Importance of other important nutrients
Inadequate are the indications that the supply of vitamins in concentrated form should have a role in cancer prevention. For antioxidants such as vitamin C or E, it has not been proven, despite extensive studies, that high doses would simultaneously provide high levels of protection. The prophylactic administration of high-dose dietary supplements is therefore not justified from the point of view of the scientists: there is currently no scientific evidence for a protective effect of such preparations.
The role of dietary fiber in the risk of colorectal cancer is a controversial topic. According to the EPIC study, the risk of colorectal cancer is reduced by 40 percent if the daily amount of fiber is increased from 15 grams to 35 grams. However, another meta-analysis found no significant association between fiber intake and colorectal cancer risk. However, several studies suggest a protective effect of whole grains. In addition to dietary fiber, they also contain other potentially protective substances such as various vitamins, minerals, sterols and unsaturated fatty acids. It is also little known that whole grains have a higher antioxidant potential than most fruits or vegetables.
Calcium binds free bile acids in the intestine and thus has a protective effect on the intestinal mucosa. This could be an important mechanism to ensure that frequent consumption of milk or dairy products reduces the risk of colorectal cancer. Such a protective effect was demonstrated in the EPIC study, and a further meta-analysis of ten studies showed a 15% risk reduction from high milk or dairy consumption. On the other hand, there are indications - albeit not completely confirmed - that high egg consumption may favor the development of intestinal polyps and thus also colon cancer.