Green tea has been consumed for thousands of years, originating from China and spreading throughout Asia before becoming popular globally. Unlike black tea, which undergoes fermentation, green tea is made from unfermented Camellia sinensis leaves, preserving higher levels of bioactive compounds such as polyphenols and catechins . This traditional beverage has evolved from a cultural practice to a subject of extensive scientific research, with numerous studies investigating its potential health benefits .

In today's world, where chronic diseases such as cardiovascular disease, type 2 diabetes, and obesity are increasingly prevalent, there is growing interest in natural products that may help prevent or manage these conditions . Green tea stands out among these natural products due to its rich composition of bioactive compounds, particularly epigallocatechin-3-gallate (EGCG), which is considered the most active component responsible for many of its health benefits .

This comprehensive review examines the scientific evidence supporting the health benefits of green tea consumption, discusses potential risks and considerations, and provides practical recommendations for optimal consumption.

Health Benefits of Green Tea

1. Cardiovascular Health Benefits

Green tea has been extensively studied for its beneficial effects on cardiovascular health, with numerous studies demonstrating its potential to reduce the risk of heart disease and stroke .

1.1 Blood Pressure Regulation

One of the most well-documented cardiovascular benefits of green tea is its ability to lower blood pressure. A meta-analysis of 24 randomized placebo-controlled trials found that green tea consumption, either in beverage or extract form for two weeks or more, significantly lowered both systolic and diastolic blood pressure . Another meta-analysis involving 25 randomized controlled trials concluded that long-term tea intake (12 weeks or more) significantly improved blood pressure, with green tea reducing systolic blood pressure by 2.1 mmHg and diastolic blood pressure by 1.7 mmHg .

The antihypertensive effects of green tea appear to be particularly pronounced in individuals with high-normal blood pressure or existing cardiovascular risk factors . Research suggests that drinking about 0.5 to 2.5 cups of green tea daily for at least one year reduced the risk of developing high blood pressure by 46%, while those consuming more than 2.5 cups reduced their risk by 65% .

1.2 Cholesterol and Lipid Profile Improvement

Green tea consumption has also been linked to improvements in cholesterol and lipid profiles. Studies have shown that regular green tea intake can reduce total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride levels while maintaining or increasing high-density lipoprotein (HDL) cholesterol .

A meta-analysis of 21 studies (including 1,700 overweight or obese subjects) demonstrated that green tea significantly reduced total plasma cholesterol (by approximately 3.38 mg/dL) and LDL-C levels (by approximately 5.29 mg/dL) . These effects are thought to be mediated by green tea catechins, particularly EGCG, which has been shown to inhibit the synthesis of fatty acids and cholesterol in the liver .

1.3 Prevention of Arteriosclerosis and Atherosclerosis

Research indicates that EGCG in green tea can help prevent heart disease by dissolving arterial plaque, thereby reducing the risk of arteriosclerosis, cerebral thrombus, heart attack, and stroke . The University of Leeds and Lancaster University researchers found that EGCG has the ability to relax arteries and improve blood flow, which contributes to its cardioprotective effects .

In vitro studies have shown that green tea catechins exert a cardioprotective effect through multiple mechanisms, including the inhibition of oxidation, vascular inflammation, and thrombogenesis, as well as the improvement of endothelial dysfunction . Animal studies have also revealed that green tea catechins influence nitric oxide production and vasodilation, thereby improving endothelial dysfunction and hypertension in rodents .

2. Antioxidant Properties and Cellular Protection

Green tea is rich in antioxidants, which help protect the body against oxidative stress caused by free radicals and reactive oxygen species (ROS) . These compounds play a crucial role in preventing cellular damage and reducing the risk of various diseases .

2.1 Free Radical Scavenging

The antioxidants in green tea, particularly the catechins, have been shown to effectively scavenge free radicals such as superoxide anion and hydroxyl radicals . This antioxidant activity helps protect cells from oxidative damage, which is associated with aging and various chronic diseases .

EGCG, the most abundant and active catechin in green tea, has been found to be particularly effective in neutralizing free radicals and protecting against metal-induced oxidation by chelating metal ions . This ability to scavenge free radicals and chelate metals contributes to green tea's potential protective effects against diseases such as cancer, cardiovascular disease, and neurodegenerative disorders .

