By Dr. Mercola
Colorectal cancer, which includes both cancers of the colon and rectum, is the second leading cause of cancer-related deaths in the United States.
An estimated 135,000 people are diagnosed with colorectal cancer each year (about 95,500 cases of colon cancer and 39,900 cases of rectal cancer1), and more than 50,000 die from it.
Historically, colon cancer has been confined to those over the age of 50, but that’s changing. According to a recent report2 by the American Cancer Society, prevalence among younger people is rising.3,4,5 As reported by STAT News:6
“Among adults between the ages of 20 and 39, colon cancer has increased by 1 percent to 2.4 percent a year since the mid-1980s. This rise has been so dramatic that those born in 1990 and afterward have rates of colon cancer not seen since 1890.”
The findings made headlines and, not surprisingly, younger people are now urged to consider colon cancer screening, which is typically done by colonoscopy.
What the study and many news sources fail to mention, however, is that if you’re in your 20s and 30s, your mortality risk from colonoscopy is FAR greater than your risk of colon cancer! This is a vitally important consideration that simply isn’t given the proper attention.
It’s a mistake to equate screening with prevention and, if anything, the findings are a wakeup call to Gen-Xers and Millennials that they really need to reassess their lifestyle choices, as the ramifications of poor diet and sedentary behavior are catching up to them at an increasingly younger age.
Colon and Rectal Cancer Rates on the Rise Among Young Adults
According to the featured report, while colon cancer incidence is on the decline overall, we’re seeing a rather rapid rise of incidence in 20- and 30-somethings. Rectal cancer is also on the rise. Some statistics revealed in the report include the following:7
- Since the mid-1980s, rates of colon cancer in adults between the ages of 20 and 39 increased by 1 percent, now affecting 2.4 percent of the population in this age-group annually
- Since the mid-1990s, colon cancer rates in adults between the ages of 40 and 54 have risen by 0.5 percent, now affecting 1.3 percent of this age group
- In adults aged 20 to 29, rectal cancer incidence rates increased 3.2 percent annually between 1974 and 2013
- In adults under the age of 55, rates of rectal cancer doubled, from 14.6 percent in 1990 to 29.2 percent in 2013
- An estimated 13,500 new cases of colon and rectal cancers will be diagnosed in adults under the age of 50 this year
According to the authors: “Consequently, compared with adults born circa 1950, those born circa 1990 have double the risk of colon cancer and quadruple the risk of rectal cancer.”
Based on these findings, the American Cancer Society is reassessing its colon cancer screening guidelines, which currently recommend screening to begin at age 50.
Comparing Your Risk of Cancer With Risks of Screening
While all of that may sound frightening, let’s take a deeper look at your risk, and compare that to the risks of colonoscopy screening. The rate of colon cancer mortality among young adults has risen by about 1 death per 100,000 among young adults, to a 3-in-100,000 risk.
However, the risk of death from colonoscopy is anywhere from 1 out of every 16,318 procedures,8 to 1 for every 1,000 procedures,9 depending on the source!
With some 15 million colonoscopies being done each year in the U.S.,10 that means as many as 15,000 Americans die as a result of this routine screening test, and numbers are likely to increase further if guidelines are changed to encourage people under 50 to get tested.
Again, an estimated 13,500 new cases of colon and rectal cancers will be diagnosed in adults under the age of 50 this year, and if you extrapolate the potential number of deaths at 37 percent (the average death rate for all age groups), then less than 5,000 individuals under the age of 50 will die from colorectal cancer.
This means you may be three times more likely to die from the screening procedure than the disease itself. Serious complications for colonoscopy also occur at a rate of about 1 per 20011 to 35012 procedures, again depending on the source of the data.
According to the report “Complications of Colonoscopy in an Integrated Health Care Delivery System,” the combined injury and kill-rate of colonoscopy-related complications is 0.5 percent, or about 70,000 per year.13
Recall, for comparison, 50,000 die each year from colon cancer and rectal cancer combined, so in the final analysis, if you’re still young, your risk of serious harm and/or death from colonoscopy is FAR greater than your risk of colorectal cancer.14
Other large studies have found that 1.5 to 3 colon cancer deaths are prevented for every 1,000 people screened once every 10 years, while 2.5 per 1,000 people screened are severely harmed or killed.15
That seems like a toss-up in terms of risk, but at least if you’re older and are in a higher risk category, screening becomes a more reasonable risk.
Also beware that X-ray exposure from virtual colonoscopy raises your lifetime risk of all forms of cancer by 20 percent. As noted by GutSense.org,16 “Virtual colonoscopies are now recommended every five years.
By age 70 one’s risk of developing any other form of cancer grows to 100 percent. Killing you with another form of cancer before the colon gets affected is one hell of [a] way to ‘prevent’ colon cancer.”
