- web-based article
Increased intake of food rich in dietary vitamin C or ascorbic acid, but not supplementary vitamin C may drastically cut the risk of mouth cancer, an epidemiologic study has found.
Oral cancer results in a higher rate of death, about 50 percent of the cases, than breast, skin or cervical cancer because of delayed diagnosis.
But the study by Nancy Nairi Maserejian from Harvard School of Public Health suggests that high intake of dietary vitamin C may reduce the risk of oral cancer by nearly 50 percent.
In the study, researchers went through data from 42,000 men in the Health Professionals Follow-up Study to examine associations between incidence of cancer and a number of major nutrients such as vitamin C, A or carotenoids. The information was updated every two to four years.
During the study, 207 oral pre-malignant lesions were documented.
With various confounding factors considered, the researchers found no significant association between reduced risk and higher total intake of vitamin C, vitamin A or carotenoids.
Dietary vitamin C, however, was associated with a reduced risk of lesions although the link was not found with the vitamin from supplements.
Risk reductions were also found for carotenoids, beta-cryptoxanthin and alpha-carotene, but not for beta-carotene, lycopene or lutein/zeaxanthin intakes.
Increased intake of vitamin E was linked with a higher risk of oral cancer, particularly among smokers who were taking supplements.
It is not clear why vitamin C supplements were not associated with reduced risk of oral cancer. The researchers suggest that maybe there is some component in vitamin C rich foods plays a role in the reduction of oral cancer risk.
Although they do not know what exactly the compound is, they say that vitamin C-rich foods are certainly beneficial.
The study was published in the May 2007 issue of International Journal of Cancer.