For a long time, scientists believed that heart attacks were mostly caused by blocked arteries due to bad cholesterol.
But a new study from researchers in Finland and the UK is changing how we understand this serious health problem.
They have found evidence that some heart attacks might actually be triggered by bacteria hiding deep inside the arteries for many years.
This surprising finding comes from a study published in the Journal of the American Heart Association.
The researchers looked at what happens in people with coronary artery disease, a condition where the arteries that carry blood to the heart become narrowed.
These arteries often have fatty buildups called plaques that are full of cholesterol. But what’s new is that scientists discovered something else inside the plaques—tiny communities of bacteria known as biofilms.
A biofilm is a sticky group of bacteria that can live silently in the body without causing any signs of illness. These bacteria can stay hidden inside the plaques for years or even decades. Because they are protected by the biofilm layer, the body’s immune system can’t detect them, and antibiotics can’t kill them.
The study suggests that if someone catches a virus or is exposed to another kind of stress, the hidden bacteria can “wake up” and start to grow again. This triggers inflammation—a response from the immune system—which can break open the plaque. When that happens, it can cause a blood clot to form, leading to a heart attack.
Professor Pekka Karhunen, one of the lead researchers, explained that until now, heart attacks were mainly blamed on damaged cholesterol (known as oxidized LDL). But their team found clear signs of bacterial DNA from common mouth bacteria inside artery plaques.
This is the first strong proof that bacteria might be playing a role in heart attacks.
To confirm their results, the team created a special antibody to detect the bacteria. When they tested artery tissue, they were surprised to see the biofilm clearly.
In cases where people had heart attacks, they also found that the bacteria had been released from the biofilm, and the immune system was reacting to it. This reaction caused the plaque to burst open.
These discoveries are important because they could change how we prevent and treat heart attacks. In the future, doctors might be able to diagnose or treat the bacterial infections hiding in artery plaques. It might even be possible to create a vaccine to stop the bacteria from triggering a heart attack.
The research was carried out by teams from Tampere and Oulu Universities, the Finnish Institute for Health and Welfare, and the University of Oxford. They used tissue samples from people who had died suddenly as well as patients who had surgery for artery disease.
This study adds a new layer to our understanding of heart health. It shows that heart attacks might not only be caused by fatty food and cholesterol but also by hidden infections. While more research is needed, this discovery could lead to new ways to protect people from heart attacks in the future.
This study provides strong evidence linking bacterial biofilms to heart attacks.
The findings challenge traditional ideas that cholesterol alone is responsible. Instead, infections hiding in the arteries could play a key role, especially when activated by stress or other infections.
The research opens up exciting opportunities for developing new treatments, including vaccines, and could lead to better ways to prevent heart attacks by targeting the bacteria instead of only focusing on cholesterol levels.
The study is published in Journal of the American Heart Association.
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