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EGCG
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Epigallocatechin Gallate, (-)-Epigallocatechin-3-gallate
- Antioxidant, Flavanol, Glycoside, Phytochemical, Polyphenol, Senomorphic, [Group: Tea]
Intestinal uptake (bioavailability) of green tea catechins is low, ranging from 1.68% in humans to up to 13-26.5% in mice. This low intake is partially due to the physical structure of catechins which form a large hydration shell; they are absorbed via passive diffusion (between intestinal cells) rather than via a transporter. Catechin absorption is improved on an empty stomach for both pure EGCG and a decaffeinated green tea extract containing multiple catechins. One study using 400 mg and 800 mg EGCG with a light breakfast noted that >92% of circulating EGCG was in the free form which has been replicated in other pharmacokinetic studies. Interestingly, the higher dose of 800mg EGCG is associated with an increased half-life, suggesting either saturation of EGCG excretion or sufficient inhibition of COMT to preserve itself from methylation. Taking EGCG fasted results in a higher Cmax (maximal amount to hit blood) of about 3.5-fold, and the overall AUC was greater fasted. Peak serum levels of green tea catechins (Tmax) tend to be around 2 hours after oral consumption, although they can be shifted sooner by consuming them in a fasted state to around 60 minutes*. - Curcumin, Piperine, Quercetin
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Ever wonder why drinking green tea and other teas has been linked to longevity— not to mention cognitive health, protection against cardiovascular disease and much more? One reason is because of EGCG, a type of polyphenol antioxidant found in a variety of tea leaves.
Polyphenols like EGCG have been shown to have free radical-scavenging abilities and other beneficial effects that help protect cells and tissues throughout the body.
While you can consume this catechin in supplement form, the best way to obtain it is by drinking several cups of high-quality, brewed tea each day. This habit has been shown in studies to support a healthy metabolism, help regulate blood pressure and protect the brain from age-related damage.
What Is EGCG?
EGCG, which stands for epigallocatechin gallate, is a beneficial plant compound called a polyphenol (which is a catechin, a type of flavonoid). It’s the most abundant catechin found in black and green tea leaves, although tea leaves contain other catechins too, such as epicatechin, gallocatechin and gallate derivatives.
Is green tea extract the same as EGCG? Green tea extract is made from dried green tea leaves, so it does contain EGCG, along with caffeine and other antioxidants. According to Examine.con, most green tea extract supplements are roughly 50 percent EGCG.
EGCG Foods/Drinks
To increase your intake of this compound, the top EGCG foods and beverages to include in your diet are:
- • Green tea (which has slightly higher amounts of catechins than black tea)
- • Black tea
- • White tea
- • Oolong tea
- • In smaller amounts, berries, including cranberries, strawberries, blackberries
- • Other fruits like kiwis, cherries, pears, peaches, apples
- • Avocados
- • Some nuts, such as pistachios, pecans and hazelnuts
Did you know that green tea and black tea both come from the same plant? The Camellia sinensis evergreen shrub, which is native to China, India and other countries in Asia, produces nutrient-rich leaves that are harvested, steamed, dried or heated to make tea.
Black tea leaves are slightly more processed than green tea leaves, which lowers the flavonoid content and EGCG levels slightly.
Which green tea has the most EGCG?
The concentration of bioactive compounds, including polyphenols, in green tea can vary widely depending on preparation methods. Generally speaking, the type of green tea with the highest EGCG level is high-quality, ideally organic, brewed green tea.
You can help increase the EGCG concentration of your tea by steeping it in boiling water (not just hot water) and letting it sit for a full 10 minutes before removing the leaves. This method results in a stronger tea with a somewhat bitter taste, although the taste can be improved by adding some raw honey or fresh lemon juice.
You’ll also find high levels of EGCG in matcha green tea, a high-grade, finely ground, concentrated green tea that has been consumed in Japan for hundreds of years.
When you drink tea while eating a meal, some of the antioxidants may bind to minerals in the food you’re eating, making them a bit less bioavailable. If you want to maximize the amount of catechins you actually absorb, then drink tea alone and between meals.
If you’re looking to benefit from drinking more tea you’ll also want to avoid sweetened, bottled teas and premixed green teas, which are often lower in antioxidants and tend to be high in sugar.
Does EGCG contain caffeine?
EGCG is not the same thing as caffeine — however both are naturally found in both black and green teas.
The amount of caffeine in tea ranges from about 20 to 45 milligrams per eight-ounce cup, with black tea having a bit more than green tea. Both have a lot less caffeine than coffee, about half as much or even less depending on the kind of tea.
