The relation between obesity and colorectal cancer
Obesity is a common condition these days, which refers to having an excess of body fat. Obesity depends on factors such as genetics, environment and lifestyle habits. When the Body Mass Index or BMI is more than 30, then the person is said to be suffering from obesity. Obesity can be a cause of many health problems and colorectal cancer is one of them.
1 What is colorectal cancer?
Colorectal Cancer refers to the state of tumour grown in either the colon or rectum. After being broken down in the stomach, the food travels to the small intestine where the nutrients are absorbed and the remains are passed on in to the large intestine or the colon. Here again the water and nutrients are absorbed and the waste or stool is stored. The stool is then passed into the rectum, which comprises the last 6 inches of the digestive system and is then passed out the body.
Out of the cell growth, the adenomas are the cancerous ones and may start in the gland cells found in the lining of the colon or rectum. Not all growths are cancerous and tests are needed to confirm the same.
2 What causes obesity?
Due to the fast life that we lead today, we often overlook the virtues of physical exertion. Obesity is the leading cause of eating too many calories that result in an increase in weight, if not consumed thoughtfully. The increases in the consumption of aerated and sweetened drinks also attributes to obesity.
Adding to this is the fact that we, as a generation, are more inclined towards television and indoor internet related work. The absence of physical activity not only results in lesser burning of the calories but it also affects our hormonal balance. This hormonal imbalance also affects the way our body handles food.
3 The relation between obesity and colorectal cancer
Obesity is an underlying cause to a lot of health problems. Its relation to colorectal cancer has been linked in some scenarios. In Europe, over 11% of the colorectal cases have been linked to obesity. Studies suggest that obesity increases the risk of colon cancer in men by a 30-70%. The risks in women are lower as compared to that in men. The factors such as metabolic syndrome, insulin resistance and modification in the adipocytokins level are of great importance.
In men, Higher BMI has been sufficiently linked to an increased risk of colorectal cancer. The distribution of fat around the abdominal area is directly related to an increases risk of colon cancer.
The same link i.e. between the BMI and waist circumference, is also found in women but the relation is weaker.
For colorectal cancer, the relation between obesity and cancer risk ranges between 1.04 and 1.3 varying as per countries.
4 What the latest studies have to say
The main hypotheses of new studies show that the production of high levels of insulin or insulin related growth adds to the risk of colon cancer development.
Insulin is the best identified relative between obesity and colon cancer. Hyperinsulinaemia, which occurs in type II diabetes, is an important factor in colon cancer. Thus, adding to the relation between colorectal cancer and obesity.
As obesity leads to insulin resistance and Hyperinsulinaemia, it leads to increased free insulin-like growth factor levels. As this IGF-1 leads to decreased cell death and increased cell growth, it is related as a precursor to colorectal cancer. Insulin also stimulates the growth of colon cancer cell lines, thus establishing a connection between obesity and colon cancer.