The Many Evidence-Based Health Benefits of Drinking Green Tea

The Amazing Health Benefits of Green Tea

Green tea has become increasingly popular in recent years due to its many potential health benefits. This aromatic beverage has been used medicinally in China and other parts of Asia for thousands of years. Modern research has confirmed that green tea contains powerful antioxidants and other active compounds that can have protective effects on the body.

Green tea is made from the leaves of the Camellia sinensis plant, which go through a process of withering and oxidation. The level of oxidation determines whether the tea becomes green, oolong, or black tea. Green tea is only lightly oxidized, so it retains many of the beneficial compounds from the original tea leaves.

Nutrients and Bioactive Compounds in Green Tea

The main active components in green tea are polyphenols, particularly catechins like epigallocatechin gallate (EGCG). The catechins found in green tea may have various protective effects on cells and tissues in the body.

Other compounds present in green tea include:

• Amino acids like theanine
• Vitamins like vitamin C and B vitamins
• Minerals like manganese and zinc
• Caffeine
• Antioxidants like flavonoids and polyphenols

The specific contents and concentrations of the compounds can vary depending on the tea plant variety, processing methods, and preparation methods. The health effects of green tea are mainly attributed to its high content of polyphenols and catechins.

1. Green Tea Contains Antioxidants That May Protect Against Cancer

Green tea is an excellent source of powerful antioxidants. The catechins found in green tea may inhibit the growth of cancer cells by reducing angiogenesis (growth of new blood vessels that feed the tumor) and metastasis (spread of cancer).

EGCG is one of the most powerful catechins and has been shown to inhibit the spread of various types of cancer. Green tea may also help sensitize cancer cells to radiation treatment.

According to some epidemiological studies, people who regularly drink green tea may have a lower risk of developing certain types of cancer like breast, prostate, colorectal, and pancreatic cancer.

However, more clinical research is still needed to confirm green tea's cancer-fighting effects in humans. But the antioxidant and anticancer potential of green tea looks promising.

2. The Catechins in Green Tea May Lower Your Risk of Heart Disease

Green tea may protect against heart disease by improving blood flow, reducing "bad" LDL cholesterol oxidation, and preventing the formation of blood clots associated with heart attacks and strokes.

An analysis of 13 studies found that green tea drinkers had a 31% lower risk of heart disease than those who didn't drink green tea. The polyphenols in green tea, especially EGCG, appear to prevent the accumulation of plaque that can clog arteries.

In addition to lowering LDL and total cholesterol levels, green tea also increases "good" HDL cholesterol. A higher HDL level is linked to a reduced risk of heart disease.

Population studies have also shown that people who regularly drink green and black tea have lower rates of stroke.

3. Green Tea May Help with Weight Loss

Green tea contains caffeine and catechins like EGCG that may boost metabolism and promote fat burning. The catechins in green tea may help inhibit enzymes that break down norepinephrine, which is a hormone that can increase the amount of fat your body breaks down.

Most studies show that green tea extract can increase fat burning and help you lose body fat, though the effects are modest. A review of 15 studies concluded that drinking green tea could help reduce body weight and body fat percentage.

Drinking green tea may support your weight loss goals by boosting metabolism and promoting the breakdown of fat. But to maintain healthy body weight, green tea should be consumed as part of an overall healthy and active lifestyle.

4. The Antioxidants in Green Tea May Lower Your Risk of Alzheimer's and Parkinson's

The catechin compounds in green tea have been shown to have protective effects on neurons, potentially lowering the risk of Alzheimers and Parkinson's. EGCG appears to decrease the production of beta-amyloid and phosphorylated tau proteins, which can form toxic, brain-damaging plaques in Alzheimer's disease.

Green tea has also been shown to improve memory and brain function in healthy individuals. The amino acid L-theanine in green tea increases activity in the inhibitory neurotransmitter GABA, which has anti-anxiety effects. L-theanine also increases dopamine and alpha wave production in the brain.

The polyphenols in green tea may help protect brain cells from dying and restore damaged brain cells after stroke. This helps lower your risk of cognitive decline and disorders like Alzheimers and Parkinsons.

5. Green Tea May Reduce Bad Breath

The catechins in green tea may inhibit the growth of bacteria in the mouth, reducing the risk of bad breath. The polyphenols in green tea can kill and reduce the amount of bacteria and viruses in the mouth that cause plaque formation and dental decay.

Regularly gargling with green tea provides long-lasting fresh breath. But be aware that green tea also contains tannins that can stain teeth if consumed excessively.

6. Green Tea May Help Prevent Type 2 Diabetes

Green tea appears to improve glucose control and reduce blood sugar levels. A Japanese study found that high green tea consumption was associated with a 42% lower risk of developing type 2 diabetes.

EGCG and other polyphenols in green tea inhibit digestive enzymes that convert carbohydrates from foods into simple sugars. This prevents spikes in blood sugar levels following meals.

