Tea is an aromatic beverage made by pouring hot or boiling water over cured leaves of the Camellia sinensis plant. Tea originated in Southwest China as a medicinal drink – but it rapidly spread around the globe (the British empire played a big part and this). Tea is now second only to water as the most common beverage consumed globally.
Herbal tea is made with infusions of fruits or herbs, and typically does not include the tea plant. We’re not going to discuss herbal tea in this article, instead we’ll focus on the traditional kind. The exclusion of the tea plant leaves in the process for making herbal tea makes it a fundamentally different beverage.
How is tea made? It starts simple – the leaves of the C. Sinensis plant are picked and dried. But then things get a little more complex. A variety of methods such as fermenting, withering, warming, baking, rolling, aging, and more can be used to vary the oxidation rate of the leaves as they dry. This will ultimately give a wide variety of flavors, appearance, and smell – and this is how we end up with the different types of tea.
- Green – Green tea is made with leaves that have undergone the least amount of oxidation. Green tea leaves are not fermented, they are withered and steamed.
- Yellow – Yellow tea involves applying heat in a humid environment – this causes the chlorophyll within the leaves to give the drink a yellow color.
- White – White tea is made with young leaves or new growth buds.
- Oolong – Oolong tea is a step in between the minimal oxidation of green tea, and the complete oxidation of black tea.
- Black – In black tea the leaves have undergone complete oxidation – and that’s what gives it the color.
The cured tea leaves are packaged into tea bags for convenience, and then “steeped” in hot water to release the flavor and nutrients of the dried leaves. Now that we have an understanding of the different types of tea – let’s talk about the nutrients.
Tea has caffeine that can increase your energy levels
A typical 8 ounce (250 Ml) serving of green tea has only 2 calories and 26 mg of caffeine. Black tea has the same number of calories, but about 47 mg of caffeine. In either case, this is significantly less caffeine than a serving of coffee (which can weigh in at 100-200 mg per 8 oz serving). Tea doesn’t have quite as much vitamin and mineral content when compared to coffee – but it is an antioxidant powerhouse.
Like coffee, a lot of the benefits of drinking tea come from the caffeine contained within. Tea is commonly recommended to those who wish to have the energizing effects and increase in alertness of caffeine consumption – but to avoid the jittery side effects. Why is this? It’s simple – a serving of tea contains about half to a quarter as much caffeine compared to coffee.
What are the benefits of caffeine? Caffeine is absorbed into your bloodstream and travels to the brain where it blocks the actions of adenosine. Caffeine consumption can improve your mood, give you more energy, and raise alertness. It’s also associated with cognitive improvements. Studies have shown that caffeine consumption (day or night) can make you mentally sharper and improve performance on tasks.
Caffeine is also a powerful metabolic stimulant – it can increase your metabolism 3-10% for up to 3 hours after consumption. It’s also associated with an increase in epinephrine. Both these factors combine to make it a fat-burning powerhouse. That’s the reason that nearly every “fat-burner” on the market includes caffeine as a primary ingredient.
But, caffeine is a drug (albeit a very safe one). These same energizing effects make some people jittery, anxious, and it can cause difficulty in falling asleep. This is why it’s often recommended to get your daily caffeine dose via tea, rather than coffee.
Overall, caffeine is associated with numerous beneficial effects in human beings, it’s safe, and you can get your dose in a low-calorie, healthy beverage – tea. Let’s talk more about what else makes tea a healthy beverage choice.
Nutrient Content of Tea – Antioxidants
Tea is not a significant source of vitamins or minerals – with the exception of manganese (25% of RDA). It also contains some folate and potassium (about 3% of daily RDA both.)
But tea does have a lot of antioxidants. What are antioxidants? They are substances that counter-act oxidation within the body. Free radicals are produced constantly in the body via natural processes. These can damage cells within the body, but antioxidants help to prevent this damage from occurring – they scavenge the free radicals and render them harmless. Oxidative stress plays a major part in the development of chronic and degenerative illness such as cancer, autoimmune disorders, aging, cataract, rheumatoid arthritis, cardiovascular and neurodegenerative diseases. And while researchers are still understanding the exact role of antioxidants and oxidative stress within the body – it’s probably wise to try and mitigate the damage.
Tea contains polyphenols – a powerful antioxidant. And it seems to be a super-concentrated source of antioxidants. Studies have shown that tea can contain up to 10x the antioxidants of fruits and vegetables. What’s more, the specific types of antioxidant found in tea, called flavonoids, are not common in fruits and vegetables.
Read on to find out what protective benefits researchers believe can be attributed to this.
Health benefits of tea – protection against disease
Various studies have been done that show tea may protect against disease, including:
- Liver disease – Drinking green tea may confer protection from: hepatocellular carcinoma, liver steatosis, liver cirrhosis, hepatitis, and chronic liver disease.
- Depression – Tea consumption is associated with a decreased risk of depression.
- Stroke – Both green and black tea consumption shows a decreased risk of stroke.
- Heart Disease – Reduced risk for Coronary Heart Disease (CHD) and cardiac death.
- Prostate cancer – Consumption of green tea, but not black tea, shows a reduction in the risk of prostate cancer.
How about other forms of cancer? The jury is still out on that – there haven’t been widespread, in-depth studies that show overall protection from cancer.
Tea is a healthy beverage – low-calorie, packed with beneficial antioxidants, and a general energy and mood improver. Make tea a part of your daily routine. We especially recommend you switch out soda and energy drinks and drink tea (or coffee) instead.
Looking for another low-calorie, healthy beverage choice? Don’t forget about coffee – which is an excellent choice as well – as long as you keep it simple.
- The effect of green tea intake on risk of liver disease: a meta analysis
- Green tea consumption and liver disease: a systematic review.
- Tea consumption and the risk of depression: a meta-analysis of observational studies.
- Green and Black Tea Consumption and Risk of Stroke
- Tea consumption and risk of cardiovascular outcomes and total mortality: a systematic review and meta-analysis of prospective observational studies”
- Green tea and black tea consumption and prostate cancer risk: an exploratory meta-analysis of observational studies.
- Green tea (Camellia sinensis) for the prevention of cancer
- Free Radicals, Antioxidants in Disease and Health