Free radicals and oxidative stress can result from metabolic processes triggered from within a human body and/or from external stimuli.
Normally the body can handle free radicals, but if antioxidants are unavailable, or if the free radical production becomes excessive, life threatening ailments, oxidative stress and premature aging can set in.
What is free radicals and oxidative stress?
The free radicals are highly unstable atoms or groups of atoms with an unpaired number of electrons, and in order to gain stability they devour electrons from surrounding molecules.
Free radical. n. An atom or group of atoms that has at least one unpaired electron and is therefore unstable and highly reactive. In animal tissues, free radicals can damage cells and are believed to accelerate the progression of cancer, cardiovascular disease and age-related diseases… Source: thefreedictionary.com
Most of the chemical reactions in our body like breathing and metabolism produce free radicals. There are many types of free radicals known to produce toxic effect on human body…
- Nitric oxide
- Singlet oxygen
- Hydroxyl radical
- Hydrogen peroxide
- Superoxide dismutase
Oxidative stress occurs when excess oxygen radicals are produced in cells, which could overwhelm the normal antioxidant capacity. When the concentration of reactive species is not controlled by internal defense mechanisms such as antioxidants (tocopherols, ascorbic acid, and glutathione) or enzymes involved in oxygen radical scavenging (catalase, peroxidase, and superoxide dismutase, SOD), oxidative damage occurs to proteins, lipids, and DNA, which could lead to cytotoxicity, genotoxicity, and even carcinogenesis when damaged (mutated) cells can proliferate… Source: www.sciencedirect.com
What triggers production of free radicals in our Body?
Free Radicals and reactive oxygen species (ROS) are derived from metabolic processes in human body and from external sources viz. exposure to radiations, pollutants and smoking. These free radicals are formed in the body cells continuously due to enzymatic and non-enzymatic reactions.
Enzymatic reactions take place in the respiratory chain, in phagocytosis, in prostaglandin system and in cytochrome p-40 system whereas non-enzymatic reactions takes place when oxygen reacts with organic compounds.
Some Internally generated sources of free radicals
- Xanthine oxidase
- Arachidonate pathways
- Ischemia/Reperfusion injuries
Some External sources of free radicals
- Air pollutants
- Ozone depletion
- Passive smoking
- Processed foods
- Industrial solvents
- Industrial chemicals
- Radiation (X-Rays, UV Rays)
Effects of Free Radicals on our Body
Adverse changes produced by free radicals’ reaction tends to accumulate with age throughout the body. These are manifested as ailments like atherosclerosis, cancer and neurodegenerative diseases like Alzheimer’s, Parkinson disease etc.
Most of the free radicals generated by chemical processes in the mitochondria; the powerhouse of cell, are used by the white blood cells of our immune system in destroying microbes BUT some of them manage to invade other cells, triggering free radical related health issues.
Given the ubiquity of free radicals, our body has evolved number of protective mechanisms against them. One of mechanism is the production of endogenous antioxidants. An antioxidant is a molecule that slows down mutation and spread of free radicals.
The imbalance between free radical production and antioxidant defense system can lead to a condition called Oxidative Stress. Signs to look out or Oxidative Stress are:
- Unusual fatigue
- Premature ageing
- Decline in memory
- Decreased eye sight
- Myalgia and Arthralgia
- Increased sensitivity to noise
- Decreased immunity against diseases
This free radical-antioxidant imbalance can lead to following diseases
1. Cardiovascular diseases. Most of the cardiovascular diseases are caused by oxidation of low-density lipoproteins (LDL). Cells in the vessel wall can release free radicals, which affect lipid peroxidation. Oxidation of LDL can either causes atherosclerosis or can directly damage vessel wall cells. All of these mechanisms lead to various cardiovascular diseases.
Antioxidants such as B-carotene and vitamin E help to prevent various cardiovascular diseases.
2. Carcinogenesis, Cancers and Tumours. Free radicals such as ROS (Reactive oxygen species) can cause damage to DNA and can causes carcinogenesis, mutation and transformation. Both of benign and malignant tumors (cancerous and otherwise) are associated with chromosomal defects and oncogene activation by free radicals produced by ionizing radiations like X-rays and UV ray.
