Health Benefits of Green Tea

Table of Contents[Hide][Show]

Green tea wasn’t always my first choice when it came to tea, but now that I know more about the amazing health benefits of green tea it is one of my favorite coffee alternatives.

This health-promoting herbal tea has been used by various cultures around the world for thousands of years, and now research confirms that it can help fight certain cancers, promote a healthy weight, support brain function, and more.

So yes, green tea is as healthy as they say! Read on to find out why.

Health Benefits of Green Tea

Green tea is made from the unfermented leaves of the Camellia sinensis tea plant. Because it is not fermented like black teas, it has a higher concentration of antioxidants (called polyphenols). Research suggests that these antioxidants can have a beneficial effect on the body by neutralizing free radicals and reducing inflammation.

The effects of green tea benefit the body in many ways. It contains catechins (most notably EGCG) that may help fight cancer, obesity, heart problems, diabetes, and more. It also has a modest amount of caffeine, about half as much as a cup of coffee, that can promote energy and wakefulness.

Theanine is also present in green tea, an amino acid that can lower blood pressure and promote optimal brain and nervous system function. Theanine on its own is often taken to promote a calm mind, and green tea can have this same effect.

Vitamin C is another nutrient found in green tea that is known for immune support and being a potent antioxidant. Together, these components give green tea its impressive health benefits.

(Learn more about the full benefits of green tea in this podcast, or read on!)

These are the most research-proven ways that green tea supports health and well-being:

Antioxidants

Green tea is an exceptional source of antioxidants. The rich antioxidant content makes this light tea beneficial to the brain, heart, and other organs. Research from the journal Nutrients in 2019 explains that antioxidants may be helpful in slowing the effects of aging. It also may help protect the body against diseases linked to free radical damage (cancer, diabetes, arthritis, and others).

Green tea gets these benefits from the catechins it contains, four in all:

  • Epicatechin
  • Epigallocatechin
  • Epicatechin-3-gallate
  • EGCG

EGCG is the most well-studied polyphenol component in green tea with the most active properties. They are not only rich in antioxidants but are antimicrobial, too. Green tea catechins are a general one-two punch for aging and disease—but you have to consume them regularly to get any type of benefit.

Cancer

Anything that can reduce the risk of or combat cancer is going to be interesting, and green tea actually has plenty of anti-cancer properties!

A 1998 study from the Japanese Journal of Cancer Research looked at 472 women with breast cancer. Those who consumed higher levels of tea both before and after the diagnosis had the lowest spread and growth of cancer in the body. They were also less likely to have a recurrence after treatment.

More recently, a review from 2018 summarizes some pretty mind-blowing benefits:

  • Delayed onset of any type of cancer over the course of 10 years
  • Prevention of colorectal cancer recurrence
  • EGCG generally works against cancer cells and their activity in the body

Regularly drinking green tea can also reduce the risk of pancreatic cancer in women by 32 percent, as compared to women who don’t regularly drink tea. In men, several studies have shown that regularly drinking green tea can lower the risk of prostate cancer by up to 70 percent. Green tea is so potently anti-cancer that it can even reduce the risk of lung cancer in people who smoke. (Imagine what it can do for people who don’t!)

Green tea has also been associated with reduced risk of esophageal cancer, liver cancer, and colon cancer. For colorectal cancer, consuming green tea just three times a week for at least six months may decrease the risk—and the more green tea you drink, the lower your risk goes.

A 2010 review in Chinese Medicine shows that green tea may also work to prevent or decrease the risk of cancer in the esophagus, mouth, stomach, small intestine, kidney, pancreas, and mammary glands.

Weight Loss and Obesity

Green tea is often touted as a weight loss aid, but how legitimate is that claim? Studies show mixed results. While it’s not a weight-loss miracle, meta-analysis of more than 44 different studies shows that green tea can lead to some weight loss. The most likely reason for the weight loss is due to the caffeine in green tea, so decaf green tea may not have the same effect.

Green tea may also lead to increased fat burning thanks to increased thermogenesis. Thermogenesis is a term meaning heat production, and the more heat production that happens in the body, the more fat is burned for energy.

Heart Health

Green tea also shines in the area of heart health thanks to the flavonoids it contains. Drinking tea leads to an increased activity of enzymes in the body that protect against reactive oxygen species. This lowers the level of nitric oxide in blood plasma. Green tea also helps to prevent plaque build-up in the arteries, which can reduce the risk of cardiovascular disease.

For people who’ve had heart attacks, a study of 1,900 people found that the death rate was 44 percent less for people who drank at least 2 cups of green tea per day. Cholesterol levels used to be implicated as a trigger of heart disease. While cholesterol alone is not responsible, oxidized LDL cholesterol does lead to potential cardiovascular problems. Green tea helps to prevent the oxidation of LDL cholesterol, and the more you drink, the better it works.

Reduced risk of heart disease isn’t the only cardiovascular benefit that comes from green tea. Animal research also shows that it lowers the absorption of triglycerides and cholesterol, increasing the way that the body burns fat.