2.2 DNA Protection

Research has shown that green tea polyphenols can protect DNA from oxidative damage, which is a key factor in the development of cancer and other diseases . A study found that higher intake of green tea might cause oxidative DNA damage of hamster pancreas and liver, but this effect was observed at very high doses that would be unlikely to occur in human consumption .

Overall, the antioxidant properties of green tea contribute to its potential benefits in preventing various diseases, including cancer, cardiovascular disease, and neurodegenerative disorders .

3. Metabolic Health Benefits

Green tea has been extensively studied for its potential benefits in improving metabolic health, particularly in relation to obesity, type 2 diabetes, and metabolic syndrome .

3.1 Weight Management and Obesity Prevention

Numerous studies have investigated the anti-obesity effects of green tea, with promising results. A meta-analysis of randomized controlled clinical trials on the influence of green tea intake on obesity indices in humans revealed a significant reduction in body weight, BMI, and waist circumference at a dosage of <500 mg of green tea per day for 12 weeks .

Green tea's weight management effects are thought to be mediated through several mechanisms, including increasing energy expenditure, improving fat oxidation, and reducing respiratory quotient . EGCG has been shown to increase the expression of thermogenic genes, including Ucp1 and Ucp2, in mice, which contributes to increased energy expenditure and fat burning .

In a 12-week study conducted on healthy Japanese men, consumption of 690 mg of tea catechins significantly reduced body weight and fat mass . Another study found that supplementation with EGCG for eight weeks significantly decreased fasting plasma triglyceride levels, blood pressure, and serum kisspeptin levels in humans .

3.2 Blood Sugar Regulation and Diabetes Prevention

Green tea consumption has been associated with improved blood sugar regulation and a reduced risk of type 2 diabetes . Epidemiological studies have detected a negative correlation between green tea consumption and the risk of type 2 diabetes .

A large cohort study of 17,400 Japanese individuals found that those who consumed 2-6 cups of green tea per day had a lower risk of type 2 diabetes compared to those who consumed less than one cup per week . Similarly, an analysis of a large European cohort study showed that tea consumption was inversely associated with the incidence of type 2 diabetes, with non-tea drinkers having a higher incidence compared to those who consumed ≥4 cups per day .

The anti-diabetic effects of green tea are thought to be due to several mechanisms, including:

3.3 Metabolic Syndrome Improvement

Metabolic syndrome (Syndrome X) is a cluster of conditions—including elevated blood sugar, elevated blood cholesterol, hyperlipidemia, excessive body fat, insulin resistance, visceral obesity, and arterial hypertension—that increase the risk of cardiovascular disease, type 2 diabetes, and other health problems .

Epidemiological studies have shown that green tea consumption is negatively correlated with metabolic syndrome and its components . A population-based cross-sectional survey revealed that green tea consumption was inversely associated with metabolic syndrome and some of its components. Individuals who consumed ≥3 cups of tea per day had lower BMI and waist circumference, although diastolic blood pressure was not affected . After adjusting for confounding factors, higher green tea consumption was significantly associated with a reduced risk of metabolic syndrome .

A recent pooled analysis of six human trials showed that consumption of beverages containing green tea catechins (540-588 mg GTC/beverage) for 12 weeks significantly reduced total fat area, visceral fat area, subcutaneous fat area, body weight, BMI, and waist circumference, and improved blood pressure . Further analysis of pre-metabolic syndrome and metabolic syndrome studies indicated significant improvement in metabolic syndrome parameters among GTC consumers .

4. Neuroprotective Effects

Green tea has been studied for its potential neuroprotective effects, particularly in relation to neurodegenerative diseases and cognitive function .

4.1 Alzheimer's Disease Prevention

Research suggests that EGCG in green tea may help prevent Alzheimer's disease by inhibiting amyloid beta plaque formation in the brain . Amyloid beta plaques are a hallmark of Alzheimer's disease, and their accumulation is thought to contribute to the neurodegeneration seen in this condition .

A study by researchers at the University of Leeds and Lancaster University found that EGCG can dissolve amyloid beta plaques, which are associated with Alzheimer's disease . This discovery suggests that green tea consumption may help reduce the risk of developing Alzheimer's disease and slow its progression .

4.2 Parkinson's Disease Prevention

Epidemiological studies have found an inverse association between tea consumption and the risk of Parkinson's disease. A meta-analysis of eight studies (including 345,000 participants) found a negative correlation between tea consumption and Parkinson's disease risk, with a 26% reduced risk for each additional two cups of tea consumed per day after adjusting for smoking .

