I am standing in line at the lunch buffet at my hospital and I have an option: a red meat steak entrée or an eggplant parmesan. If each day I choose the red meat or a processed meat entrée over a vegetarian option, I increase my chance of colorectal cancer by almost 20 percent.
If I am standing in line at McDonalds, Wendy's or Burger King and order a quarter pounder, it would increase my risk of colorectal cancer by over 50 percent.
On average Americans eats 93 grams of red meat a day, taking in account for 5 percent of American who are vegetarians (full disclosure: I am a vegetarian) -- all this adds up to a colon cancer risk that is contributing to 84,000 excessive deaths world wide from cancer due to processed and red meat.
Last week a World Health Organization panel made a definitive statement: Processed meats can cause cancer and red meat probably raises the risk of cancer.
Declaring meat, a stable part of American diet, as a carcinogen (cancer-causing agent) is stunning. But we should have seen it coming. In 2007 the American Institute for Cancer Research, and in 2009 the National Institute of Health, and in 2011 the World Cancer Research Fund International all pointed to the link between meat and cancer.
The WHO panel went further than the other studies. The panel categorized processed meat in the same risk group as cigarettes and red meat in the same risk group as DDT and mustard gas, as cancer causing agents.
It's partly unfair to say that we should look at processed meat as causing colorectal cancer just as we see cigarettes as causing lung cancer. Yes, both definitively cause cancer, but 50 gm a day of processed meat increases cancer risk by 20 percent while smoking increases risk of cancer by 2,500 percent.
So how can processed or red meat cause cancer?
When we cook at home we add salt, pepper, and cinnamon. When meat is processed for taste and preservation the manufacturers add N-nitroso-coumpond and polycyclic aromatic hyrocarbons to hot dogs, bacons and ham. (I took organic chemistry as a premed student and still don't know these compounds, but they certainly do not sound healthy.)
When baked, these cancer-causing agents transform into heterocyclic aromatic amines and when they reach our colon after a meal they can alter the DNA of the cells in the colon. Over decades it just takes one cell to mutate and grow uncontrollably leading to a cancer of colon, stomach or pancreas.
Often in scientific literature a cause and effect relationship between a behavior or food and a disease is hard to prove and so it took 800 studies over decades to show this relationship between meat and cancer. And yet, the meat industry still denies this. The tobacco executives still deny that cigarettes are addictive but they do not want their children to smoke.
So what can we do? In large part the American culture is meat-based. Our language reflects our culture. We say "Where is the beef?" or "The meat of the conversation," referring to the real substance. Likewise, an American meal is felt to be incomplete unless there is a meat entrée.
But things are changing. Since 1970 red meat consumption has declined from over 101 pounds per person per year to under 75 pounds, and vegetable consumption has increased.
But, we still have a ways to go. We just have to make the right choice next time we are standing in line.