Preventive Medicine: Ode to olive oil

My wife and I are recently back from co-hosting an Oldways-sponsored culinary travel adventure through Sicily. We ate, we drank, we toured, we made friends, we saw the dual beauties of nature and ancient civilization, and then — inevitably — we ate and drank some more. The trip and the cuisine were both memorable in many particulars, but I will focus here on one: olive oil. We experienced olive oil as only the true artisans of the craft can make it.

I did not become anything like an expert; I only really learned enough to know what a delight the world’s best olive oils can be. I recognize great olive oil when I taste it, and I love it. Primarily, that’s why I eat it. The right olive oil playing the right role — whether in sauce or sauté, salad dressing or for dipping bread — enhances a meal.

I am, as well, a strong proponent of its nutritional properties, and role in an optimal diet. Olives and olive oil are prototypical of the famously healthful, traditional Mediterranean diet, and among the key anatomical features of that dietary pattern to which favorable health effects are attributed.

The contributions of olive oil to the good health outcomes that matter most — freedom from chronic disease, vitality, and longevity — warrants some discussion, because there are colleagues I respect, and with whom I agree about much, who differ with me here. Among my friends are some who advocate not only for a plant-exclusive (vegan) diet, but such a diet with no added oil and low in total fat. I have heard them argue that olive oil is “bad” for health, and cite studies to validate the claim.

Olive oil consumption in dietary context is strongly and consistently associated with health benefit. How, then, can any credible expert argue it is harmful? There are isolated studies in which putative harms to endothelial function (a measure of blood vessel behavior and blood flow) were shown with olive oil ingestion, likely because of the dose of oil administered, the nature of the oil used, or both. In general, olive oil intake has been associated with improved endothelial function. To put such conflicting findings in context, exercise is also consistently associated with improved endothelial function, and better cardiovascular health — but isolated studies have shown endothelial dysfunction with exercise, comparably related to “dose” (intensity of exercise), and timing of the measures.

I have other colleagues, again with whom I agree about most things diet-related, who feel so strongly that unsaturated fat is the key to good nutrition that they consider it essential. Well justified enthusiasm for the Mediterranean diet can lead to guidance implying it is the only right way to eat for health, and that olive oil is an essential part of an optimal diet. That’s excessive in the other direction. The Tsimane don’t consume olive oil, and have perhaps the world’s most pristine coronary arteries. The traditional Okinawan diet is low in total fat, and olive oil free, but associated with the same great bounty of years in life, life in years as the Mediterranean diet. So, too, is the low-fat vegan diet among the Seventh Day Adventists.

My view is, predictably perhaps, in between. I am convinced a diet does not require olive oil (or one of the rarefied, rival oils) to be optimal; and equally convinced that an optimal diet certainly allows for good olive oil and may benefit from it. There is, obviously, more than one way to eat badly; there is more than one way to eat well, too. The health effects of virtually any food will depend on its specific preparation; the dose; what it is replacing; and its situation in the balance of the overall diet.

Olive oil in general is exceptionally high in healthful monounsaturated fat (oleic acid), and low in omega-6 linoleic acid (we generally overconsume omega-6 fats, and there are potential harms linked to that). The variety that figures in traditional diets, that is widely regarded as most delicious, and to which health benefits are reliably attached is “extra virgin.” This refers to oil pressed from freshly picked olives, under cool temperatures, without the use of any chemicals. Extra virgin olive oil (EVOO) preserves not only the fatty acids native to the olive, but antioxidant nutrients as well. It has fairly good heat tolerance, and holds up perfectly well for sautéing, but not for deep frying.

I want pleasure as well as health from food, and fine olive oil contributes to both in my opinion. It’s a staple in the Katz kitchen. In your kitchen, the choice, of course, is entirely up to you.