Colorectal Cancer: The Link to Red Meat and Processed Meat

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If you’ve been anywhere near a TV or computer today, you’ve probably heard that scientists are reporting a sharp rise in colorectal cancers in adults as young as their 20s and 30s. Possible explanations for this dangerous trend are obesity, sedentary lifestyles, alcohol, chronic conditions like inflammatory bowel disease and Type 2 diabetes, and HPV infection (very rarely causes rectal cancer).

What I’m not hearing a lot of discussion about yet is red meat and processed meat consumption. This is a shame, because the American Cancer Society has been advising Americans to “limit consumption of processed meat and red meat” since 2002. This is really, really old news as health breakthroughs go.

The risk of colon and rectal cancer increases by roughly 20 – 28% for every serving of red or processed meat that you eat each day. A serving is 3 1/2 ounces cooked fresh meat or 2 ounces of processed meat, way less than most people are used to seeing on their plate.

How does red meat and processed meat cause colorectal cancer? The nitrite that is used to color and preserve processed meats forms N-nitroso compounds in the gut when you’re digesting your meal. It’s not just processed meats that lead to the formation of N-nitroso compounds, though, they are also formed when we consume fresh red meat (possibly as a result of a reaction involving the heme iron in red meat). These N-nitroso compounds can be carcinogenic. Buying bacon that is labeled “no added nitrites or nitrates” or “uncured” does not help as much as people would like to believe, if it helps at all. These meats still contain nitrites and nitrates from natural sources, such as celery powder.

When we talk about “processed meat”, we are talking about all processed meat, including chicken and turkey. Turkey bacon is not safer than pork bacon.

When meats are cooked at high temperatures, mutagens are formed (specifically heterocyclic amines and polycyclic aromatic hydrocarbons), which are carcinogenic. It’s fairly simple to avoid this: marinate your meat before grilling it, microwave it for 2 minutes before grilling it, flip frequently, and don’t eat the pan drippings. Even better, choose fish more often and cook your meat using another method: baking, roasting, stir-frying, boiling, steaming, poaching and stewing are all better options than grilling.

According to the U.S. Department of Agriculture, American are eating an average of 53 – 71 pounds of red meat annually. That’s just red meat; the intake of all meats is around 271 pounds per capita every year.

We are pretty concerned about protein these days…pretty needlessly worried. Older adults need the most protein, probably around 0.45 – 0.54 grams per pound of body weight, per day. So if your mom or dad is 70 years old and weighs about 160 pounds, they need 86 grams of protein. Young and healthy adults need the same amount or even less – yes, even if you’re weight lifting. The USDA recommends only 46 grams a day for women and 56 grams a day for men.

Young adults are now consuming an average of 75 – 100 grams a day; double what the USDA recommends.

Research out of Purdue University found that when 220 overweight or obese middle-aged men and women performed strength training twice a week and aerobic exercise once a week, they gained lean muscle…obviously. Giving them 20, 40, or 60 grams of whey protein every day had no effect whatsoever on strength or muscle gain compared to a placebo. There is no solid evidence that dietary protein has an impact on body composition or skeletal muscle size, strength, or function.

Of 23 weight-loss trials that lasted about 12 weeks each, only 5 of them showed greater weight loss with higher-protein diets than with lower-protein diets. When all 23 studies were combined, those on the higher-protein diets lost an average of only 1.7 pounds more. It is true that you need adequate protein to prevent loss of lean body mass…adequate is the key word here.

This is all certainly food for thought when rates of protein and meat obsession are skyrocketing as a result of dubious health claims made by fanatics with no background in biochemistry or epidemiology and when young adults are yet again being burdened with a health condition that used to only affect the older population.