Other Side Effects of Colonoscopies
Aside from the chance of death, other risks of colonoscopy include the following:17,18
• Perforation of the colon, which occurs at a rate of 1 in 80019 (people at higher risk include those with diverticulitis, diseases of the colon and adhesions from pelvic surgery). Research20 shows the risk of death subsequent to perforation is nearly 52 per 1,000 colonoscopic perforations and 64.5 per 1000 sigmoidoscopic perforations
• Dysbiosis and other gut imbalances, caused by the process of flushing out your intestinal tract before the procedure with harsh laxatives21
• Complications from the anesthesia. Many experts agree you should opt for the lightest level of sedation possible, or none at all, as full anesthesia increases risks
• Infections caused by poorly disinfected scopes
• False positives. According to the Prostate Cancer Foundation,22 an estimated 30 to 40 percent of men treated for prostate cancer have harmless tumors that would never have caused problems in their lifetime. As noted by Jessica Herzstein, a preventive-medicine consultant and member of the U.S. Preventive Services Task Force, “you’re going to die with them, not of them.”
False positives lead to unnecessary treatments that are nearly always harmful, in addition to the anxiety a cancer diagnosis brings. For example, incontinence and erectile dysfunction are two common side effects of radiation therapy, and hormone therapy has been linked to osteoporosis and depression.
Sigmoidoscopies Are Far Safer but Not Used as Often
Sigmoidoscopies tend to have 10 times fewer complications, yet most doctors still recommend colonoscopy 95 percent of the time. Moreover, while there are three acceptable methods to screen for colon cancer,23 colonoscopy — which is the riskiest of the three — is still most commonly recommended by doctors and chosen by patients.
Aside from getting a colonoscopy every 10 years, colorectal cancer can also be diagnosed using fecal occult blood testing (FOBT) on an annual basis (to check for signs of blood in your stool), or a flexible sigmoidoscopy every five years. Researchers have found that in most instances, doctors fail to review all of these options — and the benefits and drawbacks of each — with their patients.
Interestingly, other developed countries favor the FOBT stool test. Part of the reason for this is that in other countries doctors do not get paid for procedure referrals. In the U.S., however, doctors typically do get financial kickbacks when referring patients for various procedures, and as noted by Greger, “it’s estimated that doctors make nearly a million more referrals every year than they would have if they there were not personally profiting.”
A Simple Pre-Procedure Question That May Save Your Life
As discussed in my previous interview with David Lewis, Ph.D., a retired microbiologist with the Environmental Protection Agency (EPA), non-disposable tools used for colonoscopies and flexible sigmoidoscopies carry serious risks for patients. Since these tools must be reused, they require careful cleaning and sterilization before each use.
However, these kinds of tools cannot be autoclaved (heat sterilized), and testing reveals the disinfection techniques and agents used 80 percent of the time are grossly inadequate. As a result, the tools can spread all manner of infections from one patient to another.
Considering multi drug-resistant bacterial infections are on the rise, this is a tremendous concern. The good news is you CAN protect yourself and dramatically reduce your risk of infection by asking the right questions before you schedule your appointment:
• How is the endoscope cleaned between patients?
• Specifically, which cleaning agent is used?
• If the hospital or clinic uses peracetic acid, your likelihood of contracting an infection from a previous patient is slim
• Glutaraldehyde, or the brand name Cidex (which is what 80 percent of clinics use), does NOT properly sterilize these tools. If glutaraldehyde is used, cancel your appointment and find a clinic that uses peracetic acid
• How many of your colonoscopy patients have had to be hospitalized due to infections?
Asking these questions, specifically which type of cleaning agent the clinic or hospital uses, could literally save your life. And, if you’re a health care professional, I urge you to start addressing this issue from the inside. You really need to be aware of how improper disinfection is placing your patients at risk for serious — and potentially untreatable — infections.
What Causes Colon Cancer and How Can You Prevent it?
Your colon, also known as your large intestine, plays an incredibly important role in your health. As food passes through your colon, liquid and salt are removed to prepare it for elimination. Aside from helping to form, store and eliminate waste, your colon contains billions of bacteria, a healthy balance of which is essential for optimal health.
While colorectal cancer is the second leading cause of cancer deaths in the U.S., evidence suggests many of these cases are preventable using simple lifestyle changes. Generally speaking, researchers have concluded anywhere from 90 to 95 percent of cancers are caused by environmental and lifestyle factors. As noted in a 2008 study, “Cancer Is a Preventable Disease That Requires Lifestyle Changes,”24 some of the most prominent lifestyle factors contributing to cancer are:
- Smoking and environmental pollutants
In terms of diet, fried foods, excessive amounts of protein, processed meats, alcohol, lack of fruits and vegetables and excess caloric intake have all been linked to an increased cancer risk. Processed meats such as hotdogs, sausages and lunch meats, have been linked to colorectal cancer specifically, being classified as a Group 1 carcinogen (meaning it is considered carcinogenic to humans) by the International Agency for Research on Cancer in 2015.25
The institute explicitly warns that that "there is no safe threshold" for eating processed meats, as it poses the same cancer risk as cigarette smoking and asbestos. It also recommends limiting red meat to a maximum of 18 ounces per week, to avoid raising your risk for colorectal cancer.
