Eight Potential Health Benefits of Kombucha

Kombucha is a sweet, fizzy drink made of yeast, sugar, and fermented tea. It has a number of potential health benefits, including gut health and liver function.

This article explores eight potential health benefits of kombucha and looks at the research that supports them.

What is kombucha?

A jar of raw kombucha fermented drink, on a wooden table with chopped up lemon and a stem of ginger.
Kombucha is a fermented drink that is popular for its purported health benefits.

To make kombucha, sweetened green or black tea is fermented with a symbiotic colony of bacteria and yeast, otherwise known as a SCOBY.

During the fermentation process, the yeast in the SCOBY breaks down the sugar in the tea and releases probiotic bacteria.

Kombucha becomes carbonated after fermentation, which is why the drink is fizzy.

Potential health benefits

There is a range of potential health benefits of kombucha, including:

1. Gut health

As this 2014 study confirms, the fermentation process of kombucha means that the drink is rich in probiotics. Probiotic bacteria are similar to healthful bacteria that are found in the gut.

Consuming probiotics may improve overall gut health. Probiotic bacteria have been found to help treat diarrhea, and some research suggests they may help ease irritable bowel syndrome(IBS).

More research is needed into how kombucha improves gut health, but the link between probiotics and gut health suggests it may support the digestive system.

The link between healthy bacteria in the digestive system and immune function is becoming clearer as more studies focus on gut health. If the probiotics in kombucha improve gut health, they may also strengthen the immune system.

2. Cancer risk

There is growing evidence to suggest drinking kombucha could help reduce the risk of cancer.

2008 study found that kombucha helped prevent the growth of cancer cells. Further research in 2013 found that kombucha decreased the survival of cancer cells. Both studies suggest kombucha could play a role in treating or preventing cancer.

It is important to note that these studies looked at the effects of kombucha on cancer cells in a test tube. More research is needed to see if people who drink kombucha have a reduced risk of developing cancer.

3. Infection risk

A type of acid called acetic acid, also found in vinegar, is produced when kombucha is fermented.

study carried out in 2000 found that kombucha was able to kill microbes and help fight a range of bacteria. This suggests that it may help prevent infections by killing the bacteria that cause them before they are absorbed by the body.

4. Mental health

Young smiling woman drinking fruit juice ice tea.
The probiotics in kombucha are thought to have the ability to treat depression.

There may be a link between probiotics and depression, suggesting that drinking probiotic-rich kombucha could help promote positive mental health.

There are strong links between depression and inflammation so the anti-inflammatory effect of kombucha may help alleviate some of the symptoms of depression.

2017 review looked at a number of existing studies and concluded that there is strong evidence that probiotics may help treat depression. However, further research is needed to prove how effective they are.

5. Heart disease

Levels of certain types of cholesterol increase the risk of heart disease. Studies in 2012 and 2015 found that kombucha helps to reduce levels of the cholesterol linked to heart disease. Cholesterol levels and heart disease are also influenced by diet, exercise, weight, lifestyle habits, and inflammation. However, the research cited here suggests drinking kombucha may help reduce the risk of heart disease.

At the same time, it is important to note that these studies were in rats. More research is needed to prove that kombucha reduces the risk of heart disease in humans.

6. Weight loss

When kombucha is made with green tea, it may aid weight loss. A 2008 study found that obese people who took green tea extract burned more calories and lost more weight than those who did not.

If kombucha is made with green tea, it follows that it could have a similarly positive effect on weight loss.

Again, researchers need to look at kombucha and weight loss specifically before this is certain.

7. Liver health

Kombucha contains antioxidants that help fight molecules in the body that can damage cells.

Some studies, the most recent being in 2011, have found that the antioxidant-rich kombucha reduces toxins in the liver. This suggests that kombucha may play an important role in promoting liver health and reducing liver inflammation.

However, studies to date have looked at rats and more research is needed to say with certainty how kombucha can support liver health in humans.

8. Type 2 diabetes management

Kombucha tea in iced bottles, with fruit segments fermenting.
Kombucha may help to stabilize blood sugar levels and aid in the management of diabetes.

Kombucha may also be helpful in managing type 2 diabetes.

2012 study found that kombucha helped to manage blood sugar levels in rats with diabetes. This finding suggests it may be helpful in type 2 diabetes management.

Again, more research is needed to say with certainty whether kombucha can have the same benefits in type 2 diabetes management for humans.

Are there any risks?

It is important to be careful when making kombucha at home, as it can ferment for too long. It is also possible for kombucha to become contaminated when not made in a sterile environment.

Over-fermentation or contamination may cause health problems so it may be safer to buy kombucha in a store than to make it at home.

Store-bought kombucha normally has a lower alcohol content than homemade versions, but it is important to check the sugar content.

There are many potential health benefits of kombucha. However, it is important to remember that research is ongoing and not all benefits have been proven in studies with human participants.

If made properly or bought in-store, kombucha is a probiotic-rich drink that is safe to enjoy as part of a healthful diet.

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Health Benefits of Oolong Tea

There is a record of tea being used as a beverage in China since 2,000 B.C.E. Besides water, it is consumed more than any other drink around the world. The four main types of tea are black, green, white, and oolong.

All four varieties come from the Camellia sinensis plant. Herbal teas are not considered true tea because they do not come from the Camellia sinensis plant.

