AICR celebrates its 30th Anniversary this year, and we've seen – and funded – a lot of research on colon cancer prevention. For National Colorectal Cancer Awareness Month, we're taking a look at what the research says about how you can reduce the risk of this cancer.
Research now shows that 45 percent of colorectal cancers in the United States are preventable each year through eating a mostly plant-based diet, staying a healthy weight and being physically active. Last year, AICR reported the latest evidence on colorectal cancer prevention, from the AICR/WCRF Continuous Update Project (CUP), which systematically collected and reviewed all the relevant studies.
Here are five ways research now shows you can reduce your risk of this cancer.
One of the strongest findings from the continuous update report Colorectal Cancer was the link between the cancer and excess body fat. Scientists are still investigating the reasons for this link. Excess body fat may lower immune function and increase oxidative stress, which can lead to DNA damage.
Overall, AICR estimates that excess body fat plays a role in approximately 103,000 cases of cancer in the United States every year.
BMI is the common measure of weight in population studies. Want to find out if you have a healthy BMI?
Scientists once considered all fat about the same. Not anymore. Research now links visceral fat, which lies deep inside the abdomen, to increased risk of colorectal cancer – and metabolic disorders – independent of weight.
Checking your waist size is another way to see if you're a healthy weight. All you need it a tape measure and follow these steps.
The idea that eating a diet high in fiber may reduce the risk of colorectal cancer started in the 1970s. Today, the evidence is clearer than ever. AICR's latest report on colorectal cancer found the evidence that dietary fiber could reduce the risk of colorectal cancer was convincing. For every 10 grams of fiber consumed daily – slightly less than a cup of beans – the risk of colorectal cancer is reduced by 10 percent.
Dietary fiber may protect against colorectal cancer by speeding waste through the colon and minimizing cells' exposure to potential carcinogens. Scientists are also studying how byproducts of fiber influence the gut.
How much fiber do you need and what foods have it? Get the Facts on Fiber.
The latest finding reaffirmed earlier evidence: eating too much red meat and processed meat increases colorectal cancer risk. AICR recommends you limit red meat consumption to 18 ounces per week – roughly the equivalent of five or six small cooked portions of beef, lamb or pork – and avoid processed meat.
The report showed that ounce for ounce, consuming processed meat increases the risk twice as much as consuming red meat, which is why AICR recommends avoiding all processed meats. Processed meats include hot dogs, salami and ham.
There are several hypotheses why red and processed meats increase risk. It could be the heme form of iron, which could damage the colon lining; the meats may stimulate N-nitroso compounds, which are possible carcinogens, or the processing of meats may involve smoking, which may lead to other carcinogens.
Want some red-meat substitutes?
From housecleaning to running, the latest report found that moderate physical activity – of all types – reduces the risk of colon cancer. (There was no conclusion drawn for rectal cancer.)
Want to find out if you get enough exercise to lower your cancer risk? Take our quiz.
Note: Last February, a report from the National Cancer Institute and three other organizations found significant decreases in incidences and mortality of colorectal cancer between 1975 and 2006. The reason: more people are getting screened, so colorectal cancer or its warning signs are detected and treated earlier with more success.
Visit NCI for more information on recommendations for when you should get screened.