Can Vitamin C Decrease the Incidence of Cancer?

Can Vitamin C Decrease the Incidence of Cancer?
Among all of the vitamins, perhaps vitamin C has received the most
attention as an anticancer agent. Much of the research involving vitamin
C and cancer in people has been correlation studies, which are used to
determine an association between the two or more entities. In regard to
cancer of the mouth, larynx, esophagus, and colon, as the vitamin C
content of the diet increases, the risk for these cancers decreases two to
three times. In more direct research studies it seems that individuals get-
ting less than 80 milligrams daily appear to be at greater cancer risk
than individuals with higher levels of intake. The true impact of higher
levels of vitamin C intake is difficult to assess on an individual basis and
thus a more general recommendation of 400 milligrams of vitamin C
daily seems reasonable for general health promotion. One important con-
sideration for vitamin C consumption is recognized in smokers.
Researchers have reported that it may take as much as a four to six times
greater vitamin C intake for smokers to achieve the same blood level of
vitamin C as nonsmokers. This is especially important as cigarette smoke
contains an abundant supply of free radicals and free-radical-creating
substances, and appears to increase the risk for many cancers, especially
lung cancer.