New Delhi: Exposure to ionising radiation may trigger a chain of biological changes in the brain that resemble those seen in Alzheimer’s disease, according to a new review by researchers in the US.
The review, published in Frontiers in Immunology, was conducted by researchers from Hofstra University and Northwell Health in New York. It points to a molecule called eCIRP as a possible link between radiation-induced inflammation and Alzheimer’s-related neurodegeneration. The study comes amid increasing human exposure to radiation, such as medical imaging, nuclear industry growth, and the acceleration of crewed space exploration.
The study looks specifically at ionising radiation, or high-energy radiation that carries “enough energy to eject electrons from atoms, producing charged ions that damage biological molecules.”
Highlighting increased human exposure to such radiation, the research states, “The cognitive consequences of these exposures, particularly the potential for radiation to initiate or accelerate AD (Alzheimer’s disease), are therefore relevant to an expanding population.”
Researchers Max Brenner, Archana Sharma, and Pin Wang analyse more than 100 previous papers to understand how radiation exposure may be linked to Alzheimer’s. The studies include epidemiological, mechanistic, and therapeutic evidence to study this relationship.
They carried out a meta-analysis of 18 studies to find an 11 per cent increase in dementia risk for every 100 millisieverts (mSv) of cumulative radiation exposure. Animal studies reveal similar patterns.
“Mice bred with Alzheimer’s-like symptoms showed accelerated brain dysfunction when exposed to radiation”, claims Science Alert.
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The biological chain reaction
An earlier study by some of the same researchers showed that exposure to ionising radiation triggers DNA damage, which causes a subsequent response in brain immune cells, leading to a release of a protein called eCIRP.
This then appears to cause a chemical change in tau proteins – called phosphorylation. This chemical change resembles those that precede the toxic tangles seen in the brains of people with AD.
This chain reaction provides a potential new target for the study of Alzheimer’s.
“These structural and metabolic changes accumulate over time, shaping the clinical trajectory from radiation exposure to cognitive decline,” the team said.
However, the study does not suggest that simply getting an X-Ray can lead to Alzheimer’s. The study, however, opens up a point of investigation for future research relating to the disease.
Highlighting the significance of the study, the team says, “Dementia and AD affect over 55 million people worldwide, and the number in the US alone is projected to reach 13.8 million, representing 3.8 per cent of the population by 2060”.
“Despite decades of research and the development of disease-modifying therapies targeting amyloid-β and tau pathology, effective preventive and therapeutic approaches remain elusive”, they added.
(Edited by Saptak Datta)