Rihana Bokhari, BS
You have probably heard someone tell you exercise is good for you and maybe you have even heard that exercise can help prevent a lot of diseases like diabetes and heart disease. But did you know that exercise does far more than helping you shape up for summer or feel better on a daily basis?
Exercise might be able to protect you from radiation. Radiation is well known to cause harmful effects on the human body. This study seeks to use exercise as a non-invasive and safe method to protect against the damaging effects of low amounts of radiation in astronauts and radiotherapy patients. You might say, why don’t they just wear lead vests to protect themselves? The answer is that radiation comes in many different flavors, the kind that astronauts and radiotherapy patients will encounter is delivered very slowly and cannot be protected against by metal shields.
The lack of an effective way to protect against this radiation has been a major factor in the delay of NASA missions to Mars. Although the amount of radiation an astronaut would receive over 2 years will not cause health effects during the mission it will cause damage in cells greatly increasing the risk of cancer later in life. Radiotherapy patients are also exposed to radiation similarly to astronauts. During cancer treatment a very high amount of radiation is targeted at the tumor to kill the cancerous cells; however, low amounts of this radiation effects the rest of the body. This radiation is similar to that which astronauts will experience because it is delivered over a long period of time during cancer treatment. Most scientific studies with radiation have delivered the entire amount of radiation experienced by the individual within a minute. This study will employ a rarely used radiation field that will deliver a constant and low amount of radiation to the subject animals over 4 weeks. This set up is more likely to provide information that is relevant to astronauts and radiotherapy patients.
Exercise can be a simple protection against cell damage caused by radiation. When radiation interacts with cells it creates reactive oxygen species (ROS), molecules that cause oxidative stress, a molecular imbalance that is toxic to the body. During exercise ROS activate antioxidant defenses to protect against oxidative stress. Astronauts and radiotherapy patients may benefit from exercise to protect against the harmful effects of radiation exposure. Exercise will also have the added benefit of protecting against the bone, muscle and heart damage that is usually caused by radiation. Studying changes in these tissues is one way that the protective effects of exercise will be measured. Radiation and exercise have never been studied at the same time, however, as part of a current study our laboratory will be setting up a constant low dose radiation field. Animals will exercise during their 4 week exposure period to help increase the body’s natural antioxidant defenses against radiation exposure.
Literature Cited:
1. Alwood JS, Kumar A, Tran LH, Wang A, Limoli CL, Globus RK. Low-dose, ionizing radiation and age-related changes in skeletal microarchitecture. Journal of aging research. 2012.
2. Bandstra ER, Pecaut MJ, Anderson ER et al. Long-term dose response of trabecular bone in mice to proton radiation. Radiation research. 2008;169(6):607-14.
3. Cucinotta FA, Durante M. Cancer risk from exposure to galactic cosmic rays: implications for space exploration by human beings. The lancet oncology. 2006;7(5):431-5.
4. Erg¸n H, Howland W. Postradiation atrophy of mature bone. CRC critical reviews in diagnostic imaging. 1980;12(3):225-43.
5. Gomes EC, Silva AN, Oliveira MRd. Oxidants, antioxidants, and the beneficial roles of exercise-induced production of reactive species. Oxidative medicine and cellular longevity. 2012.
6. Morgan WF, Sowa MB. Non-targeted bystander effects induced by ionizing radiation. Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis. 2007;616(1):159-64.