Antioxidant Supplementation for Health – A
Savior or A Slayer?

An antioxidant is basically a molecule capable of
slowing or preventing the oxidation of other molecules.
Oxidation is a chemical reaction that transfers
electrons from a substance to an oxidizing agent.
 Oxidation reactions can produce free radicals, which
start chain reactions that damage cells.
Antioxidants terminate these chain reactions by
removing free radical intermediates and inhibit other
oxidation reactions by being oxidized themselves.
 Antioxidants (vitamins E and C, β-carotene,
superoxide dismutase [SOD], catalase etc.) protect
cells from the damage caused by free radicals, formed
as a result of oxidative stress.
Free radicals (O  2 −  , H 2 O2,  OH −  , ROO −  etc.) are
generated during the cellular metabolism and also due to
environmental effects (cigarette smoke, ionizing
radiations).
 Excessive production of free radicals has been
implicated in the causation and progression of several
diseases, e.g.,
 Atherosclerosis,

 Cancer,
 Rheumatoid arthritis,
 Diabetes, and
 Cataract.

The general belief is that since free radicals are bad
for health, antioxidants are good.
 This led to an indiscriminate use and
supplementation of antioxidants, which is currently a
controversial issue.
While some studies suggest that antioxidants are
beneficial and protective, other interventional trials
showed no health benefits.
 There are some interventional studies which
demonstrated the deleterious effects of antioxidants
(high risk of cancer, increased mortality).
Further, antioxidant supplements were found to
diminish the beneficial effects of certain drugs.
It is suggested that indiscriminate use of antioxidant
supplements should be avoided.
Perhaps, antioxidants may be prescribed (not
exceeding the recommended daily allowance) to the
elderly, strict vegetarians or people who are on calorie-
restricted diets.

It is advisable that the antioxidants are consumed from
rich natural dietary sources rather than supplements.
Further, healthy individuals should exercise utmost
caution while overdosing themselves with antioxidant
supplements.
An attempt has been made in this Booklet to review
an updated information on the effects of supplementation
of antioxidants (vitamins E and C, β-carotene, SOD,
catalase etc.) and to provide information on oxidative
stress, free radicals, along with their beneficial and
harmful effects, besides the use and misuse of antioxidant
supplements.
……Dr.H.K.Saboowala.