Why tea is good for you

Some research suggests that caffeine may inhibit melatonin production, resulting in poor sleep quality 6. Inadequate sleep is linked to a variety of mental issues, including fatigue, impaired memory, and reduced attention span.

Some studies have found that even just mg of caffeine consumed 6 or more hours before bedtime could negatively affect sleep quality , whereas other studies have observed no significant effect 6. Certain compounds in tea may cause nausea , especially when consumed in large quantities or on an empty stomach.

Tannins in tea leaves are responsible for the bitter, dry taste of tea. The astringent nature of tannins can also irritate digestive tissue, potentially leading to uncomfortable symptoms, such as nausea or stomach ache 8.

More sensitive individuals may experience these symptoms after drinking as few as 1—2 cups — ml of tea, whereas others may be able to drink more than 5 cups 1. If you notice any of these symptoms after drinking tea , you may want to consider reducing the total amount you drink at any one time.

You can also try adding a splash of milk or having some food with your tea. Tannins can bind to proteins and carbs in food, which can minimize digestive irritation 8. Tannins in tea may irritate digestive tissue in sensitive individuals, resulting in symptoms like nausea or stomach ache. The caffeine in tea may cause heartburn or aggravate preexisting acid reflux symptoms. Research suggests that caffeine can relax the sphincter that separates your esophagus from your stomach, allowing acidic stomach contents to more easily flow into the esophagus 9.

Caffeine may also contribute to an increase in total stomach acid production Of course, drinking tea may not necessarily cause heartburn. People respond very differently to exposure to the same foods. That said, if you routinely consume large quantities of tea and frequently experience heartburn , it may be worthwhile to reduce your intake and see whether your symptoms improve.

The caffeine in tea could cause heartburn or exacerbate preexisting acid reflux due to its ability to relax the lower esophageal sphincter and increase acid production in the stomach. Exposure to high levels of caffeine from beverages like tea during pregnancy may increase your risk of complications, such as miscarriage and low infant birth weight 11 , However, most research indicates that the risk of complications remains relatively low if you keep your daily caffeine intake under — mg That said, the American College of Obstetricians and Gynecologists recommends not exceeding the mg mark The total caffeine content of tea can vary but usually falls between 20—60 mg per cup ml.

Some people prefer to drink caffeine-free herbal teas in place of regular tea to avoid caffeine exposure during pregnancy. However, not all herbal teas are safe to use during pregnancy. For instance, herbal teas containing black cohosh or licorice may induce labor prematurely and should be avoided 14 , Overexposure to caffeine from tea during pregnancy may contribute to complications, such as miscarriage or low infant birth weight.

Herbal teas should also be used with caution, as some ingredients may induce labor. Intermittent caffeine intake may help relieve certain types of headaches. However, when used chronically, the opposite effect can occur Tea tends to be lower in caffeine than other popular types of caffeinated beverages, such as soda or coffee , but some types can still provide as much as 60 mg of caffeine per cup ml 4.

If you have recurrent headaches and think they may be related to your tea intake, try reducing or eliminating this beverage from your diet for a while to see if your symptoms improve. Routinely consuming excessive amounts of caffeine from tea could contribute to chronic headaches. It fits in perfectly well with a heart-healthy lifestyle. One important warning: A cup of tea contains only a couple calories.

Processed, sugar-sweetened tea beverages are loaded with extra calories. Read the full-length article: "Tea: A cup of good health? As a service to our readers, Harvard Health Publishing provides access to our library of archived content.

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Recent Blog Articles. Health news headlines can be deceiving. Matcha is a very fine, high-quality green tea powder made from the entire leaves of tea bushes grown in the shade. Since it is the only form of tea in which the leaves are ingested, matcha contains even more antioxidants that regular green tea. In fact, some have suggested that one cup of matcha is the equivalent to 10 cups of regular green tea. However, the leaves are dried and fermented, giving black tea a darker color and richer flavor.

When you do pour yourself a cup of black tea, you benefit from flavonoids that combat inflammation and support healthy immune function. It can be steamed, cooled and then pressed on minor cuts, scrapes and bruises to relieve pain and reduce swelling.

A black tea bath can also ease inflammation caused by skin rashes and conditions such as poison ivy. The difference is how the tea is processed: Green tea is not allowed to oxidize much, but black tea is allowed to oxidize until it turns black. Oolong tea is somewhere in between the two, so it is partially oxidized. This partial oxidation is responsible for oolong tea's color and characteristic taste.

Oolong tea is notable for containing l-theanine, an amino acid that reduces anxiety and increases alertness and attention. Oolong tea is also high in polyphenols, which are linked to lowering inflammation, preventing the growth of cancers and decreasing type 2 diabetes risk.