Tea and Coffee: How Do They Affect Health?

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Tea and coffee are the second most widely-consumed beverages in the world after water. Do you prefer tea or coffee? What are the health effects of tea and coffee?



Composition of tea

Tea spread from China and India to the world, with its unique taste, smell and color, and today tea is the most preferred beverage after water. Green tea, oolong tea and black tea are produced from tea leaves. The fermentation process of the production differs between tea types. The nutritional composition is similar for black and green tea. Tea contains magnesium, fluorine, potassium, caffeine and theophylline, and various polyphenolic compounds, especially catechins. It is stated that antioxidant effect of polyphenolic compounds plays key role in health effects of tea.

Tea and health effects

Alongside the taste of the tea, researches focus on health effects of tea. It is stated that black tea and green tea have similar health effects. There are numerous studies that support tea may have preventive effects against various diseases including insulin resistance, type 2diabetes, cardiovascular diseases, hypertension and cancers such as gastric and intestine. It is stated that tea can support cognitive functions as well as may prevent chronic diseases. The recent studies have shown that theanine, which is an amino acid in tea, might improve memory and learning skills by regulating serotonin and dopamine levels. In addition to these effects, tea can prevent dental caries with its fluoride content, and can reduce the risk of kidney stone. More studies are needed to explain the potential health effects of tea.

Composition of coffee

The coffee, which is thought to have spread all over the world from Ethiopia, is derived from the coffee plant. 1 out of every 3 people in the world like coffee because of dark, aromatic and refreshing taste. The chemical structure of coffee differs in order to the type of coffee plant, the geographical origin of the plant and the processing and storage methods. Magnesium, potassium, vitamin B3 and non-nutritious compounds as polyphenols including chlorogenic acid and caffeine are the major compounds of coffee. Antioxidant effect of coffee polyphenols play key role in health effects of coffee.

Coffee and health effects

It is reported that coffee helps to regulate blood pressure and blood glucose with its antioxidant activity and as a result it can be effective in preventing diabetes, cardiovascular diseases, cancer and obesity. It is stated that coffee can improve cognitive performance and support mode with caffeine in addition to its preventive effects of chronic diseases. More studies are needed to explain the potential effects of coffee for the health.

Tea and coffee: When and how much should consume?

Health benefits of coffee and tea depends on the type, amount and preparation of coffee or tea and what they are consumed with. For example, tea or coffee prepared with cream or excess sugar may increase the energy content of the drink, tannin intake can increase by consuming a long-brewed tea and this may also adversely affect the iron absorption.

The health effects of caffeine in coffee and tea are also frequently considered. It is stated that excessive caffeine intake may cause insomnia, hypertension, palpitations and bone resorption. The European Food Safety Authority (EFSA) draws attention to the consumption of tea and coffee for pregnant and breastfeeding mothers because of these results caused by excessive caffeine intake. EFSA reports that 400 mg caffeine intake per day is safe for healthy adults, while pregnant women should limit intake to 200 mg per day. A cup of filter coffee approximately contains 100 mg of caffeine, and 1 cup of black tea approximately contains about 50 mg of caffeine.

Tea might decrease iron absorption due to its caffeine and tannin content. Studies on effect of tea consumption on iron levels do not suggest a limitation for healthy individuals. But individuals with iron deficiency should not consume tea right before and right after meals. Tea and coffee can support health when consumed at balanced amount and time as a part of adequate and balanced nutrition.

Sabri Ülker Foundation