Meat-cancer link a complicated one

Re A valid meat message, slightly overcooked, Nov. 1 The journalistic frenzy about the link between colon cancer and red meat must be taken with a grain of salt even though cured meats high in salt content may be a contributing factor.

The etiology of colon cancer is multifactorial. Frequent consumption of fatty, chemically processed red meat is known to promote colorectal neoplasia (a term referring to “new growth” that includes the sequence of benign polyps evolving into cancer). However, red meat is not the only culprit.

There has to be balance in the argument and wisdom in the conclusions. Causes for colorectal cancer include: genetic predisposition; family history of specific cancers; an individual’s history of previous polyps or long-standing inflammatory bowel disease; environmental factors such as cigarette smoking, alcohol consumption; and excessive weight.

Obesity, often a feature of individuals who indulge in processed meat diets, drives a number of cancers through hormonal influence on cancer cell proliferation. A regular diet high in animal fat, low in vegetables, fruits and vitamin D products, increases the risk for colon cancer, but is not the sole cause.

The risks for colon cancer associated with a high-fat, red-meat diet include cooking temperature of the meat (high temperatures may generate procarcinogens); iron content from blood in meat; and bacterial flora in a person’s GI tract may produce nitroso compounds from meat that stimulate cancer growth. Weight gain and obesity from eating baked potatoes filled with butter and sour cream along with the steak are perhaps greater risks for development of colon cancer and other malignancies, than enjoyment of wellcooked, lean, high-quality Canadian beef, with a side of Ontario vegetables.

The best way to prevent colon cancer is a screening colonoscopy. Looking for and removing benign polyps with colonoscopy prevents the evolution of colon cancer — no matter what you eat. Dr. Lawrence B. Cohen, gastroenterologist, Sunnybrook Health Sciences Centre