The protective effect of green tea against Parkinson's disease is thought to be due to its antioxidant properties and its ability to protect dopamine neurons from oxidative stress and degeneration .

4.3 Cognitive Function Enhancement

Several studies have investigated the effects of green tea on cognitive function, with promising results. A small randomized, single-blind study reported that drinking matcha (a type of green tea) significantly improved attention capacity and psychomotor speed in response to stimuli .

Another study found that theanine, an amino acid found in green tea, can cross the blood-brain barrier and has been shown to reduce mental and physical stress, improve attention, and enhance cognitive performance .

5. Cancer Prevention

The potential anti-cancer effects of green tea have been extensively studied, with research suggesting that regular consumption may reduce the risk of various types of cancer .

5.1 Mechanisms of Action

Green tea catechins, particularly EGCG, have been shown to have anticancer effects through several mechanisms, including:

5.2 Epidemiological Evidence

Recent epidemiological studies, systematic reviews, and dose-response meta-analyses have indicated that long-term and high-dose green tea consumption may reduce the risk of various types of cancer . For example:

5.3 Specific Cancers

Green tea has been studied for its potential protective effects against several types of cancer, including:

6. Anti-inflammatory Effects

Green tea has been shown to possess significant anti-inflammatory properties, which may contribute to its protective effects against various diseases .

6.1 Reduction of Inflammatory Markers

Research has demonstrated that green tea consumption can reduce levels of pro-inflammatory markers such as C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interleukin-1β (IL-1β) .

A study of metabolic syndrome patients receiving a daily green tea supplement (1 g; 890 mg total catechins) for 28 days demonstrated that the mRNA expression levels of dependent inflammatory genes decreased . Another study found that green tea decreased IL-6 levels in patients with Polycystic Ovary Syndrome .

6.2 Gut Inflammation Modulation

Green tea extract containing catechins has been shown to improve intestinal barrier integrity in rat models of conditions like Crohn's disease or inflammatory bowel disease . This effect helps modulate the translocation of endotoxins from the intestine and the resulting pro-inflammatory effects .

EGCG treatment has been found to significantly enhance antioxidant capacity while decreasing the severity of colitis symptoms . Additionally, green tea extract decreased the entry of immunoreactive nitrotyrosine into the colon and the overexpression of intercellular adhesion molecule 1 (ICAM-1) .

6.3 Systemic Inflammation Reduction

The anti-inflammatory effects of green tea may help reduce systemic inflammation associated with various conditions, including metabolic syndrome, cardiovascular disease, and diabetes . A meta-analysis (Asbaghi et al., 2019) found that while green tea consumption did not significantly impact CRP levels, it did reduce TNF-α levels, particularly in cases of severe inflammation .

These anti-inflammatory effects are thought to be mediated by green tea polyphenols, which suppress the expression of inducible nitric oxide synthase (iNOS) in the liver and inhibit the activation of inflammatory nuclear factor kappa-B (NF-κB) and tumor necrosis factor-α (TNF-α) .

7. Weight Management and Obesity Prevention

Green tea has gained significant attention for its potential role in weight management and obesity prevention .

7.1 Thermogenesis and Fat Oxidation

Research suggests that green tea can increase energy expenditure and fat oxidation, which may contribute to weight loss and weight maintenance . A study in obese rats found that green tea extract increased energy expenditure, improved fat oxidation, and reduced respiratory quotient, thereby influencing body mass index (BMI) and total body fat .

The combination of caffeine and catechins in green tea has been shown to have a synergistic effect on thermogenesis and fat oxidation . This effect is thought to be due to the ability of these compounds to increase the release of norepinephrine, a hormone that stimulates fat breakdown and thermogenesis .

7.2 Appetite Regulation

Some research indicates that green tea may help regulate appetite by influencing hunger hormones such as ghrelin and leptin . For example, one study found that EGCG significantly reduced leptin levels in rats .

Additionally, green tea catechins have been shown to reduce digestive lipase, gastric lipase, and pancreatic lipase activities, thus reducing fat digestion and absorption . This effect may contribute to the anti-obesity properties of green tea by decreasing the amount of dietary fat that is absorbed into the body .

7.3 Clinical Studies on Weight Loss

Several clinical studies have investigated the effects of green tea on weight loss and body composition. A 12-week study on healthy Japanese men found that consumption of 690 mg of tea catechins significantly reduced body weight and fat mass . Similarly, a randomized double-blind parallel placebo-controlled clinical trial showed that administering 400, 600, or 800 g EGCG (depending on body weight) for 12 months in men with Down syndrome resulted in weight loss, reduced body fat, and improved lipid profile .

