Potential Health Benefits and Risk Factors of Green Tea
Green tea is increasingly getting popular as a beverage of choice across the globe. Nowadays you can find it in many varieties and flavours marketed by different brands. All these different forms are made by the leaves of the Camellia sinensis plant.
The leaves of freshly harvested plants are steam dried to preserve the colour pigments and polyphenol components of the leaves while maintaining their salubrious properties. One major reason for the increasing popularity of green tea is its association with improved digestion, weight loss and brain stimulation. Very few people are familiar with the other potential effects of green tea on human health.
Here is what you actually have in your cup of green tea
Green tea has a burst of antioxidants which are the backstage players of most of its beneficial health effects. It is a zero-calorie beverage if there are no added sugars as it does not contain any fats, proteins or carbohydrates.
Its medicinal effects are due to the presence of polyphenols (catechins, tannins and flavonoids) which are abundantly found in it, the most important being Epigallocatechin gallate (EGCG). Green tea is also rich in caffeine although not as much as coffee.
A few minerals like calcium, iron and potassium have also been found in green tea in very small amounts. Along with these, it also contains L-theanine and tannins.
The health benefits of green tea
Originally, green tea was introduced as a traditional herbal medicine in China and Japan for many different conditions. Modern research has proved many of the health benefits of green tea while many others have no scientific basis.
1. Green tea is good for your heart
People who consume five cups of green tea per day have a reduced risk of death due to cardiac problems. Polyphenols present in green tea reduce blood pressure and lessen inflammation thus improving heart health. Green tea also reduces cholesterol levels in the blood.
2. It offers anti-cancer effects
Reduced cancer rate has been seen in people who consume green tea. It may be attributed to the presence of antioxidants in green tea which protect against mutagenic cancer-causing environmental effects. However, the scientific research on the association of green tea with reduced cancer rates shows inconsistent results.
3. It saves you from Stroke
Green tea also provides some protection against stroke. People who consume four cups of green tea per day are less likely to be attacked by stroke.
4. It’s beneficial for the skin
Green tea protects the skin from UV radiation thus preventing skin cancers. It’s also good for the improvement of eczema and genital warts.
5. Green tea benefits type-2-diabetes
Green tea consumption reduces the blood glucose level in type-2 diabetes patients. In this type of diabetes, the body develops insulin resistance and cannot utilise sugars properly. Green tea reduces this insulin resistance. Three cups of green tea per day improves the condition.
6. Green tea enhances brain activity
Green tea acts as a brain stimulant and keeps you alert for longer times. This effect of green tea is due to the presence of caffeine, which is a strong brain accelerator. As caffeine is in lesser amounts in green tea than in coffee, it enhances your brain activity without giving you anxiety and uneasiness.
7. Green tea reduces anxiety
Using green tea regularly reduces anxiety and anxiety-related disorders. The amino acid L- theanine along with caffeine are attributed to these anti-anxiety effects of green tea.
8. Green tea for weight loss.
The most common health benefit of green tea is considered to be its role in reducing weight. The catechins and caffeine of green tea increase metabolism resulting in weight loss. Amazingly enough, this most striking benefit that has brought green tea into the limelight has not been supported by scientific research.
No reduction in weight has been seen in individuals taking green tea in their weight loss plans. The effect of catechins and caffeine on metabolism is pronounced when these are consumed in very concentrated forms.
Harmful effects of green tea on human health
Green tea is getting so much attention due to its beneficial effects that its side effects usually get shielded and ignored. One should be aware of these harmful effects on the body in order to optimise the green tea intake and to get the maximum benefits out of it. Some of the side effects of green tea on human health are discussed here.
1. It causes stomach problems and heartburn
Green tea contains tannins which have acidic properties. So, it increases the acidity of the stomach. This abnormally high acid milieu of the stomach may cause food particles to move back to the food pipe thereby initiating heart burns. This also creates feelings of nausea and vomiting.
The excess intake of green tea may also lead to constipation. However, these effects are not much pronounced if warm water is used to make green tea beverages instead of very hot water.
People with stomach acidity problems or other related disorders should avoid green tea. Taking green tea on an empty stomach may enhance these responses, so, it’s suggested to take tea after having a meal instead of taking it on an empty stomach.
2. Green tea causes Iron deficiency
Green tea is full of antioxidants which interfere with iron absorption in the intestines. Excessive intake of green tea may cause iron deficiency or it can aggravate the condition in anaemic people. It’s better to have one hour between your green tea and meal intake so that the body is having enough time for iron to be absorbed by the body.
3. Green tea reduces bone strength
As with iron, green tea also interferes with calcium absorption in the body which may lead to calcium deficiency resulting in reduced bone density and strength while increasing the risks of fractures and osteoporosis.
Vitamin C found in lemons helps in calcium absorption. So, squeezing a lemon in your cup of tea may not only make it more palatable but also counteracts its negative effect on calcium absorption. People with osteoporosis must take green tea after consultation with health officials.
4. It may damage your liver
Excessive use of green tea may damage your liver due to its caffeine contents which may cause jaundice and liver toxicity. The EGCG, although having many healthy effects, in large quantities affects liver health. So, if you notice any signs of jaundice like yellowing of the skin and eye whites stop taking green tea and consult your health professional.
5. It causes anxiety and insomnia
Although green tea keeps your mind alert and active, higher caffeine may lead to anxiety and sleep disorders. Although the L-theanine present in green tea has calming and soothing effects, these are outweighed by the presence of caffeine.
In spite of all these side effects, green tea is the safest beverage. Most of the side effects of green tea are observed when taking tea extracts which come in the form of tablets and supplements, or by consuming excessive tea.
The green tea in your cup that comes from a tea bag, usually, is diluted enough to rule out many of these effects. The remaining ones you can avoid by following the recommendations. However, you must consult your health expert before taking green tea if you are having liver problems, stomach disorders or mineral deficiencies.