Question

why high dose antioxidant supplements may increase the risk of cancer in some cases?

which 1 of 4 options:

Antioxidants may protect "bad cells" (cells prone to developing cancer) from being damaged and tagged for destruction just as they protect "good" (normal) cells. Antioxidants become less effective at high dosages because they compete with one another Antioxidants promote oxidation when taken together. Antioxidants are typically water soluble and are therefore excreted when consumed in high amounts. It is a waste of money to take antioxidant pills because you will just lose the excess via urine.

Answer 1

Correct answer is

Option : A

Antioxidants are chemicals that interact with and neutralize free radicals, thus preventing them from causing oxidative stress and free radical damage. Some of the antioxidants our body can make, while some we get from fruits, vegetables, and grains in our diet. Supplementation of antioxidants prevent both normal healthy cells as well as cancer cells from free radicals. Many studies have shown that by reducing oxidative stress and DNA damage, anti-oxidants benefit tumour cells more than they benefit normal healthy cells in cancer patients, resulting in increased number, size, and advancement in stage of the tumours and speeding their metastasis.

Administration of high doses of antioxidants, does not make them less effective by competition between them. In fact it increases risk of toxicity. ‘The more the better’ is not true in case of antioxidants.

Antioxidants, by chemical nature are compounds that prevent or delay the oxidation of another compounds. Of two compounds, the one which becomes oxidized, functions as an antioxidant for the other.

Not all antioxidants are water soluble (example ascorbic acid- vitamin C). Fat soluble antioxidants (like beta carotene, vitamin E) are stored in liver and fatty tissues. It means that they are not excreted in urine and can also build up to toxic levels when consumed in excessive amounts. Water-soluble vitamins are easily dissolved and can be excreted in the urine. But this does not mean that they can be taken in unlimited quantities. There can be problems with excessive amounts.