Introduction to green tea
What are different green teas made of exactly, and are they totally natural? Green, black and oolong teas come from the Camellia sinensis plant. It consists of leaves that haven’t been fermented so they contain the highest level of antioxidants. For example, flavonoid antioxidants account for about 30 percent of the dry weight of tea leaves.
Some of the antioxidants and healing compounds found in green tea include polyphenols, catechins and various other types of flavonoids — the same anti-aging compounds found in things like red wine, blueberries and dark chocolate. Despite that it does contain small amounts of caffeine, green tea consumption has been associated with more health benefits than even many of the healthiest foods available to us. Studies have found that the benefits of green tea are due to the fact it contains more healing compounds than many other herbs, spices, fruits and vegetables, truly making it a powerful “superfood.”
What is the history of green tea?
Green tea consumption has its origins rooted in China, during the reign of Emperor Shennong. One book written way back in 600-900 AD by Lu Yu (translated into English as Tea Classic) is considered important in the history of green tea. Another book written in 1191 by Eisai (called The Kissa Yojoki, or Book of Tea), a Zen priest, speaks about how drinking green tea enhances the health of the five vital organs. It is important to note all of this wouldn’t hold value if not for the wonderful ingredients in green tea that render those healthful properties.
What Is The Nutritional Profile Of Green Tea?
Unsweetened brewed green tea has zero calories. If you are a calorie conscious individual, that’s simply powerful. Green tea contains flavonols and catechins (a type of polyphenols) that offer many great benefits. The catechins in it are:
- gallate derivatives
The most potent compound in green tea is EGCG, also known as epigallocatechin-3-gallate. It is what makes green tea. It has numerous benefits, some of which include enhanced metabolic rate and body weight regulation.
Other important compounds in green tea include:
- linoleic acid
- methylxanthines (caffeine, theopylline, and theobromine)
- numerous amino acids and enzymes (about 20 percent of the leaves are taken up by proteins
- carbohydrates (cellulose, pectins, glucose, sucrose, and fructose)
- trace amounts of minerals like magnesium, calcium, manganese, iron, chromium, copper, and zin
- some amounts of carotenoids
- lactones and hydrocarbons, esters, and aldehydes (all of which are volatile compounds)
- We saw the powerful constituents of green tea. Now let’s see what these constituents do and how they benefit us.
Health benefits of green tea
1. Green Tea Contains Bioactive Compounds That Improve Health
Green tea is more than just liquid. Many of the plant compounds in the tea leaves do make it into the final drink, which contains large amounts of important nutrients. Tea is rich in polyphenols that have effects like reducing inflammation and helping to fight cancer. It is about 30 percent polyphenols by weight, including large amounts of a catechin called EGCG. Catechins are natural antioxidants that help prevent cell damage and provide other benefits. These substances can reduce the formation of free radicals in the body, protecting cells and molecules from damage. These free radicals are known to play a role in aging and all sorts of diseases. EGCG (Epigallocatechin Gallate) is one of the most powerful compounds in green tea. It has been studied to treat various diseases and may be one of the main reasons green tea has such powerful medicinal properties.
It also has small amounts of minerals that are important for health.Try to choose a higher quality brand of green tea, because some of the lower quality brands can contain excessive amounts of fluoride.That being said, even if you choose a lower quality brand, the benefits still far outweigh any risk.
2. Green tea help Prevent Alzheimer’s or Memory Loss
In 2004, scientists at the University of Newcastle studied the effects of black and green tea on Alzheimer’s disease. In laboratory studies, both teas prevented the breakdown of acetylcholine, the neurotransmitter strongly linked with memory. The teas also inhibited enzymes known as BuChE and beta-secretase. These enzymes are found in protein deposits found in the brain of Alzheimer’s patients.
Japanese researchers published a study on green tea and its effect on the beta-amyloid protein plaques found in Alzheimer’s disease in the April 2008 issue of the Journal of Nutritional Biochemistry. The protein plaques associated with Alzheimer’s disease increase brain cell damage and death due to oxidative stress. The researchers found that green tea catechins reduced the level of damaging free radicals in the brains of rats. The green tea rodents showed much less plaque-induced deficits in memory compared to rodents that didn’t receive and those that were infused with beta-amyloid proteins.
