Olive Oil: What's the Best Kind?December 01, 2006
Olive Oil: What's the Best Kind?
Competency # 13 Fats; #20 Culture: Lifestyles of the Long-Lived Reference: Covas, et al Annals of Internal Medicine, Sept 5, 2006 145:(5)
We know that olive oil is good for you. It's the main fat in the Mediterranean Diet (MD). Greek men, living prior to 1950, had 10% of the heart disease incidence we have today in America. It has been repeatedly shown in the last two or three years that MD with its inclusion of olive oil to some 30-35% of total calories is a great strategy for improved health. There are lower incidences of coronary artery disease.
America went on a low-fat binge for the last 30 years and avoided all oils, much to our detriment. Now the question is asked, what is it about olive oil that makes it so good? The main oil is oleic acid, which is a mono-unsaturated fat. But there are dozens of other subcomponents and thousands of minor components in olive oil. Do the others help? And do they vary by kind of olive oil?
And the answer now is YES! This research article shows how. Extra virgin olive oil is the easiest stuff to get. It comes from the first pressing. It has more compounds called phenolic acids. Those compounds gradually decrease with each pressing of the olives. The regular old discount, cheapy stuff has much less phenolic acid content. The extra virgin has 366 mg per liter of phenolic acid. The regular least pressed had only 2.7 mg. That's about 1% of the extra virgin content.
The study took 200 men and had them eat 25 mls (about a tablespoon) of extra virgin versus regular versus blended oil for three weeks. The researchers then looked at all the biomarkers of inflammation in the volunteer's bodies. What they were most interested in were the markers of oxidative stress. Oxidative damage to lipids decreased in a linear fashion with the increase in phenolic acid content.
The fancy items they looked at were called conjugated dienes and hydroxy-fatty acids. Those things change the shape of your LDL cholesterol and help them get into the white cells in your artery walls. That's what ends up being plaque. And it's plaque that ends up causing artery damage by way of heart attack and stroke. We've followed the line of evidence back from heart attacks all the way to its source. The whole food called olives in its least refined form, extra virgin olive oil has this tiny percentage of its content called phenolic acid. And that tiny segment has a huge impact on your body. It's not just the oil, but the antioxidants in the oil. Phenolics are also present in green tea and cocoa. Antioxidants matter!
WWW: What will work for me? Extra virgin olive oil. Not the Sam'sClub 5 gallons for $ 5 stuff. It's been over-squeezed. Though it has the right oil, it's lost 99% of its phenolic acid, and that turns out to be an important component. I'm going to be an olive oil snob and get the extra virgin stuff. I'm going to have more salads for supper instead of red meat. And when I go through that buffet line at the Christmas Party, I'm going to take a few olives to make up for the cheesecake. If you want to really be an olive snob, check out the olive bar at Whole Foods. Amazing place.
This column was written by Dr. John E. Whitcomb, MD, Brookfield Longevity, Brookfield, WI, (262-784-5300)