Coffee and Blood Pressure: What a Major Review of the Evidence Found

Coffee is one of the most popular drinks in the world, and for many people it is a daily habit. A common question is whether that habit affects blood pressure, and a major review of the scientific evidence has looked closely at how coffee relates to the risk of high blood pressure.

What the review looked at

According to a summary published by The Conversation, the review examined 13 separate studies that together involved around 315,000 people. The goal was to understand whether drinking coffee is linked to a higher risk of developing hypertension over time.

One of the studies included was particularly long term. The summary described a Japanese study that followed more than 18,000 adults aged between 40 and 79 for a period of nearly 19 years, giving researchers a detailed view of long term coffee habits and health outcomes.

The main finding

The central conclusion was reassuring for regular coffee drinkers. According to the review, coffee drinking was not associated with an increased risk of developing high blood pressure across the studies that were examined by the researchers.

The finding held for most people in the analysis. For those with normal blood pressure or only mild hypertension, no clear associations were found between coffee consumption and a higher risk of developing the condition over the years studied.

An important exception

There was, however, one notable exception. The review reported that people with very high blood pressure, defined as a systolic reading of 160 or above or a diastolic reading of 100 or above, who drank two or more cups a day had double the risk of cardiovascular death compared with non drinkers.

How caffeine affects blood pressure

The review also explained how caffeine acts in the short term. Caffeine can cause a temporary rise in blood pressure, with systolic readings increasing by 3 to 15 mm Hg and diastolic readings rising by 4 to 13 mm Hg after it is consumed.

The effect is also relatively short lived. According to the summary, levels of caffeine in the blood peak between 30 minutes and two hours after drinking, and caffeine has a half life of roughly 3 to 6 hours in the body before it clears.

Who conducted the review

The analysis was summarised by Clare Collins, a Laureate Professor in Nutrition and Dietetics at the University of Newcastle, in an article published by The Conversation in May 2026, drawing together evidence from a range of earlier research on the subject.

A note of caution

The review was careful about the quality of the evidence. It noted that five studies from the United States and seven studies judged to be of low quality, which suggested a lower risk, should be interpreted with caution rather than taken as firm proof.

What it means for coffee drinkers

For most people, the message from the review is broadly reassuring, suggesting that moderate coffee drinking is not clearly linked to a higher risk of developing high blood pressure. Those with very high blood pressure, however, may have more reason to be careful.

The bigger picture

Coffee remains a widely studied part of the daily diet, and research into its effects continues to evolve over time. As with many questions in nutrition, the picture depends on individual circumstances, the amount consumed and a person's existing health.

Conclusion

Overall, the review offers a nuanced view of a familiar drink. While coffee does not appear to raise the risk of high blood pressure for most people, the evidence points to a more cautious approach for those who already have very high readings.