Of course, the heart benefits from reduced body weight, and as we saw above, green tea can help to promote weight loss.

It’s also good for blood pressure, which is an important component of heart health. A meta-analysis of 13 randomized controlled trials found that green tea consumption leads to lower blood pressure. It is especially effective for people who are in stage 1 hypertension or prehypertension, suggesting that it’s better at preventing blood pressure problems over time than correcting more severe ones.

For people with high blood pressure, green tea might be good for supporting health. You should always talk to your doctor though, to see what’s right for you.

Cognitive Health and Anti-Aging

Thanks to a compound called epigallocatechin gallate, or EGCG, green tea may also be good for the mind and for slowing aging. This compound not only protects against UV related damage but may also help halt skin aging caused by free radicals.

This same compound makes it protective of neurons and brain cells. Initial research suggests that regular green tea consumption can help protect the mind and delay deterioration from Alzheimer’s and Parkinsons.

Other compounds in green tea, like L-theanine and caffeine, can help support the brain and improve alertness and focus. L-theanine is especially good at improving alertness without adding jittery energy like caffeine can.

Blood Sugar and Diabetes

Type 2 diabetes is a metabolic disorder where your body doesn’t respond to the hormone insulin as it should. Insulin draws glucose (blood sugar) into your cells, so that your levels aren’t too high. There are lots of things that can reduce the risk of getting type 2 diabetes. Green tea happens to be one of them!

A 2009 meta-analysis of 7 studies found an 18 percent lower chance of type 2 diabetes. Another meta-analysis from 2019 found that green tea doesn’t lower diabetes risk for everyone, but works really well for lowering fasting blood sugar levels in people who are under age 55.

If you already have diabetes, green tea won’t magically make it go away. But if you don’t, green tea might help to prevent it or help to get your blood sugar levels better off so that you don’t develop it.

Types of Green Tea

There are several types of green tea. It can be loose leaf or in tea bags, but regardless of the type, unless it’s decaffeinated, the caffeine content is about the same. Most green tea has about half the caffeine of a cup of coffee per serving.

Matcha is another type of green tea that comes from the same plant. However, it is grown differently so that it has higher levels of chlorophyll, caffeine, and antioxidants. After the tea leaves are harvested, the stems and leaves are removed. It is then ground into a bright green powder.

Matcha has many of the same benefits of green tea, but due to its higher caffeine content, people tend to consume it in smaller amounts.

Both green tea and matcha can be used to make a smoothie, providing a boost of antioxidants with its light, mildly grassy flavor. I like the Pique Tea Matcha as it is quadruple toxin screened and their tea farm is located high in the mountains where cooler temperatures are a natural insect repellant.

Cautions, Side Effects, and Fluoride Content

Tea plants are known as fluorine accumulators, meaning that they can absorb and store fluoride. Those with Hashimoto’s thyroiditis or other thyroid conditions, as well as any other disorders, should ask a doctor and exercise caution with green tea consumption.

Research has found that higher quality green teas have less fluoride and lesser quality teas are more likely to contain high levels of fluoride. I buy bulk organic green tea from a trusted source and consume in moderation.

Green tea is not studied in children and not recommended during pregnancy. It can also block the absorption of folic acid, so it may not be best to consume if you’re trying to conceive. Due to its high antioxidant content, it can interact with some medications so check with your doctor before consuming green tea, especially in large amounts.

How to Make Green Tea

This tea is slightly more difficult to brew than other teas since it is more delicate and can easily become bitter. I follow these rules to ensure a non-bitter tea:

  • Start with a high quality organic green tea. I buy in bulk here and my favorite varieties are Dao Ren and Green Sencha.
  • Use hot water between 175-180°F.
  • Ideally, use a tea kettle and place the tea leaves in the kettle before adding the water. I use 2 teaspoons of tea per cup (8 ounces) of water.
  • Steep for only 1-2 minutes before pouring into a cup. Some tea kettles have a built in strainer, or else tea can be poured through a strainer.
  • To make iced tea, use the same amounts and pour over a cup of ice before consuming.

This article was medically reviewed by Dr. Lauren Jefferis, board-certified in Internal Medicine and Pediatrics. As always, this is not personal medical advice and we recommend that you talk with your doctor or work with a doctor at SteadyMD.

Are you a tea drinker? What varieties do you like?

