July 04, 2008
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Is Olive Oil the healthiest fat? In a word, no! It's a better fat, but not the best one.
-Dr. Dean Ornish-
Contrary to our hypothesis, our study found that omega-9 (oleic acid)--rich Olive Oil, impairs endothelial function after eating. If you've been using olive oil because you think it's healthy, it's time to think again.
-Dr. Robert Vogel-
This is so disappointing. I've been dipping my whole grain bread in extra virgin olive oil & balsamic vinegar and feeling "oh so virtuous"--as I soaked up every last drop of oil on my plate. Olive oil is essentially the only fat I eat & cook with. I love the stuff!
Finding out that olive oil is bad makes me feels the same as when I found out that the tooth fairy & Santa Claus were made up stories.
Truth be told--this isn't the first time I've heard this. It's just that now it's finally soaking in--just like olive oil on bread. About 4 or 5 years ago at a Grand Rounds on the benefits of a plant-based diet held at my medical center, I asked one of Dr. Esselstyn's proteges if olive oil is finally on the OK list--now that we know how healthy the Mediterranean Diet is for us.
"Absolutely not!", he said. "Olive oil, like any fat causes inflammation and harms blood vessels. The research is out there. No one is listening. No oil--no olive oil!" Needless to say, I ignored what he had to say.
"Rigid, inflexible vegetarians. How come Dr. Walter Willett of Harvard says it's good for us? What about the Lyon Diet Heart Study? And besides, it makes food taste so good," I thought to myself.
Last March when Dr. T. Colin Campbell spoke at my hospital's Wellness Grand Rounds, I decided to ask Dr. Campbell what he thought about olive oil and nuts. I just knew they had to be good for us.
"I'll let Dr. Esselstyn, who is here answer that question. He's the expert on oil & nuts." replied Dr. Campbell.
"Olive oil has been shown to injure the blood vessel's endothelium (lining). Walnuts are OK-but not if you already have heart disease. You know, here's what I've discovered. If you tell someone with heart disease that walnuts are OK, before you know it they have a bowl of nuts on their coffee table, a bag of nuts in their car and on and on. Nuts are full of calories--which is the last thing you need to eat when you're trying to lose weight. I advise my patients against eating nuts for this very reason.", Dr. Esselstyn said.
I heard what he said--but somehow it didn't apply to me. Until June 25th, when I heard Esselstyn speak on NPR's affiliate station, WCNP's Sound of Ideas about "Eradicating Heart Disease".
Here's Why You May Want to Think Twice About Olive Oil
From Dr. Dean Ornish: It's 100% fat and 14% of it is saturated. At 120 calories a tablespoon it's very easy to eat too much of "a bad thing". It won't raise your LDL as much as butter or other saturated fats will, so it might look like it's reducing your cholesterol, but it's still raising it. It's just not raising it as much other fats would! It's the omega-3's that reduce inflammation and are "heart healthy", and olive oil has very little omega-3, maybe 1%. It's mostly omega-9, which has been shown to impair blood vessel function. Canola and flax seed oil are much higher in omega-3's--and are much healthier oils to use. Just go easy on them!.
From Dr. Robert Vogel of the University of Maryland: This is the study that convinced me! Back in 2000 Vogel based his study on the Lyon Heart Study, which is the big-time study that got us all to eat the Mediterranean Diet. He wanted to see how olive oil, salmon (fish oil) and canola oil actually affect the blood vessels. Using the brachial artery tourniquet test he had 10 healthy volunteers with normal cholesterol ingest 50 grams of fat, in the form of olive oil & bread, canola oil & bread, and salmon. Measuring their arterial blood flow before & after each meal Vogel could tell whether or not a meal was causing damage to the endothelial lining of the brachial artery, based on how the blood was flowing through the artery after the meal was eaten. The results really surprised him. The olive oil constricted blood flow by a whopping 31% after the meal; the canola oil constricted it by 10%; and the salmon reduced it by only 2%. Why should we care?
Because when the arteries constrict, the endothelium (the vessel's lining) is injured, triggering plaque build-up, or atherosclerosis. Vogel RA. Corretti MC. Plotnick GD. The postprandial effect of components of the Mediterranean diet on endothelial function. Journal of the American College of Cardiology. 36(5):1455-60, 2000 Nov 1. Similar results have been found it later studies. This isn't just a one-hit wonder. Interestingly, walnuts, which have Omega-3's have also been shown to improve blood flow by 24% using the brachial artery tourniquet test. Go omega 3's!
How does olive oil constrict blood vessels?: Dr. Vogel discovered back in 1999 that a high fat meal blocks the endothelium's ability to produce that all important NITRIC OXIDE, which is a vasodilator and critical to preserving the tone & health of our blood vessels. When olive oil constricts the blood vessels it's because it's blocking the production of nitric oxide. Not a good thing!
From Dr. Lawrence Rudel of Wake Forest University Baptist Medical Center: Rudel ran a five year study feeding olive oil and saturated fat to African Green monkeys. The monkeys metabolize fat in the same way as humans, so they're good stand-ins.. At the end of five years, their autopsies showed that the monkeys who were fed olive oil had higher HDLs (the good cholesterol) and lower LDLs (the bad cholesterol) than the ones fed the saturated fat diet. The big surprise here: Both groups had exactly the same amount of coronary artery disease. The higher HDLs & lower LDLs of the olive oil group were meaningless. Rudel later repeated the study on rodents, and got the same results.
From Dr. Caldwell Esseltsyn: Dr. E tells a story in his book about Rev. William Valentine of North Carolina who had a quintuple bypass in 1990. Since his surgery he followed a strict plant-based diet, dropping from 210 pounds to 156 pounds. For 14 years he maintained his weight & his diet. But by 2004 he started to experience a recurrence of angina, especially when he exercised. He promptly contacted Dr. Esselstyn after reading about his success in reversing heart disease in a health newsletter. Valentine wanted no part of a repeat bypass or other intervention. He assured Dr. E that he only ate whole grains, legumes, vegetable & fruit. A baffled Dr. E prompted him to repeat once again everything he was eating, leaving nothing out.
"He had forgotten to mention that he was consuming "heart healthy" olive oil at every lunch and dinner and in salads. It was what they call a Eureka moment. Immediately, I advised him to give up the olive oil. He did--and within seven weeks, his angina had completely disappeared." Dr. Esselstyn
Little known fact: Olive oil, which got its big "heart healthy" start with the Lyon Study, wasn't even used in the study. The study volunteers didn't like the taste of it, so canola oil was substituted for olive oil. All the benefit that we attributed to olive oil, was actually from Omega-3 enriched canola oil.
What does Dr. Dean Ornish advise?: The best oils are canola, fish oil (omega-3s), flaxseed oil & nonstick cooking sprays. Always in small amounts. Second best, and in very small amounts, is olive oil.
What does Dr. Caldwell Esselstyn advise?: When it comes to olive oil, canola or any oil--FORGET ABOUT IT. He does advise taking a tablespoon of flaxseed every day for omega 3's.
What Am I Going to Do? Olive oil--forget about it, except in tiny amounts. (at least I say that right now) I admit it, I was using way too much of the stuff, and consuming far too many unhealthy calories than I needed. I thought that because my HDLs were so high I was in good shape. Just like the African Green monkeys, the olive oil could have been raising my HDLs, while all the while plaque was forming in my arteries. Still mulling over a bigger move in the direction of a vegan goody-goody. Except, of course, when I'm invited out!
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