Exploring the sense and nonsense of food and health

Extra Virgin Olive Oil – EVOO

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Olives in olive oil.

Image via Wikipedia

What is it about the Mediterranean Diet that has time and time again conferred health benefits to the cultures that surround this area as well as a plethora of research studies that find its positive effects on health?

Most of the original data about the Mediterranean diet came from the island of Crete. Epidemiological studies observed the low rates of heart disease and some cancers and the high life expectancies in  Crete as well as the surrounding regions of Greece, southern France, Italy and Spain.

The description of the typical “low-risk coronary male” found on the island of Crete was noted by Henry Blackburn, M.D of the University of Minnesota Division of Epidemiology.

“He is a shepherd or small farmer, beekeeper, or fisherman, or a tender of olives or vines.  He walks to work daily and labors in the soft light of his Greek isle…….

His midday, main meal is of eggplant, with large livery mushrooms, crisp vegetables and country bread dipped in the nectar that is golden Cretan olive oil.  Once, week, there is a bit of lamb, naturally spiced from sheep grazing in thyme-filled pastures.”  Henry Blackburn, M.D.

Is olive oil the magic ingredient of the Mediterranean diet?

For centuries, people of the Mediterranean region have used this golden nectar by cooking with it, dipping their bread in it, dressed their salads with it.  Based on legend, Greeks, in particular even drank a cup of it before breakfast.

Americans are now trying to emulate the healthy effects of the Mediterranean diet by using olive oil instead of other vegetable oils. Most restaurants now provide bread with olive oil dipping sauce, although we don’t know if they all use the extra virgin kind.  More on that later.

So what can it do for us?  Olive oil first of all contains compounds called phenols that are great antioxidants.  Most of the fatty acids in EVOO are monounsaturated fats called oleic acid.  Monounsaturated fats are now part of the fats we call “healthy fats” since it lowers LDL cholesterol and raises the HDL cholesterol.  Corn oil on the other hand contains linoleic (a polyunsaturated fatty acid) and even though it too lowers LDL, it can also lower HDL.

EVOO significantly lowered blood pressure in those people with hypertension when compared with equal amounts of sunflower oil.

It is thought that EVOO makes nitric oxide more available to the arteries and keeps them more dilated or open.

Olive oil also contains a phytochemical called squalene that has shown some evidence of inhibiting tumor formation in lung, pancreas, and breast cancers.

A recent randomized, double-blind, crossover design study fed two virgin olive oil-based breakfasts to 20 patients with metabolic syndrome– one with high phenolic compounds and one with low phenolic compounds. All subjects also ate a low-fat, carbohydrate-rich diet during the study period.

Analysis showed that the olive oil influenced the expression of 98 different genes (i.e. turned the genes off or on) when the phenol-rich olive oil was compared with the low-phenol olive oil.  Many of these genes seemed linked to obesity, altered lipid metabolism, and type 2 diabetes as well as inflammatory processes. Bottom line – olive oil rich in phenols were able to repress expression of several pro-inflammatory genes.   This may help to explain how olive oil can affect a lower risk of heart disease through gene expression. There is some evidence that olive oil can protect against the development of colon cancer.  A previous post may shed some light on diet and gene expression.

All these effects are best shown with extra virgin first-press which give you little processing of the oil.  This conserves the antioxidants, fatty acid, and vitamins found there.  The oil is separated without the use of heat, hot water, or solvents and it is not filtered.  The first pressing yields the best of the lot.  Seek this out – it’s more expensive, but well worth the price if this oil pans out to be as healthy as it appears.

The Mediterranean diet may be one of the healthiest in the world, but many people of this region are changing their healthy ways.  Meat is becoming more prevalent.  They still use olive oil, but other more processed oils are creeping into the food supply.  When countries change to a more “Western” diet, heart disease and other chronic disease risks also change to more dangerous higher rates.

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One thought on “Extra Virgin Olive Oil – EVOO

  1. Pingback: Olive Oil: A Natural Painkiller? « From the Flight Deck

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