Broccoli is high in vitamin C, as well as dietary fiber; it also contains multiple nutrients with potent anti-cancer properties, such as diindolylmethane and small amounts of selenium. A single serving provides more than 30 mg of Vitamin C and a half-cup provides 52 mg of Vitamin C. The 3,3′-Diindolylmethane or DIM found in broccoli is a potent modulator of the innate immune response system with anti-viral, anti-bacterial and anti-cancer activity. Broccoli also contains the compound glucoraphanin, which can be processed into an anti-cancer compound sulforaphane, though the benefits of broccoli are greatly reduced if the vegetable is boiled. Broccoli is also an excellent source of indole-3-carbinol, a chemical which boosts DNA repair in cells and appears to block the growth of cancer cells.
Steaming broccoli for 3–4 minutes is recommended to maximize potential anti-cancer compounds, such as sulforaphane. Boiling reduces the levels of suspected anti-carcinogenic compounds in broccoli, with losses of 20 – 30% after five minutes, 40 – 50% after ten minutes, and 77% after thirty minutes. However, other preparation methods such as steaming, microwaving, and stir frying had no significant effect on the compounds.
In an outstanding example of cellular rejuvenation, a study conducted at Georgetown University and reported in the British Journal of Cancer found that indole-3-carbinol, a chemical in vegetables such as broccoli, cauliflower, and cabbage, actually boosts DNA repair in cells and may stop them from being cancerous. This is a critical finding because DNA is the material inside the nucleus of cells that carries genetic information. If we are genetically predisposed to cancer, could this mean that we can repair our cells and thus help prevent cancer simply by eating broccoli? It is certainly a fascinating premise, and scientists are ardently pursing this line of study.
According to Professor Eliot Rosen, who led the research, “it is now clear that the function of crucial cancer genes can be influenced by compounds in the things we eat. Studies that monitor people’s diet and their health have found links between certain types of food and cancer risk. Our findings suggest clear molecular process that would explain the connection between diet and cancer prevention.” As we’ve learned, cartenoids also show powerful chemoprotective properties.