Oolong tea is one of the most popular teas in Asia.
Although the tea is still relatively unknown in the West, oolong tea has been grown and consumed in China for thousands of years.
Oolong tea is said to support health in various ways.
In this article I will elaborate on oolong tea and its possible health benefits and side effects.
What is oolong tea?
Oolong tea or oolong is a traditional Chinese tea. The Chinese name means ‘black dragon tea’.
It is made from the leaves of the tea plant known as Camellia sinensis . Green tea and black tea are also made from the same tea plant .
Where is the difference then? In the way oolong tea is made.
Oolong tea is half fermented (or oxidized) and black tea is fully fermented and the green tea leaves are not oxidized.
Oolong tea is mainly grown in Fukien, a province in Taiwan. Because the weather in Taiwan can be erratic, the quality of oolong tea also varies from season to season.
In terms of taste, oolong tea is more like green tea than black tea. Oolong tea is a delicious drink to try.
It is neither overly sweet nor bitter. It lacks the sweet aroma of black tea and has a fairly mild, fruity taste.
It is considered a low-calorie drink. It contains no carbohydrates, proteins or fats. Oolong tea contains a similar amount of caffeine as green tea.
Is oolong tea healthy?
Oolong tea is naturally rich in antioxidants.
It contains quite a few vitamins and minerals, including calcium, manganese, selenium, potassium and magnesium ( source ).
Oolong tea is rich in nicotinamide, one of the two forms of vitamin B3. In addition to caffeine, Oolong tea also contains the substances theobromine and theophylline. These are two chemicals that resemble caffeine.
Whether you are looking for a healthy thirst quencher or another healthy tea, oolong tea is worth adding to your diet.
How much caffeine is there in oolong tea?
On average, a cup of oolong tea contains around 30 mg of caffeine.
But remember that several factors influence the total amount of caffeine in oolong tea.
Consider how old the used tea leaves are and how long they have been brewing the tea. The longer the tea is brewed, the more caffeine content.
Buy Oolong tea?
Would you like to know where you can buy oolong tea? Then you don’t have to look any further. Oolong tea can be found in most supermarkets and drug stores. Even online it is easy to order.
Health benefits of oolong tea
With different teas you always hear a lot about their potential health benefits. These benefits are sometimes greatly exaggerated and do not always apply to people.
According to traditional Chinese medicine, drinking oolong tea provides the following health benefits:
- Improves the mind
- Prevents tooth decay
- Lowers risk of diabetes
- Reduces pain due to arthritis
- Promotes weight loss and lowers the risk of being overweight
- Lowers high cholesterol and blood pressure
- Strengthens the immune system
- Improved skin health
Although not all of these benefits are supported by scientific research, oolong tea does offer a number of beneficial effects on our health, which I will further explain below.
Advantage # 1: improvement of bone strength
Menopausal women in particular suffer from bone loss due to a decrease in the hormone estrogen.
This leads to conditions such as arthritis or osteoporosis.
Although the reasons are not entirely clear, it seems that drinking oolong tea can help women to maintain high bone density ( source ). In addition to being good for the bones, oolong tea also helps to prevent tooth decay.
Benefit # 2: good for the skin
Eczema often occurs in combination with allergies or sensitivities. Oolong tea can suppress those allergic reactions because it fights free radicals. The antioxidants in oolong tea also ensure healthy skin.
It is scientifically proven that people with eczema can benefit from drinking 3 cups of oolong tea a day. The favorable results on the skin can be seen in less than a week, according to research ( source ).
Benefit # 3: helps with diabetes
Some studies have found that drinking more than 3 cups of tea per day is associated with a lower risk of type 2 diabetes .
Studies that have looked at oolong tea and diabetes show mixed results.
A small-scale study of 20 participants with type 2 diabetes was drunk either 1.5 liters of oolong tea or water (as a control group) for 30 days.
The researchers discovered that the group that drank oolong tea saw a significant decrease in their blood sugar levels compared to the control group ( source ).
Other researchers show similar results. In another study, 22 diabetes patients drank 1 liter of oolong tea a day. This group also saw an improvement in their blood sugar levels.
Compared to the control group, the group that drank oolong tea saw a significant reduction in blood sugar and hemoglobin A1c levels after 4 weeks.
HbA1c is a protein found in red blood cells that carries oxygen to the body. Hemaglobin cells are constantly being broken down and replaced, but they have an average lifespan of 3 months.
Glucose tends to attach hemoglobin. If too much glucose is attached to the hemoglobin cells, then you know that you have a high HbA1c value.
In a 2011 study, healthy male participants drank 6 cups of oolong tea a day. The oolong tea they drank contained additional antioxidants. The researchers did not see any improvement in blood sugar levels or insulin levels ( source ).