Benefits/Uses
What is EGCG good for exactly? Based on what we know from available research, EGCG has certain anti-aging effects and can act like a natural therapeutic agent to aid prevention of some diseases.
This catechin has been shown to have these protective effects:
- • Acts as an antioxidant and free radical scavenger
- • Fights inflammation/inflammatory diseases by suppressing activity of pro-inflammatory chemicals
- • Blocks neurodegeneration
- • Acts as an anti-carcinogenic (protects against cancer)
- • Has metal-chelating abilities
- • Supports metabolic activities that may prevent weight gain and metabolic syndrome
- • May help reduce development of cancer, diabetes, heart disease and neurodegenerative disorders
Here’s a bit more about some of the most well-known ECGC benefits and uses:
1. Fights Oxidative Stress/Inflammation
Studies investigating EGCG have found that it suppress accumulation of reactive oxygen species, alters signaling pathways in a way that prevents excessive inflammatory responses, lowers nitric oxide levels and reduces oxidative stress.
There’s also evidence suggesting that this polyphenol directly interacts with proteins and phospholipids and regulates signal transduction pathways, transcription factors, DNA methylation, mitochondrial function and autophagy (how the body cleans out damaged/dead cells).
All of this translates to enhanced protection against a wide range of health problems, especially those related to inflammation and aging.
2. Supports Heart Health
Catechins in tea leaves are thought to be responsible for many of their beneficial health effects linked to the heart and blood vessels.
According to Harvard Health Publishing, flavonoids help quell inflammation, and that in turn may reduce plaque buildup inside arteries, improve vascular reactivity, improve blood pressure and help lower LDL cholesterol levels.
There’s also evidence that regular tea drinkers may have a reduced risk of experiencing a heart attack or stroke.
3. Helps Protect the Brain
Researchers believe that EGCG has neuroprotective benefits due to its antioxidant effects and ability to invoke a range of cellular mechanisms in the brain. Consumption has been linked to increased protection against neurodegenerative diseases, such as Alzheimer’s disease, dementia and Parkinson’s disease.
Some studies have found that catechins can help reverse neural damage and prevent further neural death, decreasing declines in cognitive function as people age.
A number of large studies have found that adults who consume two to three cups of green tea daily for at least several years experience reduced prevalence of cognitive impairment, such a 30 percent to 40 percent lower risk of developing Parkinson’s.
In addition to suppressing cognitive dysfunction, EGCG may help increase learning ability by reducing oxidative damage in the brain.
4. Supports a Healthy Metabolism/Weight Loss
While not a quick fix for weight loss, there’s some evidence demonstrating that this compound can protect against metabolic syndrome and promote fat loss in several ways— such as by decreasing inflammation, suppressing your appetite and increasing energy expenditure. EGCG may also work in part by boosting thermogenesis (the body producing heat by using energy), although not every study has found evidence that these effects are substantial.
Consumption of two or more cups daily has been linked to a healthier body composition in certain studies.
For even stronger effects, EGCG and caffeine can be consumed together (such as from tea or some extracts and supplements). One study found that taking EGCG supplements along with caffeine for several months helped support fat loss among overweight adults.
Dosage Recommendations
One cup (eight ounces or 250 milliliters) of brewed green tea naturally contains about 50–100 milligrams of EGCG (and 30 to 40 milligrams of caffeine).
In addition to being found naturally in tea, EGCG supplements are also available over-the-counter.
What’s the best EGCG supplement to take?
Unfortunately, many supplements are not strictly regulated, making it difficult to ensure you get a pure product. Therefore the safest way to consume ECGC seems to be from real food/beverage sources, especially green and black tea.
Drinking one to four cups daily is thought to be healthy for most adults and poses little risk, unless someone is very sensitive to caffeine or oxalates found in tea (for example, because he or she has a kidney issue). Consuming two to three cups per day of high-quality brewed green tea (not bottled, sweetened green tea) is a common recommendation by health experts if you’re looking to benefit from catechins.
If you do decide to take EGCG supplements, how much should you take? There isn’t a standard recommendation, however one meta-analysis found that dosages between 150 and 2,500 milligrams of catechins daily from green tea or green tea extract was capable of helping improve patients’ cholesterol profiles.
Most experts recommend taking up to 400 milligrams in supplement form at first and not more than 800 milligrams before knowing how you react (and ideally with help from a health care provider).
Because there is a big range in terms of dosage recommendations, to narrow down how much you should consume, consider starting with a low dose between 150 and 400 milligrams daily and increasing slowly if needed. One study found beneficial effects on body weight when adults consumed up to 460 mg/day — therefore high doses might not be needed in most instances.
