The Paleo Diet - Loren Cordain [10]
• Monounsaturated fats are good. They’re found in olive oil, nuts, and avocados; are known to lower blood cholesterol; and help prevent artery clogging or atherosclerosis.
• Saturated fats are mostly bad. They’re found in processed meats, whole dairy products, and many bakery items; most of them are known to raise cholesterol. A key exception is a saturated fat called stearic acid, which, like monounsaturated fats, lowers blood cholesterol levels.
• Polyunsaturated fats are a mixed bag—some are more beneficial than others. For example, omega 3 polyunsaturated fats (the kind found in fish oils) are healthy fats, which can improve blood chemistry and reduce your risk of many chronic diseases. But omega 6 polyunsaturated fats (found in vegetable oils, many baked goods, and snack foods) are not good when you eat too much of them at the expense of omega 3 fats.
People in the Paleolithic Age ate a lot of monounsaturated fats; they had saturated and polyunsaturated fats in moderation—but when they did have polyunsaturated fats, they had a proper balance of the omega 3 and omega 6 fats. They consumed far fewer omega 6 polyunsaturated fats than we do today. In addition, the main saturated fat in wild animals was healthful stearic acid, not the cholesterol-raising palmitic acid, which dominates the fat of feedlot cattle.
How important are fats in the diet? Here’s a modern example: People who live in Mediterranean countries, who consume lots of olive oil, are much less likely to die of heart disease than Americans or northern Europeans, who don’t consume as much olive oil. Instead, our Western diet is burdened by high levels of certain saturated fats, omega 6 fats, and trans fats and sadly lacking in heart-healthy, artery-protecting omega 3 fats.
Our studies of hunter-gatherers suggest that they had low blood cholesterol and relatively little heart disease. Our research team believes that dietary fats were a major reason for their freedom from heart disease.
Saturated Fats, Reconsidered
In the first edition of The Paleo Diet, I was adamant that you should avoid fatty processed meats such as bacon, hot dogs, lunch meats, salami, bologna, and sausages because they contain excessive saturated fats, which raise your blood cholesterol levels. That message still holds true today, but new information subtly alters this fundamental point of Paleo Dieting, and, as always, the devil lies in the details. Should you now go out and eat bacon and processed meats to your heart’s desire? Absolutely not! Processed meats are synthetic mixtures of meat (muscle) and fat combined artificially at the meatpacker’s or butcher’s whim, with no regard for the true fatty acid profile of wild animal carcasses that our hunter-gatherer ancestors ate. In addition to their unnatural fatty acid profiles (high in omega 6 fatty acids, low in omega 3 fatty acids, and high in saturated fatty acids), processed fatty meats are full of preservatives such as nitrites, which are converted into potent cancer-causing nitrosamines in our guts. To make a bad situation worse, these unnatural meats are typically full of salt, high-fructose corn syrup, wheat, grains, and other additives that have multiple adverse health effects.
So, artificially produced, synthetic, factory meats have little or nothing to do with the wild animal foods our hunter-gatherer ancestors ate, and they should be avoided. But how about the unprocessed fatty meats that we routinely eat, day in and day out, that are produced in feedlots and butchered without adding fats or preservatives? These are meats such as T-bone steaks, spareribs, lamb chops, and chicken legs and thighs, as well as fatty cuts of pork and other fatty domestic meats. Are they a problem?
I realize that many, perhaps most, readers are not hunters and have never seen carcasses of wild animals, such as deer, elk, or antelope. Nor have you had the opportunity to visually contrast the carcasses of feedlot-produced animals to wild animals.