Free Radicals: Unstable Molecules in Our Internal Battlefield
Free radicals, also known as Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS), are unstable molecules with unpaired electrons. These unpaired electrons make them highly reactive, seeking to steal electrons from other molecules to achieve stability [1]. This electron-stealing act disrupts the delicate balance within cells and can lead to cellular damage.
Where do free radicals come from?
Our bodies naturally produce free radicals during normal cellular processes, particularly in the mitochondria, the powerhouses of our cells [2]. Exposure to environmental factors like pollution, cigarette smoke, and ultraviolet radiation also contributes to free radical production [3].
The Good, the Bad, and the Imbalanced:
Free radicals aren’t all villains. In low to moderate amounts, they play a role in cell signaling and fighting off infections [4]. However, an imbalance between free radical production and the body’s natural antioxidant defenses leads to a condition called oxidative stress.
Oxidative Stress and Its Consequences:
Oxidative stress occurs when free radicals overwhelm the body’s antioxidant defenses. This disrupts cellular function and damages important molecules like DNA, proteins, and lipids [1]. Chronic oxidative stress has been linked to various health problems, including:
- Age-related diseases: Alzheimer’s disease, Parkinson’s disease, and macular degeneration [5].
- Cancer: Free radical damage can contribute to uncontrolled cell growth, a hallmark of cancer [6].
- Cardiovascular diseases: Oxidative stress can damage blood vessels and contribute to atherosclerosis, a buildup of plaque in arteries [7].
Citations:
- [1] Halliwell, B., & Gutteridge, J. M. C. (1989). Free radicals in biology and medicine (Vol. 1). Clarendon Press Oxford.
- [2] Finkel, T. (2001). Oxidative stress: a concept adrift. The Journal of Clinical Investigation, 108(8), 1095-1103. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7555448/
- [3] Schieber, M., & Chandel, A. (2014). ROS signaling in mitochondrial dynamics. Trends in Cell Biology, 24(1), 7-19. https://www.mdpi.com/2075-1729/11/4/332
- [4] Kumar, S., & Pandey, A. K. (2015). Free Radicals: Health Implications and their Mitigation by Herbals. Journal of Advances in Medicine and Medical Research, 7(6), 438–457. https://journaljammr.com/index.php/JAMMR/article/view/1056
- [5] Salazar, G., Nencioni, A., Valenzuela, A., & Rios, C. (2006). [Role of oxidative stress in the pathogenesis of Parkinson’s disease]. Revista medica de Chile, 134(6), 741-748. https://pubmed.ncbi.nlm.nih.gov/24252804/
- [6] Hanahan, D., & Weinberg, R. A. (2011). Hallmarks of cancer: the next generation. Cell, 144(5), 646-674. https://www.sciencedirect.com/science/article/pii/S0092867411001279
- [7] Forstermann, U., Xia, N., & Li, H. (2017). Roles of Vascular Oxidative Stress and Nitric Oxide in the Pathogenesis of Atherosclerosis and Arterial Hypertension. Circulation research, 120(7), 1213-1235. https://pubmed.ncbi.nlm.nih.gov/28209797/