Risks and Side Effects
Because there’s limited evidence about the effectiveness and safety of EGCG supplements, it’s important to both follow dosage recommendations and to buy a high-quality product. Consuming high doses in supplement form has been linked to potential liver damage, so be careful to avoid taking too much.
To ensure you take an appropriate amount, look for a supplement that lists the amount of catechins and EGCG per serving. To limit risks for potential side effects, stick to doses under 800 mg/day.
If you’re very sensitive to caffeine or oxalates, minimize your tea consumption and avoid supplements that contain caffeine and other stimulants.
Stop using EGCG supplements if you notice any of the following symptoms:
- • dizziness
- • low blood sugar
- • weakness
- • anemia
- • indigestion
EGCG supplements and green tea extract also shouldn’t be taken by pregnant women or patients suffering from renal failure, liver disease or certain heart conditions. If you take medications daily to control your cholesterol or blood pressure levels, talk to your doctor before supplementing.
Conclusion
EGCG stands for epigallocatechin gallate. It’s a type of plant compound called a catechin that is found most abundantly in green and black tea leaves.
EGCG benefits and uses include fighting inflammation and oxidative stress, supporting heart health and metabolic function, supporting weight loss, and protecting the brain against degeneration.
To reap the benefits of this compound, most adults can safely consume two to four cups of brewed green tea daily.
Be cautious when using EGCG supplements, starting with a low dose under 400 mg/day and monitoring your reaction.
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EGCG (Epigallocatechin Gallate): Benefits, Dosage, and Safety
Epigallocatechin gallate (EGCG) is a unique plant compound that gets a lot of attention for its potential positive impact on health.
It’s thought to reduce inflammation, aid weight loss, and help prevent heart and brain disease.
This article reviews EGCG, including its health benefits and possible side effects.
What is EGCG?
Formally known as epigallocatechin gallate, EGCG is a type of plant-based compound called catechin. Catechins may be further categorized into a larger group of plant compounds known as polyphenols.
EGCG and other related catechins act as potent antioxidants that may protect against cellular damage caused by free radicals.
Free radicals are highly reactive particles formed in your body that can damage your cells when their numbers get too high. Eating foods high in antioxidants like catechins may help limit free radical damage.
Additionally, research suggests that catechins like EGCG may reduce inflammation and prevent certain chronic conditions, including heart disease, diabetes, and some cancers.
EGCG exists naturally in several plant-based foods but is also available as a dietary supplement usually sold in the form of an extract.
Naturally found in various foods
EGCG is probably best known for its role as the major active compound in green tea.
In fact, the numerous health benefits associated with drinking green tea are typically credited to its EGCG content.
Though EGCG is predominantly found in green tea, it also exists in small amounts in other foods, such as:
- Tea: green, white, oolong, and black teas
- Fruits: cranberries, strawberries, blackberries, kiwis, cherries, pears, peaches, apples, and avocados
- Nuts: pecans, pistachios, and hazelnuts
While EGCG is the most researched and potent catechin, other types like epicatechin, epigallocatechin, and epicatechin 3-gallate may offer similar benefits. Plus, many of them are more widely available in the food supply.
Red wine, dark chocolate, legumes, and most fruit are a few examples of foods that offer a hefty dose of health-promoting catechins.
May offer powerful health benefits
Test-tube, animal, and a few human studies indicate that EGCG provides numerous health benefits, including reduced inflammation, weight loss, and improved heart and brain health.
Ultimately, more research is needed to better understand how EGCG may be used as a preventative tool or treatment for disease, though current data is promising.
Antioxidant and anti-inflammatory effects
Much of EGCG’s claim to fame comes from its strong antioxidant capacity and potential to reduce stress and inflammation.
Free radicals are highly reactive particles that can cause damage to your cells. Excessive free radical production leads to oxidative stress.
As an antioxidant, EGCG protects your cells from damage associated with oxidative stress and suppresses the activity of pro-inflammatory chemicals produced in your body, such as tumor necrosis factor-alpha (TNF-alpha).
Stress and inflammation are linked to a variety of chronic illnesses, including cancer, diabetes, and heart disease.
Thus, the anti-inflammatory and antioxidant effects of EGCG are thought to be one of the main reasons for its broad disease-preventing applications.
Heart health
Research suggests that EGCG in green tea may support heart health by reducing blood pressure, cholesterol, and the accumulation of plaque in blood vessels — all major risk factors for heart disease.