Antioxidants can reduce this oxidative stress induced carcinogenesis. Some examples of Antioxidants are:
- B- carotene: It has photo protective property which protect us from UV rays induced carcinogenesis
- Vitamin C: It enhances immune response and helps in detoxifying liver enzymes
- Vitamin E: It increases cell mediated immunity and inhibits mutagen formation it helps to repair membranes in DNA and stimulates immune system
3. Aging and Oxidative Stress: Major cause of aging is attributed to free radical induced DNA alteration and accumulation of cellular and functional damage. Recent research indicates that antioxidants including Vitamin E and Vitamin C help to control free radical damage associated with advancing age.
4. A few other diseases triggered by free radicals are:
- Gastric ulcers
- Ulcerative colitis
- Inflammatory diseases
- Rheumatoid arthritis
- Respiratory disorders
- Neurological disorders
- Macular degeneration and cataracts
How to get rid of Free Radicals?
The best way to fight free radicals is with the right amount of antioxidants, antioxidants found in vegetables & grains and carefully reducing the exposure to oxidation.
1. By reducing exposure to Oxidation
As mentioned earlier oxidation increases with increase in stress, environmental toxins, radiations, infections and processed foods.
- Avoid processed food and Sugar as they produce excessive free radicals.
- Take a sleep of 7-8 hours of sleep that allows body to recover on its own
- Take vitamin C, Vitamin D, vitamin A and zinc as they boost your immune system
- Take prebiotics: They help to increase immunity and decrease susceptibility to infections.
- Avoid toxins: Choose organic food over canned processed food, avoid cigarettes, candles, hair and nail salons, plastic and aluminum cooking as much as possible.
- Avoid Stress: Stress does not allow the body to recover so practice Meditation, Yoga, Exercise, Socialising, Watching some humorous movie, Quality time with friends & family, Breathing exercises, Nature walks.
2. By incorporating Antioxidants
An antioxidant is a chemical molecule, which has ability to reduce free radical’s capacity to damage other cells by donating an electron to it and by neutralizing it.
Different levels of antioxidant action: Antioxidants or radical scavenger works at different levels
- Preventive: by suppressing free radical reaction.
- Radical scavenging: By breaking or suppressing chain reaction.
- Repair: By recognizing, repairing/degrading or removal of oxidized proteins.
- Adaptation: Appropriate antioxidant reaches the right site by getting signal from free radical formation.
3. Antioxidant foods
- Corn (Lutein)
- Prunes (Phenols)
- Peaches (Phenolic)
- Oranges (Vitamin C)
- Apricots (Lycopene)
- Turmeric (Curcumin)
- Apples (Polyphenols)
- Lentils (Anthocyanin)
- Grapefruit (Lycopene)
- Tomatoes (Lycopene)
- Walnuts (Polyphenols)
- Cherries (Anthocyanins)
- Watermelon (Lycopene)
- Spinach (B—Carotene)
- Cranberries (Vitamin C)
- Kidney beans (Manganese)
- Black Berries (Ellagic acid)
- Bell peppers (Carotenoids)
- Alfalfa sprouts (Vitamin E)
- Onions (quercetin flavonoid)
- Raspberries (Ellangitannins)
- Strawberries (Phytonutrients)
- Green tea/black tea (Polyphenols)
- Asparagus (Vitamic C, E, Zinc, Selenium)
- Spinach (Carotenoids, Lutein and Zeaxanthin)
- Broccoli (Flavonoids, Kaempferol and Quercitin)
- Garlic (Allyl cysteine, Alliin, Allicin, and Allyl disulfide)
- Garlic (Allyl cysteine, Alliin, Allicin, and Allyl disulfide)
- Ginger (Polyphenols, Vitamin C, β carotene, Flavonoids)
Since synthetic antioxidants are reportedly dangerous to human health, consumption of dietary and plant-derived antioxidants is becoming a more suitable alternative.