When I am questioned about how I eat, I usually answer that I eat a whole food, plant-based, no oil diet. I actually don’t like to use the term vegan since simply being a vegan isn’t a guarantee that one has a healthy diet. After all, a can of coke and a bag of potato chips fits the definition of vegan. It is, however, a good shorthand term to quickly get across the point that I don’t eat animal products. People are usually not surprised that I don’t eat beef, chicken, fish, cheese, milk, eggs or yogurt. What really catches their attention is not using any oil. “What?”, they ask. “Not even olive oil? What about the Mediterranean diet? I thought that was healthy!”
One thing I have discovered in the three years that I have been researching nutrition is that there are many myths surrounding what constitutes a healthy diet, (see my post about the protein myth) and there are numerous political and economic agendas that perpetuate them. The idea that oils are health promoting is one of the myths that I have discovered. I am not licensed to give nutritional advice. I am speaking from only my own experience and passing along some of the information that I have gathered in order to make decisions about my own health. There are a number of reasons I believe consuming oil is not health-promoting, including:
Oil is not a whole food. It was once a whole food that has had all of the nutrients stripped away. No more proteins, carbohydrates, vitamins, and minerals or fiber, just extracted fat calories.
Oil has too many unnecessary calories. At 9 calories/gram, oil has more than twice the caloric density of protein or carbohydrates. The only diets so far proven to reverse heart disease (Dr. Esselstyn and Dr. Ornish) include only 10% calories from fat . If average caloric requirements are 3000/day for men, and 2000/day for women (on the high side), a diet of 10% fat intake would allow for 33g/day for men and 22g/day for women. Do the math. A tablespoon of oil has 120 calories, or 13g of fat, just for reference. Staying under 10% fat is difficult enough to achieve with fat from meat and dairy in the diet, and added empty calories from oil just make it more difficult.
All oils (even olive oil!) contain saturated fat which injures the endothelial lining of the arteries. It is this lining that produces nitric oxide, the powerful vaso-dilator that widens and relaxes arteries so that they can carry more blood throughout the body. How quickly does the damage occur? Several studies have been conducted where subjects were fed a high fat meal and a tourniquet was applied to their brachial artery. Then ultrasound was used to measure the artery’s ability to rebound. The impairment of blood flow could be seen within hours and lasted for at least 4 hours after the meal. And, the food that impaired flow the worst (31%)? Olive oil.
OK, so what about the Mediterranean diet? The “original” Mediterranean Diet study was the Lyon Diet Heart Study. This was the one that really put olive oil on the map as being heart-healthy. Here is an interesting bit of trivia: how many of you know that the oil used in the (Lyon) Mediterranean Study was not olive oil? The study subjects were given canola oil, not olive oil!
There really is no one Mediterranean diet, as the countries surrounding the Mediterranean include Croatia Spain, Morocco, Italy, Greece, Portugal, and Cyprus. The diets of these countries are quite different. The Lyon study was structured to mimic the post war diet of Crete. This was a diet high in consumption of fruits and vegetables, low consumption of meat and fish (especially compared to the American diet) and consumption of olive oil and red wine. (What seems to have dropped out of the discussion of the Cretans is that they walked, on average, 8-9 miles/day).
Researchers reported that the Mediterranean-style diet followers were doing dramatically better than the control group, which followed a diet similar to the American diet. They were 50-70% less likely to experience all cardiac ailments, from minor to major such as heart attack and death. Sounds impressive, until the study is viewed from the perspective that 1 in four (25%) of the Mediterranean diet followers had either died or had a new cardiovascular event. That is not such an impressive statistic. Sure, they did better than the control group. But the control group diet, with about 34% fat, was anything but healthy. This is a little like cutting cigarette smoking from a full pack a day to 1/2 pack. Sure, you’ll see some improvement, but could you do better? Incidentally, for those of you thinking that Greeks still are healthy, it may surprise you to know that Greece has some of the highest obesity rates in the world. The olive oil is probably not helping!
Olive oil contains more than one kind of fat. As you probably already know, olive oil has monounsaturated fat. But it also has 14-17% saturated fat, the same as meat. It causes heart disease to progress at the same rate as saturated fat, as shown by angiograms in this study. Those that want to promote the health benefits of olive oil make a big deal about research showing that good(HDL) cholesterol is raised, and bad (LDL) cholesterol is lowered by olive oil. What they don’t tell you is that autopsies have shown no difference in the development of cardiovascular disease with use of monounsaturated vs. saturated fat. Better numbers don’t necessarily lead to better health. (There are some studies on monkeys (who metabolize fats similarly to humans) on the Pritikin site that discuss this.)
Basically, it come down to this for me: I am trying to get the most nutrient-dense foods in my diet, and olive oil just doesn’t have a nutrient dense profile. If I want the nutrients that olive oil has, I’ll just eat olives!