A meta-analysis of randomized controlled trials on the influence of green tea intake on obesity indices in humans revealed a significant reduction in body weight, BMI, and waist circumference at a dosage of <500 mg of green tea per day for 12 weeks . However, it's important to note that these effects are generally modest and that green tea should be viewed as a complementary approach to a healthy diet and regular exercise rather than a miracle weight-loss solution .

8. Diabetes Prevention and Management

Green tea has been studied for its potential benefits in preventing and managing type 2 diabetes .

8.1 Insulin Sensitivity Improvement

Research indicates that green tea can improve insulin sensitivity, which is crucial for maintaining normal blood sugar levels and preventing type 2 diabetes . A study in mice showed that EGCG improved insulin resistance by restoring the phosphorylation of insulin receptor substrate-1 (IRS-1) and protein kinase B (AKT) in skeletal muscle and adipose tissue .

Another study found that when EGCG intake was combined with regular exercise in overweight or obese postmenopausal women, it resulted in reduced plasma glucose concentration in subjects with impaired glucose tolerance . These findings suggest that green tea may enhance the beneficial effects of exercise on glucose metabolism .

8.2 Glucose Absorption Regulation

Green tea has been shown to slow down the absorption of glucose from the intestines, which can help prevent blood sugar spikes after meals . This effect is due to the ability of green tea catechins to inhibit α-glucosidase, an enzyme that breaks down complex carbohydrates into simple sugars .

Additionally, green tea flavonoids can increase glucose transporter 4 (GLUT4) expression, which allows glucose to be absorbed into cells more efficiently, thereby increasing insulin sensitivity .

8.3 Clinical Studies on Diabetes

Several clinical studies have investigated the effects of green tea on diabetes parameters. A systematic review of the effects of green tea and green tea extracts on insulin resistance and glycemic control found that in short-term trials, green tea supplementation reduced fasting insulin and blood sugar levels .

Another study in Japan showed that intake of green tea extract reduced hemoglobin Alc levels, an indicator of glucose control and a marker used to diagnose diabetes, in 60 subjects with mild hyperglycemia .

A meta-analysis of 17 trials revealed that in patients with obesity, type 2 diabetes, or high blood pressure, drinking green tea led to reduced levels of fasting glucose, HbA1c, and fasting insulin . The study also noted that green tea may influence diabetes via its effects on adiponectin, a protein that plays a key role in the relationship between adiposity, insulin resistance, and inflammation .

9. Neuroprotective Effects and Mental Health

Green tea has been studied for its potential neuroprotective effects and benefits for mental health .

9.1 Alzheimer's Disease Prevention

Research suggests that EGCG in green tea may help prevent Alzheimer's disease by inhibiting amyloid beta plaque formation in the brain . Amyloid beta plaques are a hallmark of Alzheimer's disease, and their accumulation is thought to contribute to the neurodegeneration seen in this condition .

Additionally, EGCG has been shown to inhibit the activity of enzymes involved in the production of amyloid beta, such as beta-secretase, which may further contribute to its protective effects against Alzheimer's disease .

9.2 Parkinson's Disease Prevention

Epidemiological studies have found an inverse association between tea consumption and the risk of Parkinson's disease . A meta-analysis of eight studies (including 345,000 participants) found a negative correlation between tea consumption and Parkinson's disease risk, with a 26% reduced risk for each additional two cups of tea consumed per day after adjusting for smoking .

The protective effect of green tea against Parkinson's disease is thought to be due to its antioxidant properties and its ability to protect dopamine neurons from oxidative stress and degeneration .

9.3 Anxiety and Depression Reduction

Recent research has explored the potential of green tea to alleviate symptoms of anxiety and depression . Theanine, an amino acid found in green tea, has been shown to have calming effects and may help reduce anxiety and improve mood .

A study on the effects of tea on anxiety and depression found that tea and its main functional components (catechins, theanine, theaflavins, and theobromine) have potential amelioration effects on anxiety and depression . These effects are thought to be mediated through multiple pathways, including modulation of neurotransmitter systems (such as dopamine and serotonin), reduction of stress hormones, and anti-inflammatory effects .

10. Oral Health Benefits

Green tea has also been studied for its potential benefits for oral health .

