The following studies provide evidence for the atherosclerosis-promoting effect of olive oil, in monkeys, mice, and humans:
1. Hepatic Origin of Cholesteryl Oleate in Coronary Artery Atherosclerosis In African Green Monkeys, Enrichment By Dietary Monounsaturated Fat, Journal of Clinical Investigation, 1997
“[We observed in monkeys] that the amount of coronary artery atherosclerosis was similar in the monounsaturated and saturated fat groups, in spite of the significantly improved LDL cholesterol concentration and LDL/HDL cholesterol ratio in the former.”
2. Dietary Monounsaturated Fatty Acids Promote Aortic Atherosclerosis In LDL Receptor–Null, Human ApoB100–Overexpressing Transgenic Mice, Arteriosclerosis, Thrombosis, and Vascular Biology, 1998
Mice were fed one of 6 diets with different fatty acid content: saturated, monounsaturated (cis and trans), polyunsaturated (n-3 and n-6), and a control diet.
“The reduction in aortic atherosclerosis was not found when either cis or trans monounsaturated fatty acids were fed. Rather, just as much atherosclerosis was seen when cis monounsaturated fat diets were fed as when saturated fat was fed, and significantly more atherosclerosis was seen when the trans monounsaturated fatty acids were fed.”
This is an important outcome when one considers that monounsaturated fats, often in the form of olive oil, are widely promoted as being healthful and effective for protection against heart disease.
3. Effect Of Fat And Carbohydrate Consumption On Endothelial Function, Lancet, December, 1999
“Consumption of a meal high in monounsaturated fat was associated with acute impairment of endothelial function when compared with a [low-fat] carbohydrate-rich meal.”
4. The Postprandial Effect Of Components Of The Mediterranean Diet On Endothelial Function, Journal of the American College of Cardiology, November 2000
“Contrary to part of our hypothesis, our study found that omega-9 (oleic acid)-rich olive oil impairs endothelial function postprandially.
The mechanism appears to be oxidative stress because the decrease in FMD was reduced (71%) by the concomitant administration of vitamins C and E. Balsamic vinegar (red wine product) and salad reduced the postprandial impairment in endothelial function to a similar extent (65%).
In a clinical study, olive oil was shown to activate coagulation factor VII to the same extent as does butter (44). Thus, olive oil does not have a clearly beneficial effect on vascular function.”
The major unsaturated fatty acids in olive oil are oleic acid (18:1n-9) and linoleic acid (18:2n-6) (42). A high-oleic and linoleic acid meal has recently been shown to impair FMD in comparison with a low-fat meal (28). (That’s the study above by Ong et al.)
In terms of their effects on postprandial endothelial function, the beneficial components of the Mediterranean and Lyon Diet Heart Study diets appear to be the antioxidant-rich foods—vegetables, fruits … not olive oil. Dietary fruits, vegetables, and their products appear to provide some protection against the direct impairment in endothelial function produced by high-fat foods, including olive oil.”
Clearly, olive oil is not the heart-healthy food it’s made out to be. It truly is a feat of marketing that a food which has been shown over and over to impair artery function exists in peoples’ minds as an elixir. The Mediterranean diet, with its generous portions of fruits, vegetables, and whole grains, improves health not because of olive oil, but in spite of it.
I’m no expert, clearly, but these all are rather old studies. Here’s one from 2013 that seems to suggest the opposite: http://www.ncbi.nlm.nih.gov/pubmed/22872323
This study compared two groups. One took olive oil. The other took olive oil. How do you know what not taking olive oil does? You can’t tell from this study. It didn’t have a non-olive oil control group. They admit so much in the Discussion.
This one from 2012 suggests it’s still an open question. http://www.ncbi.nlm.nih.gov/pubmed/22760979
From that paper: “Nevertheless, evidence of the potential of isolated compounds or the right combination of them to achieve the antiatherosclerotic effect of virgin olive oil is inconclusive and will undoubtedly require further experimental support.”
They are focusing on phenolic compounds. You don’t need to eat olive oil to get phenols. They are found in abundance in plant foods … fruits, vegetables, whole grains, beans and legumes, coffee and tea. All of these foods are low in fat, unlike olive oil. Fat has been shown to impair artery function.
List Of High Phenol Foods
Another suggestive 2013 study: http://www.ncbi.nlm.nih.gov/pubmed/23406576
This paper discusses phenolic compounds found in olive oil, not olive oil itself. Olive oil is a fat, 14% of which is saturated. Fat has been shown to impair endothelial function. You can get phenolic compounds in foods that aren’t oils.
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This makes perfect sense. It seems like common sense that oil has no purpose being in our blood. It’s not a natural foodvinvthe sense that it has to be squeezed out of seeds or olives. It is a modern food and an isolated ingredient. People lived with excellent cardiac health before eating oil, and sure we will without it.
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