Cancer is largely a preventable illness. Two-thirds of cancer deaths in the U.S. can be linked to tobacco use, poor diet, obesity, and lack of exercise. All of these factors can be modified. Nevertheless, an awareness of the opportunity to prevent cancer through changes in lifestyle is still under-appreciated.
Because colorectal cancer is a highly curable disease when detected early, the best form of prevention is screening and early detection. When an adenomatous polyp, which is a precursor lesion, develops, it takes 10 to 15 years to transform into cancer; therefore, people with an increased risk for developing colorectal cancer may want to undergo screening at a younger age and continue with screening frequently in an attempt to prevent this development. Several screening programs may be used to detect early stage colorectal cancer and polyps. These polyps can then be removed, thereby preventing the development of colorectal cancer.
Diet: Diet is a fertile area for immediate individual and societal intervention to decrease the risk of developing certain cancers. Numerous studies have provided a wealth of often-contradictory information about the detrimental and protective factors of different foods.
There is convincing evidence that excess body fat substantially increases the risk for many types of cancer. While much of the cancer-related nutrition information cautions against a high-fat diet, the real culprit may be an excess of calories. Studies indicate that there is little, if any, relationship between body fat and fat composition of the diet. These studies show that excessive caloric intake from both fats and carbohydrates lead to the same result of excess body fat. The ideal way to avoid excess body fat is to limit caloric intake and/or balance caloric intake with ample exercise.
It is still important, however, to limit fat intake, as evidence still supports a relationship between cancer and polyunsaturated, saturated and animal fats. Specifically, studies show that high consumption of red meat and dairy products can increase the risk of certain cancers. One strategy for positive dietary change is to replace red meat with chicken, fish, nuts and legumes.
High fruit and vegetable consumption has been associated with a reduced risk for developing at least 10 different cancers. Some researchers believe that this may be a result of potentially protective factors such as carotenoids, folic acid, vitamin C, flavonoids, phytoestrogens and isothiocyanates, often referred to as antioxidants.
For many years, researchers speculated that the low incidence of colorectal cancer in parts of Africa could be linked to a high-fiber diet; however, several studies have failed to support this theory. In 1999, three pivotal clinical studies evaluating the effects of a high-fiber diet on colorectal cancer failed to establish a correlation between high fiber consumption and reduction in the incidence of colorectal cancer. In two of these studies, researchers directly compared two groups of individuals with either high or low fiber consumption and found an equal number of polyps in each group. There are many reasons to eat a diet high in fiber, particularly to help reduce the risk for coronary artery disease; however, such a diet does not appear to help prevent the development of colorectal polyps or cancer.
There is strong evidence that moderate to high alcohol consumption also increases the risk of certain cancers. One reason for this relationship may be that alcohol interferes with the availability of folic acid. Alcohol in combination with tobacco creates an even greater risk.
Exercise: Higher levels of physical activity may reduce the incidence of some cancers. According to researchers at Harvard, if the entire population increased their level of physical activity by 30 minutes of brisk walking per day (or the equivalent energy expenditure in other activities), we would observe a 15-percent reduction in the incidence of colon cancer.
A group of Swiss researchers compared the physical activity levels of 223 individuals with colorectal cancer and 491 individuals without colorectal cancer. The results indicated an increased that individuals with a sedentary lifestyle have an increased risk of developing colorectal cancer. This association was present regardless of age, gender, weight or alcohol intake. Although there is no sure way to prevent any cancer from developing, these researchers concluded that increasing one's level of physical activity may help to prevent one-fifth to one-third of all colorectal cancer cases.
Updated information on the topic of colorectal cancer will be forthcoming.