Study finds constipation may increase risk of heart attack

When you search for “constipation” and “heart attack,” Elvis Presley’s name often appears. He reportedly suffered from chronic constipation, and it’s believed that straining during bowel movements may have triggered a fatal heart attack. While the exact circumstances of his death in 1977 remain unclear, this theory is among several. Following this famous case, researchers began investigating the potential link between constipation and heart attack risk, including a recent study by Australian researchers involving data from thousands of participants.

Are constipation and heart attacks linked?

Large population studies indicate a link between constipation and an increased risk of heart attacks. An Australian study of over 540,000 hospital patients aged 60+ found that those with constipation had a higher risk of high blood pressure, heart attacks, and strokes compared to non-constipated patients. Similarly, a Danish study of over 900,000 individuals confirmed this association. However, it’s unclear if this link applies to healthy people outside hospitals, and both studies didn't account for hypertension medications, which can cause constipation.

How about this new study?

A recent international study led by researchers at Monash University has found a significant link between constipation and an increased risk of heart attacks, strokes, and heart failure in the general population. The study analyzed data from the UK Biobank, which includes health information from around half a million people in the United Kingdom. 

The researchers identified over 23,000 cases of constipation and considered the effects of blood pressure medications, which can cause constipation. The findings revealed that individuals with constipation were twice as likely to suffer from a heart attack, stroke, or heart failure compared to those without constipation. 

Additionally, the study highlighted a strong connection between high blood pressure and constipation, with constipated individuals with hypertension facing a 34% higher risk of major heart events. Although the study focused on people of European ancestry, similar findings were observed in a Japanese study, suggesting the link may apply across



different populations.

How might constipation cause a heart attack?

Chronic constipation can lead to straining during bowel movements, which can cause labored breathing and a rise in blood pressure. A Japanese study involving ten elderly participants revealed that their blood pressure was elevated just before and during bowel movements, continuing to rise for an hour afterwards. This pattern was not observed in younger individuals. The study suggests that the stiffer blood vessels in older people, due to atherosclerosis and other age-related changes, contribute to this prolonged increase in blood pressure. In contrast, younger people, with more elastic blood vessels, experience a quicker return to normal blood pressure levels.

As blood pressure rises, so does the risk of heart disease. A persistent rise of 20 mmHg in systolic blood pressure can double the risk of developing heart disease. During straining, systolic blood pressure can temporarily spike by as much as 70 mmHg, which, if frequent due to chronic constipation, could elevate the risk of heart attacks.

Additionally, some individuals with chronic constipation may have impaired vagus nerve function, which regulates various bodily functions, including heart rate and digestion. This impairment can lead to heart rate irregularities and heightened blood pressure through the over-activation of the body’s stress response.

Research also suggests that an imbalance in gut bacteria, known as dysbiosis, may contribute to increased heart disease risk by triggering low-grade inflammation and stiffening arteries. Genetic factors shared between constipation and heart disease have also been identified.

What can we do about this?

Constipation impacts approximately 19% of the global population aged 60 and older, putting a significant number of people at higher risk of heart disease due to their bowel health. To manage chronic constipation and lower the risk of heart disease, it's essential to adopt dietary changes, particularly by increasing fibre intake, engaging in regular physical activity, staying well-hydrated, and using medications if needed. These measures are crucial for improving bowel function and promoting overall heart health.