In an 8-week study in 33 people, taking 250 mg of EGCG-containing green tea extract daily resulted in a significant 4.5% reduction of LDL (bad) cholesterol.
A separate study in 56 people found significant reductions in blood pressure, cholesterol, and inflammatory markers in those taking a daily dose of 379 mg of green tea extract over 3 months.
Though these results are encouraging, more research is needed to better understand how EGCG in green tea may reduce heart disease risk.
Weight loss
EGCG may also promote weight loss, especially when taken alongside the caffeine naturally found in green tea.
Although much of the study results on EGCG’s effect on weight are inconsistent, some long-term observational research noted that consuming about 2 cups (14.7 ounces or 434 ml) of green tea per day was associated with lower body fat and weight.
Additional human studies have collectively found that taking 100–460 mg of EGCG together with 80–300 mg of caffeine for at least 12 weeks is linked to significant weight loss and reduction of body fat.
Still, changes in weight or body composition are not consistently seen when EGCG is taken without caffeine.
Brain health
Early research suggests that EGCG in green tea may play a role in improving neurological cell function and preventing degenerative brain diseases.
In some studies, EGCG injections significantly improved inflammation, as well as recovery and regeneration of neural cells in mice with spinal cord injuries.
Additionally, multiple observational studies in humans found a link between a higher intake of green tea and a reduced risk of age-related brain decline, as well as Alzheimer’s and Parkinson’s disease. However, the available data is inconsistent.
What’s more, it remains unclear whether EGCG specifically or perhaps other chemical components of green tea have these effects.
More research is needed to better understand whether EGCG may effectively prevent or treat degenerative brain diseases in humans.
Dosage and possible side effects
Although EGCG has been studied for decades, its physical effects are quite varied.
Some experts believe this may be because EGCG easily degrades in the presence of oxygen, and many people don’t absorb it efficiently in the digestive tract.
The reason for this is not completely understood, but it may be related to the fact that a lot of EGCG bypasses the small intestine too quickly and ends up being degraded by bacteria in the large intestine.
This has made developing specific dosage recommendations difficult.
A single cup (8 ounces or 250 ml) of brewed green tea typically contains about 50–100 mg of EGCG. Dosages used in scientific studies are often much higher, but exact amounts have been inconsistent.
Daily intakes equal to or above 800 mg of EGCG per day increases the blood levels of transaminases, an indicator of liver damage.
One group of researchers suggested a safe intake level of 338 mg of EGCG per day when ingested in solid supplemental form.
Possible side effects
It’s important to note that EGCG is not 100% safe or risk-free. In fact, EGCG supplements have been associated with serious side effects, such as:
- • liver and kidney failure
- • dizziness
- • low blood sugar
- • anemia
Some experts theorize that these negative effects may be related to toxic contamination of the supplements and not the EGCG itself, but regardless, you should be very cautious if you’re considering taking this supplement.
Taking supplemental doses of EGCG is not recommended if you’re pregnant, as it may interfere with the metabolism of folate — a B vitamin essential for fetal growth and development — increasing the risk of birth defects like spina bifida.
It remains unclear whether EGCG supplements are safe for women who are breastfeeding, so it’s likely best to avoid it until more research is available.
EGCG may also interfere with the absorption of some prescription medications, including certain types of cholesterol-lowering and antipsychotic drugs.
To ensure safety, always consult with your healthcare provider prior to starting a new dietary supplement.
The bottom line
EGCG is a powerful compound that may benefit health by reducing inflammation, aiding weight loss, and preventing certain chronic diseases.
It’s most abundant in green tea but also found in other plant foods.
When taken as a supplement, EGCG has occasionally been associated with serious side effects. The safest route is to consult with your healthcare provider prior to adding EGCG to your routine to ensure this supplement is right for you.
Source
Note 9: Dietary Copper Reduces the Hepatotoxicity of (-)-Epigallocatechin-3-Gallate in Mice
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Most doses are standardized against EGCG. Although the amount of EGCG-equivalent varies from one cup of tea to another, depending on many factors (species of tea, length of steeping, time spent oxidizing), one cup of camellia sinensis green tea contains approximately 50 mg of EGCG-equivalent.
The benefits of green tea catechins on lipid oxidation and related fat-burning pathways are achieved in a dose dependent manner. Significant effects in humans are noted only at high doses, such as 400-500 mg EGCG equivalent per day (most Green Tea Extract supplements are roughly 50% EGCG). Fat burning effects are highly synergistic, almost dependent, on not consuming caffeine habitually. *
One cup (eight ounces or 250 milliliters) of brewed green tea naturally contains about 50–100 milligrams of EGCG (and 30 to 40 milligrams of caffeine).
