Oolong tea is a product made from the leaves, buds, and stems of the Camellia sinensis plant. This is the same plant that is also used to make black tea and green tea. The difference is in the processing. Oolong tea is partially fermented, black tea is fully fermented, and green tea is unfermented.
Oolong tea is used to sharpen thinking skills and improve mental alertness. It is also used to prevent cancer, tooth decay, osteoporosis, and heart disease.
Some people use oolong tea to treat obesity, diabetes, “hardening of the arteries” (atherosclerosis), high cholesterol and skin allergies such as eczema; and to boost the immune system.
How does it work?
Oolong tea contains caffeine. Caffeine works by stimulating the central nervous system (CNS), heart, and muscles. Oolong tea also contains theophylline and theobromine, which are chemicals similar to caffeine.
Uses & Effectiveness
Likely Effective for…
Mental alertness. Drinking oolong tea or other caffeinated beverages throughout the day seems to maintain alertness and mental performance. Combining caffeine with sugar as an “energy drink” seems to improve mental performance better than either caffeine or sugar alone.
Possibly Effective for…
Preventing ovarian cancer. Women who regularly drink tea, including black tea, green tea, or oolong tea, appear to have a significantly lower risk of developing ovarian cancer. One study found that drinking 2 or more cups of tea daily seems to cut ovarian cancer risk by almost half.
Insufficient Evidence to Rate Effectiveness for…
Treating skin allergies (eczema). Developing research suggests that drinking about 4 cups (34 oz or 1000 mL) of oolong tea per day in 3 divided doses improves eczema that hasn’t responded to other treatments. It may take 1 or 2 weeks of treatment to see improvement.Treating diabetes. Some research suggests that drinking about 6 cups (50 oz or 1500 mL) of oolong tea for 30 days might lower blood sugar in people with type 2 diabetes. However, tea drinking doesn’t seem to prevent diabetes.
Preventing high blood pressure. Some research in Chinese people shows that drinking 1 or 2 cups (4-20 oz or 120-599 mL) of oolong tea or green tea daily seems to prevent high blood pressure. Drinking more tea seems to lower the risk even more.Weak bones (osteoporosis). There is some evidence that drinking oolong tea for 10 years is associated with stronger bones (increased bone mineral density).Promoting weight loss.Preventing tooth decay.Reducing the risk of cancer.Other conditions.More evidence is needed to rate the effectiveness of oolong tea for these uses.
Too much oolong tea, more than five cups per day, can cause side effects because of the caffeine. These side effects can range from mild to serious and include headache, nervousness, sleep problems, vomiting, diarrhea, irritability, irregular heartbeat, tremor, heartburn, dizziness, ringing in the ears, convulsions, and confusion.
Special Precautions & Warnings:Pregnancy and breast-feeding: If you are pregnant or breast-feeding, oolong tea in small amounts is probably not harmful. However, do not drink more than 2 cups a day of oolong tea. That amount of tea contains about 200 mg of caffeine. Too much caffeine during pregnancy might cause premature delivery, low birth weight, and harm to the baby. Too much caffeine during breast-feeding might cause irritability and increase bowel movements in nursing infants.
Children: Caffeine is probably safe in children in amounts commonly found in foods.
Anxiety disorders: The caffeine in oolong tea might make anxiety disorders worse.
Bleeding disorders: Some research suggests that caffeine might slow blood clotting. Though this research was not done in humans, there is still some concern that caffeine might make bleeding disorders worse.
Heart conditions: Caffeine in oolong tea can cause irregular heartbeat in some people.
Diabetes: Some research suggests that the caffeine in oolong tea may affect the way people with diabetes process sugar and may complicate blood sugar control. Caffeine has been reported to both increase and decrease blood sugar. There is also some interesting research that suggests caffeine may make the warning signs of low blood sugar in people with type 1 diabetes more noticeable. This might increase the ability of people with diabetes to detect and treat low blood sugar. However, the downside is that caffeine might actually increase the number of low-sugar episodes. If you have diabetes, talk with your healthcare provider before using oolong tea.
Diarrhea. Oolong tea contains caffeine. The caffeine in oolong tea, especially when taken in large amounts, can worsen diarrhea.
Irritable bowel syndrome (IBS): Oolong tea contains caffeine. The caffeine in oolong tea, especially when taken in large amounts, can worsen diarrhea and might worsen symptoms of IBS.
Glaucoma: The caffeine in oolong tea increases the pressure inside the eye. The increase occurs within 30 minutes and lasts for at least 90 minutes.
High blood pressure: The caffeine in oolong tea might increase blood pressure in people with high blood pressure. However, this doesn’t seem to happen in people who regularly drink oolong tea or other caffeinated products.
Weak bones (osteoporosis): Drinking oolong tea can flush out calcium in the urine. That can affect bone health. If you have osteoporosis, don’t drink more than 3 cups of oolong tea per day. Consider taking calcium supplements to make up for the calcium that is flushed out. If you have a genetic condition that harms the way your body processes vitamin D, get medical advice before consuming a lot of caffeine.
AmphetaminesInteraction Rating: Major Do not take this combination.
Stimulant drugs such as amphetamines speed up the nervous system. By speeding up the nervous system, stimulant medications can make you feel jittery and increase your heart rate. The caffeine in oolong tea might also speed up the nervous system. Taking oolong tea along with stimulant drugs might cause serious problems including increased heart rate and high blood pressure. Avoid taking stimulant drugs along with oolong tea.
CocaineInteraction Rating: Major Do not take this combination. Read More