Obesity Causes Cancer?
Laurence T. Gayao MD, Fitness Physician
Studies have shown that overweight causes one in twenty cancer cases in the United Kingdom. Among the preventable causes of cancer, obesity is number two, second to only to smoking. How does obesity cause cancer?
The increased occurrence of cancer among overweight individuals have long been noted in studies after studies but it has been only lately that a new discovery could explain why they are more likely to develop cancer.
Obesity and Cause of Cancer
Researchers have gained more understanding of how obesity causes cancer. The human body has an immune surveillance system using natural killer (NK) cells that limit the spread of tumors. These NK cells recognize tumor cells as targets and destroy them.
In overweight individuals the presence of excess fat, the immune surveillance fails due to a buildup of fat infiltrating the NK cells suppressing or choking their metabolism and trafficking. This causes the NK cells being disabled to do their function. Researchers have called this a metabolic paralysis. This was the finding of a study by a team from Trinity College Dublin.
The good news is the metabolic paralysis could be reversed and the antitumor activity of the NK cells restored by losing weight. Scientists are now trying drugs to block fat from entering the NK cells.
The importance of NK cells is not only in preventing the development and spread of cancer. Scientists have now developed an immunotherapy that uses immune NK cells cultured from stem cells instead of cells that are taken from patients to seek and destroy cancer cells.
Despite the efforts to increase public awareness of the dangers of overweight or obesity, is still a growing problem worldwide. Over 1.9 billion adults are either overweight or obese. In the United States a 2012study, findings showed approximately 28,000 new cases of cancer in men and approximately 72,000 in women were associated with being overweight or obese.The International Agency for Research on Cancer (IARC)external icon has identified 13 cancers associated with overweight and obesity: meningioma, multiple myeloma, adenocarcinoma of the esophagus, and cancers of the thyroid, postmenopausal breast, gallbladder, stomach, liver, pancreas, kidney, ovaries, uterus, colon and rectum (colorectal).
Dr. Leo Carlin, from the Cancer Research UK Beatson Institute, said: “Although we know that obesity increases the risk of 13 different types of cancer,” there are many other serious medical problems it causes.
Best Approach to Cancer is Prevention
From personal experience, prevention is better than cure. When I was just out of medical school I served in a mission hospital. During that time we had a therapeutic x-ray machine donated from the USA that came and I was assigned to assemble it. This machine produced radiation many times stronger than diagnostic x-ray machines. Assembling the machine with my team was not difficult and it was up and running in no time. I learned how to calibrate the machine and soon we were using it for cancer radiation. About 25 years later I had a mass in my neck and during surgery, I was diagnosed to have thyroid cancer.
I have been having close follow up for the last 15 years and has had three other surgeries and radiation. Through all these, I have always felt well but if I have to do it over again I would have been more careful handling the ionizing radiation while handling the therapeutic x-ray machine which causes the kind of thyroid cancer I was diagnosed with papillary carcinoma.
The bottom line is many forms of cancers are known to be preventable. In spite of the many advances in cancer treatment, we still are losing many lives to this deadly disease. Today our best bet against cancer should be directed a prevention.
Cancer Prevention
To reduce risk:
- keep a healthy weight
- stop smoking
- eat a healthy diet
- avoid the use of alcohol
- avoid sunburn
- regular exercise
- avoid toxic materials
- avoid unnecessary ionizing radiation
