.||↵||Arab L, Liu W, Elashoff D. Green and black tea consumption and risk of stroke: a meta-analysis. Stroke. 2009;40:1786-92. http://stroke.ahajournals.org/content/40/5/1786.long|
|8.||↵||Lee AH, Su D, Pasalich M, Binns CW. Tea consumption reduces ovarian cancer risk. Cancer Epidemiol. 2013;37:54-9. https://www.ncbi.nlm.nih.gov/pubmed/23107758|
|9, 15.||↵||Nechuta S, Shu XO, Li HL, et al. Prospective cohort study of tea consumption and risk of digestive system cancers: results from the Shanghai Women’s Health Study. Am J Clin Nutr. 2012;96:1056-63. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3471195/|
|10, 12.||↵||Ryan L, Petit S. Addition of whole, semiskimmed, and skimmed bovine milk reduces the total antioxidant capacity of black tea. Nutr Res. 2010;30:14-20. https://www.ncbi.nlm.nih.gov/pubmed/20116655|
|11.||↵||Arts MJ, Haenen GR, Wilms LC, et al. Interactions between flavonoids and proteins: effect on the total antioxidant capacity. J Agric Food Chem. 2002;50:1184-7. https://www.ncbi.nlm.nih.gov/pubmed/11853501|
|16.||↵||Johnson R, Bryant S, Huntley AL. Green tea and green tea catechin extracts: an overview of the clinical evidence. Maturitas. 2012;73:280-7. https://www.ncbi.nlm.nih.gov/pubmed/22986087|
|17.||↵||Yang YC, Lu FH, Wu JS, Wu CH, Chang CJ. The protective effect of habitual tea consumption on hypertension. Arch Intern Med. 2004;164:1534-40. https://www.ncbi.nlm.nih.gov/pubmed/15277285|
|18.||↵||Hodgson JM, Puddey IB, Woodman RJ, et al. Effects of black tea on blood pressure: a randomized controlled trial. Arch Intern Med. 2012;172:186-8. https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/1108657|
|19.||↵||Jurgens TM, Whelan AM, Killian L, Doucette S, Kirk S, Foy E. Green tea for weight loss and weight maintenance in overweight or obese adults. Cochrane Database Syst Rev. 2012;12:CD008650. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD008650.pub2/full|