Read the label on any energy drink and you&#;ll likely find green tea extract among the ingredients working to give you extra zip. But is this so-called &#;natural energy booster&#; really a fatigue fighter? And are there other potential benefits?
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Before you open that bottle of jolt juice or swallow a green tea extract supplement, let&#;s take a closer look with integrative medicine specialist Irina Todorov, MD.
Odds are you&#;re familiar with green tea, one of the most consumed drinks in the world. Well, green tea extract is basically a concentrated form of the popular tea that&#;s made from dried green tea leaves.
Green tea extract does contain caffeine, which explains why it frequently lands in energy drinks.
It&#;s also chock full of antioxidants and plant compounds called catechins that provide the foundation for many boost-your-health claims.
A catechin named epigallocatechin gallate, or EGCG, gets most of the marketing attention. You&#;ve probably seen its presence hyped on energy drinks and supplements.
The resume for green tea extract is pretty expansive. Aside from adding some oomph to your system with caffeine, it&#;s touted for weight loss, lowering your risk of heart disease, skin health and more.
But here&#;s the question: Does it really do all of that?
The caffeine does pack a definite punch. But Dr. Todorov cautions against relying on energy drinks &#; responsible for a rising incidence of caffeine toxicity among adolescents &#; to power through the day.
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Studies of green tea extract&#;s effect on athletic performance have been inconclusive, too, so don&#;t look for it to provide a competitive edge.
Quite simply, there are better ways to boost your energy besides unscrewing the top of a bottled drink and guzzling down the contents, says Dr. Todorov. She suggested lifestyle changes such as:
Research on using green tea extract for weight loss has found it can help lower the number on your scale &#; but don&#;t expect miracles. One study, for instance, shows any connection to be &#;modest at best.&#;
&#;In my opinion, patients can achieve the same amount of weight loss with lifestyle changes, and avoid the risk of side effects and the cost of supplements,&#; says Dr. Todorov.
Drinking green tea itself is associated with a lower risk of coronary artery disease. So, what happens when you pack all of that goodness into green tea extract? Basically, you see similar results.
One study found that taking a 379 milligram (mg) daily dose of green tea extract can help improve blood pressure and cholesterol numbers.
Dr. Todorov also gives green tea extract a thumbs up for skin health because of its antioxidant properties. Studies show it can help reduce acne and help aging skin reclaim some of its lost glow.
Too much caffeine is never a good thing, and it&#;s possible to push the limits with green tea extract. Excessive caffeine can lead to heart palpitations, high blood pressure, anxiety and other issues.
In addition, overdoing it on green tea extract has been linked to liver problems.
Part of the issue has to do with federal labeling requirements. Food and drink manufacturers don&#;t have to list the amounts of green tea extract or EGCG, which means you won&#;t know how much of it you&#;re consuming.
How do bottled green teas rate as a beverage? After all, they contain ECGC.
Bottled green teas also contain sugar or other sweeteners, notes Dr. Todorov. Plus, they&#;re expensive, and &#; as mentioned &#; their caffeine and EGCG content is not stated on the label.
&#;It&#;s better to enjoy a cup of green tea,&#; she says. &#;No evidence of toxicity has been reported from drinking green tea, even when you regularly consume two to four cups a day.&#;
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This article lists some potential health benefits and types of green tea, its nutrition content, and the potential side effects.
Some research suggests green tea may positively affect weight loss, liver disorders, type 2 diabetes, Alzheimer&#;s disease, and more. However, more evidence is necessary for researchers to definitively prove these health benefits.
Green tea comes from unoxidized leaves of the Camellia sinensis bush. It is one of the least processed types of tea, containing the most antioxidants and beneficial polyphenols.
People have hailed the health benefits of green tea for centuries. Studies suggest that consuming green tea may positively affect skin health, help with weight loss, and reduce the risk of cardiovascular disease, among other benefits.
Overall, more research on humans is necessary to prove the benefit of green tea on the overall risk of cancer.
A review suggests green tea catechins have some positive impacts on the following types of cancer:
The topical application of green tea polyphenol extracts may have a role in protecting the skin from UVB radiation. A review of in vitro, in vivo, and human studies demonstrated the potential benefits of tea polyphenols in the chemoprevention of UVB-induced skin cancer .
A database review of epidemiological and experimental studies in humans produced inconsistent results and limited evidence of green tea&#;s benefits for lowering cancer risk.
In countries with high green tea consumption, some cancer rates tend to be lower. However, human studies have not shown consistent evidence that drinking green tea reduces the overall risk of cancer.
Learn more about green tea and weight loss .
However, the impact of drinking green tea on weight loss is unlikely to be of clinical importance. Most studies that have shown small changes in metabolism used green tea extracts with extremely high concentrations of catechins.
