Cancer is a formidable foe. According to the World Health Organization, the global cancer burden is estimated to have risen to 18.1 million new cases and 9.6 million deaths in 2018. The WHO notes that current estimates indicate one in eight men and one in 11 women will die from cancer.
Statistics like those from WHO paint a scary picture, but those who have been diagnosed with cancer or watched as a brave loved one fought the disease know it is far scarier than any statistic. However, despite its prevalence, cancer can, and often is, beaten. Preventive efforts like applying sunscreen before spending time in the sun and adhering to cancer screening guidelines can help people lower their risk for cancer and/or detect it early, when the disease is most treatable.
People looking to lower their risk for cancer will uncover lots of information, some legitimate and some questionable, by simply entering "cancer prevention" into an online search engine. Two of the terms that are likely to pop up in such a search are "free radicals" and "antioxidants." Understanding these terms and their relationship to cancer can shed light on the disease.
What are free radicals?
The National Cancer Institute notes that free radicals are highly reactive chemicals that have the potential to harm cells. Free radicals form naturally in the body and actually play a key role in various cellular processes. However, high concentrations of free radicals can damage all major components of cells, including DNA and cell membranes. Researchers have long felt that the damage caused by free radicals may play a role in the development of cancer.
What are antioxidants?
Antioxidants, some of which are made by the body, are chemicals that interact with free radicals and neutralize them, thereby preventing the damage that they can cause. The body needs more antioxidants than it can produce on its own and gets most of them via a person's diet. These are referred to as dietary antioxidants, which can be gleaned from foods like fruits, vegetables and whole grains. The NCI notes that some dietary antioxidants are available as dietary supplements.
Can antioxidant supplements prevent cancer?
According to the NCI, analysis of nine randomized controlled clinical trials did not provide evidence that dietary antioxidant supplements can prevent cancer. However, this should not discourage people from consuming antioxidants in foods, which the NCI notes contain complex mixtures of antioxidants, vitamins and minerals.
Men and women concerned about cancer and the role that antioxidants can play in cancer prevention should discuss their diets with their physicians.