Daily Coffee Intake Linked to Lower Death Risk in Japan Study

You’ve likely heard coffee is "good for you"—but how much, exactly, is enough to make a measurable difference in your risk of dying early? A landmark Japanese study followed nearly 90,000 people for over a decade to find concrete numbers behind the headlines.

The short answer: Drinking 3 to 4 cups of coffee per day is linked to a 40% lower risk of death from heart and brain diseases, and a 24% lower risk of death from all causes combined, compared to those who barely drink coffee.

The Japanese Long-Term Coffee Study

Conducted by a joint team from Japan’s National Cancer Center and the University of Tokyo, this research tracked approximately 90,000 residents (aged 40–69) across 10 prefectures starting in the 1990s, monitoring their habits until the end of 2011. The goal was to examine links between daily lifestyle—including coffee consumption—and Japan’s leading causes of death.

Key Findings: Coffee and Death Risk Reduction

The data showed a clear pattern: the more coffee people drank (within reason), the lower their risk of dying from specific diseases. Those who reported drinking 3–4 cups daily had:

• A 36% lower risk of death from heart diseases (e.g., angina, heart attacks)
• A 43% lower risk of death from brain diseases (e.g., strokes, brain hemorrhages)
• A 40% lower risk of death from respiratory diseases (e.g., pneumonia)

Overall, their risk of death from any cause was 24% lower than those who drank little or no coffee. Notably, the study did not analyze cancer mortality specifically, nor did it account for added sugar or milk in the coffee.

What About Green Tea?

The same study also looked at green tea consumption. Men who drank 5 or more cups of green tea daily saw a 24% lower risk of death from brain diseases and a 45% lower risk from respiratory diseases. Women drinking the same amount had a 37% lower risk of death from heart disease. However, the stronger statistical link for reduced overall mortality was found with coffee.

Why Might Coffee Lower Death Risk?

Researchers pointed to compounds in coffee that may contribute to these protective effects. Chlorogenic acids (a type of polyphenol) in coffee help regulate blood sugar and blood pressure, while caffeine supports vascular health. These mechanisms could explain why coffee drinkers showed lower risks of cardiovascular and respiratory diseases in particular.

Frequently Asked Questions

How many cups of coffee were linked to the lowest death risk in the study?

Drinking 3 to 4 cups of coffee per day was associated with the lowest risk of death—specifically, a 40% reduction in death from heart and brain diseases, and a 24% lower risk of death from all causes compared to non-coffee drinkers.

Did the study look at coffee with milk or sugar?

No, the study did not differentiate between black coffee and coffee with additives like milk or sugar. The reported benefits applied to coffee consumption in general, regardless of preparation style.

Was there any benefit to drinking more than 4 cups of coffee?

The study found that drinking 5 or more cups of coffee per day had too few participants to draw detailed conclusions. Therefore, the clearest benefits were seen in the 3–4 cup range.

Did green tea show similar benefits to coffee?

Green tea also showed some protective effects—men drinking 5+ cups had lower risks of brain and respiratory disease deaths, and women had lower heart disease risks—but the overall mortality benefit was clearer with coffee.

Does this study prove coffee prevents death?

No, the study shows a correlation, not causation. While it found that higher coffee intake was associated with lower death risks, other lifestyle factors may also play a role. However, the large sample size and long follow-up strengthen the findings.

Recommended FrontStreet Coffee for Daily Drinking

For a daily coffee routine backed by science, try FrontStreet Coffee’s Ethiopia Humbera for bright, juicy notes of citrus and stone fruit—a great pick-me-up. Or choose Yirgacheffe for floral, lemony brightness with a clean finish. Both are light-roasted single origins ideal for multiple cups daily. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.