Scientists have also discovered that the antioxidants flavonoids may also protect the brain from oxidative stress. The scientists extrapolated that a human would need to drink about three liters of liquid infused with 0.5 percent of the catechins to get similar effects. However, because humans ingest other antioxidants in the form of vitamins and plant polyphenols, it’s likely that a much lower quantity could be effective in protecting memory.
3. Drinking green tea cuts the risk of cancer
According to the National Cancer Institute, the polyphenols (especially catechins) are responsible for the tea’s anticancer properties. The most promising of these is EGCG (epigallocatechin-3-gallate). This, along with other polyphenols, fights free radicals and protects the cells from DNA damage that is caused by the reactive oxygen species. Green tea polyphenols can also modulate immune system function. As per another study, it helps prevent a range of cancers. These include cancers of the lung, skin, breast, liver, colon, and pancreas. The constituents of the tea prevent cancer cell proliferation and can even accelerate recovery.
EGCG has also been found to kill cancer cells without affecting the healthy ones. This could be a breakthrough in cancer treatment – as the destruction of healthy cells is what makes cancer all the more painful and even act as a hindrance to recovery. As per research, drinking about 4 cups of green tea can aid in cancer treatment.
4. Green tea enhances brain functions
Drink tea and be smarter! Sound too good to be true? Until last year, the effects of the tea on cognitive function were speculative, but with the improvements in functional magnetic resonance imaging (fMRI), Dr. Stefan Borgwardt could view the increased connectivity in the cortices of the brain after consumption of green tea. Specifically, drinkers showed increased connectivity in key parts of the brain associated with memory.
The study used healthy male volunteers and found that when given a soft drink containing green tea extract, those consuming it, extract not only showed increased connectivity in parts of the brain, but improved performance on working memory tasks as well.
5. Green tea helps in hair growth
According to many researches green tea helps stops hair fall and promotes hair growth in both men and women. Green tea is full of catechins that help in suppressing dihydrotestosterone that causes hair loss. Other compounds like ascorbic acid and zinc that are present in the tea aids in hair growth. You can take honey along with green tea for better results. Honey is another such element which can work wonders for your hair. If your hair is dry or increased pollution and direct exposure to the sun has made them lifeless, then use of honey can bring back that lost sheen and shine of your hair. Thus, regular consumption of tea with honey can prove to be beneficial in the long run for those seeking long, lustrous locks. Find out the different ways you can use honey for hair.
6. Green tea relives from skin diseases
A 2007 study concluded that green tea could hold promise as a new treatment for skin disorders such as psoriasis and dandruff. Researchers studied an animal model for inflammatory skin diseases, often characterized by patches of dry, red, flaky skin caused by the inflammation and overproduction of skin cells. Those treated with green tea showed slower growth of skin cells and the presence of a gene that regulates the cells’ life cycles.
7. Green tea increases Fat Burning and Improves Physical Performance
If you look at the ingredients list for any fat burning supplement, chances are that green tea will be on there. This is because it has been shown to increase fat burning and boost the metabolic rate, in human controlled trials. In one study in 10 healthy men, green tea increased energy expenditure by 4%. Another study showed that fat oxidation was increased by 17%, indicating that green tea may selectively increase the burning of fat.However, some studies on green tea don’t show any increase in metabolism, so the effects may depend on the individual. Caffeine itself has also been shown to improve physical performance by mobilizing fatty acids from the fat tissues and making them available for use as energy. In two separate review studies, caffeine has been shown to increase physical performance by 11-12%, on average.
8. Green tea helps to prevent Diabetes or Insulin Resistance
Certain studies indicate that intake of flavan-3-ols and/or anthocyanidins found in green tea may improve glycemic control and help normalize blood sugar levels. Due to its anti-inflammatory properties, green tea is believed to be beneficial for those who are at-risk or diagnosed with type 2 diabetes. Green tea’s catechins, especially EGCG, appear to have anti-obesity and antidiabetic effects.
