Low-Dose Diagnostic Radiation May Increase Risk of Heart Disease

Diagnostic and work-related radiation can elevate the lifetime risk of heart disease even in low doses, a new study finds.

Radiation exposure has been long linked to potential health risks to astronauts, most notably to increased cancer risk. Nevertheless, researchers thought a threshold could be lowered so there would be no risk of going to space.

The new study published in the British Medical Journal suggests that there is no such threshold, meaning that more people should be concerned about radiation exposure, including:

• People who receive radiation therapy for cancer.
• Individuals who undergo diagnostic radiation, such as computerized tomography (CT) scans of the chest.
• People who work in healthcare, nuclear weaponry and energy, astronauts, and transcontinental pilots.

The researchers note that while oncologists are well aware of possible long-term effects and working on minimizing the risks, the other two groups would benefit from further research and potential policy changes.

One CT scan poses a low risk

To evaluate links between cardiovascular diseases and exposure to radiation, the researchers examined 93 studies, most of which were published in the past decade. They found a "modest but significantly increased excess lifetime risk of 2.3-3.9 deaths per 100 people exposed to one gray (Gy)," defined as absorbed energy per unit mass of tissue.

Francis A. Cucinotta, one of the study’s co-authors, a professor of health physics and diagnostic sciences at UNLV’s School of Integrated Health Sciences, says that the doctors must weigh the value of that CT scan and discover a problem versus the risk from the radiation.

"This is a small risk for an individual undergoing a single CT scan with a dose of about 0.02 Gy; however, a large population risk with millions of both CT scans per year and medical and other radiation workers," he adds.

The study also suggests people at higher risk of cardiovascular disease from radiation should better control other medical and behavioral risk factors for heart disease.

What is heart disease?

Heart disease is the leading cause of death for men, women, and most ethnic and racial minorities in the United States., and was responsible for one in five deaths in 2020.

The term refers to several types of heart conditions, including coronary artery disease (CAD), which affects the blood flow to the heart and is the most common type of heart disease in the U.S.

The key risk factors for heart disease are high blood pressure, high blood cholesterol, and smoking. Certain medical conditions, such as diabetes and obesity, can also elevate the risk of the disease.