10.1 Antibacterial Effects

Research indicates that green tea catechins have antibacterial properties that may help prevent dental caries (tooth decay) and periodontal disease . These compounds have been shown to inhibit the growth of Streptococcus mutans, a bacterium that is a major cause of dental caries .

Additionally, green tea catechins have been found to inhibit the formation of dental plaque by preventing bacteria from adhering to tooth surfaces .

10.2 Prevention of Periodontal Disease

Green tea has been shown to have anti-inflammatory effects that may help prevent or reduce the severity of periodontal disease . Research indicates that green tea catechins can inhibit the production of pro-inflammatory cytokines such as interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNF-α) in response to periodontal pathogens .

Furthermore, green tea may help reduce the risk of oral cancer, as suggested by some studies that have found an inverse association between green tea consumption and the risk of oral cavity and pharyngeal cancers .

Potential Risks and Side Effects of Green Tea Consumption

While green tea offers numerous health benefits, it's important to be aware of potential risks and side effects associated with its consumption .

1. Caffeine-Related Effects

Green tea contains caffeine, which can cause side effects in some individuals, particularly when consumed in large amounts .

1.1 Nervous System Effects

Caffeine stimulates the central nervous system and can cause symptoms such as nervousness, irritability, tremors, and insomnia . These effects are more likely to occur in individuals who are sensitive to caffeine or who consume large amounts of green tea .

To minimize these effects, individuals sensitive to caffeine may consider drinking decaffeinated green tea or limiting their intake to one or two cups per day .

1.2 Cardiovascular Effects

Caffeine can increase heart rate and blood pressure in some individuals . People with heart conditions or major cardiovascular problems should consult their healthcare provider before increasing their green tea intake .

Pregnant and breastfeeding women should also limit their green tea consumption to no more than one or two cups per day, as caffeine can cross the placenta and enter breast milk, potentially affecting the developing fetus or infant .

1.3 Diuretic Effect

Caffeine has a diuretic effect, which means it increases urine production . This can lead to increased urination and potential dehydration if fluids are not adequately replaced .

2. Potential Toxicity at High Doses

While green tea is generally safe when consumed in moderation, high doses may cause adverse effects .

2.1 Liver Toxicity

Some studies have suggested that high doses of green tea extract, particularly EGCG, may cause liver toxicity . For example, EGCG in green tea extract is cytotoxic, and higher consumption of green tea can exert acute cytotoxicity in liver cells, a major metabolic organ in the body .

A study found that higher intake of green tea might cause oxidative DNA damage in the pancreas and liver of hamsters . Yun et al. clarified that EGCG acts as a pro-oxidant, rather than an antioxidant, in pancreatic beta cells in vivo, suggesting that high intake of green tea may be detrimental for diabetic animals to control hyperglycemia .

2.2 Thyroid Effects

At a high dose (5% of diet for 13 weeks), green tea extract induced thyroid enlargement (goiter) in normal rats . This high-level treatment modified the plasma concentrations of thyroid hormones . However, it's important to note that drinking even very high dietary amounts of green tea would be unlikely to cause these effects in humans .

2.3 Gastrointestinal Effects

Excessive consumption of green tea may cause gastrointestinal discomfort, including nausea, vomiting, and diarrhea . These effects are more common with concentrated green tea extracts than with regular green tea consumption .

3. Interactions with Medications

Green tea may interact with certain medications, potentially affecting their efficacy or increasing the risk of side effects .

3.1 Anticoagulant/Antiplatelet Medications

Green tea may enhance the effects of anticoagulant or antiplatelet medications, such as warfarin (Coumadin), clopidogrel (Plavix), and aspirin . This could increase the risk of bleeding, particularly in individuals at risk of bleeding disorders .

3.2 Stimulant Medications

The caffeine in green tea may enhance the effects of stimulant medications, such as those used to treat attention deficit hyperactivity disorder (ADHD), potentially leading to increased heart rate, blood pressure, and anxiety .

3.3 Antidepressants

Green tea may interact with certain antidepressant medications, such as monoamine oxidase inhibitors (MAOIs) and selective serotonin reuptake inhibitors (SSRIs), potentially increasing the risk of side effects .

3.4 Iron Absorption

Green tea catechins may have an affinity for iron and can cause a significant decrease in the bioavailability of dietary iron . This is particularly important for individuals with iron deficiency anemia or those at risk of iron deficiency .

