Intake High Levels of Calcium and Vitamin D either From Food or Supplements
Colon cancer begins in the large intestine (called the colon). Rectal cancer begins in the rectum, the part of the large intestine closest to the anus (the outside opening to the intestine). These forms of cancer have many common features. Sometimes they are referred to together as colorectal cancer (CRC).They make up the second-leading cause of cancer-related deaths in the United States. Only lung cancer claims more lives.
The human colon is a muscular, tube-shaped organ measuring about 4 feet long. It extends from the end of your small bowel to your anus, twisting and turning through your abdomen (belly). The colon has 3 main functions.
*To digest and absorb nutrients from food
*To concentrate fecal material by absorbing fluid (and electrolytes) from it
*To store and control evacuation of fecal material
Most cases of colon cancer begin as small, noncancerous (benign) clumps of cells called adenomatous polyps. Over time some of these polyps become cancerous.The right side of your colon plays a major role in absorbing water and electrolytes, while the left side is responsible for storage and evacuation of stool.Cancer is the transformation of normal cells. The transformed cells grow and multiply abnormally.
Polyps of the colon and rectum are usually benign and produce no symptoms, but they may cause painless rectal bleeding. There may be single or multiple polyps and they become more common as people age. Over time, certain types of polyps, called adenomatous polyps, may develop into cancer. Another common type of polyp found in the colon is called a hyperplastic polyp, which is generally not at risk for developing into colon cancer.These mushroom-like growths are usually benign, but some may develop into cancer over time. The majority of the time, the diagnosis of localized colon cancer is through colonoscopy.
Screening for colorectal cancer is strongly recommanded.Several screening methods are effective in reducing mortality from CRC.The benefits of screening outweigh its risks by periodic fecal occult blood testing (FOBT) reduces mortality from CRC.In addition, there is fair evidence that sigmoidoscopy, either alone or in combination with FOBT, reduces CRC mortality.
Colorectal cancer incidence rates are approximately ten-fold higher in developed than in developing countries , and it has been suggested that diet-related factors mayaccount for up to80%of the differences in rates between countries . The best established diet-related risk factor is overweight/obesity and physical activity has been consistently associated with a reduced risk of colon cancer (but not of rectal cancer) . These factors together, however, do not explain the large variation between populations in colorectal cancer rates. There is almost universal agreement that some aspects of the “westernized” diet are a major determinant of risk; for instance, there is some evidence that risk is increased by high intakes of meat and fat, and that risk is decreased by high intakes of fruits and vegetables, dietary fibre, folate and calcium, but none of these hypotheses has been firmly established.
Get your vitamins and minerals. Calcium, magnesium, pyridoxine (vitamin B-6) and vitamin B-9 may help reduce your risk of colorectal cancer. Good food sources of calcium include skim or low-fat milk and other dairy products, shrimp, tofu and sardines with the bones. Magnesium is found in leafy greens, nuts, peas and beans. Food sources of vitamin B-6 include grains, legumes, peas, spinach, carrots, potatoes, dairy foods and meat. Folate is the natural form of vitamin B-9. It's found in certain foods naturally, including dark leafy greens such as spinach and lettuce, and in legumes, melons, bananas, broccoli and orange juice. Folic acid is the synthetic form of the vitamin, and it's used in fortified breads, cereals and supplements.
People who consume relatively high levels of calcium and dairy products and take vitamin D supplements seem to be protected to some degree against colorectal cancer, researchers have found.
"Colorectal cancer is one of the most commonly diagnosed cancers worldwide, and dietary factors are considered to be important in its risk," Dr. Song-Yi Park, of the University of Hawaii, Honolulu, and colleagues write in the American Journal of Epidemiology.
Park's team examined the association between calcium and vitamin D intake and the risk of colorectal cancer in 191,000 subjects between the ages of 45 and 75 years, who completed a food frequency questionnaire between 1993 and 1996.
During an average follow-up of 7 years, a total of 2110 new cases of colorectal cancer were identified -- 1138 in men and 972 in women.
High total calcium intake (from food and supplements) lowered the risk of colorectal cancer in both men and women. Comparing the highest calcium intakes with the lowest, the risk of developing colorectal cancer was reduced by 30 percent for men and by 36 percent for women.
"Total vitamin D intake was inversely associated with colorectal cancer risk in men but not in women," Park and colleagues report.
A high intake of dairy products also reduced the risk of colorectal cancer risk, especially for people who didn't take supplemental calcium; the risk reduction was 23 percent for men and 34 percent for women.
"These findings support the hypothesis of protective roles for calcium, vitamin D and dairy products in the risk of colorectal cancer," the researchers conclude.