Based on PubMed | Does drinking green tea reduce the risk of heart disease?

Drinking green tea is associated with a modestly lower risk of heart disease, but the evidence is stronger for improving certain risk factors (like LDL cholesterol and blood pressure) than for preventing hard cardiovascular events, and benefits seem to depend on dose and how it’s consumed. ^{[1] [2]}

What the evidence shows

• Observational data: People who drink more green tea appear to have a lower risk of coronary artery disease (heart attacks and related conditions). In a meta‑analysis of observational studies, the highest green tea intake was linked to about a 28% lower risk of coronary artery disease, and each additional cup per day was associated with roughly a 10% lower risk. ^[1]
• Clinical trials on risk factors: Randomized trials suggest green tea or catechin‑rich extracts can reduce total and LDL (“bad”) cholesterol, with smaller or inconsistent effects on HDL and triglycerides; these studies are generally short‑term. ^[2]
• Overall synthesis: Reviews conclude evidence for direct reduction in coronary events is not robust, but there is supportive evidence for improvements in lipid profiles and possibly blood pressure, which could translate to lower long‑term risk. ^[2]

Potential heart‑protective mechanisms

• Antioxidant catechins (especially EGCG) may improve endothelial function (the lining of blood vessels), insulin sensitivity, and nitric oxide availability, which can help blood vessels relax and may lower blood pressure. ^{[3] [4]}
• Green tea has been linked with increases in HDL and reductions in LDL and triglycerides, pathways that support cardiovascular health. ^[5]

How much might help?

• Observational findings suggest a dose‑response pattern, with more cups per day associated with lower risk (e.g., ~1 cup/day linked to about 10% lower CAD risk), though such studies cannot prove causation. ^[1]
• Clinical trials often use standardized extracts; for safety, lower EGCG doses (e.g., ~200 mg twice daily) have been reported as safe over a year, while very high doses (around 800 mg/day) have been associated with elevated liver enzymes. ^[6]

Practical guidance

• Consider 1–3 cups of brewed green tea daily as a reasonable, food‑based approach that may support heart health alongside proven lifestyle steps (diet quality, exercise, not smoking, blood pressure and cholesterol control). ^{[1] [2]}
• If you are considering supplements, be cautious: extracts concentrate catechins and have different safety and interaction profiles than tea. ^[7]
• Green tea is generally safe in moderate amounts, but caffeine can cause jitteriness or sleep issues, and excessive intake may pose risks. ^[7]

Safety and medication interactions

• Liver safety: Take green tea extracts with food and avoid high‑dose products; discontinue if you notice symptoms like abdominal pain, dark urine, or yellowing of the skin/eyes. ^[7]
• Drug interactions: Green tea can affect drug transporters and enzymes, which may alter blood levels of some medications. For example, it can lower absorption and plasma levels of nadolol (a beta‑blocker), and has shown effects on transporters relevant to some statins and other drugs; clinical relevance varies by medication and dose. ^{[8] [9] [10]}
• If you take heart or blood‑thinning medicines, or other chronic medications, it’s wise to discuss regular green tea extract use with your clinician to avoid unintended interactions. ^[11]

Bottom line

• Green tea can be a heart‑healthy beverage choice and may modestly lower the risk of coronary artery disease, especially when part of an overall healthy lifestyle. ^[1]
• The strongest evidence is for improvements in cholesterol and possibly blood pressure rather than definitive reductions in heart attacks or strokes, and more long‑term, high‑quality trials are needed. ^[2]

Quick comparison: brewed tea vs. extract

Aspect	Brewed green tea	Green tea extract (capsules/tablets)
Typical benefit signal	Associated with lower CAD risk in observational studies; small improvements in risk factors likely	Short‑term LDL/total cholesterol reductions in trials; variable on BP
Dose	1–3 cups/day commonly studied; greater intake linked with more benefit in cohorts	Trials vary; ~200 mg EGCG twice daily reported safe in one‑year data; high doses (e.g., 800 mg/day) linked to liver enzyme elevations
Safety	Generally safe; caffeine‑related symptoms possible	Higher risk of liver enzyme elevations and drug interactions; take with food
Drug interactions	Fewer concerns, but still possible with large amounts	More likely; can affect transporters/enzymes and drug levels (e.g., nadolol)

^{[1] [2] [6] [7] [9] [10] [8]}