To minimize this effect, it's recommended to avoid consuming green tea with meals, especially meals rich in iron, and to wait at least one hour after a meal before drinking green tea .

4. Aluminum Accumulation Concerns

Some studies have revealed the capacity of tea plants to accumulate high levels of aluminum . This is important for patients with renal failure because aluminum can accumulate in the body, potentially leading to neurological diseases .

Individuals with kidney disease should therefore control their intake of foods with high aluminum content, including green tea .

5. Potential Risks for Specific Populations

Certain populations may be more susceptible to the potential risks of green tea consumption .

5.1 Pregnant and Breastfeeding Women

Pregnant and breastfeeding women should limit their green tea consumption to no more than one or two cups per day due to the caffeine content, which can cross the placenta and enter breast milk . High caffeine intake during pregnancy has been associated with an increased risk of miscarriage and low birth weight .

5.2 Individuals with Anxiety Disorders

Individuals with anxiety disorders may be more sensitive to the stimulating effects of caffeine in green tea and may experience increased anxiety symptoms .

5.3 Individuals with Heart Conditions

People with heart conditions or major cardiovascular problems should consult their healthcare provider before increasing their green tea intake, as caffeine can increase heart rate and blood pressure .

5.4 Individuals with Gastrointestinal Disorders

Individuals with gastrointestinal disorders such as peptic ulcers, gastroesophageal reflux disease (GERD), or irritable bowel syndrome (IBS) may be more sensitive to the potential gastrointestinal effects of green tea .

5.5 Individuals with Diabetes

While green tea may have benefits for individuals with diabetes, some studies suggest that high intake of green tea may be detrimental for diabetic animals to control hyperglycemia . Yun et al. clarified that EGCG acts as a pro-oxidant, rather than an antioxidant, in pancreatic beta cells in vivo, which could potentially affect blood sugar control .

5.6 Individuals with Kidney Disease

Patients with renal failure should be cautious with green tea consumption due to the potential for aluminum accumulation and the diuretic effects of caffeine .

Optimal Green Tea Consumption Guidelines

To maximize the health benefits of green tea while minimizing potential risks, consider the following guidelines .

1. Daily Intake Recommendations

The optimal daily intake of green tea for health benefits appears to be 3 to 5 cups per day . This amount provides a balance between obtaining beneficial compounds and avoiding potential negative effects from excessive consumption .

Research suggests that drinking about 0.5 to 2.5 cups of green tea daily for at least one year reduced the risk of developing high blood pressure by 46%, while those consuming more than 2.5 cups reduced their risk by 65% .

For those using green tea extracts or supplements, the recommended daily dose of EGCG is typically 300 to 400 mg, divided into two or three doses . However, it's important to note that the bioavailability of EGCG in supplements may differ from that in brewed green tea .

2. Timing of Consumption

To maximize the absorption of green tea's beneficial compounds and minimize potential interactions with food and medications, consider the following timing guidelines :

3. Choosing High-Quality Green Tea

The quality of green tea can significantly impact its health benefits . Here are some tips for choosing high-quality green tea:

4. Brewing Methods for Maximum Benefit

The way you brew green tea can affect the concentration of beneficial compounds in your cup . Here are some recommendations for optimal brewing:

5. Enhancing Green Tea Benefits

There are several ways to enhance the benefits of green tea :

Green tea offers a wide range of potential health benefits, supported by extensive scientific research . Its rich composition of bioactive compounds, particularly EGCG, contributes to its antioxidant, anti-inflammatory, and metabolic effects, which may help prevent or manage various diseases .

The evidence suggests that regular green tea consumption may reduce the risk of cardiovascular disease, improve blood pressure and cholesterol levels, enhance insulin sensitivity, aid in weight management, protect against neurodegenerative diseases, and potentially reduce cancer risk .

While green tea is generally safe for most people when consumed in moderation (3-5 cups per day), it's important to be aware of potential risks and side effects, particularly at high doses or in specific populations . These include caffeine-related effects, potential liver toxicity at high doses, interactions with certain medications, and reduced iron absorption .

To maximize the health benefits of green tea while minimizing potential risks, consider choosing high-quality green tea, using proper brewing techniques, consuming it in moderation, and being mindful of timing relative to meals and medications .

Incorporating green tea into a balanced diet and healthy lifestyle may provide a simple yet effective way to support overall health and well-being. As with any dietary change, it's advisable to consult with a healthcare provider before making significant changes to your green tea consumption, especially if you have existing health conditions or take medications .