How being overweight causes cancer
Research has shown that many types of cancer are more common in people who are overweight or obese, including cancers of the breast (in women after the menopause), bowel, womb, oesophageal (food pipe), pancreatic, kidney, liver, upper stomach (gastric cardia), gallbladder, ovarian, thyroid, myeloma (a type of blood cancer), and meningioma (a type of brain tumour).
Dr. Stegall’s comments: Fat cells have a negative effect on the endocrine (hormonal) system and the immune system. They also affect metabolic pathways and cause inflammation. The result of these alterations in the body is a significantly increased risk of cancer.
Does body weight affect cancer risk?
The World Cancer Research Fund estimates that about 20% of all cancers diagnosed in the US are related to body fatness, physical inactivity, excess alcohol consumption, and/or poor nutrition, and thus could also be prevented.
These factors are all related and may all contribute to cancer risk, but body weight seems to have the strongest evidence linking it to cancer. Excess body weight contributes to as many as 1 out of 5 of all cancer-related deaths.
Dr. Stegall’s comments: One of the most important things you can do to lower your risk of developing cancer is to maintain a healthy body weight. Being overweight or obese causes a complex cascade of reactions in the body, almost all of which are bad. Despite all of the concern over poor genetics, obesity is a much more significant cause of cancer.
Fat fuels cancer’s spread in mice
The cells responsible for cancer’s spread — and for most deaths from cancer — may have a fatal weakness according to studies in mice: a reliance on certain fats to fuel their invasion.
It is a difficult and hazardous undertaking for a cancer cell to uproot itself, travel through the bloodstream and take hold in an entirely different part of the body. (Non-cancerous cells are often programmed to self-destruct if they leave the tissue they live in.) Researchers have long struggled to understand which cancer cells can manage the feat, and how they do so.
Dr. Stegall’s comments: Although body fat fuels the spread of cancer, this should not be confused with dietary fat. The two are entirely different. When it comes to diet, carbohydrates are the main macronutrient responsible for the development and growth of cancer cells. This is why I recommend a low carbohydrate, moderate protein, high fat diet for both cancer treatment as well as cancer prevention.