Oolong tea accounts for only 2 percent of tea consumption around the world. Although less popular, oolong tea still has a variety of benefits. Read on to find out more information about oolong tea and its associated health benefits.

What is oolong tea?

Oolong tea is commonly consumed in China and Taiwan. In Asian countries, drinking tea is a large part of the culture and social gatherings. Friends and business associates often meet over tea.

Oolong
Oolong tea has a range of health benefits.

Although all true tea comes from the same plant, the differences occur in the harvesting and processing. Oolong tea is partially fermented, while black tea is fully fermented.

Tea can also differ in amounts and types of antioxidants. Green tea is high in a class of antioxidants known as catechins. Antioxidants in black tea are theaflavins and thearubigins. Oolong tea falls in the middle, regarding the antioxidant amounts.

Oolong tea and green tea contain similar amounts of caffeine, approximately 10 to 60 milligrams (mg) per 8-ounce cup. For comparison, coffee contains approximately 70 to 130 mg of caffeine per 8-ounce cup.

Unsweetened brewed tea is considered a zero-calorie beverage. It contains no fat, carbohydrates, or protein.

Potential health benefits of oolong tea

There are a number of health benefits that are thought to derive from drinking oolong tea, as with other types of tea.

Heart disease

Researchers in China studied the relationship between drinking oolong tea and cholesterol levels, as high cholesterol levels can be associated with an increased risk for heart disease.

They found that people who drank at least 10 ounces of oolong tea per week had lower risks of having high total cholesterol, triglyceride, and LDL or “bad” cholesterol levels. The same was also true of people who drank similar amounts of green and black teas.

People who had been consuming oolong tea for the longest time had lower total cholesterol, triglyceride, and LDL cholesterol levels.

In another study, Japanese men and women were studied for the impact of consuming coffee, green tea, black tea, and oolong tea on their risk of heart disease. Researchers found that men who drank 1 or more cups of oolong tea per day had a lower risk of heart disease.

Weight loss

study in mice showed that the animals receiving oolong tea extract while being fed a high fat, high sugar diet, gained less abdominal fat than mice on the same diet that did not receive the tea extract.

Green tea and black tea extracts also resulted in the less abdominal fat gain. The mice that received the green tea extract also consumed fewer calories.

study in overweight and obese Chinese adults looked at the effect of oolong tea consumption on body weight. Study participants drank 300 milliliters (mL) of oolong tea four times per day. After 6 weeks, more than half of the participants had lost more than 1 kilogram.

Cancer

Researchers in Taiwan examined the association between drinking tea and the risk of head and neck or throat cancer.

Each cup of oolong tea consumed per day equated to a 4 percent lower risk, but the result was not significant. Each cup of green tea consumed per day equated to a 6 percent lower risk for head and neck cancer, which was more significant.

Another study in Chinese women found that drinking green, black, or oolong tea was linked to a decreased risk of ovarian cancer.

However, according to the National Cancer Institute, there is not currently enough research to say for certain that drinking tea decreases cancer risk.

Diabetes

Some studies have shown that drinking 3 or more cups of tea per day is associated with a lower risk of type 2 diabetes.

However, studies specifically looking at oolong tea have had varied results.

In one study, healthy men drank almost 6 cups per day of oolong tea. At different times, they drank oolong tea that contained supplemental antioxidants, which were in the form of catechins or polyphenols. Each of the teas was consumed for 5 days. Researchers found that drinking oolong tea did not improve blood sugar or insulin levels.

Interestingly, one study found that working men who drank 2 or more cups of oolong tea per day had a higher risk of developing diabetes than men who consumed 1 cup of oolong tea per day or no oolong tea.

Dental health

Fluoride is an element that is often added to drinking water, toothpaste, and mouthwash to help prevent dental cavities.

Tea leaves naturally contain fluoride, so drinking oolong tea could help prevent cavities. Excess fluoride can be harmful, but drinking less than 1 liter of oolong tea per day is safe for most adults.

Other possible benefits:

While there is not enough current research to support the following benefits, drinking tea has also been associated with:

  • healthier gut bacteria
  • lower risk of Alzheimer’s disease
  • lower risk of Parkinson’s disease
  • natural defense from the sun’s ultraviolet rays
  • stronger bones

Studies that examined long-term consumption of oolong tea showed the greatest results. Although it is not a cure for any condition, drinking tea regularly appears to have numerous health benefits.

Risks and Considerations

Oolong Too much
Too much oolong can affect the absorption of iron into the blood.

Although oolong tea contains less caffeine than coffee, people who are sensitive to caffeine should still limit their intake.

Tea can decrease the amount of iron absorbed from plant foods. Also, some researchers found that young children who drank tea were more likely to have lower iron levels.

It may, therefore, be better to drink tea outside of meals to limit its impact on iron absorption. When consumed together at meals, eating foods rich in vitamin C can increase the amount of iron absorbed from plant foods.

Tea is a healthy beverage that has been consumed by people around the world for centuries. Oolong tea is a lesser known variety that may also provide health benefits. However, from some of the research reviewed above, drinking green tea may offer the most health advantages.

Bottled tea contains smaller amounts of beneficial polyphenols and may have excessive amounts of added sugar. If buying bottled teas, it may be better to look for ones that are unsweetened or to brew tea at home and sweeten it with a small amount of honey.

Oolong tea should be steeped for as long as possible to increase flavonoids, and people can consume 2-3 cups per day.