Question: What are antioixidants? what do they have to do with cancer?

Leo Garcia answered on 24 Jun 2010:

When we expose some metals to the oxygen in the air around us they break down and go rusty. The same is true (roughly) inside our bodies, where exposure to oxygen (or pollution, cigarette smoke and UV radiation in sunlight) can cause cells to break down. When cells break down in this way they produce unstable molecules known as oxidants or ‘free radicals’. These free radicals can damage our DNA, cause aging and weaken our immune system, making us more likely to develop diseases such as cancer.

The word ‘anti’ means against so antioxidants work against these oxidants or free radicals by mopping them up and repairing damage to cells. Some antioxidants are produced by our own bodies and some are found in certain foods. Whenever you see something labelled as a ‘superfood’ this usually means that it contains high levels of antioxidants. These foods include blueberries, pecans, black beans and cranberries.

If antioxidants help stop our cells becoming damaged then we should eat as many of them as possible, right? Not necessarily! As always we must back up good ideas with evidence, for example a clinical trial. Studies have been conducted where one group of people were given antioxidant pills and the other group were (unknowingly) given plain old sugar pills. In some cases these trials were stopped early because – contrary to expectations – the group taking the antioxidants were dying quicker! Further studies have shown that eating extra antioxidants does nothing (at best) or kills you. Many people are still convinced that antioxidants can prevent or cure disease, slow aging and make us all gorgeous and more research will help us know for sure.

When it comes to cancer, some trials have shown that eating extra antioxidants can help prevent cancer or slow it down. However, other trials have shown the opposite.

You definitely don’t need to worry about free radicals and as long as you eat a varied diet with fresh fruit and vegetables you don’t need to swallow buckets of cranberries or take special pills. Take a look at these links for some more information:

http://www.cancer.gov/cancertopics/factsheet/prevention/antioxidants

http://www.badscience.net/2007/12/epistemological-indulgences/