The fermented process of brewing kombucha makes it a potential source of probiotics, which are live organisms that help balance good and bad bacteria in the gut. Proposed benefits of kombucha include its potential to reduce inflammation, boost immunity, and increase metabolism, according to the aforementioned review. (1) It’s important to note that there is not a wealth of human research on the potential health benefits of kombucha, as the Cleveland Clinic points out. (2) Nonetheless, it’s possible to speculate on its benefits given what the drink is made of, says Alissia Zenhausern-Pfeiffer, MD, a licensed naturopathic medical doctor practicing in Scottsdale, Arizona.
7 Potential Health Dangers of Too Much Kombucha
There’s no short list of potential health benefits of kombucha. Some people also believe that it can help detoxify the body, reduce blood sugar, and inhibit the growth of cancer cells, according to the Cleveland Clinic. (2) But despite possible therapeutic benefits, kombucha isn’t right for everyone, and there’s the risk of adverse effects from drinking too much and improper preparation, notes the Mayo Clinic. (3) Here’s a look at seven reported side effects of too much kombucha:
1. Drinking Too Much Kombucha May Upset Your Stomach
Even though kombucha might promote gut health and improve conditions like constipation and hemorrhoids, too much of any good thing can be bad, according to one review. (1) For that matter, drinking a large amount of kombucha may cause nausea and diarrhea. (1,2) Kombucha is acidic, so it’s possible for the drink to trigger nausea in those who are sensitive to acidic drinks. (1) Also keep in mind that some brands of kombucha may have sweeteners added to them. Eating too much sugar and too many sweeteners can lead to diarrhea or watery stools, according to a study. If your body isn’t used to probiotics, consuming too many too quickly can lead to similar symptoms. (4)
2. Overdoing It With Your Kombucha Habit May Lead to Headaches
Headaches are another possible adverse side effect of drinking too much kombucha. (1) The exact cause of a headache is unknown, but kombucha does contain caffeine and alcohol, which alone or together might induce headaches in those who are sensitive. Caffeine is sometimes used as a headache reliever. But while an effective treatment, repeated exposure to caffeine can have the opposite effect, triggering chronic daily headaches, past research has noted. (5)
3. Excess Kombucha May Contribute to Lactic Acidosis
The philosophy that too much of a good thing can be bad applies to kombucha. Though the occasional kombucha drinker needn’t worry about this side effect, those drinking multiple bottles of kombucha every day may be at risk for a condition called lactic acidosis. Lactic acid is an organic acid produced in the muscles. (6) Swigging kombucha can cause an accumulation of this acid in the bloodstream, causing the body’s pH to become too acidic. This can lead to problems with liver and kidney function, and become life-threatening, past research has suggested. (7) The amount of kombucha linked to lactic acidosis hasn’t been established. Yet the Centers for Disease Control and Prevention (CDC) has reported two illnesses associated with kombucha and elevated levels of lactic acid. In these cases, both women consumed 4 to 12 ounces (oz) of home-brewed kombucha daily for two months. Still, there is no proof the kombucha itself caused the lactic acidosis; the CDC simply observed a link between the two. More research is needed to determine the amount of kombucha that can cause this condition. (8) Symptoms of lactic acidosis include muscle aches, disorientation, nausea, headaches, fatigue, rapid heart rate, and jaundice (yellowing of the eyes or skin). (9) Among the known causes of this condition are human immunodeficiency virus (HIV) drugs, which can cause lactic acidosis buildup. The risk of poisoning is greater when kombucha is home-brewed in a clay vessel or ceramic pot containing high levels of lead. The lead can leach or dissolve into the beverage, causing a buildup of lead in the body. (2) In fact, past research showed at least one incident of lead poisoning linked to a lead-glazed earthenware jug used to store kombucha tea. (10) Symptoms of lead poisoning include high blood pressure, headache, abdominal pain, mood disorders, difficulty concentrating, and muscle pain. (11) Not only do some ceramic pots contain lead, but so do some china and porcelain containers. (11)
5. Drinking Kombucha Every Day May Damage Your Teeth
“Drinks that have high-acid levels, such as kombucha, can wear away your teeth, which can lead to decay, sensitivity, and discoloring,” says Jeffrey Sulitzer, DMD, the chief clinical officer at SmileDirectClub, a teledentistry company, who is based in Woodland, Washington. Because kombucha has a high acidic level that may be harmful to your teeth and gums, Dr. Sulitzer suggests several ways to help keep your teeth healthy and safe. “I would suggest drinking kombucha through a straw, to help reduce the direct contact the beverage has to your teeth. Directly after you finish your drink, rinse your mouth out with water to help remove the sugars and acidic components from your mouth,” he adds. So while kombucha contains relatively less sugar compared with soda, it is not sugar-free, like tap or unsweetened sparkling water. While sugar alone isn’t responsible for weight gain, eating too much can contribute, according to a review. (14)
7. Kombucha Could Trigger an Allergic Reaction in Some People
Problems could also arise if you’re allergic to kombucha tea. Signs of an allergic reaction vary from person to person, but might include shortness of breath, throat tightness, nausea, and dizziness after consuming the drink. (1,2)
Who Shouldn’t Drink Kombucha?
