The American Cancer Society ranks colorectal cancer as the third most common form of cancer, after skin cancer, in the United States, and the second leading cause of cancer-related deaths. Optimizing lifestyle factors such as diet, weight and exercise can help to offset other risk factors such as age, previous health history and genetics. Many foods and nutrients offer protective benefits directly related to lowering the risk of colon cancer.
Vitamin B6
A study published in the 2010 "Journal of the American Medical Association" revealed that vitamin B6, or pyridoxal 5'-phosphate, decreases risk of colon cancer. According to the study, a meta-analysis of previously published research experiments, the risk of colorectal cancer decreased by 49 percent for every 100-pmol/mL increase in blood levels of pyridoxal 5'-phosphate. The researchers concluded that higher blood levels of vitamin B6 lowered the risk of colon cancer.
Vitamin D and Calcium
Bone mineral density reflects a variety of factors related to nutritional and health status, including estrogen, calcium, physical exercise and vitamin D, all of which have also been associated with colon cancer risk, according to a study published in the 2010 "International Journal of Cancer." High bone mineral density is therefore associated with decreased risk of colorectal cancer, says the study. The study went one step back to see if there was a similar association between colorectal adenoma -- a precancerous lesion and bone mineral density. Of 167 patients undergoing colonoscopy scans, the researchers found that those in the top two-thirds of bone mass density had the lowest incidence of colorectal adenoma. Additionally, the researchers reported a stronger trend of high bone mass density with low adenoma occurred in women.
Gamma Tocopherol
A study in the 2003 "BMC Cancer" evaluated the effectiveness of gamma tocopherol as a means of preventing colon cancer, citing differences between gamma tocopherol and alpha tocopherol to detoxify certain substances, inhibit cancer cell growth and inhibit inflammation. Levels of the anti-inflammatory molecule PPARgamma, considered to be anticarcinogenic due to its ability to inhibit cancer cell reproduction and promote cancer cell death, were used as a measure of the activity of gamma tocopherol. Tissue cultures of colon cancer cells treated with both forms of vitamin E revealed that while both alpha and gamma tocopherol activate PPARgamma, gamma tocopherol had the greater ability of the two. Gamma tocopherol-treated cells also contained higher levels of tocopherol than cells treated with the same amount of alpha tocopherol. This study shows that vitamin E is effective as a cancer preventive and that the gamma tocopherol form may be more effective than the alpha tocopherol form.
References
- PubMed: "Journal of the American Medical Association"; Vitamin B6 and risk of colorectal cancer: a meta-analysis of prospective studies; 2010 March
- PubMed: "International Journal of Cancer"; Higher bone mineral density is associated with a decreased risk of colorectal adenomas; 2010 October
- PubMed: "BMC Cancer"; Gamma (gamma) tocopherol upregulates peroxisome proliferator activated receptor (PPAR) gamma (gamma) expression in SW 480 human colon cancer cell lines; 2003 October
- American Cancer Society: Colorectal Cancer