Green tea also increases insulin sensitivity and reduces blood sugar production in the liver, helping maintain steady blood sugar levels. Several studies show that green tea drinkers have up to a 30-40% lower risk of developing type 2 diabetes.

7. Green Tea May Help Prevent Cardiovascular Disease

Green tea protects heart health on several fronts. The antioxidants in green tea improve cholesterol levels, triglycerides, and total and LDL ("bad") cholesterol. Green tea also prevents the oxidation of LDL particles, another factor that drives heart disease.

Green tea improves the function of endothelial cells lining the blood vessels, providing a smooth surface for blood to flow. The catechins prevent blood clot formation, further reducing heart disease risk.

Given the many cardio-protective effects, it's no surprise that green tea drinkers have up to a 31% lower risk of heart disease according to population studies.

8. Green Tea May Benefit Exercise Performance and Recovery

The combination of caffeine and catechins found in green tea extracts may benefit performance by mobilizing fatty acids from fat tissue to support energy production. The catechins in green tea may also support muscle endurance during physical activity.

In a study of 12 healthy males, fat oxidation was 17% higher after ingesting green tea extract than after a placebo. This could translate into enhanced exercise performance.

Antioxidants in green tea may also reduce muscle damage and accelerate recovery after strenuous exercise. More research is needed to confirm these effects.

9. Green Tea May Help Keep Skin Looking Youthful

The powerful antioxidants in green tea neutralize free radicals and reduce inflammation in the skin. This may help keep skin looking fresh and protect it from sun damage.

An observational study involving over 4,000 women found that those who drank more than 2 cups of green tea daily had less skin redness and damage. The polyphenols promote blood flow and oxygen to the skin surface, keeping it smooth and supple.

Topical green tea creams and extracts have been shown to reduce signs of aging, provide sun protection, hydrate skin, and improve skin elasticity. Green tea may also help treat skin conditions like psoriasis, rosacea, and dandruff.

10. Green Tea Can Help You Live Longer

Given the many health benefits of green tea, it may not come as a surprise that it's linked to longer life expectancy. In fact, those who regularly drink green tea may be at a lower risk of death from any cause.

A large study of over 40,000 adults in Japan found that those who drank 5 or more cups of green tea per day were 26% less likely to die during the 11 year study period:

• Men who drank 5+ cups had a 12% reduced risk of death
• Women had a 23% reduced risk

The antioxidants and other beneficial compounds in green tea may help protect cells from damage that can lead to disease and premature aging. This may in part explain the association between green tea consumption and longevity.

How to Prepare Green Tea

To make green tea, leaves are steamed, rolled, and dried after harvest. The dried leaves can then be steeped in hot (not boiling) water to make the tea. The best flavor and maximum amount of active compounds are extracted when water is 80-85C.

Avoid using boiling water, which can destroy some of the delicate compounds. Steep green tea leaves for 1-3 minutes; higher-grade teas need less steeping time. The green tea leaves can be reused a couple of times.

Many drink green tea plain, but it can also be combined with other healthy ingredients like mint, ginger and lemon. Matcha is a type of powdered green tea that is dissolved in hot water instead of steeped.

How Much Green Tea Should You Drink?

Most of the health benefits linked to green tea are based on about 35 cups per day. Green tea extract supplements contain a higher concentration of the active compounds. For example, a green tea extract capsule may contain the same polyphenol content as 35 cups of tea.

Consuming more than 5 cups of green tea daily may cause side effects due to excess caffeine. Side effects can include anxiety, headaches, diarrhea and irregular heartbeat. Most people can safely drink up to 4-5 cups of green tea per day.

Possible Side Effects and Precautions

Green tea is generally safe for most adults when consumed in moderation. However, some people should limit green tea intake or avoid it altogether.

Since green tea contains caffeine, be cautious combining it with other caffeinated foods and drinks. Excess caffeine can trigger side effects like anxiety, insomnia and upset stomach.

Pregnant and breastfeeding women should limit caffeine intake to less than 200mg per day. Those sensitive to caffeine should also limit intake.

Green tea supplements contain high levels of active compounds. Adhere to the dosage instructions on the package to avoid adverse effects. Certain medications can also interact with the compounds in green tea.

Green tea can decrease the absorption of iron from plant foods. Consider avoiding green tea with meals if you have low iron levels or an iron deficiency.

Drinking green tea on an empty stomach may cause nausea and stomach ache. Have it with food to minimize potential side effects.

The Bottom Line

For centuries, green tea has been consumed for its health benefits, from promoting weight loss to boosting immunity. Modern research confirms that the antioxidants and other active compounds in green tea offer protective effects for many aspects of health.

Regularly drinking green tea can help you lose weight and reduce your risk of heart disease, Alzheimer's, diabetes, and other chronic diseases while improving brain function and extending your lifespan.

To maximize the health benefits from green tea, avoid adding milk and sugar. Simply brew a few cups from high-quality loose leaf or tea bags and enjoy the many health benefits of this legendary beverage.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.