Do you have a friend or family member who has been diagnosed with colorectal cancer? For most of us, the disease has touched someone close to us or in our lives. Colorectal cancer is the third most commonly diagnosed cancer in the United States in both men and women. This year we can expect to see over 100,000 new cases of colon cancer and over 40,000 new cases of rectal cancer. Over a lifetime, Americans have about a 5% (1 in 20) risk of colorectal cancer.
That's the bad news, but the good news is much is known about what prevents colon cancer and how you can reduce your risks for being one of those statistics. Factors known to raise the risk of colorectal cancer include a personal history of colorectal polyps, cancer or inflammatory bowel disease, and a family history of colorectal cancer. There is an increased risk for African-Americans compared to other ethnic groups. Advancing age is a risk: over 90 percent of all colorectal cancers occur in people over the age of 50. So whether you have increased risk or are someone with a clear personal and family medical history, we are all at increased risk as we grow older, and can all be interested in the steps necessary to reduce our risk.
Prevention of Colorectal Cancer
Eat a wide variety of vegetables and fruits, including every color of vegetable every two or three days. If you include grains in your diet, choose whole grains and sprout them before eating. Eat 2 Brazil nuts a day for their selenium content. Include citrus, berries and green tea in your diet for extra protection.
What about meat? Wild salmon and other cold water fish provide valuable fatty acids and vitamins. Red meats have long been associated with an increased colorectal cancer risk, but it is likely that the problem applies to non-grass-fed meats and processed red meats. I’ll just mention four factors to consider when making that statement. (If you’re still curious, you’ll enjoy reading a thorough discussion at Real Food University, a great resource for food information!)
There have been no formal studies that separate grass-fed from grain-fed beef, but grass-fed meats contain conjugated linoleic acid (CLA), well-known for its anti-tumor properties.
In most studies associating red meat and cancer, processed meats have been lumped together with red meats, but processed meats – containing nitrites and nitrates – increase colorectal polyps and cancers significantly on their own.
Cook your meat gently. It matters how you cook the meat: higher risks have been observed for heavily browned meats, and no association for roasted or water cooked meats (steaming, boiling).
Argentina, with the highest meat consumption in the world, has lower rates of colorectal cancer than we do in the U.S., and meat-eating Mormons have lower rates than vegetarian Seventh Day Adventists!
Beyond Food, What Else?
At a very minimum, a food-based multivitamin is likely to cover any nutrients lacking in your diet. Supplementing with the valuable vitamins D and K2 may be helpful as both reduce your risk of cancer. Even keeping vitamin D levels above the minimal normal level, or about 32 ng/mL, has been shown to reduce colon cancer risk. I recommend a level of 40-65 ng/mL. In laboratory studies, vitamin K2 inhibits cancer cell growth.
Take the chlorine out of your water, it’s associated with an increased risk of colorectal cancers, as well as cancers of the bladder, esophagus, and breast.
Maintain a normal weight. Easier said than done! The Weight Loss Eating Plan on my website is a simple presentation of a healthy way to eat low-carb that can be sustained for a lifetime, not just a diet fix.
Type 2 diabetics have an increased risk of colorectal cancer, which we now know is a risk factor that you can control. Type 2 diabetes is always preventable and almost always reversible with an intentional and appropriate program of diet and exercise. See the discussion on type 2 diabetes (here) for more information.
Stay active! Physical inactivity appears to increase the risk of colorectal cancer.
Avoid smoking: long-term smoking is a well-established risk factor.
Heavy alcohol use, either directly or because of an associated vitamin deficiency, is thought to be associated with an increased risk of colorectal cancer.
The prognosis for colorectal cancer varies widely depending on how early it is diagnosed. Identified and treated (sometimes with just removal) in its earliest stages, there is a high degree of success and can be a low rate of recurrence with appropriate lifestyle modification. If the cancer has progressed and grown from the lining of the colon into the muscle layer, the outlook is much more grim.
The earliest signs and symptoms of colorectal cancer include any change in the way you feel in your abdomen, particularly if there are changes in your stool pattern, such as constipation, diarrhea, or a change in the consistency of size of your stool. If you notice rectal bleeding , with or without a bowel movement, or a feeling that your bowel doesn’t empty completely, check with your physician. General symptoms of concern include weakness, fatigue, unexplained weight loss, or anemia, indicating blood loss. Your doctor may check you for invisible rectal bleeding, have you do a similar test through a laboratory or refer you for a colon inspection by a gastroenterologist, surgeon or other experienced practitioner.
The Ketogenic Diet and Cancer
Improved understanding of the how cancer cells work has revealed that many if not most tumors are dependent on glucose for food and on insulin for glucose to gain admission to the every-hungry growing cancer cell. A few initial studies, including some patients with colorectal cancers, have shown remission of cancer associated with a ketogenic diet. A ketogenic diet is one composed of moderate protein, high in fat and extremely low in carbohydrate that encourages the body to burn fat for fuel and starves the glucose system, rendering insulin production obsolete and thus decreasing the level of insulin in the blood. When the body becomes adapted to a low carb diet and starts to burns fat for fuel, "ketone bodies" are produced, becoming "keto-adapted" and raising the level of ketones in the blood. (You may have heard of ketones and ketosis pertaining to diabetic emergencies. In type 1 diabetics the emergency is caused when ketones and ketosis rise to a level of keto-acidosis, something that does not happen in people who do not have type 1 diabetes. Low carbohydrate ketosis is not only harmless, it is beneficial in a wide variety of clinical conditions from epilepsy to Parkinson's Disease to some forms of mental illness. I know we will be reading more about the medical application of ketogenic diets in the near future.) The rest of the body survives well on ketone bodies and a small amount of glucose. Meanwhile, the insulin- and glucose-dependent cancer cells are starved for energy and can go into remission.
Does this mean that a ketogenic diet would also be useful to prevent colorectal cancer? There is no definite clinical evidence to answer this question with confidence, but I am fairly confident that insulin in excess offers no benefit and a ketogenic diet offers a wide variety of health enhancements. In my kitchen, that means we eat a gently modified ketogenic diet all the time. Have you tried keto-adaptation?