The Relationship Between Nutrition and Colon Cancer
Colorectal cancer is the third most common cancer diagnosis when skin cancers are excluded. The rate of colon cancer in people age 55 and older has declined since the 1980’s due to more screening. Rates of colon cancer in adults age 20-39 years have increased 1.0%-2.4% per year. Even more surprisingly adults born around 1990 have double the risk of colon cancer than people born around the 1950’s. The relationship between nutrition and colorectal cancer is important and two modifiable factors, our food choices and maintaining a healthy weight, influence this risk.
Key findings from the American Institute of Cancer Research shows body weight and some dietary choices either increase or lower the risk of colorectal cancer.
- Carrying excess body fat is the strongest factor that increases risk because people who carry excess weight have higher levels of insulin in the blood. Our body’s fat tissue responds less to insulin, increasing levels in the blood. High levels of insulin promote all types of cancer cell growth. Research shows that losing even 10% of your body weight may help lower insulin levels.
- Consuming high amounts of red meat increases risk in several possible ways. Specifically, the heme in red meat (this gives the meat its color) can damage the lining of the colon. Smoking or grilling meat at high temperatures increases cancer-causing compounds called heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs). New evidence also suggests that red meat may promote the growth of certain unhealthy microbes in the intestine causing chronic, low-grade inflammation. This inflammation is often linked with cancer. It is recommended to eat no more than 18 ounces of red meat (beef, pork, and lamb) per week (a deck of cards=3 ounces).
- Consuming processed meats (hot dogs, bacon, sausage, or deli meats) also increase risk because of nitrates and nitrites that are added to keep these meats fresh. Enjoy these meats as an occasional treat.
- Eating whole grains and foods containing fiber lowers the risk for colorectal cancer. Fiber is protective because it helps lower blood sugar levels, protects the lining of the colon, and increases the amount of healthy gut microbes. Increasing whole grains (whole wheat bread, brown rice, or quinoa), fruits, vegetables, beans, and legumes is a great way to eat more fiber. Eating a diet rich in fiber slows digestion, keeping people feeling satisfied longer and can help people lose weight or maintain a healthy weight.
- Alcohol in most beverages contain ethyl alcohol or ethanol which increases risk for many cancers including colorectal cancer. If you choose to drink alcohol do so in moderation, no more than two drinks a day for men and one drink a day for women.
It can seem overwhelming to make many dietary changes at once. I often recommend making one change at a time and I like to think of a change as an “experiment.” An experiment is something to try, see how it goes, and over time the change can become a habit. A few examples of dietary experiments include:
- Add a fruit or vegetable to a meal
- Try a meatless meal one time a week
- Treat meat like a condiment, filling just a quarter of your plate
- Switch to whole grain pasta, brown rice or whole wheat bread
Remember small dietary changes can have a big impact on your overall health. What experiment would you like to try?
Connect with others talking about living with colorectal cancer in the Colorectal Cancer support group.