Green tea is one of the most popular healthy beverages, thanks to its antioxidants that help reduce inflammation and protect against certain chronic conditions. However, consuming it in large amounts may lead to several potential health risks that should not be overlooked.
1. Digestive Issues
Most people can drink green tea safely, but concentrated green tea extract supplements may cause nausea, stomach discomfort, or constipation. These side effects become more common with high doses.
2. High Blood Pressure
Moderate amounts of green tea are generally safe, but exceeding the recommended daily caffeine limit (400 mg) may lead to elevated blood pressure, rapid heartbeat, headaches, anxiety, and sleep disturbances.
3. Sleep Problems
Drinking green tea late at night or consuming too much caffeine throughout the day can negatively affect sleep quality and increase anxiety, which further contributes to insomnia.
4. Reduced Iron Absorption
Green tea contains catechins — powerful antioxidants — but these compounds can hinder the body’s ability to absorb iron from food. This may increase the risk of anemia, especially in individuals who already have low iron levels.
5. Liver Damage
Although green tea is generally safe, rare cases of liver damage have been linked to green tea extract in people with certain genetic variations. Those with a history of liver conditions should consult a doctor before using it.
6. Drug Interactions
High doses of green tea can interact with several medications. Its compounds may reduce drug concentration in the blood, potentially weakening their effectiveness. Affected medications may include some blood pressure drugs, blood thinners, antidepressants, cholesterol medications, and osteoporosis treatments.
Groups That Should Avoid Green Tea:
• Individuals with anemia
• People with liver disease
• Pregnant and breastfeeding women (due to caffeine)
• Those sensitive to caffeine
Recommended Daily Amount:
Most adults can safely consume green tea within the daily caffeine limit of 400 mg. A single cup generally contains around 22–40 mg of caffeine. However, experts warn against excessive intake for individuals taking medications for heart disease, high blood pressure, cholesterol issues, liver disease, anxiety, depression, or osteoporosis due to possible drug interactions.
