Colorectal cancer prevention
A Pound of Prevention
A friend of mine named Jim recently experienced a rite of passage; at age 53 he had his first colonoscopy. How did it go? The worst part, he says, was the preparation on the day before the procedure. The prep requires an intake of clear liquids, no solid food, and a foul-tasting concoction that clears the bowels. “No fun,” he says.
And the procedure? “A breeze.”
The “twilight” anesthesia turned out to be more like “night, night”
anesthesia. When Jim regained consciousness his first thought was, “When are we going to start?” By then it was all over and he was handed a page with half a dozen full-color photos of the interior of his colon. “A weird thing to look at when you’re still a little loopy.”
Jim’s doctor detected the early stages of diverticulosis; pockets that occur at weak points in the bowel wall. This problem is easily addressed by including more roughage in the diet. Other than that, Jim was fine: no sign of polyps.
Polyps can be removed on the spot while a colonoscopy is performed, which is why this procedure is the premier tool in colorectal cancer prevention. But there are other effective ways you can help protect yourself from this common cancer without having to enter an operating room.
That was then
In the e-Alert “Counting the Ways” (6/24/04), I told you about a study that helps illustrate the importance of calcium in the prevention of colorectal cancer.
Researchers at the Dartmouth-Hitchcock Medical Center in Lebanon, NH, analyzed data collected from 930 patients enrolled in the Calcium Polyp Prevention Study. All of the study subjects had been diagnosed with colorectal polyps. Divided into two groups, participants received either a 1,200 mg daily supplement of calcium carbonate, or a placebo. Two colonoscopies were conducted approximately one year and four years after
each subject’s initial exams.
The researchers found that while calcium supplements appear to provide some protection against the development of polyps, the supplements proved most effective against advanced polyps. The lead author of the study, Dr. John A. Baron told Health Day News that calcium may help lower the risk of advanced polyps by as much as 45 percent.
this is now
At a meeting last month of the American Association for Cancer Research, Dr. Baron reported on an update to the 2004 study.
The Dartmouth team followed up on more than 800 of the original 930 subjects and found that the protective effects of the calcium
supplements appeared to continue for at least five years after the
supplementation was discontinued. During those five years, polyp risk was reduced by more than 40 percent, and the risk of all colon cancers was reduced by 35 percent.
Most surprising: These risk reductions are greater than the reductions observed immediately after the initial testing. Dr. Baron told Reuters Health that, “there appears to be a delayed, more pronounced suppression of colorectal neoplasia during the five years after treatment.”
Calcium “how to”
The type of supplement used in the Dartmouth study was calcium
carbonate. And as HSI Panelist Allan Spreen, M.D., told us in the
e-Alert “Absorbing it All” (4/19/04), calcium carbonate is the most
common, most readily available and least expensive type of calcium supplement. But the carbonate form does have two drawbacks: It’s not as well absorbed as some other inorganic forms of calcium, and it binds the most acid.
The latter problem presents both a potential plus, as well as a minus. Some scientists believe that calcium’s ability to bind acids may be the very reason it protects against cancer. But binding digestive acids may also result in poor absorption of nutrients and indigestion. So if a 1,200 mg supplement of calcium is taken daily, along with good sources of calcium in the diet, keep an eye out for digestive problems that may be managed by adjusting the dosage of the supplement.
In addition, Dr. Spreen notes that, “Calcium is not found in nature (in edible form) without magnesium, and they therefore should always be given together.”
Foods that are high in magnesium include leafy green vegetables, whole grains, bananas, apricots, meat, beans, and nuts.
Plenty of prevention
In 2002 I told you how a daily folate supplement may significantly cut the risk of colon cancer for those who have a family history of the disease. And later that same year I examined a study that showed how a diet containing ample amounts of fruits and vegetables may be a key factor in preventing precancerous polyps from developing into cancer.
According to a report from the Mayo Clinic, colorectal cancer is the second-leading cause of cancer-related deaths in the United States. I hope you’ll share this e-Alert with your family and friends to let them know just how easy it is to lower the risk of colorectal cancer.
To Your Good Health,
Jenny Thompson
Health Sciences Institute
Sources:
“Effect of Calcium Supplementation on the Risk of Large Bowel Polyps” Journal of the National Cancer Institute, Vol. 96, No. 12, 6/16/04,jncicancerspectrum.oupjournals.org
“Calcium Wards Off Colon Polyps Over Long Term” Megan Rauscher, Reuters Health, 4/20/05, reutershealth.com