A further meta-analysis of several different tea polyphenols-induced weight loss mechanisms suggested that catechins and caffeine synergistically produced weight loss effects, as opposed to them being the result of caffeine alone.
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A review suggests green tea and the catechin epigallocatechin gallate (EGCG) it contains may help people with obesity to reduce their body weight.
A analysis of tea extract use in cosmetics determined that solutions including tea extracts promoted anti-inflammatory responses when applied topically. The authors also found that skin microcirculation improved in the affected areas.
Green tea has anti-inflammatory properties. Research highlights the anti-inflammatory effects of green tea.
Separate reviews from and also found that the polyphenols in green tea may lower blood pressure, decrease inflammation , and improve epithelial function, which can help reduce heart disease risk in people with excess weight or obesity.
Another study associated green tea consumption with a lower risk of the following conditions:
A study of 18,609 Japanese participants found no correlation between green tea consumption and death from heart disease , regardless of blood pressure levels .
A review suggests green tea catechins have anti-inflammatory properties that target free radicals and protect heart health.
However, the authors highlight the need for more research, particularly longer studies with more diverse populations.
A review concluded that green tea consumption can significantly lower total cholesterol and low-density lipoprotein cholesterol in people with moderate weight, overweight, or obesity.
A review and meta-analysis supports this, associating moderate green tea consumption with a lower risk of stroke after evaluating five studies with 645,393 participants and 11,421 incidents of stroke.
According to the American Heart Association (AHA) , drinking large amounts of green tea without sugar may reduce the risk of stroke.
However, further research is necessary to fully determine the relationship between diabetes risk and green tea.
A further review of dietary polyphenol studies also associated green tea, as part of the Mediterranean diet , with a reduced risk of type 2 diabetes.
One study of people with and without diabetes in China associates daily green tea consumption with a lower risk of type 2 diabetes. It also associated daily green tea consumption with a lower risk of all-cause mortality in people with diabetes.
Some have suggested a lower risk of type 2 diabetes in people who drink green tea than in those who consume no tea.
Studies concerning the relationship between green tea and diabetes have been inconsistent.
According to a review , certain amino acids in green tea have an anti-stress element that helps to slow brain aging.
Similarly, another study examined the effect of green tea catechins on adults ages 50&#;69 in Japan. The authors suggest daily green tea supplementation may benefit working memory.
Several smaller studies support this. A study suggests acute green tea extract supplementation improved working memory capacity in 10 women ages 50&#;63, although there was no significant effect for younger adults.
A study of 264 adults in China associates regular green tea consumption with better cognitive function, particularly executive function and memory.
However, further research is necessary to strengthen this evidence.
This may be due to the neuroprotective effects, including anti-inflammation and anti-oxidative stress, of certain catechins in green tea.
According to a systematic review , current research generally supports the hypothesis that green tea may reduce the risk of Alzheimer&#;s disease and dementia .
However, further human clinical trials are necessary to firm up these theories.
Other research suggests green tea may have the following effects:
Green tea may also benefit other conditions. For example, the United States Food and Drug Administration (FDA) has approved a green tea extract ointment as a prescription treatment option for genital warts .
Green tea contains one of the highest amounts of antioxidants of any tea. Green tea is about 30% polyphenols by weight, of which approximately 80% is EGCG.
The caffeine in a cup of tea can vary according to the duration of infusing time and the amount of tea infused.
Green tea contains a relatively small amount of caffeine, approximately 29 milligrams (mg) per 8-ounce cup, compared with black tea, which has around 47 mg per cup, and coffee, which has about 95 mg per cup.
Unsweetened brewed green tea contains fewer than 3 calories per cup.
Green tea is available in many types and forms, including:
Always check with a doctor before starting any herb or supplement regimen.
The Food and Drug Administration (FDA) does not regulate green tea supplements. As a result, these supplements may contain other substances that are unsafe for health or have unproven health benefits.
Most research suggests that the rare cases of liver injury from green tea extract consumption are idiosyncratic reactions. Reviews of these instances have yet to conclude direct causality.
In adults, there are few known side effects associated with drinking green tea. However, the following risks and complications are important to note:
Below are some common questions about green tea.
Further research is necessary to determine the best time to drink green tea. However, since green tea contains caffeine, some people may prefer to drink it in the morning.
Research suggests it is safe for most adults to drink up to 8 cups of unsweetened green tea daily. However, people should be aware of the amount of caffeine in the brand they choose.
Very high quantities of green tea may lead to liver damage or interact with certain medications.
Some research suggests that regular tea consumption, including green tea, may help to reduce body weight and waist-to-hip ratios. However, several factors can influence fat loss, including total calorie intake and exercise levels.
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