In addition to being found naturally in tea, EGCG supplements are also available over-the-counter.
What’s the best EGCG supplement to take?
Unfortunately, many supplements are not strictly regulated, making it difficult to ensure you get a pure product. Therefore the safest way to consume ECGC seems to be from real food/beverage sources, especially green and black tea.
Drinking one to four cups daily is thought to be healthy for most adults and poses little risk, unless someone is very sensitive to caffeine or oxalates found in tea (for example, because he or she has a kidney issue). Consuming two to three cups per day of high-quality brewed green tea (not bottled, sweetened green tea) is a common recommendation by health experts if you’re looking to benefit from catechins.
If you do decide to take EGCG supplements, how much should you take? There isn’t a standard recommendation, however one meta-analysis found that dosages between 150 and 2,500 milligrams of catechins daily from green tea or green tea extract was capable of helping improve patients’ cholesterol profiles.
Most experts recommend taking up to 400 milligrams in supplement form at first and not more than 800 milligrams before knowing how you react (and ideally with help from a health care provider).
Because there is a big range in terms of dosage recommendations, to narrow down how much you should consume, consider starting with a low dose between 150 and 400 milligrams daily and increasing slowly if needed. One study found beneficial effects on body weight when adults consumed up to 460 mg/day — therefore high doses might not be needed in most instances. *
Note 2: Assessing the Hepatic Safety of Epigallocatechin Gallate (EGCG) in Reproductive-Aged Women
Note 4: EFSA assesses safety of green tea catechins
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Drinking too much green tea may cause the adverse effects associated with caffeine intake. These include anxiety, accelerated heart rate, and sleep disturbances. L-theanine found in green tea can in turn cause dizziness, headaches, and digestive problems.
Due to the effects of caffeine on heart rate, people suffering from heart conditions, as well as pregnant and breastfeeding women, should drink green tea in moderation.
Because caffeine has diuretic effects, people on diuretics should drink green tea in moderation.
Some studies have revealed the capacity of tea plants to accumulate high levels of aluminum. This heavy metal may build up in the body and cause brain and kidney damage. To reduce your potential exposure to aluminum, make sure to obtain green tea from reputable sources.
Although rare, excessive epigallocatechin gallate (over 400 mg/day) can cause liver toxicity and even liver failure.
Tea polyphenols reduced iron absorption in rats. People with anemia may want to cut down on green tea intake.
Epigallocatechin gallate acted as a pro-oxidant, rather than an antioxidant, in the pancreatic insulin-secreting cells of diabetic mice. Further clinical studies should determine its safety in people with type 2 diabetes.
In rats, green tea consumption lowered testosterone levels by 20% and sperm count by 2%, suggesting its potential to reduce male fertility.
At high doses, green tea extract induced thyroid enlargement (goiter) and altered thyroid function in rats. However, people drinking green tea are unlikely to reach these doses.
Drug and Supplement Interactions
Supplement/Herb/Nutrient-drug interactions can be dangerous and, in rare cases, even life-threatening. Always consult your doctor before supplementing and let them know about all drugs and supplements you are using or considering.
- Fish oil: its combination with green tea catechins may increase fat and glucose metabolism.
- Ubiquinone: this supplement increased the antioxidant effects of epigallocatechin gallate in rats.
- Curcumin: its combination with epigallocatechin gallate reduced cancer cell growth.
- Capsicum vanilloids: found in hot peppers, capsicum vanilloids help kill cancer cells. Their combination with green tea had synergistic effects.
- Vitamin E: its combination with green tea polyphenols improved exercise capacity, lowered glucose levels, and reduced body weight in humans. *
Note 3: EGCG exposure during pregnancy affects uterine histomorphology in F1 female mice and the underlying mechanisms
Note 4: EFSA assesses safety of green tea catechins
Note 7: Epigallocatechin Gallate During Dietary Restriction - Potential Mechanisms of Enhanced Liver Injury
Note 8: Prenatal EGCG consumption causes obesity and perturbs glucose homeostasis in adult mice
Note 1: Food Inhibits the Oral Bioavailability of the Major Green Tea Antioxidant Epigallocatechin Gallate in Humans
Note 5: Piperine Enhances the Bioavailability of the Tea Polyphenol (-)-epigallocatechin-3-gallate in Mice
Note 6: Bioavailability of Epigallocatechin Gallate Administered With Different Nutritional Strategies in Healthy Volunteers
2023-03-13