Oils

The largest diet and health study, co-sponsored by the National Institutes of Health and the American Association of Retired Persons, followed about 545,000 people aged 50 to 71 over the course of a decade and was the first to separate out the role of fats from plant sources, such as those found in nuts, seeds, avocados, and olive and vegetable oils, versus all animal sources, including meats, dairy products, and eggs. The consumption of animal-sourced fat was significantly associated with pancreatic cancer risk, but no correlation was found with the consumption of plant fats.

Does that mean plant-based oils are appropriate for a healthy diet and we need only avoid animal-based fats?

We’ve known for nearly two decades that a single fast-food meal, such as a Sausage and Egg McMuffin, can stiffen our arteries within hours, cutting in half their ability to relax normally. And, just as this inflammatory state starts to calm down five or six hours later, we may once again assault our arteries with another load of harmful food, leaving many stuck in a danger zone of chronic, low-grade inflammation. Indeed, unhealthy meals don’t just cause internal damage decades down the road, but within hours of consumption—and the relative paralysis of our arteries for hours after eating fast food may also occur after consuming olive oil.

It’s not only olive oil, however. Other oils have also been shown to have deleterious results on endothelial function: a significant and constant decrease in endothelial function three hours after each meal, independent of the type of oil or whether the oil was fresh or deep fried. Olive oil might be better than omega-6-rich oils or saturated fats, but may still show adverse effects.

I think of oil as the table sugar of the fat kingdom. Similar to how manufacturers take healthy foods like beets and throw out all their nutrition to make sugar, they take wholesome corn and scorch-earth it down to corn oil. Like sugar, corn oil calories may be worse than just empty.

As even extra-virgin olive oil may impair our arteries’ ability to relax and dilate normally, its use should be curtailed. Cooking without oil is surprisingly easy. To keep foods from sticking, sauté in wine, sherry, broth, vinegar, or just plain water. For baking, I’ve successfully used mashed bananas or avocado, soaked prunes, and even canned pumpkin to substitute for oil to provide a similar moistness.

The information on this page has been compiled from Dr. Greger’s research. Sources for each video listed can be found by going to the video’s page and clicking on the Sources Cited tab. References may also be found at the back of his books.

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