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Chapter 10. Colon Cancer

“Adopting a diet that is low in fat and high in fiber, fruits, and vegetables does not influence the risk of recurrence of colorectal adenomas.”
The New England Journal of Medicine [1]

Dietary Fiber: Naturally Grown Killer

Okay, so fiber isn’t good for constipation and it causes all kinds of nasty, but not yet deadly problems. But what about colon cancer? Aren’t we getting rid of one plague (fiber), to gain another (cancer)?

That’s an excellent and appropriate question. And I’m the last person to encourage you to play Russian roulette. So let’s check out the odds.

Colorectal cancer and dietary fiber

The question whether dietary fiber contributes to colorectal cancer has (at least for me) been answered time and again—yes, it absolutely does. But this isn’t what you’ve probably heard before, or are likely to accept on faith alone. So let’s review this issue in greater depth. Undoubtedly, it will come up again and again in your discussions with doctors, relatives, and peers, and you’ll need all the armor you can find to deflect the onslaught of ignorance, misinformation, and outright falsehoods.

The term colorectal cancer refers to cancers of the colon and the rectum. In general, surgery to remove colon cancer causes less damage than surgery for rectal cancer, because the latter almost always involves removing an entire important organ (the rectum), while with colon cancer, if there’s no metastasis, only a section of the colon is removed so that the normal defecation remains functional.

There are also three somewhat confusing terms used in relation to colorectal cancers: colorectal carcinoma, adenoma, and adenocarcinoma. Technically, carcinoma refers to malignant tumors, while adenoma to benign. That said, colorectal adenomas and carcinomas present physicians with similar risk profiles, hence you’ll frequently hear the term colorectal adenocarcinoma. In either case, surgery is required to remove the intestinal obstruction caused by the tumor, and to halt further spread of the cancer.

The actual nature of the tumor is established by a pathologist from the biopsy sample taken before the surgery, or from a post-surgical tissue sample. In general, when communicating with patients most doctors refer to carcinomas and adenomas interchangeably (colorectal cancer or adenocarcinoma,) because they themselves may not know the distinction until the pathology report.

In medical literature you may encounter yet another, even broader term that specialists use among themselves: a neoplasm. It simply means an abnormal growth of tissue mass, which is dif­ferent from regular tissue, and may be either benign or malig­nant. Anything abnormal—adenoma, carcinoma, sarcoma (connec­tive tissue malignancy) is therefore a neoplasm. The rest of this chapter uses the term colorectal cancer, which for clarity’s sake encompasses all other meanings and definitions.

It’s a well-established fact that most colorectal cancers are preceded by the formation of precancerous polyps—cellular growths that visibly protrude from the mucous lining of the large intestine. Therefore, anything that can cause temporary or permanent damage to the mucous lining is capable of causing the growth of po­lyps, that eventually may become tumors.

The terms polyp is actually an euphemism for tumor and neoplasm. Don’t kid yourself over the issue of early detection—you should be more concerned about preventing the polyps from developing in the first place, rather than hoping that regular colonoscopies will make you safe. Unless you remove the causes of these polyps, colonoscopies aren’t going to save, quite literally, your butt. Thinking otherwise is very profitable for medical sector, but in practical terms, this “prevention” approach is as asinine as putting out fires with gasoline.

So what should you do to prevent polyps?

Protect yourself from harm. The mucosa damage that precedes the appearance of polyps can be (a) mechanical (a cut or abrasion), (b) chemical (caused by an irritant, such as laxatives, fatty acids, bile, etc), (c) viral or bacterial, or (d) a combination of all these factors. Just as with any other organ, the mucosa react with inflammation to superficial injury, or with ulceration and bleeding if the exposure is long-lasting and unrelenting. Can this be from an exposure to fiber? Well, let’s think aloud:

So what is this substance that can cause both mechanical and chemical damage of the intestinal mucosa? There is only one such substance in the daily diet of most Westerners—dietary fiber that reaches the gut undigested.