9. Green tea promotes bone strength
University of Hong Kong researchers published a study in the August, 2009 Journal of Agricultural and Food Chemistry concerning green tea and bone health. When the bone cells of rats were exposed to green tea catechins, EGC in particular stimulated an enzyme that promotes bone growth by 79 percent. The catechins also increased bone mineralization and weakened the activity of cells that reabsorb bone rather than form it.
10. Green tea has anti-anxiety properties
Green tea comes packed with l-theanine, and l-theanine may help you to relax and avoid anxiety. A study published in the Journal of Trends in Food Science & Technology by Dr. Juneja and team states that theanine acts as a neurotransmitter that increases alpha waves in the brain. Alpha waves are considered to be an indicator of relaxation. Human volunteers were given 50-200 mg of l-theanine and were shown to have increased alpha waves without drowsiness. So it appears you can drink green tea to help mellow you out, without falling asleep.
11. Green tea improves heart health
One report by the Harvard Medical School states how the tea can protect the heart and prevent disease. It says that green tea can lower bad cholesterol levels that otherwise directly contribute to heart disease. Most of the studies have been conducted using green tea capsules – however, the benefits can be scaled to the tea as well. Green tea has also shown to dramatically increase the antioxidant capacity of blood – which, in turn, protects the heart from reactive oxygen species and prevents heart attacks. In fact, green tea drinkers were found to have 31% lower risk of cardiovascular ailments.
Green tea catechins can also help prevent atherosclerosis, a major cause of cardiovascular disease. These catechins were found to inhibit the condition. Further studies have found that though green tea lowers bad cholesterol levels, it doesn’t affect good cholesterol.
12. Green tea prevents eye disorder and protects vision
One study that was published in the February 2010 issue of the Journal of Agricultural and Food Chemistry investigated the effects of catechins on eye diseases and found that consuming more catechins may help protect the eyes from oxidative damage and vision loss. Scientists involved in the study found evidence that catechins can pass from the digestive tract of rodents to the tissues of their eyes and reduce oxidative stress for up to 20 hours after ingestion.
Green tea recipes
Green Tea with Honey:
- 1 cup water
- 1 tsp Honey
- 1 tea bag/tsp Green tea
- Boil water & add green tea
- Let it rest for 2 minutes
- Add honey & stir
- Serve hot
Green Tea with Lemon and Honey
- 2 cups water
- 1 tsp green tea
- Few drops of lemon juice
- 1 tsp Honey
- Bring water & add green tea
- Let it rest in the water for 1-2 minutes
- Add drops of lemon juice & honey and stir
- Serve hot or cold
Green Tea with Ginger and Honey
- 1 cup water
- 1 tsp tea
- Freshly squeezed ginger juice
- 1 tsp Honey
- Boil water and pour tea
- Let it rest for 1 minute
- Add ginger juice & honey and stir
- Serve hot
The benefits of Honey are innumerable as it not only helps in weight management but also in many other things as well. For example, if you are suffering from cold and cough, mix some ginger and honey and consume the mixture daily. The mixture will act as an antioxidant and will cure your illness naturally.
Green tea side effects and risks
There are little to no known side effects or contraindications to drinking green tea for adults. However, the following risks or complications should be made clear:
- Caffeine sensitivity – those with severe caffeine sensitivities could experience insomnia, anxiety, irritability, nausea, or upset stomach.
- Blood thinners – those taking blood thinners (anticoagulant drugs) such as Coumadin/warfarin should drink green tea with caution due to its vitamin K content. It’s also recommended to avoid green tea and aspirin, because they both reduce the clotting effectiveness of platelets.
- Other stimulants – if taken with stimulant drugs, green tea could increase blood pressure and heart rate.
Green tea supplements contain high levels of active substances that can trigger side effects and interact with other herbs, supplements, or medications. It supplements are unregulated by the FDA and may also contain other substances unsafe for health or with unproven health benefits. Always check with a doctor before starting any herb or supplement regimen. In particular, pregnant or breastfeeding women, those with heart problems or high blood pressure, kidney or liver problems, stomach ulcers, or anxiety disorders should not take green tea supplements or extracts.
If you want to feel better, lose weight and lower your risk of chronic diseases, then you might want to consider making green tea a regular part of your life.