Benefit # 4: beneficial effect on weight loss
Oolong tea can help stimulate fat burning after you drink it. Oolong also contains polyphenols that are capable of blocking enzymes that store fat.
A study among mice showed that the mice that received oolong tea exactly and ate sugar-rich food had much less belly fat than the mice that ate only sugar-rich food ( source ).
A study among people showed similar effects. Obese and obese participants drank 300 ml oolong tea four times a day. After 6 weeks, more than half of the participants had lost 1 kg of body weight ( source ).
In another small-scale study, male participants had to drink either water or oolong tea for a three-day period. The men who drank oolong tea increased their energy consumption by almost 3%. This means an extra calorie burn of more than 200 calories per day. That is easy to lose weight with little effort.
Although more research is needed into the effects of oolong tea on weight loss, current studies show a beneficial effect.
Advantage # 5: oolong tea is rich in polyphenols
Just like green tea, oolong tea contains many polyphenols.
Polyphenols are antioxidants found in plants that are thought to have potential health benefits.
A rat study from 2014 found that polyphenol extracts from oolong tea have an anti-inflammatory effect ( source ).
Unfortunately, there are no results available that say anything about the effect of polyols from oolong tea on humans.
We do know that epigallocatechin gallate (EGCG) – a powerful catechin in tea – has a beneficial effect on modest weight loss ( source ).
Benefit # 6: can help with stress and tension
Every tea drinker is probably familiar with the calming feeling of drinking tea. Scientific research also shows that tea can reduce stress.
In a mouse study, oolong tea was found to reduce stress levels in rodents by 20% ( source ).
Oolong tea contains the amino acid L-theanine that stimulates the production of dopamine and alpha waves in the brain and reduces anxiety ( source , source , source ). This reduces stress and makes you feel more relaxed.
Benefit # 7: improves concentration
Oolong tea contains caffeine, so we can feel alert and improve focus and concentration.
Even caffeine in a low dose can already improve people’s focus and concentration.
In a randomized, double-blind study, the caffeine consumption of 0.3 mg per kg body weight allowed the subjects to perform better on cognitive capacity tests ( source ).
This study used a caffeine dose that is equivalent to half a cup of oolong tea.
Side effects of oolong tea
Oolong tea is safe for consumption when it is drunk in normal quantities. The chance of side effects is then minimal.
However, some people are sensitive to caffeine and even a small amount of caffeine can cause side effects.
More than four cups of oolong tea per day is not recommended because of the amount of caffeine.
These symptoms can range from mild to severe and consist of:
- Sleep problems
- Irregular heartbeat
- Hot temper
I advise pregnant women or women who are breastfeeding to drink oolong tea.
Norwegian research has shown that babies born to mothers who drank a lot of caffeine during their pregnancy were more likely to grow excessively overweight in their first years of life ( source ).
According to the National Cancer Institute , a US government organization, there is insufficient evidence that oolong tea can reduce the risk of cancer. However, there are a number of small-scale studies that suggest that oolong tea can inhibit skin cancer, lung cancer, and ovarian cancer ( source ).
Animal studies have shown that polyephenols, which occur naturally in oolong tea, can protect cells against DNA damage and possibly inhibit the growth of tumor cells. These polyphenols can also strengthen the immune system ( source ).
In any case, epidemiological research shows that female oolong tea drinkers are 25% less likely to have breast cancer ( source ). The oolong tea extract was found to inhibit the growth of breast cancer cells.
It is therefore possible that oolong tea can help to reduce the risk of cancer as part of a healthy lifestyle. But more research is needed before stronger conclusions can be drawn.
Finally, research has shown that the most important polyphenol in oolong tea can inhibit the absorption of heme iron from food (source). Heme iron is found in animal products such as red meat and crustaceans (lobster, shrimp, etc.).
It is therefore better not to drink oolong tea during meals to increase its influence on the absorption of iron from foods.
Oolong tea is a healthy thirst quencher and a better alternative to soda.
Besides that it tastes good, it also has a beneficial effect on our health. However, most health benefits are small and we should not expect too much from drinking a few cups of oolong tea a day.
And then I have one last tip for all avid tea drinkers. Recent research has shown that drinking hot tea (temperature above 65 degrees) increases the risk of esophageal cancer ( source ).
Therefore, always let oolong tea – or another type of tea – cool for a few minutes before you drink it.
Oolong tea bonus recipe
Oolong tea tastes great. But if you like iced tea and want a little more variety in flavors, I have an extra recipe below for you to try.
oolong iced tea with lemon
What do you need:
- 1.5 liters of water
- 6 oolong tea bags
- ¼ pressed lemon juice
- 2-3 teaspoons stevia (optional)
- Put the tea bags in hot water for about 5 minutes.
- Remove the tea bags and add the freshly squeezed lemon juice.
- Let the oolong tea cool in the fridge for 2-3 hours.