You probably know someone who has had a blood clot in the leg or lung. The scare rarely ends with the first one. Many survivors spend years worrying that another is on the way.
The new work was published in October 2026 in Research and Practice in Thrombosis and Haemostasis. It followed 2,071 Norwegian adults who had already had a first, confirmed clot.
Those who drank 1 to 2 cups of coffee a day before that first clot had a 51% lower estimated risk of another clot than people who did not drink coffee at all.
The finding is observational, so it points to a link, not proof. But the size of the association was large enough to be noticed.
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What a blood clot actually is
The medical term is venous thromboembolism, or VTE. It covers two linked problems. A deep vein thrombosis is a clot that forms in a deep vein, usually in the leg.
If part of that clot breaks loose and travels to the lungs, it becomes a pulmonary embolism, which can be fatal within minutes.
Up to 900,000 Americans are affected each year, according to the Centers for Disease Control and Prevention, and 60,000 to 100,000 die from it. About one in three survivors has another clot within 10 years.
What the Norwegian cohorts found
Researchers pooled data from the Tromsø Study and the Trøndelag Health Study, two of Norway's largest long-running population surveys.
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All 2,071 participants had already survived a first, confirmed clot. Over an average of 2.8 years of follow-up, 310 of them had another.
Light coffee drinkers did best. One to two cups a day was tied to the 51% lower recurrence risk, after adjusting for age and sex.
The pattern was not a straight line, though. Drinking more coffee did not keep lowering the risk in step with intake.
Among people whose first clot had an obvious trigger, such as recent surgery, a hospital stay or a long stretch of immobility, the link was even stronger. In that group, 1 to 2 cups a day was tied to a 67% lower estimated risk of a second clot.
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For clots that had struck without an obvious cause, no significant link appeared.
Why the finding should be read with care
The study is observational, so it cannot prove coffee itself is doing the work. Something else about coffee drinkers, from diet to activity level, could sit behind the lower risk.
The comparison group was small, just 140 people who said they drank no coffee at all. Information on blood thinner use was incomplete.
The participants were almost all white Norwegians, and coffee intake was measured only before the first clot. The authors called for other studies to confirm the pattern.
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What could explain the link
Coffee is rich in a plant compound called chlorogenic acid. A review in PLoS ONE tied the compound to lower platelet activity and reduced clot formation in laboratory settings.
That is a plausible mechanism. But it has mostly been shown in cell and animal studies so far, and the Norwegian team did not test it directly.
Current medical guidance after a first clot focuses on blood thinners, early movement after surgery and treating any known trigger. Coffee is not part of standard prevention, and the research team said it is too early to make it so.
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This article is made and published by Jesper Bengtson, who may have used AI in the preparation.