The common understanding of obesity is a condition where an individual person or persons has an abnormal high and unhealthy proportion of body fat. The measurement of obesity is often done using the BMI scale. This is believed to provide a more reliable and accurate measure of obesity or overweight as oppose to the use of weight alone. Now of what interest do we have in the ascertainment of peoples’ weight? This is because the prevalence of obesity and overweight is growing into a catastrophic situation and people’s health is at risk. National Health and Nutrition Examination Survey (NHANES) is giving an estimation of about 68% in US alone as the adult population age 20 and above to be struggling with either obesity or overweight. With this impact and the complications that come with being obese or overweight, it has become necessary that both the professionals and the laymen take a position in fighting the scourge. To this effect, we want to discuss some of the facts about relationship between obesity and cancer with a view of creating awareness to the society to be on the look out of the consequences that are attached to these two conditions.
Experts have established that obesity is closely associated with increased risks of various types of cancer including the following among many others:
- Colon and rectum
- Breast (after menopause)
- Endometrium (lining of the uterus)
According to of the studies done using NCI Surveillance, Epidemiology, and End Results (SEER) data, estimated that in 2007 in the United States alone, about 34,000 new cases of cancer in men representing 4 percent and 50,500 in women representing 7 percent were due to obesity. Even though there were some cases attributed to obesity, there were some variances in the cancer types with endometrial cancer and esophageal adenocarcinoma being as high as 40%. Experts while analyzing this, could make a projection that if the trend continues as it is now, then in the next two decades the future health and economic burden of obesity will lead to about 500,000 additional cases of cancer. On the other hand, while analyzing the same findings, it was established that if the average adult was to reduce their BMI with just 1%, then this would translate into preventing an increase of the number of new cancer cases by about 100,000. That is how closely obesity is related to cancer.
In the meantime, we spoke to the experts at AWAREmed Health and Wellness Resource Center under the able leadership of doctor Dalal Akoury and she says that several possible mechanisms have been suggested in the past to explain the association of obesity with increased risk of certain cancers. The following are some of the tabled suggestions:
- Fat tissue produces excess amounts of estrogen, high levels of which have been associated with the risk of breast, endometrial, and some other cancers.
- Obese people often have increased levels of insulin and insulin-like growth factor-1 (IGF-1) in their blood (a condition known as hyperinsulinemia or insulin resistance), which may promote the development of certain tumors.
- Fat cells produce hormones, called adipokines that may stimulate or inhibit cell growth. For example, leptin, which is more abundant in obese people, seems to promote cell proliferation, whereas adiponectin, which is less abundant in obese people, may have anti-proliferative effects.
- Fat cells may also have direct and indirect effects on other tumor growth regulators, including mammalian target of rapamycin (mTOR) and AMP-activated protein kinase.
- Obese people often have chronic low-level, or “sub-acute,” inflammation, which has been associated with increased cancer risk.
Other possible mechanisms include altered immune responses, effects on the nuclear factor kappa beta system, and oxidative stress.
Many studies have shown that overweight and obesity are associated with an overbearing increase in risk of postmenopausal breast cancer. This higher risk is seen mainly in women who have never used menopausal hormone therapy (MHT) and for tumors that express both estrogen and progesterone receptors.
Overweight and obesity have, by contrast, been found to be associated with a reduced risk of premenopausal breast cancer in some studies.
The relationship between obesity and breast cancer may be affected by the stage of life in which a woman gains weight and becomes obese. Epidemiologists are actively working to address this question. Weight gain during adult life, most often from about age 18 to between the ages of 50 and 60, has been consistently associated with risk of breast cancer after menopause. The increased risk of postmenopausal breast cancer is thought to be due to increased levels of estrogen in obese women. After menopause, when the ovaries stop producing hormones, fat tissue becomes the most important source of estrogen. Because obese women have more fat tissue, their estrogen levels are higher, potentially leading to more rapid growth of estrogen-responsive breast tumors.
The relationship between obesity and breast cancer risk may also vary by race and ethnicity. However, there is limited evidence that the risk associated with overweight and obesity may be less among African American and Hispanic women than among white women.
Overweight and obesity have been consistently associated with endometrial cancer. This is the cancer of the lining of the uterus. Obese and overweight women have two to four times the risk of developing this disease than women of a normal weight, regardless of menopausal status. A number of studies have also found that the risk of endometrial cancer increases with increasing weight gain in adulthood, particularly among women who have never used MHT.
Although it has not yet been determined why obesity is a risk factor for endometrial cancer, some evidence points to a role for diabetes, possibly in combination with low levels of physical activity. High levels of estrogen produced by fat tissue are also likely to play a role. In conclusion to part with the prevalence of obesity and all the relationships we are observing with different kinds of cancers, we all have a duty to perform in the realization of good health. It begins with the mutual acknowledgement that these two conditions are a threat to our health. Up on that we can begin to talk to the experts both at AWAREmed Health and Wellness Resource Center and other institution where professionalism is practiced in offering treatment of the same. You can schedule for an appointment with doctor Dalal Akoury today and she will be there to help you overcome whatever challenge you may be having.