Colon cancer, also known as colorectal cancer, is the second major cause of American cancer deaths. In 2007, the latest year for which statistics are available, 53,219 people died from colon cancer and 142,672 people were diagnosed with it, according to The Centers for Disease Control and Prevention. Studies have shown that increasing your calcium intake through your diet and through calcium supplements can reduce your colon cancer risk, but you must be careful not to take too much calcium or you can develop other illnesses.
Colon Cancer
All of your cells have strands of DNA, a complex substance which directs your cells' growth. When cancer occurs, a cell with damaged DNA begins multiplying and dividing, creating new abnormal cells. The abnormal cells do not have the built-in signals that instruct normal cells to repair broken DNA or die. Instead, the abnormal cancer cells start spreading throughout the body.
Colon cancer attacks the colon and the rectum, a long passageway which carries feces out of your body after your food has been digested in your stomach. Colon cancer usually begins as a tumor growing out of the colorectal lining or as an area of abnormal cells within the lining.
Colon Cancer Prevention
Colon cancer can be cured if it is detected early. Because colon cancer is often not detected until it has progressed too far to be cured, scientists have been searching for ways of preventing it. One possible way of preventing colon cancer is increasing the amount of calcium in your diet. Calcium is an important dietary mineral, essential to the health of your bones, teeth, nerves, muscles and heart, so getting an adequate amount of calcium may also improve your overall health.
Calcium Studies
A National Cancer Institute Factsheet "Calcium and Cancer Prevention" describes in detail 11 long-term studies done before 2008 of the effect of dietary calcium and calcium supplements on rates of colon cancer among thousands of study participants in several different countries. Nine of the studies showed that people who ate more calcium than other study participants through eating more calcium-containing foods or taking calcium supplements reduced their risk of colon cancer by 20 to 45 percent. Only two studies showed little or no protective effect from calcium.
Scientists are still debating how calcium creates this protective effect. A 2011 study by Professor James Varani at the University of Michigan Medical School suggests that calcium helps control the growth of cells lining the colon and thereby stops cancer cells from starting their destructive fast-growth cycle.
Safe Calcium Amounts
You can add more calcium to your diet from a wide variety of foods, including milk, yogurt, cheese, salmon, sardines canned with their soft bones, almonds, sunflower seeds and dried beans. You can also take calcium supplement pills. Before you start adding more calcium to your diet, consult your physician and a dietitian-nutritionist to determine how much calcium you can safely take. Ingesting too much calcium can cause illnesses such as milk-alkali syndrome, in which excessive consumption of milk and calcium supplements, including calcium-containing antacid pills, can cause kidney failure.
References
- National Cancer Institute: Calcium and Cancer Prevention
- Centers for Disease Control and Prevention: Colorectal (Colon) Cancer:
- "Histology and Histopathology"; Calcium ... growth control in the colonic mucosa; James Varani, Ph.D., June 2011
- Genetics Home Reference: What Is DNA?
- American Cancer Society: Colorectal Cancer
- U.S. National Library of Medicine: MedlinePlus: Calcium in Diet