Common-Sense Tips to Prevent Colorectal Cancer
Below are several diet and fitness suggestions that may significantly lower your risk of colorectal cancer, regardless of your age:
✓ Eat more vegetables
Vegetables contain an array of antioxidants and other disease-fighting compounds that are very difficult to get anywhere else, like magnesium. Results from one meta-analysis indicated that for every 100-milligram (mg) increase in magnesium intake, the risk of colorectal cancer was lowered by 12 percent.26
The researchers noted magnesium’s anti-cancer effects may be related to its ability to reduce insulin resistance, which may positively affect the development of tumors.
Beyond magnesium, plant chemicals called phytochemicals can reduce inflammation and eliminate carcinogens, while others regulate the rate at which your cells reproduce, get rid of old cells and maintain DNA.
Vegetables are also one of the best forms of dietary fiber. Studies have repeatedly shown that people with higher vegetable intake have lower rates of cancer.27
Cruciferous vegetables may be particularly beneficial due to the sulforaphane they contain. If you’re healthy, consuming fruit in moderation may also be beneficial. According to one study, dried plums (i.e. prunes) may lower your risk of colon cancer.28
✓ Eat more fiber
For optimal health, I recommend getting about 50 grams of fiber per 1,000 calories. If you follow the tip above and eat more vegetables, you’ll naturally be eating more fiber from the best possible source.
Psyllium seed husk, flax seeds, hemp seeds and chia seeds also provide valuable sources of soluble and insoluble fiber that nourish healthy gut bacteria, promote healthy bowel movements and lower your risk of colorectal cancer.
✓ Optimize your vitamin D level
Vitamin D deficiency is a risk factor for colorectal cancer. According to one recent study:29 “Evidence suggests protective effects of vitamin D and antitumor immunity on colorectal cancer risk.
Immune cells in tumor microenvironment can convert 25-hydroxyvitamin D to bioactive 1α,25-dihydroxyvitamin D3, which influences neoplastic and immune cells … High plasma 25(OH)D level is associated with lower risk of colorectal cancer with intense immune reaction, supporting a role of vitamin D in cancer immunoprevention through tumor–host interaction.”
Sensible ultraviolet exposure, ideally from the sun, and/or vitamin D3 supplementation can get your vitamin D levels into the optimal range of 45 to 60 nanograms per milliliter (ng/mL). You’ll need to monitor your level to be sure you stay within this target range.
✓ Lower your protein intake and avoid processed meats entirely
Most Americans eat far more protein than they need, thereby raising their risk for cancer. A more ideal protein intake is likely around one-half gram of protein per pound of lean body mass.
The quality of your animal protein and mode of cooking should also be considered. When it comes to beef, I recommend eating organically raised grassfed meats only, and cooking your steak only lightly (rare, not well-done), to avoid heat-generated toxins.
Avoid processed meats of all kinds, i.e., those preserved by smoking, curing, salting or the addition of chemical preservatives. This includes bacon, ham, pastrami, salami, pepperoni, hot dogs, some sausages, hamburgers (if preserved with salt or chemical additives) and more.
✓ Get regular exercise
There’s convincing evidence that regular exercise can significantly reduce your risk of colon cancer.30 For instance, one study31 revealed physically active men and women have about a 30 percent to 40 percent reduction in the risk of developing colon cancer compared with inactive persons.
Exercise drives your insulin levels down, and controlling insulin levels is one of the most powerful ways to reduce your cancer risk. It's also been suggested that apoptosis (programmed cell death) is triggered by exercise, causing cancer cells to die.
Exercise also improves the circulation of immune cells in your blood. The job of these cells is to neutralize pathogens throughout your body, as well as destroy precancerous cells before they become cancerous.
The better these cells circulate, the more efficient your immune system is at defending itself against infections and diseases like cancer.
✓ Maintain a healthy weight and control belly fat
A number of studies have linked obesity to an increased risk for about a dozen different cancers, including colon cancer. If you’re overweight or obese, even a modest amount of weight loss can lead to significant benefits for your health.
In terms of cancer prevention, losing excess belly fat is particularly important, as belly fat is linked to an increased risk of colon cancer regardless of your body weight.
✓ Limit alcohol and quit smoking
Both excessive alcohol intake and smoking are associated with an increased risk of colorectal cancer. When it comes to alcohol, I generally define "moderate" alcohol intake (which is allowed in the beginner phase of my nutrition plan) as a 5-ounce glass of wine, a 12-ounce beer or 1 ounce of hard liquor, with a meal, per day.
As you progress further in the nutrition plan, I recommend eliminating all forms of alcohol. If you’re a smoker, you can find tips for quitting here.
✓ Eat more garlic
Research has shown that women who regularly ate garlic (along with fruits and vegetables) had a 35 percent lower risk of colon cancer.32 Another study also found that those who consume high amounts of raw garlic have a lower risk of stomach and colorectal cancers.33
When you add raw garlic in your diet, the fresh clove must be crushed or chopped in order to stimulate the release of an enzyme called alliinase, which in turn catalyzes the formation of allicin.
Allicin, in turn, rapidly breaks down to form a number of different organosulfur compounds. So to “activate” garlic’s medicinal properties, compress a fresh clove with a spoon prior to swallowing it, chop it finely to add to a salad, or put it through your juicer to add to your vegetable juice.