The Health Benefits of Oolong Tea

Oolong Tea

Made from the leaves of the Camellia sinensis plant, oolong tea is semi-oxidized, giving it a taste and color that fall somewhere between green and black tea. The unique processing methods used to create oolong tea result in a brew rich in antioxidants, vitamins, minerals, and amino acids. Research has shown that regularly drinking oolong tea may provide several health advantages.

Weight Loss and Obesity Prevention

Studies show oolong tea can help with weight loss and fighting obesity.

  • A 1999 study showed enhanced fat breakdown through its caffeine content. Caffeine stimulates lipolysis or fat breakdown in fat cells. This indicates that oolong may be useful for fatty liver disease and obesity.
  • A 2005 study found that polymerized polyphenols from oolong tea inhibited pancreatic lipase, an enzyme needed to absorb fat. This suggests the polyphenols may hinder fat absorption.
  • A 2007 study on animals found that oolong extracts reduced weight gain without affecting how much they ate.
  • A 2009 clinical trial gave overweight and obese subjects oolong extracts. After 12 weeks, those taking the extract had significant decreases in body fat. The fat-burning effects were attributed to oolong’s antioxidants targeting lipid metabolism.

Research suggests that oolong and its parts can help break down fat, decrease fat absorption, and reduce body fat. The polyphenols appear to be key compounds contributing to oolong’s anti-obesity potential.

Oolong tea leaves

Diabetes Control

Studies have also looked at oolong’s benefits for managing blood sugar in those with diabetes or high blood sugar.

  • A 2003 study of people with type 2 diabetes found that drinking oolong tea significantly lowered blood sugar levels.
  • A 2011 observational study in Japanese men found that long-term oolong tea consumption was associated with a lower risk of developing diabetes.
  • Test tube studies show that oolong tea polysaccharides may have anti-diabetic effects through inhibiting the enzyme alpha-amylase. This enzyme breaks down carbohydrates into simple sugars.
  • Animal studies also indicate the polyphenols in oolong tea may increase insulin sensitivity and plasma adiponectin, a hormone involved in blood sugar regulation.

The compiled research suggests oolong tea may be valuable for managing diabetes and blood sugar spikes. The Oolong tea polysaccharides, polyphenols and bioactive compounds appear to act through various mechanisms related to insulin function and carbohydrate digestion.

Oolong tea health benefits infographic

Cancer Prevention

Researchers have extensively studied the potential cancer-fighting abilities of the antioxidant polyphenols in oolong tea, particularly epigallocatechin gallate (EGCG).

  • Lab tests show that EGCG from oolong tea can stop cancer cells from growing and spreading, and even kill them.
  • Oolong tea or EGCG may stop tumor growth, shrink tumors, and prevent cancer from spreading or coming back.
  • Drinking more oolong tea is linked to lower chances of getting breast, ovarian, head and neck, stomach, and colorectal cancers.

Oolong tea’s polyphenols fight cancer in multiple ways. They act as antioxidants, causing cancer cells to die. They also change how cancer cells communicate and make chemotherapy more effective.

Heart and Brain Health

Regular oolong consumption may also improve heart and brain health.

  • A 2004 study found drinking oolong tea daily for more than a year lowered the risk of developing high blood pressure by 46% in Chinese adults at risk for hypertension.
  • In 2001, a study discovered that specific compounds in oolong tea have the ability to prevent damage to blood cells. This finding suggests that consuming oolong tea may potentially lower the risk of heart disease.
  • Drinking oolong tea for a long time can lower LDL cholesterol, total cholesterol, and triglyceride levels, according to studies. This may reduce buildup in the arteries.
  • L-theanine in oolong tea can reduce stress and anxiety and boost alpha brain waves. This may sharpen focus and improve mental alertness.

The antioxidants and bioactive components in oolong tea appear to strengthen heart and brain function through various biological mechanisms. However, high-quality clinical trials are still needed.

Safety and Potential Risks

Oolong tea is generally very safe, especially when consumed in normal food amounts. However, there are some risks to keep in mind:

  • Drinking concentrated oolong on an empty stomach may irritate the stomach. It’s best to avoid overindulging.
  • The caffeine in oolong tea may cause headaches, anxiety and insomnia in sensitive people. Moderate your caffeine intake.
  • High amounts of fluoride from oolong and other sources over time can lead to bone and tooth fluorosis, causing problems.
  • The polyphenols may bind to iron, inhibiting its absorption. People at risk of iron deficiency should avoid drinking oolong tea with meals.
  • Oolong tea contains oxalate, which can increase the risk of kidney stones in susceptible individuals. Those prone to kidney stones should limit intake.
  • Excessive oolong tea intake may cause mineral deficiencies or interactions with certain medications. Consult a doctor about potential interactions.

Moderation is key in brewing and drinking oolong tea. Consuming around 2-3 cups per day appears safe and beneficial for most people. But it’s also wise to listen to your own body’s responses.


What are the benefits of Oolong tea?


1999 study on oolong tea and fat breakdown:

Han, L.K., Takaku, T., Li, J., Kimura, Y., Okuda, H. Anti-obesity action of oolong tea. International Journal of Obesity, 1999 Jan;23(1):98-105.

2005 study on oolong tea polyphenols and pancreatic lipase:

Nakai M, Fukui Y, Asami S, Toyoda-Ono Y, Iwashita T, Shibata H, Mitsunaga T, Hashimoto F, Kiso Y. Inhibitory effects of oolong tea polyphenols on pancreatic lipase in vitro. Journal of Agricultural and Food Chemistry, 2005 Jul 27;53(15):4593-8.

2009 clinical trial on oolong tea extract and body fat:

He RR, Chen L, Lin BH, Matsui Y, Yao XS, Kurihara H. Beneficial effects of oolong tea consumption on diet-induced overweight and obese subjects. Chinese Journal of Integrative Medicine, 2009 Feb;15(1):34-41.

2003 study on oolong tea lowering blood sugar:

Hosoda K, Wang MF, Liao ML, Chuang CK, Iha M, Clevidence B, Yamamoto S. Antidiabetic effects of oolong tea in type 2 diabetes. Diabetes Care, 2003 Jun;26(6):1714-8.

2011 observational study on oolong tea and diabetes risk:

Hayashino Y, Fukuhara S, Okamura T, Tanaka T, Ueshima H. High oolong tea consumption predicts future risk of diabetes among Japanese male workers: a prospective cohort study. Diabetes Medicine, 2011 Aug;28(8):965-9.

For an overview of the different types of tea please follow this link.

For the health benefits of other teas, please follow these links:

Tea Health

Black tea health benefits

Green tea health benefits

White tea health benefits

Puerh tea health benefits

Herbal tea health benefits