Many foods have been investigated for their beneficial effects at decreasing cancer risk. Many of these foods have been chemically analysed and their contents characterised. From such studies isolated compounds have been identified as probable agents responsible for the anti-cancer effects. As a result many of these chemicals are now available in supplements. But should you take isolated supplements or are the whole foods more beneficial?
Whole Food Synergy
Generally it is far more efficient to obtain cancer prevention from whole foods. Isolating chemicals is interesting and serves a purpose for pharmacological testing. However, in reality plant foods are far more than single chemicals. Most foods such as red wine, tea and most fruits and vegetables are complex mixtures of different chemicals that work together to protect plant cells. This synergy is transferable to human cells and so consuming isolated chemicals may be counter productive.
Beta Carotene And Isoflavonoids
Two potential anti-cancer compounds that originate in plants are beta carotene from vegetables such as carrots and spinach, and the isoflavonoids from soya. Both of these chemicals have been isolated and are available in supplements. Studies show that taking high concentrations of these compounds may actually increase the risk of certain cancers. However, intakes that could be obtained from consuming plant foods have beneficial effects.
Whole Foods Are Best For Phytonutrients
Phytonutrients then act synergistically and are potentially problematic when isolated and concentrated. In addition, supplements can be prohibitively expensive for some of the best anti-cancer agents that are available cheaply and readily in certain foods. The amount of supplements you would have to take to get close to the variety of anti-cancer compounds in plants would be prohibitive and therefore the practicalities also favour eating whole foods.
But What About Selenium?
Selenium is a trace mineral required as a cofactor for the cellular enzyme glutathione peroxidase. In this roles selenium is thought to confer protection against cancer. Areas of the World with low intakes of selenium have some of the highest cancer rates, and supplementation of selenium deficient people reduces cancer deaths by half. However, selenium is deficient from soils and therefore deficient from plants. The only real way to ensure an adequate intake is to supplement.
Whole Foods And Supplements
Whole foods provide complex mixtures of anti-cancer compounds. However, because the soil they grow on is devoid of meaningful level of minerals, the plants are mineral deficient and the people who eat them become mineral deficient. Supplementing with those minerals thought to have anti-cancer effects, particularly selenium, iodine, zinc, calcium and magnesium, makes sense as studies show obtaining adequate intakes from foods is difficult.