You have probably heard about the many benefits of green tea. How can it help you as an athlete?
Carlos Soler, CrossFit athlete and sports nutritionist at INDYA, explains.
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Green Tea Nutrition Facts
Green tea comes from the Camellia sinensis plant. We could describe this infusion as virtually calorie-free, as it is very low in calories. Here is the nutritional information for a cup of tea (approximately 240 ml):
- 2 calories
- 0 grams of fat
- 0 grams of protein
- 0.5 grams of carbohydrates
- 0 grams of fibre
These infusions can be a good option for people seeking a calorie deficit, as they provide just 2 calories and, as you can see, barely contain any macronutrients.
Green tea’s benefits mainly come from its antioxidant power, due to its high polyphenol content. It also provides vitamins, including vitamin C, vitamin K, folic acid and B vitamins.
It also contains essential minerals such as potassium, fluoride, magnesium and manganese. The latter supports the production of sex hormones.
How Much Caffeine Does Green Tea Contain?
First, what is caffeine?
The substance caffeine is a natural alkaloid found in various plants, known for its stimulating properties, which can improve concentration and increase energy.
There are several natural caffeine sources, including green tea.
As mentioned, green tea comes from the Camellia sinensis plant and is distinguished by its oxidation process. This influences the caffeine content of green tea, which varies with factors including the tea type or variety, harvest time, leaf age, climate and production process.
Here is an estimate of the caffeine content in different types of green tea:
- Sencha green tea: One of the most common types, generally containing around 20-50 milligrams of caffeine per approximately 230-240 millilitres.
- Matcha green tea: Matcha usually has a higher caffeine concentration, giving it a distinctive aroma and flavour. A cup is estimated to contain 70-100 milligrams.
- Gyokuro green tea: Grown differently from sencha, it usually has a higher concentration. It can contain 35 to 70 milligrams of caffeine.
- Genmaicha green tea: Mixed with roasted rice grains, this tea contains around 20-30 milligrams of caffeine.
- Bancha green tea: The mildest variety, with less caffeine than sencha, approximately 20-30 milligrams.
Green tea offers a moderate caffeine content compared with coffee or energy drinks. This makes it a gentler alternative for people seeking stimulation and green tea’s benefits without extremely high caffeine levels.
What Are the Benefits of Green Tea?
The drink green tea has antioxidant and anti-inflammatory properties thanks to its high polyphenol content. Catechins are the most abundant polyphenols, helping neutralise free nitrogen and oxygen radicals.
There is plenty of information claiming that green tea offers anti-ageing or anticancer effects, but no study confirming this.
This infusion is recognised worldwide for its many health benefits and positive effects. These benefits of green tea are largely associated with compounds possessing anti-inflammatory, thermogenic, cardioprotective and hepatoprotective properties.
These compounds are catechins, natural antioxidants that help prevent cell damage. They include epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG) and epigallocatechin gallate (EGCG), the most abundant.
Why Is Green Tea Good for You?
Green tea’s many benefits include:
- Antioxidant power: Tea is packed with polyphenols, especially catechins, which help protect cells against free radicals responsible for cellular ageing and disease.
- Better cardiovascular health: Green tea may improve some major risk factors for conditions such as heart disease or stroke. It has been shown to lower LDL cholesterol and triglycerides while protecting LDL against oxidation.
- Potential support for weight loss: One component of tea is caffeine, also known as theine, an alkaloid in the xanthine family with stimulating effects. It can increase fat oxidation in the short term by increasing lipolysis, allowing more fat to be oxidised. This is why the catechins in tea, together with the mild diuretic action of caffeine, are thought to support weight loss.
- Improved brain function: Thanks to caffeine and L-theanine, which have shown potential synergistic effects. This combination can be effective in improving cognitive function, concentration and alertness, as it blocks adenosine receptors in the brain.
Green tea usually contains less caffeine than coffee, but enough to produce the same effects.
- Anti-inflammatory effects: The catechins mentioned above, mainly EGCG, have anti-inflammatory properties that can benefit people with chronic inflammation.
- Antimicrobial properties: Green tea consumption is associated with better dental health and a lower risk of infections. Its catechins can kill bacteria and inhibit viruses. Studies show they can inhibit Streptococcus mutans, the mouth’s most harmful bacterium.
What Is Matcha Tea?
It is a type of powdered Japanese green tea made from the Tencha variety. Different cultivation, harvesting, drying and grinding processes make it particularly rich in antioxidants and increase its benefits.
Its flavourful leaves are grown in shade, protected from sunlight. This increases levels of chlorophyll, theanine and caffeine, explaining its intense colour and distinctive flavour.
