What Is Green Tea?
Green tea is a beverage or dietary supplement that may improve mental alertness, relieve digestive symptoms and headaches, and help with weight loss.
It's been a popular drink as well as a traditional medicine in China and Japan for thousands of years. Early in the 17th century, it was introduced to consumers in Europe who instantly welcomed the beverage. In 18th century England, green tea was so valuable and popular that it was frequently smuggled in to avoid taxes.
These days there's no need to resort to smuggling. Green tea is widely available across the globe. Dozens of brands of bagged green tea can be found on store shelves, blended from a variety of green tea. There are flavored and sweetened varieties, as well as green tea powder and loose leaf tea. Whatever way you want to consume green tea, there's probably a product already on the market.
Green tea is often consumed for reasons other than for its health benefits. However, there's actually quite a lot happening in a cup of green tea, and it's worth getting to the bottom of.
Green Tea Nutrition
While there are many compounds, nutrients, vitamins, and minerals in green tea leaves, those elements are extremely diluted in a single cup of tea. Once steeped, the resulting green tea beverage is almost entirely water.
There are less than 3 calories in 8 fluid ounces of green tea. There are no measurable amounts for protein, fat, carbohydrates, fiber, or sugar.
Vitamins and minerals found in green tea are also minimal. A few that can be found in small quantities include:
Green tea does pack a potent punch of polyphenols, a type of antioxidants.
Does green tea have caffeine?
Yes.As a caffeine-rich drink, it may pose a risk to people with diabetes. Caffeine has been shown to potentially raise blood sugar of people with type 2 diabetes. As for the amounts, 8 fluid ounces of green tea has about 28 milligrams of caffeine. That's compared with 47 milligrams of caffeine for the same amount of black tea and 96 milligrams of caffeine for the same amount of coffee.
Green Tea Benefits
Many health benefit claims have been made about green tea for centuries. Traditionally, in China and India, green tea was a medicine for controlling bleeding, aiding digestion, and regulating body temperature. In modern times, research has been able to demonstrate some of its health benefits more solidly than others.
One large study in Japan followed 40,000 adult participants over 11 years and showed that daily consumption of green tea was linked to a low risk of death from cardiovascular diseases. In particular, the study examined the link between polyphenols (antioxidants) in green tea and cardiovascular diseases. The minimum daily consumption required to see this benefit was 5 cups per day.
Diabetes
Green tea can help regulate your blood sugar levels. It lowers your fasting blood sugar and your HbA1c when you have type 2 diabetes.
Stroke prevention
Another large Japanese study, this one following more than 82,000 participants over 13 years, showed that higher consumption rates of green tea were associated with a reduced risk of stroke. Participants who drank 4 cups per day or more saw the highest benefit.
Genital wart treatment
The FDA has approved a topical green tea extract treatment to treat breakouts of genital warts. This ointment is available by prescription only and is estimated to be effective for 24%-60% of patients.
Benefits for your skin
Studies show green tea may have anti-inflammatory and anticancer benefits that may help you have healthier skin. Their findings suggest skin products with green tea in them may be good for you. But more research is needed.
Green tea and ginger
Both green tea and ginger have been shown to have health benefits when ingested on their own. Throughout history, green tea has been thought to aid in digestion, regulate body temperature, and control bleeding. For centuries, ginger has been used to treat digestive problems, arthritis, asthma, diabetes, and menstrual symptoms. Scientific studies support its ability to alleviate nausea and vomiting associated with pregnancy, surgery, cancer therapy, and motion sickness. Ginger is also proven to reduce inflammation and pain. So it's not surprising to think that ginger and green tea would have health benefits when consumed together.
Weight loss
Some studies show that green tea and ginger may help with weight loss. In one study, weight loss capsules containing green tea, ginger, and capsaicin (the spicy component of chili peppers) were significantly more effective in promoting weight loss than a placebo.
But more research is needed to know how much the capsaicin contributed to those results.
Green Tea Side Effects
There's not much evidence that drinking green tea and ginger could be harmful. However, too much ginger can cause diarrhea, heartburn, and even an irregular heartbeat. While it would be pretty difficult to overdose on ginger by drinking ginger and green tea, it's much easier to do by taking diet pills that promote their green tea and ginger content.
Always check with your doctor before taking supplements and follow dosing instructions carefully. Drinking 8 cups per day or less of green tea is considered safe for most adults. However, there are risks posed by consuming green tea in high concentrations, especially as an extract.
In rare cases, green tea extract may cause liver problems. While the research is limited, you should avoid green tea extract if you have liver problems.
Stop taking green tea extract and contact your doctor if you have abdominal pain, dark urine, or jaundice.
How to Make Green Tea
Use these ingredients to make green tea:
- Three cups filtered water
- Four green tea bags
- One tablespoon ginger root, peeled and thinly sliced
- Two tablespoons fresh lemon juice, plus four slices for garnish
- Two tablespoons honey
Then follow these directions:
- Bring water to just below boiling point. Remove from heat.
- Place tea bags in a pitcher and add ginger slices. Pour hot water over the tea bags. Let them steep for 8-10 minutes. Remove the tea bags. Stir in lemon juice and honey.
- Serve warm or iced.
There's no evidence that, health-wise, it matters when you drink green tea. That's a matter of your personal preference.