Be mindful that while kombucha might be beneficial for some people in moderate amounts, certain people should avoid it. To be clear, there haven’t been any large-scale studies examining the effects of kombucha in pregnancy or while breastfeeding, and a definitive recommendation has not been reached, says Casey Seiden, RD, CDE, a registered dietician and certified diabetes care and education specialist based in New York City. Some pregnant women might choose to avoid kombucha because there’s a small amount of alcohol from the fermentation process. (2) Others may consult their doctor and find it’s safe to drink during pregnancy. “Pregnant women are advised to not consume any alcohol-containing beverages; however, given the very small amount present, drinking kombucha is seen as a personal choice, with the guidance of your doctor, during pregnancy,” explains Seiden. For this same reason, one study from 2022 recommended that children ages 4 or younger should not drink kombucha. Because of the acidic nature of the beverage, those who have liver or kidney disease should also avoid kombucha. Additionally, people who have a compromised immune system, such as the elderly and those with HIV or cancer should avoid kombucha, warns Seiden. “This beverage is unpasteurized, so it could lead to food poisoning–like illness,” she continues. (1,2,3) To err on the side of caution, you may also choose to avoid this beverage if you have an alcohol dependency. “If you suffer from digestive upset following excess carbonation, you may want to limit your kombucha to one small glass daily to reap the probiotic benefits, but save yourself some bloating discomfort,” advises Seiden. You can drink store-bought kombucha, which is available in different flavors, or make your own at home with an online tutorial. If you’re shopping for kombucha, there are no hard-and-fast rules regarding how much sugar is too much in a bottle, though you can cut your intake by opting for a variety without added fruit juice. If you’re concerned about your weight and overall health, consider how kombucha fits into your calorie and sugar intake for the day, says Seiden. “The good thing is that there are many brands out there of varying calorie and sugar levels, so you can likely find one that helps you meet your goals,” she says. If you’re up for a challenge and want to make your own kombucha tea at home, there are plenty of recipes you can follow. There are even homemade kombucha kits that include essential ingredients like SCOBY (symbiotic culture of bacteria and yeast), which helps with the fermentation process. This is the thick liquid that floats at the top of a batch of kombucha. (2) You can purchase SCOBY, or use leftover SCOBY from a previously brewed batch. An example of a simple recipe: (15)
Boil 4 cups of unchlorinated waterAdd 8 tea bags (black or green) and 1 cup of sugarLet the tea steep for 15 minutes, and then strain any loose teaAdd 12 cups of cold water, pour the tea into a glass jar, and add 1 kombucha SCOBYUse paper towel to cover the jar and secure the towel with a rubber bandAllow tea to ferment for about 7 to 10 days
Always start with a clean pot. “The biggest concern with brewing kombucha at home is cleanliness. If proper cleaning precautions aren’t taken, the risk of molds or harmful bacteria growing are increased, which could lead to illness,” cautions Seiden. “To help decrease these risks, use only glass containers (versus metal) and keep an eye on the color and smell of the SCOBY. If the starter starts to grow black or green spots, or it starts to smell rancid, it’s time to toss that SCOBY and start again with a new one.” Also, you can use pH strips to ensure you ferment to a pH of 2.5 to 3.5, since under- and overfermenting can both be dangerous. (14)
A Final Word on Kombucha Side Effects
Kombucha might be the secret ingredient to improve your gut health, fight inflammation, and help you feel better. But drinking too much can have adverse side effects, causing more harm than good. So only consume Kombucha in moderation. Whether you’re buying the drink or making your own, make sure it has the right pH level and is steeped in a safe container.
