In a study from National Cancer Institute and elsewhere, scientists found exposure to low doses of ionizing radiation is associated with a modestly increased excess risk of heart disease.
Researchers suggest that these risks should now be carefully considered in protection against radiation in medicine and elsewhere.
It’s well-recognized that exposure to high-dose radiation can damage the heart.
But there is a lack of firm evidence linking low-dose radiation to heart disease (e.g., the scatter radiation dose from radiotherapy or working in the nuclear industry).
In the current study, researchers reviewed studies evaluating links between a range of heart diseases and exposure to radiation (mostly radiotherapy and occupational exposures).
These studies covered a broad range of doses, and brief and prolonged exposures, and evaluated the frequency (incidence) and mortality of various types of vascular diseases.
The researchers found consistent evidence for a dose-dependent increase in heart risks across a broad range of radiation doses.
For example, the relative risk per gray (Gy) increased for all heart diseases and for specific types of heart disease, and there was a higher risk per dose unit at lower dose ranges (less than 0.1 Gy), and also for lower dose rates (multiple exposures over hours to years).
At a population level, the team found excess absolute risks ranged from 2.33% per Gy for the current England and Wales population to 3.66% per Gy for Germany, largely reflecting the underlying rates of cardiovascular disease mortality in these populations.
This equates to a modest but significantly increased excess lifetime risk of 2.3-3.9 heart deaths per 100 persons exposed to one Gy of radiation, explain the authors.
The researchers suggest that mechanisms for the heart disease effects are poorly understood, even at high doses.
They also say that few studies assessed the possible modifying effects of lifestyle and medical risk factors on radiation risk, particularly major modifiable risk factors for heart disease like smoking, obesity, diabetes, high blood pressure, and high cholesterol, and say further research is needed in this area.
If you care about heart health, please read studies about vitamin K that may help cut heart disease risk by a third, and as a teen, she saw her mom die from the same heart problem she inherited.
For more information about heart health, please see recent studies that Paleo diet plus exercise could boost heart health in people with diabetes and results showing Olive oil could help lower risks of heart disease and stroke.
The study was conducted by Mark Little et al and published in The BMJ.
Copyright © 2023 Knowridge Science Report. All rights reserved.
