Long before the dawn of agriculture, our ancestors spent 2.5 million years fine-tuning their metabolism and collective physiology to an opportunist’s diet that included everything from found or hunted meats and seafood to plants, insects and perhaps an occasional spot of honey. No doubt early humans feasted on plenty of leafy greens, nuts and other seeds as well as high-quality animal proteins and fats, all of which were loaded with vitamins, minerals and essential fatty acids. Our scavenger predecessors would’ve likely raised their eyebrows at shortening, margarine and other processed vegetable and animal fats, and likely even at breads, cakes and cookies.
A lot has happened to the human diet since then.
About 10,000 years ago, humans developed agriculture and discovered it was possible — even desirable — to settle in, tend the land, develop the mind, create art and populate the Earth. In living this new, good life, our diet shifted from that of the widely diverse hunter-gatherer’s to one consisting of more fats, dairy products, grain-derived carbohydrates and sugars from cultivated fruits.
Now, fast-forward to the 1950s, when the U.S. food industry was beginning to take off, already capitalizing on cheap fossil fuels and cheap raw materials from the farm that were about to become a lot cheaper thanks to astronomical government subsidies. Rather than producing meat, eggs and dairy products from animals raised on pasture and supplemented with grain, the United States shifted to livestock production systems that removed animals from pasture and fed them much higher quantities of grain. That swap caused some big changes in the composition of the fats from those animals.
In 1956, nutrition scientist Ancel Keys drew the spotlight to the lipid hypothesis, which held that a high-fat diet — particularly one high in saturated fat — contributed to high cholesterol, which in turn led to heart disease in the form of plaque buildup in the arteries. Following suit, the food industry, medical community and media all jumped on the low-fat bandwagon, vilifying saturated fats (mostly animal fats) and promoting vegetable fats and low-fat diets. Interestingly, at the time, plenty of money stood to be made in processing cheap vegetable oils into their solid, hydrogenated forms to then be used in making cheap, processed foods — far more money than could be made in marketing traditional animal fats.
Cut to the present, and the idea that corn, soy and other vegetable oils are preferred for optimal health continues to be dominant, yet the United States still has high rates of cardiovascular disease. We are overweight and unhealthy despite five decades of low-fat and no-fat health advice and faddism. How could the medical community, our Food and Drug Administration and so many others be so wrong about dietary fats? To untangle this mess — which involves shunning the widely held nutritional belief condemning saturated fats — let’s go back to basics.