I was recently asked about eating lunch meats – thinly sliced turkey or chicken – and turkey bacon, since these are convenient ways to add protein to salads. This is a very good question indeed, and cannot be simply answered without exploring a number of nutritional issues. Nevertheless, my initial approach would be to apply the evolutionary template which clearly indicates our hunter gatherer ancestors would have never consumed processed, cured or canned meats.1 Their staples were the fresh meats, flesh and organs of wild animals along with gathered wild plant foods.2
Processed meat contains additives
Common additives to canned, cured and processed meats include: salt, corn syrup, high fructose corn syrup, dextrose (glucose), sucrose (table sugar), modified food starch (made from wheat, corn, potatoes, soy, etc. ) sodium lactate, potassium lactate, calcium sulfate, BHA, BHT, citric acid, propyl gallate, silicon dioxide, vinegar, sodium nitrite, sodium nitrate, potassium nitrite, potassium nitrate, sodium tripolyphosphate, hexametaphosphate, acid pyrophosphate, orthophosphates, erythorbate, vitamin C, vitamin E, oleoresins, spices, monosodium glutamate (MSG), sodium diacetate, bromelin, carrageenan, ficin, gelatin, hydrolyzed proteins (wheat, soy, milk), papain, sodium caseinate, dried whey.
Read the labels of most lunch meats, processed meats, canned meats, sausages, salamis and bacon, and you will invariably find numerous additives listed above.
Clearly refined sugars, salt, soy, dairy and cereals added to processed meats are not “Paleo” ingredients. Many other compounds in this list are added to prevent food-borne illnesses, bacterial contamination, and spoilage. Prominent in these functions are added nitrites and nitrates.3 We all know that fresh, raw meats rapidly spoil and can cause illness, gastric distress, and diarrhea if left unrefrigerated at room temperatures for long periods. So this fact alone should tip you off to potential health hazards associated with the consumption of processed meats, which typically don’t spoil at room temperatures because of their chemical additives. If the chemicals in these meats are “bad” for bacteria, they just might be “bad” for our body’s cells as well. Before I get into nitrite and nitrate health concerns, let’s talk about more wide-ranging nutritional issues involving consumption of processed meats.
Unless you can find a supplier who manufactures their processed meats from wild game or grass-fed animals, any processed meat you consume originates mainly from feed lot animals eating virtually nothing but grains (corn primarily) before they are slaughtered. As my research group and I have previously pointed out,4, 5 this practice produces inferior meat with an unnatural fatty acid balance characterized by high omega 6 fatty acids, low omega 3 fatty acids, a low protein content, a high fat content and many other important nutritional shortcomings.6 So, with almost all processed meats, we’ve got a nutritionally inferior product to start with even before it is transformed into hams, bacon, lunch meats, bologna, hot dogs, salamis, sausages, deli meats, canned spam, Vienna sausages, etc.
They may contain pesticides, antibiotics, and hormones
Feed lot-produced animals like cattle, hogs, chickens, or turkeys are invariably exposed to pesticides,7, 8 or are deliberately administered antibiotics,9 and hormones;10-12 all of which may ultimately find their way into our food supply.
Virtually all feedlot cattle in the U.S. are implanted with estrogenic hormones in their ears to promote rapid growth and weight gain. Although the jury is still out, exposure to these hormones may compromise our health.10-12 Hence, most processed meats should be avoided on at least one level because they are significant dietary sources of pesticides, antibiotics and hormones which have the potential to disrupt our health. In contrast, grass-produced or free-ranging animals are not fed cereal grains, thereby potentially reducing pesticide exposure. Further, most grass-fed animals are never given hormones to increase their growth rate and rarely are routinely administered antibiotics.
They may cause cancer
Almost all processed meats typically are cooked for long periods, frequently at high temperatures. Cooking meats in this manner produces at least two cancer-causing compounds: 1) heterocyclic amines (HCAs) and 2) polycyclic aromatic hydrocarbons (PAHs).13
Further, consumption of cooked, canned and cured meats causes high levels of advanced glycation end products (AGEs) to accumulate in the bloodstream.14 As AGEs build up in higher and higher concentrations in the blood they increase the risk for heart disease,15 cancer16 and inflammation,17 a process that underlies virtually all chronic disease. If these events weren’t enough to make you shy away from eating these adulterated meats, they are also concentrated sources of oxidized cholesterol,18 a potent compound known to promote artery clogging or atherosclerosis.19
They contain nitrates
One of the original reasons scientists advised us to limit consumption of processed meats was because of their high concentration of nitrites and nitrates. These chemicals are added to salami, lunch meats, bacon, sausages and other processed meats because they inhibit bacteria which cause food-borne illnesses while also enhancing the color and flavor of processed meats.20
Many early scientific studies examining dietary nitrites and nitrates suggested that the metabolism of these compounds in our bodies produced potent cancer causing chemical called nitrosamines. Hence, consumers were advised not to eat processed meats containing nitrites or nitrates.20 This viewpoint has been challenged in the past decade by a number of researchers who suggest that dietary nitrites and nitrates are actually protective against cancer, heart disease and other illnesses.20-23 In the body, these compounds are metabolized to nitric oxide, a chemical which promotes cardiovascular health and has many other therapeutic effects.21-23
In the U.S. diet, nitrates and nitrites are not only found as additives in processed meats, but rather their greatest dietary source comes from fresh fruits and vegetables 20, 22 which are protective for cardiovascular disease, cancer and other illnesses. Hence, the available evidence suggests that the cancer causing effects of processed meats stems not from their nitrite or nitrate additives, but rather from HCA, PAH or other chemicals added to them during processing.
The bottom line
The scientific data showing that consumption of processed meats has multiple adverse health effects is persuasive, unambiguous and overwhelming.24, 25 These facts are not surprising when considered in the evolutionary light. Our hunter-gatherer ancestors had practically no evolutionary experience with these Johnnie come lately foods, and consequently, our physiological and metabolic systems have had virtually no time to overcome these food-borne toxins with genetic adaptations.
I believe that consumption of fresh, grass-produced meats under the context of a diet high in fruits and veggies (i.e. The Paleo Diet) will reduce your risk for all chronic diseases that plague western societies.
