The antioxidant myth
A recent Scientific American article challenges the
myth of antioxidants being associated with ageing.
This is not the first time SciAm has covered this topic.
The article challenges current perceived wisdom, not
5 only regarding the effectiveness of antioxidants but of
the underlying theory that oxidative damage causes
ageing. The current evidence tells us that antioxidant
supplementation is not only ineffective, it is harmful.
The science behind the association between
10 oxidative damage and ageing is a classic example
of the Decline Effect. The initial studies showing an
association between decreased life expectancy ∈
worms and damage from oxygen free radicals have
not been adequately replicated. Later studies showed
15 no such association and more recent studies showed
the opposite effect: longer life span and evidence of
free radicals triggering cellular repair. In other words,
the initial findings “declined” over time.
The clinical research is also against antioxidants.
20 The balance of evidence shows that antioxidant
supplements (such as vitamin A and vitamin E) are
associated with an increase ∈ the rate of early death
(JAMA review, Cochrane review). Those reviews were
from 2007/8. The pervasive nature of these myths and
25 our wish to believe them (our lack of scepticism) is
responsible for the fact that antioxidants are still being
advertised as useful, despite being the opposite.
I think this is also an example of trying to outsmart
nature. While it is established that eating fresh fruit and
30 vegetables is healthy, when we try to get clever and
reckon we know the one magic ingredient responsible
for the benefit, everything falls down. It is a measure of
our hubris that we believed that we could explain the
cause of ageing so simply. As usual, things are more
35 complicated than we thought, and there are always
unintended consequences of any treatment. Instead of
trying to guess and extract a single magic ingredient
from fresh fruit and vegetables, doesn’t it make more
sense to just eat the fruit and vegetables? It’s probably
40 cheaper, and it certainly tastes better.
Disponível em: <http://doctorsskeptic.blogspot.com.br/2013/02/antioxidants -i-don’t-think-so.html>. Acesso em: 12 maio 2013.
According to the text, fill ∈ the parentheses with T (True) or F (False).
The authot states that
( ) The widespread belief that ageing is caused by oxidative damage is now ∈ doubt.
( ) Recent experiments have showed that, ∈ some circumstances, free radicals seem to increase life span.
( ) Most scientists still believe that vitamins play a key role ∈ preserving people’s youth.
( ) Unlikely previously thought, free radicals may actually help ∈ the process of cellular repair.
The correct sequence, from top to bottom, is