It’s apparent that nothing but indigestible dietary fiber, whatever the source, can cause mechanical damage either directly or indirectly, by means of the by-products of bacterial fermentation.

But there’s a bit more to it. The majority of indigestible fiber comes in the nice wrapping of digestible carbohydrates—those proverbial fruits, vegetables, breads, pasta, and cereals, whose ten to fifteen servings you’re supposed to consume daily to stay healthy:

“Digestible” Carbohydrate May Boost Colorectal Cancer Risk

Previous studies have not agreed on whether or not eating lots of carbohydrates is a risk for colon cancer. In a new study, Canadian researchers set aside the fiber content of carbohydrates, which may reduce the risk, and examined the remainder, or “digestible” carbohydrate, namely sugars and starches. The result: their study showed that people consuming the highest amounts of digestible carbohydrates had a higher risk for developing colorectal cancer compared with those eating the lowest amounts.[2]

Add to the mix age, stress, medication, dietary and environmental carcinogens, dysbacteriosis, and chronic deficiency of essential nutrients—all aggravating factors that impede digestion and harm the immune system—and we inevitably get what we so dread:

[Colorectal cancer is] the 2nd leading cancer killer in the United States. In 2004, an estimated 146,940 new cases of colorectal cancer (cancer of the colon or rectum) will be diagnosed in the United States, and 56,730 men and women will die of the disease.[3]

From all corners we’ve been urged to consume a high-fiber diet to lower the risk of colon cancer. Would this lower it? Not a bit! Here’s an excerpt from an article about fiber from The Harvard School of Public Health, published in 2004:

For years, Americans have been told to consume a high-fiber diet to lower the risk of colon cancer—mainly on the basis of results from a number of relatively small studies. Unfortunately, this recommendation now seems mistaken, as larger and better-designed studies have failed to show a link between fiber and colon cancer.[4]

Is this something new, or is this book the lone voice of reason? No, it isn’t new at all. The wide-open public discourse on the role of fiber started years ago. Here are some excerpts from mainstream sources. Please note the dates and headlines:

“Study Finds Fiber Ineffective Against Colon Cancer

BOSTON (Reuters)—The conventional wisdom that a high-fiber diet can protect against colon and rectal cancers may be wrong, a study published in Thursday’s New England Journal of Medicine said.”; January 21, 1999

“High-fiber diet may not prevent colon cancer

NEW YORK (Reuters Health)—A low-fat, high-fiber diet is often recommended as a way of preventing polyps in the lining of the colon—growths associated with an increased risk of colon cancer. But new research casts doubt on this oft-repeated advice. Adopting a low-fat diet rich in fruits, vegetables and other sources of fiber does not prevent the development of intestinal polyps in people who have already had polyps removed, US researchers report.”; April 19, 2000

“Fiber Doesn’t Prevent Cancer

LONDON (Associated Press)—Evidence is mounting that fiber might not prevent colon cancer after all, with a new study suggesting that one type of supplement might even be bad for the colon.”; October 12, 2000

“Fiber May Raise Risk of Colon Polyps

NEW YORK (Reuters Health)—Last year, a major study reported that dietary fiber had no effect on a person’s chances of developing colon cancer. The findings surprised the medical community, which had been recommending that patients consume more fruits, vegetables and whole grains to lower their risk of the number two cancer killer in America.”; October 13, 2000

As you can see, these quotes were collected from news wires years ago. Could our esteemed scientists have missed these sto­ries? Sure they could have. So let’s review the articles in the must-read publications such as Cancer, The Lancet, or The New England Journal of Medicine, that they couldn’t miss.

Because the connection between dietary fiber and colorectal cancer is so controversial, I’ll cite the following abstracts in close to their original format, except that I shortened the list of co-authors, removed the hard-to-understand discussions of statistical results, and underlined the most pertinent revelations. Here we go:

Dietary Fiber and the Risk of Colorectal Cancer and Adenoma in Women

New England Journal of Medicine; Jan 21 1999; 340:169–176,
Fuchs C. S., [et al]

BACKGROUND: A high intake of dietary fiber has been thought to reduce the risk of colorectal cancer and adenoma.

