UPSC Prelims 2011 Q91: Science & Technology – Health & Diseases
Regular intake of fresh fruits and vegetables is recommended in the diet since they are a
good source of antioxidants. How do antioxidants help a person maintain health and promote
longevity?
- (a) They activate the enzymes necessary for vitamin synthesis in the body and help prevent vitamin deficiency
- (b) They prevent excessive oxidation of carbohydrates, fats and proteins in the body and help avoid unnecessary wastage of energy
- (c) They neutralize the free radicals produced in the body during metabolism
- (d) They activate certain genes in the cells of the body and help delay the ageing process
Answer: (c) They neutralize the free radicals produced in the body during metabolism
Explanation
How antioxidants help maintain health and longevity
Antioxidants in fruits and vegetables combat a specific kind of cellular damage.
| Option | Verdict | Reason |
|---|---|---|
| (a) Activate enzymes for vitamin synthesis | Incorrect | This misdescribes the antioxidant mechanism; antioxidants don't primarily work by synthesizing vitamins |
| (b) Prevent excessive oxidation of nutrients, avoiding energy wastage | Incorrect | This confuses antioxidants' role with general metabolic efficiency, not their actual protective mechanism |
| (c) Neutralize free radicals from metabolism | Correct | Free radicals, byproducts of normal metabolism, can damage cells; antioxidants neutralize them, protecting cells from oxidative stress |
| (d) Activate genes to delay ageing | Incorrect | This is a broader, less precise claim; the direct, well-established mechanism is free-radical neutralization, not gene activation |
Antioxidants and free radicals:
| Point | Detail |
|---|---|
| Free radicals | Reactive byproducts of normal cell metabolism |
| Damage caused | Oxidative stress, linked to ageing and disease |
| Antioxidant role | Neutralize free radicals, protecting cells |
Answer: (c) They neutralize the free radicals produced in the body during metabolism.
Why each option is right or wrong
- (a) Incorrect. Antioxidants are not primarily enzyme activators for vitamin synthesis.
- (b) Incorrect. This describes general metabolic efficiency, not the specific free-radical-neutralizing mechanism of antioxidants.
- (c) CORRECT. Antioxidants neutralize free radicals generated during normal metabolism, protecting cells from oxidative damage.
- (d) Incorrect. Gene activation is not the established, direct mechanism; free-radical neutralization is.
Key point
Antioxidants protect health and promote longevity mainly by NEUTRALIZING FREE RADICALS — reactive byproducts of normal metabolism that would otherwise damage cells.
Remember
Antioxidants protect health by neutralizing free radicals produced during normal body metabolism.
Common mistakes
- Confusing antioxidants' role with vitamin synthesis or general metabolic efficiency.
- Overcomplicating the mechanism with gene activation claims instead of the simpler, correct free-radical explanation.
- Not knowing what free radicals are and why they are harmful.
Exam tip
Antioxidants = free-radical neutralizers. Any option describing enzyme activation or gene activation is a distractor from this core mechanism.
Sources
- Barry Halliwell and John M. C. Gutteridge — Free Radicals in Biology and Medicine (Oxford University Press)
- National Institute of Nutrition (ICMR) — Dietary Guidelines for Indians: A Manual (2011)