Why do we care about free radicals?
Free radicals attack important macromolecules in our body (e.g. lipids, nucleic acids, proteins) leading to cell damage and disruption of normal physiological functions. If these attacks are kept unchecked, many diseases may arise as a result of free radical damage. Read on to find out more.
What are free radicals?
“A free radical can be defined as any molecular species capable of independent existence that contains an unpaired electron in an atomic orbital. Many radicals are unstable and highly reactive. They can either donate an electron to or accept an electron from other molecules, therefore behaving as oxidants or reductants.”
– Excerpt from V. Lobo, A. Patil, A. Phatak, and N. Chandra. Free radicals, antioxidants and functional foods: Impact on human health. Pharmacogn Rev. 2010 Jul-Dec; 4(8): 118–126.
How are free radicals produced?
Free radicals are generated from either endogenous (from our body internally) or exogenous (external) sources.
Free radicals are generated in our body from immune cell activation, inflammation, mental stress, excessive exercise, ischemia, infection, cancer, aging.
External free radicals result from air and water pollution, cigarette smoke, alcohol, cooking (smoked meat, re-used oil, fat), radiation.”
How do free radicals impact our health?
Free radicals are usually neutralized by the antioxidants generated by our body. Oxidative stress arise when our cells do not have sufficient antioxidants to adequately destroy the excess of free radicals formed. Chronic oxidative stress leads to ageing and many degenerative diseases,
Cancer – “It is well established that oxidative DNA damage is responsible for cancer development. Cancer initiation and promotion are associated with chromosomal defects and oncogene activation induced by free radicals.”
Cardiovascular disease – “in vivo and ex vivo studies have provided precious evidence supporting the role of oxidative stress in a number of CVDs such as atherosclerosis, ischemia, hypertension, cardiomyopathy, cardiac hypertrophy and congestive heart failure.”
Neurological diseases – “numerous experimental and clinical studies have demonstrated that oxidative damage plays a key role in the loss of neurons and the progression to dementia. The production of ß-amyloid, a toxic peptide often found present in Alzheimer’s patients’ brain, is due to oxidative stress and plays an important role in the neurodegenerative processes.”
Pulmonary diseases – “There is now substantial evidence that inflammatory lung diseases such as asthma and chronic obstructive pulmonary disease (COPD) are characterized by systemic and local chronic inflammation and oxidative stress.”
Rheumatoid arthritis – “The pathogenesis of this disease is due to the generation of ROS and RNS (free radicals) at the site of inflammation. Oxidative damage and inflammation in various rheumatic diseases were proved by increased levels of isoprostanes and prostaglandins in serum and synovial fluid compared to controls.”
Kidney diseases – “Heavy metals (Cd, Hg, Pb, As) and transition metals (Fe, Cu, Co, Cr)-induced different forms of nephropathy and carcinogenicity are strong free radical inducers in the body.”
Eye diseases – “Oxidative stress is implicated in age-related macular degeneration and cataracts by altering various cell types in the eye either photochemically or nonphotochemically. Under the action of free radicals, the crystalline proteins in the lens can cross-link and aggregate, leading to the formation of cataracts. In the retina, long-term exposure to radiation can inhibit mitosis in the retinal pigment epithelium and choroids, damage the photoreceptor outer segments, and has been associated with lipid peroxidation.”
Fetus and pre-eclampsia – “Oxidative stress is involved in many mechanisms in the development of fetal growth restriction and pre-eclampsia in prenatal medicine. Some reports indicate that blood levels of lipid peroxidation products (F2-isoprostanes, MDA) are elevated in pre-eclamptic pregnancy and intra-uterine growth retardation and it has been suggested that ROS/RNS play a role in the etiology of these diseases. In pregnancies complicated by pre-eclampsia, increased expression of NADPH oxidase 1 and 5 isoforms which are the major enzymatic sources of superoxide in the placenta is seen.”
– Excerpt from Lien Ai Pham-Huy, Hua He, and Chuong Pham-Huy. Free Radicals, Antioxidants in Disease and Health. Int J Biomed Sci. 2008 Jun; 4(2): 89–96.
How can we protect ourselves from free radicals?
Whilst it is best to obtain antioxidants from fresh fruits and vegetables to mop up these free radicals, supplementation with antioxidants may be necessary if you lead a high-stress fast-paced lifestyle, where you may experience higher levels of free radicals or not eating enough food rich in antioxidants.
Anthocyanins are natural plant pigments with a powerful antioxidant properties. Click here to read more on how eating or drinking purple foods rich in anthocyanins can help protect you from free radicals damage.
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