Obesity has always been a problem for segments of the population. However, over the past decades the number of obese and overweight children and adults has increased in a remarkable way. Obesity refers to a condition where a person has an unhealthy and abnormally high proportion of body fat. Obesity is measured using the body mass index scale (BMI). In addition to the health issues caused by carrying around excessive amounts of weight, it has been determined that obesity is becoming the leading cause of cancer.
What is the Link between Cancer and Obesity?
Obesity is linked to an increased risk of several forms of cancer. Some of the cancers that have been linked to obesity include:
• Rectum and colon
A study that was carried out in 2007 using Epidemiology, NCI Surveillance, and the End Results data in USA showed that approximately 4% of new cancer cases in men and 7% of new cancer cases in women were as a result of obesity. The number of new cancer cases linked to obesity varied largely for the various types of cancer but the percentage was particularly high for esophageal and endometrial cancers.
A projection concerning future economic and the health burden associated with obesity by the year 2030 estimates that, if the existing trends continue, obesity will result in approximately 500,000 new cancer cases in United States alone by 2030.
Mechanisms that Explain the Link between Obesity and Increased Cancer Risk
There are various mechanisms that attempt to explain why obesity is becoming the leading cause of cancer:
• There are increased IGF-1 (insulin-like growth factor-1) and insulin levels in the blood of obese people; this condition is referred to as insulin resistance or hyperinsulinemia. Insulin resistance is known to trigger the growth of various tumors.
• Fat tissue in the body produces excess estrogen levels; the excess estrogen has been linked to an increased link of endometrial, breast, as well as other cancer types.
• Fat cells in the body produce adipokines hormones which can inhibit or stimulate cell growth, i.e. the leptin hormone which is prominent in obese people is known to accelerate cell proliferation which can result in some types of cancer.
• Fat cells may have indirect and direct effects on various tumor regulators, i.e. kinase.
• Obese people tend to have chronic inflammation which has been linked to several cancer types.
• Other mechanisms that have been associated with an increase in cancer risks include: oxidative stress, effects on the kappa beta system, and the alteration of the immune system.
Trials concerning weight loss that have been carried out in the past have shown that losing the extra pounds decreases the risk of the onset of chronic diseases, i.e. diabetes and cardiovascular disease as well. In most cases, observing healthy eating habits and exercising on a regular basis can be of great help in managing obesity. In other cases, a doctor should be consulted. Hopefully, a concerted focus on this issue will help to reverse the current trends in the interest of future generations.