METHODS: We conducted a prospective study of 88,757 women, who were 34 to 59 years old and had no history of cancer, inflammatory bowel disease, or familial polyposis, who completed a dietary questionnaire in 1980. During a 16-year follow-up period, 787 cases of colorectal cancer were documented. In addition, 1012 patients with adenomas of the distal colon and rectum were found among 27,530 participants who underwent endoscopy during the follow-up period.

RESULTS: After adjustment for age, established risk factors, and total energy intake, we found no association between the intake of dietary fiber and the risk of colorectal cancer; [...] No protective effect of dietary fiber was observed when we omitted adjustment for total energy intake, when events during the first six years of follow-up were excluded, or when we excluded women who altered their fiber intake during the follow-up period. No significant association between fiber intake and the risk of colorectal adenoma was found.

CONCLUSIONS: Our data do not support the existence of an important protective effect of dietary fiber against colorectal cancer or adenoma.

Carbohydrates and Colorectal Cancer Risk
among Chinese in North America

Cancer Epidemiology Biomarkers & Prevention Vol. 11, 187–193, February 2002
Marilyn J. Borugian, [et al]

BACKGROUND: Previous studies have analyzed total carbohydrate as a dietary risk factor for colorectal cancer (CRC) but obtained conflicting results, perhaps attributable in part to the embedded potential confounder, fiber.

METHOD: The aim of this study was to analyze the nonfiber («effective») carbohydrate component (eCarb) separately and to test the hypothesis that effective carbohydrate consumption is directly related to CRC risk.

RESULTS: The data (473 cases and 1192 controls) were from a large, multicenter, case-control study of Chinese residing in North America. [...]

CONCLUSION: These data indicate that increased eCarb and total carbohydrate consumption are both associated with increased risk of CRC in both sexes, and that among women, relative risk appears greatest for the right colon, whereas among men, relative risk appears greatest for the rectum.

Q&A: The Polyp Prevention Trial and the Wheat Bran Fiber Study by National Cancer Institute

Posted: 04/24/2000, [link]

What is the Polyp Prevention Trial?
The Polyp Prevention Trial was a clinical trial (a research study conducted with volunteers) to determine the effect of a low-fat (20 percent of calories from fat), high-fiber (18 grams per 1,000 calories), high fruit/vegetable (3.5 servings per 1,000 calories) eating plan on the recurrence of precancerous polyps in the colon and rectum.

What were the results of the Polyp Prevention Trial?
The Polyp Prevention Trial provided no evidence that adopting a low-fat, high-fiber, fruit- and vegetable-enriched eating plan reduces the recurrence of colorectal polyps. Polyp recurrence rates were about the same in the two study groups.

What is the Wheat Bran Fiber Study?
The Wheat Bran Fiber Study was a clinical trial to assess the role of a wheat bran fiber supplement in the prevention of colorectal polyp recurrence. A group of 1,429 men and women who had had one or more polyps removed at colonoscopy within the previous three months were randomized to a high wheat bran fiber cereal supplement (13.5 grams of fiber in 2/3 cup cereal per day) or low wheat bran fiber cereal supplement (2 grams of fiber in 2/3 cup cereal per day).

What were the results of the Wheat Bran Fiber Study?
The Wheat Bran Fiber Study provided no evidence that adding a wheat bran fiber cereal supplement to the diet reduces the recurrence of colorectal polyps.

Calcium and fibre supplementation in prevention of colorectal adenoma recurrence: a randomized intervention trial

Lancet 2000; 356: 1300–06

Claire Bonithon-Kopp, [et al] for the European Cancer Prevention Organisation Study Group.
BACKGROUND: Some epidemiological studies have suggested that high dietary intake of calcium and fibre reduces colorectal carcinogenesis. Available data are not sufficient to serve as a basis for firm dietary advice. We undertook a multicentre randomised trial to test the effect of diet supplementation with calcium and fibre on adenoma recurrence.[...]

