Which Olive Oil is Healthiest?

By now, everyone knows that olive oil is healthy. We may not know why or in what way, but we know that if we're going to be eating it for our health, we want to choose the one that is healthiest. Here's what you need to know about the potential health benefits and which oil is healthiest.
All oil from olives is composed of monounsaturated fat, which is the best kind of fat to eat. If your only criteria for the relative 'healthiness' is monounsaturated fat composition, then any grade will do. From the lowest grade (pomace) to the highest (extra virgin), all contain monounsaturated fat and will serve your needs.

 But if we don't stop there, if we seek to exploit the oil's potential to increase health in several ways, then the differences become apparent. As far as relative 'healthiness' is concerned, one cannot judge by grade. An extra virgin oil is not necessarily healthier than plain virgin. The 'virginity' is based on basically one criterion: the acid level. The lower oleic acid, the higher grading the oil attains, with extra virgin oils having lower than 1%. But the acid content is irrelevant to the health benefits. Aside from being composed of monounsaturated fats, it can also contain phytochemicals which contribute health benefits.

Phytochemical is a catch-all term meaning non-nutritive plant chemicals that have protective or disease preventive properties. Non-nutritive means they are not carbohydrates, fats, or proteins. But that doesn't mean they don't have a powerful effect on our health. One phytochemical in fresh oils that has proven health benefits is oleocanthol.
Oleocanthol has been shown to have a mild painkilling effect, and also acts as an anti-inflammatory. While one cannot replace their painkillers with olive oil, daily intake of oil containing oleocanthol can, over time, limit damage caused by chronic inflammation. Therefore, the answer to the question 'which olive oil is healthiest' is this: the healthiest one has the highest level of oleocanthol.
Unfortunately, oleocanthol levels are not listed on labels. But we can tell whether an oil contains oleocanthol by tasting. Oleocanthol is the component responsible for the peppery bite, and produces a stinging sensation in the throat. This bite is why it combines so well with bread or cheese, because they produce a nice contrast of sensations.

Those same phytochemicals are suspected to be responsible for the oil's known effect to reduce blood pressure and increase HDL (high density lipoprotein) cholesterol. HDL is the good cholesterol and raising HDL levels reduces risk of heart attack and stroke.
In addition to all of that, blood vessels in people who consume oil with high polyphenol (a group of phytochemicals) levels are shown to have more 'elastic' blood vessels, which is good for overall heart health and circulation.
Lastly, consumption of this natural oil together with tomatoes has been shown to protect against sunburn and decrease wrinkles. The exact action is unknown, but researchers suspect that the phytochemicals in fresh oil from olives are responsible. Long term consumption reduced sunburn tendency by 30% and increases 'pro-collagen' in the skin. Loss of collagen is responsible for the development of wrinkles.

So, what's the downside? All oils are made of fat and highly calorie dense. While fat is part of a healthy diet, a high fat diet can make it difficult to maintain a healthy weight. So, one must replace the unhealthy fats with healthy fats rather than just adding more fat to the diet to really gain all the benefits. Some good suggestions are to reduce meat intake, eat vegetables and bread with oil instead of butter, and reduce use of dairy products.

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