Association between coffee consumption and risk of recurrent venous thromboembolism - Results from the Trøndelag Health Study and Tromsø Study.
Olsen M, Brækkan S, et al. • Research and practice in thrombosis and haemostasis • 2026
Coffee consumption was associated with a nonlinear, lowered risk of VTE recurrence, particularly after provoked VTE, suggesting that coffee can be safely consumed after VTE, potentially with a beneficial effect on recurrence risk.
Key Findings
Results
Overall coffee consumption was not linearly associated with VTE recurrence risk, but showed a nonlinear protective pattern.
The cohort consisted of 2071 patients with incident VTE recruited from 4 surveys of the Tromsø Study (1994-2008) and the third survey of the Trøndelag Health Study (2006-2008).
During a median follow-up of 2.8 years, 310 recurrent VTEs occurred.
Cox regression models were used to estimate hazard ratios (HRs) with 95% CIs for VTE recurrence.
There was no linear relationship between increasing coffee intake and VTE recurrence.
Results
Consuming 1 to 2 cups of coffee per day was associated with a significantly reduced risk of VTE recurrence compared to non-coffee consumers.
HR for recurrence was 0.49 (95% CI, 0.30-0.81) for those consuming 1 to 2 cups of coffee per day compared with noncoffee consumers.
This represents approximately a 51% lower hazard of recurrence in the lowest consumption category.
The reference group was noncoffee consumers.
Results
High coffee consumption (>6 cups/day) was not significantly associated with reduced VTE recurrence risk compared to non-consumers.
HR for recurrence was 0.71 (95% CI, 0.44-1.12) for those consuming >6 cups compared with noncoffee consumers.
The 95% confidence interval crossed 1.0, indicating this association was not statistically significant.
This finding contributed to the characterization of the association as nonlinear.
Results
The protective association between coffee consumption and VTE recurrence was more pronounced for provoked index VTE events than for unprovoked events.
HR for recurrence after provoked index VTE was 0.50 (95% CI, 0.30-0.82) for coffee consumers (yes/no) compared to nonconsumers.
HR for recurrence after unprovoked index VTE was 1.01 (95% CI, 0.53-1.94) for coffee consumers compared to nonconsumers.
The confidence interval for unprovoked VTE crossed 1.0, indicating no significant association in this subgroup.
The binary coffee exposure variable (yes/no) was used for the provoked/unprovoked subgroup analyses.
Background
This study is the first to investigate whether coffee consumption influences the risk of VTE recurrence.
Prior epidemiological studies had shown coffee consumption is associated with a lowered risk of incident (first) VTE.
No previous study had explored whether coffee consumption influences the risk of VTE recurrence.
The study drew on population-based cohorts from two large Norwegian health studies, the Tromsø Study and the Trøndelag Health Study (HUNT).
Information on coffee consumption (cups/d) and potential confounders was extracted from survey data.
What This Means
This research studied whether drinking coffee affects the chances of having a second blood clot (venous thromboembolism, or VTE) in people who have already had one. The researchers followed over 2,000 patients from two large Norwegian population studies for a median of about 2.8 years after their first blood clot, during which time 310 people experienced a recurrence. They found that coffee consumption was associated with a reduced risk of recurrence, but not in a straightforward 'more coffee, more benefit' way — instead, the relationship was nonlinear, with moderate consumption (1-2 cups per day) showing the strongest protective association (about 51% lower risk), while very high consumption (more than 6 cups per day) did not show a statistically significant benefit.
The protective effect of coffee appeared to depend on what caused the original blood clot. Among people whose first clot had a clear trigger — such as surgery, injury, or immobility (called 'provoked' VTE) — coffee drinkers had about half the risk of recurrence compared to non-drinkers. However, among people whose first clot had no obvious cause ('unprovoked' VTE), coffee consumption did not appear to meaningfully reduce the risk of a second clot.
This research suggests that coffee does not need to be avoided after a blood clot and may even offer some protective benefit, particularly for those whose first clot was provoked by a specific event. The authors note this is the first study to examine this question. Because this is an observational study using self-reported coffee intake from population surveys, further research would be needed to confirm these findings and understand the biological reasons behind them.
Olsen M, Brækkan S, Hveem K, Grønning K, Hansen J. (2026). Association between coffee consumption and risk of recurrent venous thromboembolism - Results from the Trøndelag Health Study and Tromsø Study.. Research and practice in thrombosis and haemostasis. https://doi.org/10.1016/j.rpth.2026.106966