Once harvested, the leaves are spread on a surface for drying. The process continues with steaming to separate the leaves from their stems, before grinding them into a very fine powder.
It can be served hot or cold. Unlike other infusions, the whole leaf is consumed, providing more fibre.
If you have never tried it, this version is a favourite among the tea lovers on our team. The flavour is excellent.
Benefits of Matcha Tea
This infusion is said to have properties and advantages beyond other teas. In particular, it is said to multiply by 137 the benefits of conventional green tea .
Matcha is very rich in antioxidants, with abundant polyphenols that help increase enzyme activity and neutralise free radicals. It is particularly rich in catechins, including the EGCG mentioned earlier, which combat free radicals to help prevent cell damage, strengthen the immune system and reduce the risk of chronic disease.
This enzyme activity is also enhanced by caffeine, which is more concentrated in matcha than in green tea. Caffeine inhibits the secretion of pro-inflammatory cytokines , producing an anti-inflammatory effect.
The antioxidants and phenolic acids have high anti-inflammatory potential, reducing cholesterol and blood pressure and helping prevent heart disease.
Matcha also provides higher concentrations of essential vitamins and minerals . It supplies vitamin C to support immunity, as well as calcium and potassium to support muscle contraction and nerve impulses.
As you can see, matcha green tea offers many benefits.
What Happens If I Drink Green Tea Every Day?
The drink green tea is generally safe in moderation, but excessive intake can cause unwanted side effects.
Most side effects relate to its caffeine content. Although concentrations are not high, excessive daily intake can produce some of the following effects.
It may cause insomnia, nervousness or anxiety. Avoid large amounts or drinking it near bedtime so it does not interfere with sleep.
It may also cause headaches in some caffeine-sensitive people when consumed excessively.
Besides digestive problems, it can irritate the stomach and cause gastrointestinal discomfort, including heartburn. Excessive tea intake has been associated with possible liver damage from epigallocatechin-3-gallate (EGCG), one of the most abundant catechins, but controlled daily consumption of these drinks has no contraindication.
It may even cause cardiovascular problems by raising blood pressure, so people with hypertension should monitor their intake.
The amount of green tea we can drink varies between individuals. In general, it is recommended not to exceed 400 milligrams of caffeine daily, roughly equivalent to 4-5 cups of tea. This is more than enough to enjoy the benefits of green tea.
When Should You Avoid Green Tea?
Tea can reduce the absorption of iron because it contains substances such as polyphenols and tannins, which prevent proper absorption. Excessive intake is therefore unsuitable for people prone to anaemia.
Certain groups also need particular care, as excessive green tea intake can cause problems.
It is recommended that pregnant women limit green tea intake, as excessive caffeine may increase miscarriage risk and problems with foetal development.
People with pre-existing heart conditions should limit caffeine because it can increase heart rate and blood pressure.
Finally, people sensitive to caffeine should avoid it before bedtime, as it can disrupt rest and cause insomnia.
In all these cases, potential drawbacks may outweigh green tea’s potential benefits.
What Is the Best Time to Drink Green Tea?
The best time depends on your needs and preferences.
If you prefer it first thing, it can help improve attention and concentration during the morning.
Its epigallocatechin gallate (EGCG) helps regulate carbohydrate metabolism by lowering and regulating blood sugar and inhibiting gluconeogenesis. Drinking it before or after meals may therefore be an option, except for people prone to iron deficiency or anaemia because, as mentioned, it inhibits absorption of minerals including iron.
Whether afternoon or evening green tea is recommended depends on factors such as the dose or amount of green tea and your caffeine tolerance.
Are There Benefits to Drinking Green Tea on an Empty Stomach?
The practice of drinking green tea on an empty stomach has become popular because of the belief that it can support weight loss. Although advertising promotes this benefit, attributing weight loss solely to green tea on an empty stomach is mistaken: an isolated drink cannot be credited with this effect.
Many factors must be considered for weight loss. First, you need a calorie deficit alongside appropriate nutrition, adequate rest and daily physical activity. There is insufficient scientific evidence to conclude that drinking it on an empty stomach provides this benefit.
Green tea has many benefits, but it is no magic food.
Drinking it first thing on an empty stomach may improve cognitive function through greater focus and concentration for morning tasks. It also supports hydration during those fasting hours. However, these benefits do not differ from drinking it at other times.
Is Drinking Green Tea at Night Appropriate?
If you are sensitive to caffeine , it is not a good idea and is not recommended. Although tea’s caffeine content is usually modest, it can cause effects associated with excessive caffeine, such as insomnia, nervousness, anxiety and increased heart rate.
If you want an infusion before bed, choose caffeine-free alternatives or relaxing herbal teas such as valerian or chamomile.
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