A new study led by Hiroyasu Iso and his team, published in the Journal of the American Heart Association, has found that people with severe high blood pressure might need to rethink their coffee habits. The research shows that drinking two or more cups of coffee daily may significantly increase the risk of dying from heart disease for individuals with very high blood pressure.
The study examined the health records of over 18,000 participants, both men and women, aged between 40 and 79. These participants were followed for nearly 19 years, ending in 2009.
During this long period, 842 people passed away due to heart-related problems. This provided researchers with enough data to see patterns and understand the impact of coffee consumption on heart health, especially for those with high blood pressure.
One of the key findings of the study was that people with blood pressure readings of 160/100 mm Hg or higher—classified as severe hypertension—were at much greater risk of heart-related death if they drank two or more cups of coffee daily. In fact, the risk of dying from heart disease doubled for these heavy coffee drinkers compared to those who drank less or none at all.
Interestingly, the study found that drinking just one cup of coffee per day did not increase the risk of heart disease, no matter what the person’s blood pressure was. This suggests that moderate coffee consumption might be safe even for those with some degree of high blood pressure.
The researchers also looked at green tea, another popular caffeinated drink, to compare its effects. Surprisingly, unlike coffee, drinking green tea every day did not increase the risk of heart disease at any blood pressure level.
This difference may be due to green tea’s rich content of polyphenols—powerful antioxidants that help reduce inflammation and protect the heart. These natural compounds seem to counteract the negative effects of caffeine, making green tea a safer option for those with high blood pressure.
The study used a clear system to categorize blood pressure levels:
- Optimal and Normal: Less than 130/85 mm Hg
- High Normal: 130-139/85-89 mm Hg
- Grade 1 Hypertension: 140-159/90-99 mm Hg
- Grade 2 Hypertension: 160-179/100-109 mm Hg
- Grade 3 Hypertension: Higher than 180/110 mm Hg
It was particularly in the Grade 2 and Grade 3 categories—those with the most severe high blood pressure—that the risks associated with drinking two or more cups of coffee each day were the highest.
This study’s findings align with earlier research, which has had mixed results about coffee’s impact on heart health. Some studies have suggested that moderate coffee drinking might even lower the risk of heart attacks and strokes, especially in healthy people.
Regular coffee consumption has also been linked to reduced risks of chronic diseases, better mood, increased alertness, and even better appetite control.
However, there is also evidence that drinking too much coffee can lead to problems like higher blood pressure, anxiety, heart palpitations, and trouble sleeping. For people with already high blood pressure, these effects can be particularly harmful, potentially outweighing any of the benefits that coffee might provide.
The difference between coffee and green tea in this study highlights how not all caffeinated drinks affect the body in the same way. While both contain caffeine, green tea seems to have protective effects against heart disease, possibly due to its antioxidant properties.
The results of this study suggest that people with severe high blood pressure should be especially cautious about how much coffee they drink.
For those in the highest blood pressure categories, cutting back on coffee might help reduce their risk of heart disease. On the other hand, green tea could be a healthier option, providing caffeine along with heart-protective benefits.
In conclusion, this research emphasizes the importance of personalized dietary choices. For people with severe high blood pressure, moderate or limited coffee consumption could be key to protecting heart health, while green tea might serve as a safer alternative. Consulting with a healthcare provider can help determine the best approach based on individual health needs and risks.
If you care about high blood pressure, please read studies about unhealthy habits that may increase high blood pressure risk, and drinking green tea could help lower blood pressure.
For more information about high blood pressure, please see recent studies about what to eat or to avoid for high blood pressure, and 12 foods that lower blood pressure.
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