Chapter 81
Colorectal Cancer
Intestinal, or colorectal, cancer (affecting the colon and rectum) claims 50,000 lives in the United States each year and is among the most commonly diagnosed cancers. The average person has a 1 in 20 chance of developing colorectal cancer at some point in life. Fortunately, it is one of the most treatable cancers if caught early enough, and thanks to routine screenings, doctors can now detect and remove colorectal cancer before it metastasizes. In the United States alone, there are more than one million cured colorectal cancer patients, and among those whose colorectal cancer was discovered before it had spread beyond the colon, the five-year survival rate is about 90 percent. In its early stages, colorectal cancer rarely causes symptoms. If it is discovered later, treatment is less effective and more difficult. In my book How Not to Die, I recommend getting screened for colorectal cancer starting at 50, but it may be even better to start five years earlier.
In 2018, the American Cancer Society was the first major organization to suggest that people at average risk for colorectal cancer should begin screening not at 50, but at 45. The American College of Physicians, on the other hand, reaffirmed age 50 as the starting point, while the U. S. Preventive Services Task Force (USPSTF), the most prestigious guidelines organization mentioned earlier, debated the pros and cons. Because an increase in advanced-stage tumors had been observed at the time in the 40-to-50 age group, the USPSTF agreed in 2021 to lower the age for first screening to 45.
“Early” colorectal cancer—that is, a diagnosis before age 50—accounts for only 10 percent of cases, but that is twice as many as in the mid-1990s. The current incidence among 45-year-olds is comparable to that of 50-year-olds in the 90s, which led back then to the recommendation to start screening at age 50. This increase has been attributed primarily to the rising prevalence of obesity, although the also increased excessive use of antibiotics in children may play a role as well. African American men have a particularly high risk, as seen in the tragic death of actor Chadwick Boseman, who died of colorectal cancer at age 43. The risk of dying of colorectal cancer is 40 percent higher in African Americans than in white Americans, yet when surveyed, most mistakenly believed they had a lower disease risk. The American College of Physicians now recommends that African Americans get their first screening at 40.
Colonoscopies Matter
According to the USPSTF, there are six appropriate strategies for colorectal cancer screening. Starting at 45, everyone should undergo one of the following screening procedures: a colonoscopy once every ten years, an annual test of the stool for hidden blood, and stool testing for DNA markers every one to three years (for example, by Cologuard), as well as a “virtual” colonoscopy via CT scans or X-rays or, if DNA markers are tested annually, a flexible sigmoidoscopy using flexible endoscopes, either every five or every ten years.
Why do nearly all doctors in the United States recommend colonoscopies, even though in the rest of the world noninvasive stool tests are preferred? Perhaps because most practitioners outside the United States are not paid for the procedure. To quote a U.S. gastroenterologist: “Colonoscopy is the goose that lays the golden eggs.” In my book How Not to Die, I discuss colonoscopy in detail, with its risks and benefits, to help you make your decision. Ultimately, the best screening method is the one you will actually get.
Colorectal Cancer Prevention
Ironically, among the downsides of screening is the “health certificate effect,” meaning that those who make it through screening with no findings feel validated in their health, and their motivation to live healthy wanes. In fact, after randomized colorectal cancer screening, participants reduced their intake of fruits and vegetables, which can undermine the purpose of screening. Perhaps this can be counteracted by counseling patients on lifestyle after screening.
While regular screenings to detect colorectal cancer are, of course, sensible, it is even better to prevent the cancer. The share of colorectal cancer cases prevented through colonoscopies and endoscopic exams is estimated at about 30 percent, but 71 percent of cases are preventable if you make a few changes in your life, such as eating less meat. To examine the key lifestyle elements, researchers looked at where colorectal cancer rates are lowest.
In the United States, colorectal cancer is the second most common cancer; in rural Africa, by contrast, it occurs ten times less often. Studies of migrants show that global differences are not hereditary, because sometimes it takes only one generation for immigrants’ colorectal cancer rates to approach those of their new home country. The change in diet is most likely responsible, but when moving from one culture to another, there are all kinds of changes—from smoking to the fact that you are exposed to different chemicals, infections, and antibiotics. You only know whether it is due to diet once you test it.
Watch my video see.nf/switchdiets to find out what happens in the gut of African Americans who switched to a traditional African-style diet high in fiber, and what it was like for Africans who were subjected to the sad U.S. standard diet. The study leader summed it up succinctly: “Different diet, different cancer risk!”
Studies with more than three million participants make it possible to associate a plant-based diet with significantly lower tumor rates in the digestive tract, including colon and rectal cancer. In view of the “incredibly positive effect” of whole-food plant-based diets on cancer risk, the comment was made: “It would be unrealistic to expect rapid and profound lifestyle change in the general population, but we are pleased to be able to offer sensible, effective advice to those who want to do something for their healthy longevity.”
Urinary Incontinence
We have talked extensively about maintaining bowel function. But what about the bladder? Urinary incontinence is defined as involuntary urine leakage. There are two types: urge incontinence, defined as involuntary urine leakage associated with a sudden, strong urge to urinate, and stress incontinence, in which accidents happen, for example, when you sneeze. Women are affected two to three times more often than men, especially as they get older. The number of voluntary muscle fibers in the female sphincter decreases with age. This occurs in parallel with the diminishing ability of aging kidneys to concentrate urine and with a reduced bladder capacity, which is also more prone to irritation and may not always empty completely. On top of all this, there is also delayed perception of when the bladder is full.
In the United States, about one third of respondents said they believe the myth that incontinence is an inevitable part of aging, but it is true that it becomes more common as you get older. Of women over 70, probably 40 percent are affected, and among those over 80, this number can rise to 55 percent. But no matter how old you are, urinary incontinence always means a reduction in quality of life. What can we do to prevent or treat it?
Diets Are a Load of Piss
One reason women are affected by this problem more often than men is that women give birth to children. Vaginal delivery makes it three times more likely than a C-section that a woman will later suffer from urinary incontinence, presumably because muscles and nerves are stretched during delivery. This seems to be especially the case when a woman has children later in life.