Sources:

  1. Suzuki, Y., Miyoshi, N., & Isemura, M. (2012). Health-promoting effects of green tea. Proceedings of the Japan Academy. Series B, Physical and biological sciences, 88(3), 88–101. https://doi.org/10.2183/pjab.88.88
  2. Hidese, S., Ogawa, S., Ota, M., Ishida, I., Yasukawa, Z., Ozeki, M., & Kunugi, H. (2019). Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial. Nutrients, 11(10), 2362. https://doi.org/10.3390/nu11102362
  3. Prasanth, M. I., Sivamaruthi, B. S., Chaiyasut, C., & Tencomnao, T. (2019). A Review of the Role of Green Tea (Camellia sinensis) in Antiphotoaging, Stress Resistance, Neuroprotection, and Autophagy. Nutrients, 11(2), 474. https://doi.org/10.3390/nu11020474
  4. Reygaert W. C. (2018). Green Tea Catechins: Their Use in Treating and Preventing Infectious Diseases. BioMed research international, 2018, 9105261. https://doi.org/10.1155/2018/9105261
  5. Nakachi, K., Suemasu, K., Suga, K., Takeo, T., Imai, K., & Higashi, Y. (1998). Influence of drinking green tea on breast cancer malignancy among Japanese patients. Japanese journal of cancer research : Gann, 89(3), 254–261. https://doi.org/10.1111/j.1349-7006.1998.tb00556.x
  6. Fujiki, H., Watanabe, T., Sueoka, E., Rawangkan, A., & Suganuma, M. (2018). Cancer Prevention with Green Tea and Its Principal Constituent, EGCG: from Early Investigations to Current Focus on Human Cancer Stem Cells. Molecules and cells, 41(2), 73–82. https://doi.org/10.14348/molcells.2018.2227
  7. Wang, J., Zhang, W., Sun, L., Yu, H., Ni, Q. X., Risch, H. A., & Gao, Y. T. (2012). Green tea drinking and risk of pancreatic cancer: a large-scale, population-based case-control study in urban Shanghai. Cancer epidemiology, 36(6), e354–e358. https://doi.org/10.1016/j.canep.2012.08.004
  8. Miyata, Y., Shida, Y., Hakariya, T., & Sakai, H. (2019). Anti-Cancer Effects of Green Tea Polyphenols Against Prostate Cancer. Molecules (Basel, Switzerland), 24(1), 193. https://doi.org/10.3390/molecules24010193
  9. Khan, N., & Mukhtar, H. (2013). Tea and health: studies in humans. Current pharmaceutical design, 19(34), 6141–6147. https://doi.org/10.2174/1381612811319340008
  10. Chacko, S. M., Thambi, P. T., Kuttan, R., & Nishigaki, I. (2010). Beneficial effects of green tea: a literature review. Chinese medicine, 5, 13. https://doi.org/10.1186/1749-8546-5-13
  11. Hursel, R., Viechtbauer, W., & Westerterp-Plantenga, M. S. (2009). The effects of green tea on weight loss and weight maintenance: a meta-analysis. International journal of obesity (2005), 33(9), 956–961. https://doi.org/10.1038/ijo.2009.135
  12. Diepvens, K., Westerterp, K. R., & Westerterp-Plantenga, M. S. (2007). Obesity and thermogenesis related to the consumption of caffeine, ephedrine, capsaicin, and green tea. American journal of physiology. Regulatory, integrative and comparative physiology, 292(1), R77–R85. https://doi.org/10.1152/ajpregu.00832.2005
  13. Shimazu, T., Kuriyama, S., Hozawa, A., Ohmori, K., Sato, Y., Nakaya, N., Nishino, Y., Tsubono, Y., & Tsuji, I. (2007). Dietary patterns and cardiovascular disease mortality in Japan: a prospective cohort study. International journal of epidemiology, 36(3), 600–609. https://doi.org/10.1093/ije/dym005
  14. Yokozawa, T. & Dong, E. (1997). Influence of green tea and its three major components upon low-density lipoprotein oxidation, Experimental and Toxicologic Pathology, Volume 49, Issue 5. https://doi.org/10.1016/S0940-2993(97)80096-6.
  15. Raederstorff, D. G., Schlachter, M. F., Elste, V., & Weber, P. (2003). Effect of EGCG on lipid absorption and plasma lipid levels in rats. The Journal of nutritional biochemistry, 14(6), 326–332. https://doi.org/10.1016/s0955-2863(03)00054-8
  16. Peng, X., Zhou, R., Wang, B., Yu, X., Yang, X., Liu, K., & Mi, M. (2014). Effect of green tea consumption on blood pressure: a meta-analysis of 13 randomized controlled trials. Scientific reports, 4, 6251. https://doi.org/10.1038/srep06251
  17. Weinreb, O., Mandel, S., Amit, T., & Youdim, M. B. (2004). Neurological mechanisms of green tea polyphenols in Alzheimer’s and Parkinson’s diseases. The Journal of nutritional biochemistry, 15(9), 506–516. https://doi.org/10.1016/j.jnutbio.2004.05.002
  18. Kondo, Y., Goto, A., Noma, H., Iso, H., Hayashi, K., & Noda, M. (2018). Effects of Coffee and Tea Consumption on Glucose Metabolism: A Systematic Review and Network Meta-Analysis. Nutrients, 11(1), 48. https://doi.org/10.3390/nu11010048
  19. Lu, Y., Guo, W. F., & Yang, X. Q. (2004). Fluoride content in tea and its relationship with tea quality. Journal of agricultural and food chemistry, 52(14), 4472–4476. https://doi.org/10.1021/jf0308354

Source link

Related posts

Leave a Comment