INTERPRETATION: Supplementation with fibre as ispaghula husk may have adverse effects on colorectal adenoma recurrence, especially in patients with high dietary calcium intake. Calcium supplementation was associated with a modest but not significant reduction in the risk of adenoma recurrence.

(Author’s note: Ispaghula huskcomes from the crushed seeds of the Plantago ovata plant, a native herb from parts of Asia, the Mediterranean, and North Africa. From the same plant family come Plantago psyllium seeds [5], the source of psyllium husks used in popular bulking fiber laxatives, such as Metamucil, and added to some breakfast cereals to increase their fiber content and decrease blood cholesterol. In the context of the above-cited research, think twice before using these constipation and cholesterol “remedies”—you may be making a deal with the devil.)

Lack of Effect of a High-Fiber Cereal Supplement
on the Recurrence of Colorectal Adenomas

New England Journal of Medicine 2000; 342:1156–1162, Apr 20, 2000;
David S. Alberts, M.D., [et al] for The Phoenix Colon Cancer Prevention Physicians’ Network; [link]

BACKGROUND: The risks of colorectal cancer and adenoma, the precursor lesion, are believed to be influenced by dietary factors. Epidemiologic evidence that cereal fiber protects against colorectal cancer is equivocal. We conducted a randomized trial to determine whether dietary supplementation with wheat-bran fiber reduces the rate of recurrence of colorectal adenomas.

METHODS: We randomly assigned 1429 men and women who were 40 to 80 years of age and who had had one or more histologically confirmed colorectal adenomas removed within three months before recruitment to a supervised program of dietary supplementation with either high amounts (13.5 g per day) or low amounts (2 g per day) of wheat-bran fiber. [...]

CONCLUSIONS: As used in this study, a dietary supplement of wheat-bran fiber does not protect against recurrent colorectal adenomas.

As you can plainly see from these top-notch studies by mainstream researchers and institutions, fiber not only doesn’t offer any protection from colorectal cancer, but potentially elevates the risks. And I’m not even touching on the subject of other cancers: deadly mouth cancer, even deadlier esophageal cancer, “curable” stomach cancer (curable because the victims can live for a while without the stomach), the deadliest of all, pancreatic cancer, cancers of the small intestines, you name it—all of the digestive organs that are one way or another overloaded by the over­con­sumption of dietary carbohydrates and fiber.

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And don’t get me started on non-digestive cancers. For example, it’s a well-established fact that the overweight and diabetic have the highest rates of cancer, and that one can become fat or diabetic only one way: by consuming more carbohydrates than one’s body needs or can safely process.

The connection is so obvious here that you don’t, mon ami, need the dissecting mind of Hercule Poirot to figure this out in less than a minute. The U.S. Center for Disease Control and Prevention,theMinistry of Health of Mexico,and theAmerican Institute for Cancer Research spent a huge amount of money to “prove” the cancer-carbohydrate connection:

Results: Carbohydrate intake was positively associated with breast cancer risk. Compared with women in the lowest quartile of total carbohydrate intake, the relative risk of breast cancer for women in the highest quartile was 2.22. [...] No association was observed with total fat intake.[6]

Please note that most of the research I cited regarding colon cancer is four to five years old. But none of that changed the minds and opinions of the leading authorities charged with protecting our health. They continue to insist on their enshrined, universal remedy:

Take More Fiber
Avoid Meat And Animal Fat
Eat More Fruits And Vegetables

Here’s their most recent and egregious advice as to how to fend off colorectal cancer:

Colorectal Cancer: Who’s at Risk?

