A Closer Look
Researchers Urge Caution, Greater Scrutiny of Colon-related CAM Treatments
With a general push toward cleaner, more “natural” lifestyles, many Americans are turning to complementary and alternative medicine (CAM) to try to improve the health of their large intestines.
March is National Colorectal Cancer Awareness Month. According to NCI’s Physicians Data Query (PDQ) summary:
- Age, obesity, lack of exercise, smoking, and alcohol may increase the risk of colorectal cancer.
- Hormone replacement therapy and polyp removal may decrease the risk of colorectal cancer.
- The effect of non-steroidal anti-inflammatory drugs, vitamins, diet, and cholesterol-lowering drugs on colorectal cancer risk is still unclear.
More information from NCI about colon and rectal cancer, including clinical trials to test new ways of diagnosing, treating, and preventing the disease, is available online.
Given our position in the food chain, the thinking goes, our colons may be a target for toxic elements in the environment, from pollutants in the air and water to artificial colors and preservatives in our foods.
Anecdotes favoring the use of colon-CAM regimens are widespread, but is there sufficient scientific evidence to support a belief that they can prevent cancer? The answer is no, but the existence of these trends warrants closer inspection into why such beliefs persist.
A “Hygienic” Approach?
One such practice that is increasing in popularity is colonic hydrotherapy, commonly referred to as a “colonic.” It involves inserting a special nozzle into the rectum, where warm filtered water is gently flushed through the large intestine, drained back out into a waste receptacle, and then repeated with fresh solution. The procedure lasts about an hour and consumes up to 20 gallons of liquid, removing all fecal material in the process.
Dr. Kamau Kokayi, an integrative medicine practitioner and medical director of the Integrative Healing Center & Spa, said of all the holistic therapies offered at his clinic, colonics are the most popular. His office in Manhattan, NY, performs approximately 2,000 of them a year. “If the main pipeline in our body is clogged with sludge and isn’t moving properly, it creates a state of autotoxicity,” he explained. “This procedure is actually useful in cleaning up the body.”
Approximately half of the people who come in for this procedure mention a concern about reducing their risk for colon cancer, said Barbara Chivvis, a registered nurse who works with Dr. Kokayi. Some of the people who come for colonics have already gone through cancer treatment, she said, and are hoping the procedure will help to clean out toxic residues leftover by chemotherapy or radiation.
Both Ms. Chivvis and Dr. Kokayi admit that there is no published scientific evidence of a cancer-preventive effect for the treatment that they feel certain is helping people.
Plausible or Placebo?
Anatomy of the lower digestive system, showing the colon and other organs (© 2009 Terese Winslow) [Enlarge]
Dr. Brooks Cash, chief of gastroenterology at the National Naval Medical Center in Bethesda, MD, acknowledged, “People will absolutely feel different after they have a colonic. They will feel lighter or cleaned out, whatever that means. But there is no evidence that our intestines clog like old metal pipes. Stool isn’t adherent like spackle. It’s constantly being pushed along for evacuation.”
He added, “In terms of deriving a health benefit, the fact that there are no supporting data for colonics, despite this practice going on for hundreds of years, should give people pause.”
Most articles published in scientific journals on colonics are cases where people used liquids other than water for the flush—coffee or peroxide solutions, for example—and suffered serious injuries afterward. Other dangerous side effects include electrolyte imbalance, bacterial infections, fluid overload, and bowel perforation.
Because of the weight of negative evidence and the lack of research providing positive evidence, the American Cancer Society issued a statement in 2007 to discourage people from believing claims that colonics are effective treatments for cancer or any other disease.
Dr. Jeffrey White, who directs NCI’s Office of Cancer Complementary and Alternative Medicine, said that a randomized, prospective clinical trial examining the health effects of colonics in the future could come from the cancer research community, the medical community, or even the “alternative” health care community—as long as they can provide potential funding agencies in the government or private sector with some preliminary data suggesting how the treatment might work (specific effects on bacterial populations in the gut, for example) and indicating how the procedure affects the development or progression of premalignant colon polyps. But no such data have been gathered yet.
“Clinical research would also help determine what types of patients are most likely to benefit from a CAM therapy such as this, and identify the characteristics of those patients who are unlikely to benefit,” Dr. White said.
Bringing in Bacterial Reinforcement
Another CAM trend that is becoming more mainstream, and that is the focus of early clinical investigation, is the use of probiotics and prebiotics. Probiotics are live microorganisms (mostly bacteria) that are available commercially as supplements or in food products such as yogurt and kefir, a fermented version of yogurt. According to the National Center for Complementary and Alternative Medicine, American spending on probiotic supplements nearly tripled between 1994 and 2003.
Prebiotics are related supplements; a food source for bacteria living in our gut. The goal with both of these is to increase the population of “helpful” bacteria that may improve digestion and create a healthier environment for the surrounding tissues. The probiotic trend also relates to colonics, in that people sometimes take these supplements after the procedure to replace bacteria that get lost in the flush.
There is a growing body of published research investigating how probiotics and/or prebiotics might work to prevent cancer.
For example, a randomized, prospective, 12-week trial was conducted in which 80 patients who had been treated for colon cancer or suspicious polyps ate a combination of a prebiotic long-chain sugar derived from chicory root, known as inulin, and the bacterial strains Bifidobacterium lactis and Lactobacillus rhamnosus. The regimen resulted in some changes in their colon biomarkers for cell survival, including the levels of interleukin-2 and interferon gamma, cytokines that the immune system uses to fight infection. The responses were different for cancer patients, however, than for those who had a history of polyps.
To examine this more closely, NCI is currently sponsoring a phase II clinical trial to test the effect of inulin on the risk for precancerous lesions called aberrant crypt foci, comparing it with a combination of the cholesterol-lowering drug atorvastatin (Lipitor) and non-steroidal anti-inflammatory drug sulindac.
Dr. Asad Umar, chief of the Gastrointestinal and Other Cancers Research Group in NCI’s Division of Cancer Prevention, noted that these trials are not designed to investigate cancer incidence and, at best, can only point toward the direction in which research may be continued in the future.
Other preclinical animal studies have shown that some short-chain fatty acids produced by bacteria during the process of fermentation in the gut can stimulate an immune response in the surrounding mucosal tissue. Dr. Umar noted, however, that human and animal gut bacteria are very different. “If the initial study for biomarker modulation is positive, any extension of these findings would have to be answered in randomized clinical trials,” he said.
He emphasized that the best thing people can do to mediate their risk for colon cancer is still to follow screening guidelines, which help clinicians to identify precursors or early stages of the disease, when it is more easily and successfully treated.
Dr. Umar said that he finds the trend of colonic hydrotherapy alarming. Those who are concerned, he said, about long-term exposure of their gut to “toxic” elements in fecal matter during the course of digestion, should know that studies such as the Polyp Prevention Trial have not been able to show that low-fat, high-fiber diets including fruits and vegetables can reduce the risk of colon polyps.
“It’s true that the environment is a factor in many cancers,” he said, “but family history is still one of the strongest predictors.”
—Brittany Moya del Pino