Alkaline-Friendly Teas: A Guide to Black, Green and Herbal Tea

Is tea acidic or alkaline?

It depends on which question you are asking. In the cup, most brewed tea is mildly acidic. Black tea usually lands around pH 5, and tart herbal blends such as hibiscus are more acidic still. That number describes the drink itself, the same way orange juice and coffee have a pH.

The alkaline diet is about something different: the acid or base a food leaves for your kidneys to clear after digestion. Researchers estimate that with PRAL, short for potential renal acid load, a formula published by Thomas Remer and Friedrich Manz in 1995. Foods rich in protein and phosphorus score above zero. Foods rich in potassium and magnesium score below zero.

Brewed tea has no protein to speak of and only traces of phosphorus, but it does contain some potassium. Using USDA FoodData Central values, plain brewed black tea works out to roughly -0.8 per 100 grams, or about -2 for an 8-ounce cup. Brewed green tea is close to zero. In other words, tea is close to neutral, leaning slightly alkaline, once you drink it.

Your blood pH does not change with your tea

Your body keeps blood pH in a narrow range, roughly 7.35 to 7.45, using your lungs and kidneys. No tea, food or water changes that in a healthy person. What diet can shift is the acidity of your urine, which is what PRAL predicts.

That is why we describe foods as alkaline-friendly rather than alkalizing. A pattern of eating that is rich in vegetables, fruit and plant foods tends to have a lower acid load, and tea fits that pattern well because it adds flavor without adding sugar, salt or protein.

Green and black tea

Green, black, white and oolong tea all come from the same plant, Camellia sinensis. The difference is how the leaves are processed. Green tea is heated soon after picking to stop oxidation, and black tea is fully oxidized, which gives it a darker color and stronger taste.

Both contain caffeine. USDA FoodData Central lists about 47 milligrams in an 8-ounce cup of brewed black tea and about 28 milligrams in green tea, though brewing time and leaf amount change that a lot. The FDA says up to 400 milligrams of caffeine a day is not generally associated with negative effects for healthy adults. People who are pregnant, sensitive to caffeine or taking certain medications should ask their clinician what is right for them.

Tea also contains tannins, which can reduce how much iron your body absorbs from plant foods. If you rely on beans, greens and grains for iron, drink tea between meals rather than with them.

Herbal teas

Herbal teas, or tisanes, are made from flowers, roots, leaves and spices rather than tea leaves, and most are naturally caffeine free. Like regular tea, they are almost all water, so their acid load is close to neutral.

Peppermint, ginger, chamomile and rooibos are easy everyday choices. Ginger tea pairs well with lemon. Rooibos, a red bush tea from South Africa, has a naturally sweet, mellow flavor that works hot or iced.

A few herbs deserve caution. The National Center for Complementary and Integrative Health notes that people allergic to plants in the daisy family, such as ragweed, can react to chamomile. Licorice root contains glycyrrhizin, which in large amounts or over long periods can raise blood pressure and lower potassium. Hibiscus is tart and quite acidic in the cup, and it may interact with some medications. If you take prescription drugs, check with a pharmacist before drinking a lot of any one herbal tea.

How to make tea fit an alkaline-friendly day

Keep it plain or lightly sweetened. A spoonful of sugar or honey is fine for most people, but sweetened bottled teas can carry as much sugar as soda.

Add fresh flavor instead of sugar: a slice of lemon or orange, a few mint leaves, a coin of fresh ginger or a cinnamon stick.

Try plant milk in black tea or chai if you like it creamy. Unsweetened almond or oat milk keeps the drink light.

Make a big jar of iced tea for summer. Steep 6 to 8 tea bags in a quart of cold water in the fridge overnight, then strain. Cold brewing tastes smoother and less bitter.

Sources

Remer T, Manz F. Potential renal acid load of foods and its influence on urine pH. Journal of the American Dietetic Association, 1995.

USDA FoodData Central: https://fdc.nal.usda.gov/

U.S. Food and Drug Administration, Spilling the Beans: How Much Caffeine Is Too Much?: https://www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much

National Center for Complementary and Integrative Health, Chamomile and Licorice Root fact sheets: https://www.nccih.nih.gov/health/herbsataglance