“Diet: Studies suggest that diets high in fat (especially animal fat) and low in calcium, folate, and fiber may increase the risk of colorectal cancer. Also, some studies suggest that people who eat a diet very low in fruits and vegetables may have a higher risk of colorectal cancer.”

What You Need To Know About™ Cancer of the Colon and Rectum
National Cancer Institute; NIH Publication No. 03–1552; March 2004 [link]

Who Is at Risk?

“Other factors that may contribute to the risk for colorectal cancer include low fruit and vegetable intake, a low-fiber and high-fat diet, obesity, alcohol consumption, and tobacco use.”

Colorectal Cancer: The Importance of Prevention and Early Detection
2003 Program Fact Sheet
National Center for Chronic Disease Prevention and Health Promotion [link]

What Are the Risk Factors?

“The exact causes of colorectal cancer are not known. However, studies show that the following risk factors increase a person’s chances for developing colorectal cancer:

Diet. Diets high in fat and low in fiber seem to be associated with colorectal cancer.”

Colorectal Cancer Detection and Prevention
The American Gastroenterological Association [link]

Health implications of dietary fiber

“Go for legumes and whole grains: A diet high in fiber and low in fat may protect you from colon and rectal cancer. Fiber helps move waste through your digestive tract faster so harmful substances don’t have much contact time with your intestinal walls.

Try to consume more complex carbohydrate and fiber-rich foods. Choose fruits with edible skins, legumes, vegetables and whole-grain foods. Your goal should be to consume at least two fruit servings, three vegetable servings and three servings of whole-grain breads and cereals every day.

[...] Despite the inconsistency in the results of fiber and colon cancer studies, the scientific consensus is that there is enough evidence that dietary fiber protects against colon cancer that health professionals should be promoting increased consumption of dietary fiber.”

American Dietetic Association
Journal of American Dietetic Association 2002;102:993–1000 [link]

As you can see, their attitude is the opposite of what has already been said, studied, and known about the fiber-cancer connection. I am at a loss to explain why. But you still worry about meat and fat, correct? The Dietary Guidelines for Americans specifically implies that there’s a fat-cancer connection:

Choose a diet low in fat, saturated fat, and cholesterol to reduce your risk of heart attack and certain types of cancer.[7]

To make sure that this isn’t so, I checked out the comparative health (sorry, death) statistics vis-à-vis meat consumption, courtesy of the World Health Organization. Since meat is one of the primary sources of saturated fat and cholesterol in the diet, the countries with the largest meat consumption should have the largest rates of digestive cancers, right? Wrong! In fact, population statistics indicate the complete opposite:

Meat consumption and the occurrence of digestive cancers [8]

USA France Colombia Cuba Armenia
Life expectancy 79.5 82.9 74.8 79.2 73
Healthcare (per capita) $4,499 $2,335 $616 $186 $192
Meat consumption (kg) 119 90 37 22 16
Digestive cancers (per 1000)
 Esophagus (C15) 1.1 1.1 1.9 1.2 0.6
 Stomach (C16) 2.1 2.7 13.1 3.2 6.7
 Colon & Rectum (C19-C21) 1.4 2.2 1.2 2.1 2.3
Total 4.6 6 16.2 6.5 9.6

As you can see, the United States—the country with the highest annual consumption of meat (119 kg) had the lowest rate of digestive cancers in general (4.6), and the second lowest of colorectal cancers (1.4). On the other hand, Armenia—a relatively poor country with the lowest annual consumption of meat (16 kg)—had the highest rate of colorectal cancers. Why?

There’s no contest here: if the poor people of Armenia can’t consume as much meat as the Americans can, they have to replace it with something plentiful and cheap. Invariably, dietary carbohydrates, which also carry along loads of fiber, are the only food that reliably fit into the category of “cheap and plentiful.”

And notice the dramatic rate of stomach cancer in Armenia and Columbia—respectively three and six times higher than in the United States. The stomach (the organ designed exclusively for the digestion of meats) is even more adversely affected by carbohydrates and fiber than the better-adapted large intestine.

