First, it is important to note that one should not change their diet suddenly and completely based upon the results of one study or one news report about the effect that any one food, vitamin, mineral, dietary supplement, or additive has on cancer. "Studies" and "reports" are published all the time, and many of these studies and reports are based upon limited research. The conclusions are not established within any medical degree of certainty.
Now, having said that, we do know with a high degree of medical certainty that certain foods, beverages, vitamins, minerals, etc., do impact cancer risk. For example:
We know that consuming two alcoholic drinks per day by a man increases his risk of getting cancer of the mouth, pharynx (throat), larynx (voice box), esophagus, liver, and breast, and probably of the colon and rectum. A daily intake of only one alcoholic drink by a woman creates the same risk.
We also know that the body uses the antioxidants found in fruits and vegetables to fight cancer. Results of research tells us that people who eat more vegetables and fruits that are rich sources of antioxidants have a lower risk for some types of cancer.
It has been established that the consumption of processed meat as well as red meat is linked to a higher risk of certain kinds of cancer. However, there is no indication that reducing cholesterol (found in processed and red meat) has either a positive or a negative effect on cancer risk. Lowering cholesterol does, however, lower the risk of heart disease and stroke.
The red-orange carotene pigment called lycopene is mainly found in tomatoes and tomato-based foods and to some extent in pink grapefruit and watermelon. There have been several studies that have reported that consuming tomato products reduces the risk of some cancers.