Generally, free radicals are always considered bad and anti oxidants are looked upon as an antidote for everything that goes wrong in our body. In this article, lets see the role played by free radicals and the dangers of eating too many antioxidants.
The cells of our body produce certain molecules like peroxide, super oxide, nitric oxide . They are called as free radicals. These molecules are formed naturally and continuously in our body as a by product when the food we eat is converted into energy . They are also produced in our body due to environmental toxins , UV radiation, x rays etc.
These FREE RADICALS are highly energetic , reactive, unstable molecules .they are unstable and energetic because they have an unpaired electron in their outer orbit.
We can describe free radicals as hungry and angry molecules. In order to become stable they are always on the look out for electrons from stable molecules .
And they knock off an electron from vital cellular molecules like proteins lipids and the DNA they come across.
After losing an electron these molecules now become a free radical themselves and this sets off a chain reaction leading to formation of a lot more free radicals.
These free radicals are counteracted by molecules called anti oxidants . Antioxidants act in three ways
- preventing free radical formation
- scavenging the already formed free radicals
- repairing the damaged cell molecules.
There are two types of antioxidants
- Endogenous – produced by our own body.
- Exogenous – obtained from our diet.
Endogenous anti oxidants
| ENZYMATIC | NON ENZYMATIC |
| Super oxide dismutase | Glutathione, Coenzyme Q10 |
| Catalase | Melatonin, Lipoic acid |
| Glutathione peroxidase | L – Arginine etc |
The exogenous antioxidants which we get from the diet are
- Vitamin C
- Vitamin E
- Carotenoids
- Selenium
- Manganese
- Zinc
- Flavonoids
- Omega-3 and Omega 6 fatty acids etc
Whenever the free radical load is much more than the antioxidants can handle , oxidative stress occurs in our body. This leads to inflammation and disease.
Effects of oxidative stress in our body
Premature aging
Free radicals hasten the aging process. Damage to the skin is the most obvious sign because it is visible to our eyes as deep wrinkles, roughness, discoloration and dullness.
Brain
Oxidative stress accelerates brain aging. It alters brain vasculature and morphology, altered levels of the neurotransmitters and hormones. Initially, it results in milder forms of memory loss depression and cognitive impairment. When left unchecked, it can progress to Alzheimer’s disease and Parkinson’s disease.
Lungs , eyes and heart
It can lead to asthma, chronic obstructive pulmonary disease and in the eyes it can precipitate age related macular degeneration and cataract formation. Oxidative stress also plays a crucial role in the development of atherosclerosis and hypertension which can ultimately result in ischaemic heart disease.
Cancer
One major cause of all types of cancer is oxidative stress. When the DNA of the cell is repeatedly attacked by the free radicals, it undergoes mutation and the cells undergo uncontrolled multiplication resulting in cancer.
How to prevent oxidative stress ?
Preventing excess formation of free radicals would be the first step. This is by avoiding obvious stressor of our body like junk foods, alcohol , and smoking, mental and physical stress
Junk food
Junk food is energy dense, low nutrient, low fibre, fatty food. Eating too much of this leads fat accumulation.
There are two types of fat deposits. Subcutaneous fat and visceral fat. Subcutaneous fat is the fat deposit beneath the skin . Visceral fat is the fat deposited in the abdominal cavity near the vital organs like liver, stomach and intestines. This fat is metabolically active and dangerous because it releases potentially harmful molecules that cause oxidative stress.
Tobacco
Tobacco smoke contain more than thousand toxins all of which can cause high oxidative stress in the blood vessels and wreck havoc in the clotting mechanisms of the blood.
Alcohol
Alcohol is metabolised in the liver .The metabolites of alcohol produce more free radicals and drastically decrease anti oxidant production. Liver is the master organ of our body ,an engine on which the body runs . Regular consumption of alcohol can cause full blown oxidative stress to the liver , liver injury and ultimately liver cell death.
Emotional stress
When a person is emotionally stressed for a prolonged period, stress hormones like cortisol , adrenaline and noradrenaline are released. This can be considered a sub healthy stage where there is no disease and health either. In the long term, there will be chronic inflammation and oxidative stress resulting in frank diseases.
Physical stress
Intense physical exercise can boost metabolism and result in weight loss and in the process a lot of free radicals are produced. So exhaustive physical exercise should always be countered with nutritious antioxidant rich diet and adequate water intake On the other hand, physical inactivity also causes oxidative stress , especially in the blood vessels. Long term moderate exercise is the indispensable key for health. It not only increases the production of antioxidants enzymes, but also improves the musculoskeletal function, immune and endocrine system. Exercise single handedly can reduce the occurrence of many types of cancer.
Diet
Enzymes produced in our body are basically protein molecules .So good intake of protein is a must for improving anti oxidant enzymes. We have to improve antioxidant uptake by eating wholesome food rather than supplements because we can go overboard with supplements which can have negative effects .Foods that are rich in antioxidants are leafy vegetables, colourful fruits and vegetables, spices and nuts.
Too much of antioxidants?
According to many studies, too much of antioxidant paradoxically increase the chances of getting cancer.
Role of free radicals in our body.
Free radicals play an important role in the host defence mechanism. Phagocytes are our body’s first line defence cells. They are white blood cells that engulf and digest toxins and microorganisms .They do so by producing a burst of free radicals.
Not only that, free radicals are the signalling molecules for many cellular events within the cells and between many cells of our body.
Antioxidant supplements
Supplements do come in handy when our diet is lacking in antioxidants . They can be used for short period of time and are generally recommended in certain medical conditions, where the oxidative damage has already occurred or in certain gastro intestinal disorders.
It is important to get medical advice before starting antioxidant supplements . Facts about the dosage and how long it is to be eaten should be analysed. Antioxidant supplements cannot counteract our unhealthy lifestyle entirely. On the contrary, we have to be cautious with antioxidant supplements as they can become pro oxidants when consumed in excess.
The bottom line
We have to maintain minimum required amount of free radicals for the cell functions and also keep them in check so that they do not cause any damage. So, maintaining the delicate balance between free radicals and antioxidants is the key to our wellbeing.
References
- Pham-Huy LA, He H, Pham-Huy C. Free radicals, antioxidants in disease and health. Int J Biomed Sci. 2008;4(2):89-96.
- Birben E, Sahiner UM, Sackesen C, Erzurum S, Kalayci O. Oxidative stress and antioxidant defense. World Allergy Organ J. 2012;5(1):9-19. doi:10.1097/WOX.0b013e3182439613
- Laufs U, Wassmann S, Czech T, Münzel T, Eisenhauer M, Böhm M, Nickenig G. Physical inactivity increases oxidative stress, endothelial dysfunction, and atherosclerosis. Arterioscler Thromb Vasc Biol. 2005 Apr;25(4):809-14. doi: 10.1161/01.ATV.0000158311.24443.af. Epub 2005 Feb 3. PMID: 15692095.