Hormesis refers to low doses of radiation that stimulate specific repair mechanisms and processes within cells to mitigate the risk or provide protection against a health condition. It is a hypothetical concept characterized by a body system stimulation via low doses of any agent, including radiation.
Most agents' low and high doses produce antagonistic effects and negative responses from a body system. A threshold dose is the one that elicits a specific response and separates positive from negative effects. For that parameter, a threshold dose is called "zero equivalent point" or ZEP.
Remember, this is where the concept of Hormesis becomes important, meaning low doses of ionizing radiation are beneficial, whereas higher doses are lethal. It is crucial for health professionals and researchers to consider the dose-response curves and focus on bio-positive and bio-negative effects before prescribing the dose. Read on!
What Does Research Evidence Say?
A 2019 research study examined the advantages and disadvantages of radiation from nuclear energy. It concluded that the world could not afford incorrect perceptions of health implications resulting from nuclear energy reactors' radiation output.
Therefore, it is necessary to perform thorough research to find the effects of low and high ionization radiation on human health. Exposure to low doses of radiation produces protective effects against a wide range of conditions, including chronic cancers.
However, another study concludes that it is impossible to completely rule out the risk of cancer and other chronic conditions with exposure to low doses of radiation. A research study published on PNAS highlights regulation on radiation using the linear non-threshold (LNT) model.
According to the LNT model, the association between exposure to radiation and risks of health conditions is linear. The study also highlights that the LNT model is inconsistent with Hormesis in Radiation because it assumes all radiation exposures are harmful, including low doses.
According to this article, exposure to low dose radiation may or may not increase cancer risk. However, researchers observed the death of people with cancer after getting exposed to low doses.
It means Hormesis in Radiation requires ongoing research to understand the concept completely, develop sophisticated/safe methods, and implement them with low risks to human health.
Biological Effects of Hormesis
Scientists and researchers view Hormesis in the light of adaptive responses and focus on a living system's performance and resilience. These systems include cell and tissue repair, fecundity, cell proliferation, cognitive and behavioral endpoints, disease resistance, aging, and other systems needed for survival in challenging environments.
So, the term "Hormesis in Radiation" refers to the ionizing radiation in doses above the range of natural levels. For example, radiation doses in an appropriate range can produce beneficial effects by stimulating various repair mechanisms.
That way, a biological system in the body makes substantial efforts to prepare defense mechanisms and processes to reduce the risk of diseases. A study published by the European Heart Journal states that ionization radiation can activate numerous compensatory and reparatory mechanisms, such as:
Enzymatic DNA repair activation
Immune system activation
Radiation hormone can also simultaneously stimulate cellular functions, trigging biological effects/processes/mechanisms, such as antioxidant defenses, DNA repair, autophagy, etc.
A low radiation dose regulates various interactor receptors and signaling pathways to produce a coherent cellular response integrated with metabolic processes. As a result, Hormesis occurs, leading to the coordinated cellular responses to protect against a disease caused by pathogens or environmental stimuli.
Radiation Hormesis is a phenomenon that focuses on the response of a biological system after getting exposed to a particular dose. It is an alternative hypothesis that low doses of ionizing radiation can benefit human health.
For instance, it triggers repair mechanisms and stimulates defensive biochemical processes to protect against disease. Some biological mechanisms at cellular and tissue levels remain inactive due to the absence of ionizing radiation.
It means providing low doses of radiation in a controlled environment can trigger and activate these processes and regulate disease protection mechanisms. However, there is a need for more research studies to test the effects and validate the results.
What is Hormesis in Radiology?
Hormesis is the term used to describe the beneficial effects of low doses of ionizing radiation. These beneficial effects include the stimulation of repair mechanisms and the induction of adaptive responses that make the cells more resistant to the damaging effects of high doses of radiation.
Radiologists are interested in hormesis because ionizing radiation is a stressor that can cause damage at high doses but may have protective effects at low doses. This is known as the radiation hormesis hypothesis, and it is a controversial topic in the field.
Some studies have found evidence for hormesis, while others have not.
What is an example of hormesis?
An example of hormesis is the beneficial effects of low doses of ionizing radiation, such as those received during medical imaging, which stimulates the body's repair mechanisms and thus confers a health benefit.
However, ionizing radiation is harmful at higher doses, so the hormetic effect is how a small amount of something can be beneficial while a larger amount is harmful.