Colorectal Cancer
Colorectal cancer is a type of cancer which affects the lower digestive tract, in the colon (large intestine) and rectum. This is the second most commonly diagnosed cancer in women and the third in men, and this is increasing, with over 1.4 millions new cases worldwide in 2012 (Li, Ma, Huang, Chen & Zhou, 2017). The increased incidence has been attributed to many environmental factors, such as the typical Western diet and modern lifestyles (Del Cornò, Donninelli, Conti & Gessani, 2017).
Symptoms of colorectal cancer include the following:
The risk factors of colorectal cancer include the following:
Inflammation is a key driver of all types of cancer, and inflammation can be caused by most of the above risk factors. Chronic inflammation causes epigenetic changes to genes in the cells of the colon, to initiate colon cancer. Inflammation can be increased by many different foods and food compounds which have cancer promoting effects, but many other foods and nutrients offer protective effects against cancer (Del Cornò, Donninelli, Conti & Gessani, 2017).
Symptoms of colorectal cancer include the following:
- Rectal bleeding or blood seen on bowel motions
- Abdominal pain, bloating, nausea or and vomiting
- Unexplained weight loss
- Change in bowel motion frequency or size and shape
- Sensation of incomplete passing of bowel motions
- Rectal pain (if the cancer is located in the rectum) (Osiecki, 2012, p387).
The risk factors of colorectal cancer include the following:
- Age - the risk increases with age, and most common in people over 50 years of age (Osiecki, 2012, p386).
- Family history - there is a family connection in 10-25% of people with colorectal cancer (Osiecki, 2012, p386).
- Diet – with the proximity of digested food to the digestive tract, it's not surprising that food ingredients, particularly of poor choices and non-nutrients in foods, can be a causative factor in colorectal cancer. In addition, food choices affect the gut microbiome, which in turn can cause epigenetic changes to the epithelial cells of the digestive tract. Diets high in some animal meats and omega-6 fats increase inflammation, and a low fibre intake increases cancer risk (Del Cornò, Donninelli, Conti & Gessani, 2017).
- Type 2 diabetes - people with diabetes (type 2) have a 20-40% higher risk of colorectal cancer, likely caused by hormonal changes and increased inflammation in diabetes (de Kort et al., 2017).
- Polyps - colonic polyps can increase the risk, but less than 1% can become cancerous (Osiecki, 2012, p386).
- Smoking and alcohol - smoking and a high intake of alcohol can increase the risk of colorectal cancer (Osiecki, 2012, p386).
- Vitamin D deficiency - having low vitamin D levels can increase the incidence (Osiecki, 2012, p387).
- Poor sleep quality - increased amounts of light exposure reduces the levels of melatonin, the sleep hormone. Melatonin has been shown to protect against cancer, improve immune function, reduce the risk of metastasis and reduce the toxic effects of anti-cancer drugs (Li, et al., 2017).
- Increased weight and metabolic changes – chronic intestinal inflammation and obesity are major risk factors. Abdominal obesity is associated with a 1.5 to 3.5-fold increase in colorectal cancer risk compared to lean people (Del Cornò, Donninelli, Conti & Gessani, 2017).
- Genetics – there are some gene mutations which can increase the risk of this type of cancer (Osiecki, 2012, p386).
- Physical inactivity - having a sedentary lifestyle with little physical activity increases cancer risk, while regular physical activity is protective against colorectal cancer by approximately 20-25% (Namasivayama & Lim, 2017).
Inflammation is a key driver of all types of cancer, and inflammation can be caused by most of the above risk factors. Chronic inflammation causes epigenetic changes to genes in the cells of the colon, to initiate colon cancer. Inflammation can be increased by many different foods and food compounds which have cancer promoting effects, but many other foods and nutrients offer protective effects against cancer (Del Cornò, Donninelli, Conti & Gessani, 2017).