The colossal rate of stomach cancers in Colombia is likely related to two factors: the high rate of smoking and the even higher rate of ceaseless coffee drinking among Colombians. Both factors—the swallowing of nicotine-laced saliva while smoking and the bitterness of coffee, especially on an empty stomach—stimulate the secretion of potent digestive juices. In the absence of food, this causes high rates of gastritis and stomach ulcers, and chronic inflammation and ulceration of the stomach’s mucosa, exact­ly the same two conditions that precede the development of cancers of the large intestine.

So, if you live in the United States, eat plenty of meat, don’t smoke, don’t chew gum (again, the saliva factor), and don’t abuse coffee, consider yourself lucky. In places where they don’t get to eat plenty of meat and fat, and do other stupid things, the risk of digestive cancer is much, much higher.

But again, in terms of cancer, it’s the fiber and carbohydrates that are the most damaging. The majority of French men smoke too, and most of them drink plenty of coffee, yet the rate of digestive cancers in fat- and meat-loving France is only slightly higher than in the United States, notwithstanding the Gallic devotion to baguettes and croissants liberally smothered with real butter (82% fat) and triple brie (60% fat).

As France’s health statistics prove, the protective properties of meat, saturated fat, and cholesterol are more than skin deep. The French manage to weigh less and live longer than Americans, while spending half as much for health care, and probably twice as much for food. Please note that I am not endorsing all aspects of the French lifestyle, just providing a context for comparative statistics. If the French didn’t smoke as much and drank less, perhaps they would live even longer.

Finally, a few words on prevention. When it comes to cancers, we are all in God’s hands. That said, digestive cancers are among the easiest to avoid just by letting your digestive organs function the way Mother Nature intended: the mouth, to chew non-fibrous food; the stomach, to digest meats; the small intestine, to absorb nutrients and transport liquid chyme; and the large intestine, to slowly propel the remaining residue along without getting stuffed with pounds and pounds of undigested crap—pardon me, with undigested fiber.

It’s simple: do no harm. You don’t have to be Hippocrates to understand this. Ignore the hypocrites who continue to insist that to prevent colorectal cancer you should consume more fiber, avoid meat and fat, and eat more fruits, vegetables, grains and legumes. You may as well move to Colombia and enjoy your freshly brewed coffee before, after, and between meals, puff on a fine cigar, and chew sugar-free gum the rest of the time to freshen up your mouth.

Please share this information about the fiber-cancer connection with the avowed vegetarians in your family, social, and business circles—it’s never too late to help them reverse their well-intentioned but self-destructive lifestyle.



1Arthur Schatzkin, M.D et al.; Lack of Effect of a Low-Fat, High-Fiber Diet on the Recurrence of Colorectal Adenomas; The New England Journal of Medicine; April 20, 2000; 342:1149-1155.

2Joene Hendry; ‘Digestible’ Carbohydrate May Boost Colorectal Cancer Risk; Reuters Health; June 27, 2002.

3National Center for Chronic Disease Prevention and Health; Colorectal Cancer Information; [link]

4Fiber: Start Rounding It. Harvard School of Public Health. [link]

5Psyllium; Alternative Field Crops Manual; [link]

6Isabelle Romieu, et al.; Carbohydrates and the Risk of Breast Cancer among Mexican Women; Cancer, Epidemiology, Biomarkers & Prevention 2004 13: 1283–1289.

7Federal Citizen Information Center, The Food Guide Pyramid; [link]

8WHO Cancer Mortality Databank; [link]. The most recent (2014) epidemiological data for digestive cancers is available here: [link]

9Joene Hendry; ‘Digestible’ Carbohydrate May Boost Colorectal Cancer Risk; Reuters Health; June 27, 2002.

10Isabelle Romieu, et al.; Carbohydrates and the Risk of Breast Cancer among Mexican Women; Cancer, Epidemiology, Biomarkers & Prevention 2004 13: 1283–1289.