Scientists in Sweden have found three genetic variants that can strongly increase a person’s risk of developing blood clots in the legs, a condition known as venous thrombosis.
The study, done by researchers at Lund University, showed that some people may face up to 180% higher risk due to their genes. This discovery helps us understand more about why these clots happen and how they might be prevented.
Blood clots can form in arteries or veins, but they develop for different reasons. Arterial clots usually happen when plaque inside blood vessels breaks apart. The body treats this like an injury and forms a clot, which can lead to heart attacks or strokes.
Venous clots are more common in the legs and usually occur when blood flow slows down. This triggers the body’s clotting system and can block a vein. If the clot moves to the lungs, it can cause a life-threatening problem called pulmonary embolism.
Venous thrombosis is a major cause of death around the world, though it doesn’t get as much attention as arterial clots. In Sweden alone, more than 10,000 people are affected by this type of blood clot every year.
Several factors increase the risk of venous clots. These include older age, being overweight, and being tall. Tall people are more at risk because their blood has to travel a longer distance from the legs to the heart, which slows down circulation in the leg veins.
Veins carry blood under lower pressure than arteries, so they’re not usually affected by high blood pressure or high cholesterol. However, obesity is a major risk because it can slow down blood flow, especially in people who don’t move much. Being overweight also affects certain clotting factors in the body.
Lifestyle also plays a part. Eating a lot of ultra-processed foods may raise the risk slightly, while healthy, plant-based diets might lower it. One interesting study found that commercial fishermen had a lower risk, possibly because they eat more fish rich in omega-3 fats.
Blood clots are more likely to happen during times of low activity, like sitting for long hours on a plane or staying in bed after surgery. Pregnancy can also raise the risk because the body increases clotting factors while reducing protective proteins. In these situations, doctors might give blood-thinning medicines to prevent clots.
Genes also have a strong influence. One known gene mutation is called Factor V Leiden. It affects about 10% of people in Sweden and is common among people of European background. This mutation interferes with a protein that helps prevent clots.
While it may have been helpful in the past by reducing bleeding, it’s not good for today’s less active lifestyles.
In the new study, scientists looked at 30,000 people from the Malmö Kost Cancer study. They studied 27 genes linked to clotting and found three—ABO, F8, and VWF—that increased clot risk by 10 to 30%. People with five risk genes had nearly double the chance of getting a clot.
Unlike Factor V Leiden, which is mostly found in Europeans, these three gene variants are found in many populations worldwide. This means the findings could be useful for people everywhere. Researchers now want to find out if people with more risk genes should take blood thinners longer after having a clot.
To reduce your risk of blood clots in the legs, you can stay active, avoid sitting for too long, wear compression stockings when needed, follow your doctor’s advice on medications, avoid estrogen-based birth control if you’ve had clots, quit smoking, eat healthy, exercise regularly, and get vaccinated since infections can also raise clotting risk.
Blood clots form when blood thickens and blocks a blood vessel. Whether in arteries or veins, knowing your risk and taking action can help protect your health.
If you care about heart disease, please read studies that herbal supplements could harm your heart rhythm, and how eating eggs can help reduce heart disease risk.
For more health information, please see recent studies that apple juice could benefit your heart health, and results showing yogurt may help lower the death risks in heart disease.
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