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All, Like Michael, I've got a huge backlog of posts I want to get to, and unlike Michael, I'm actually planning to get to them all. So I'm going to try to keep this one short. We'll see how that works out... OK - I admit brewing olive oil is a strange idea, and really a misnomer. The title is an allusion to a similar thread about chocolate/cacao - So Why Don't We Brew Our Chocolate? Brewing chocolate, instead of eating it, is a practice I've engaged in since that thread began in November, in order to get the health-promoting phytonutrients in cacao without the calories, refined sugar, saturated fat or heavy metals (e.g. cadmium) that chocolate products generally contain. Now, in researching this recent post for the cold exposure thread about the ability of extra virgin olive oil (EVOO) and olive leaf extract (OLE) to promote beneficial thermogenesis and the browning of white fat, I realized the same argument about brewing vs. eating can and perhaps should be made for olive polyphenols that I made for cacao polyphenols in the brewing chocolate thread. As we all know by now, EVOO may be one of the keys to the health benefits of a Mediterranean diet, although it's merits relative to nuts & seeds is a perennial topic of debate on these forums. I personally come down on the side of nuts & seeds. But one thing I believe everyone can agree on, is that, while the MUFA in EVOO is relatively harmless compared to other forms of fat, the real reason EVOO is considered healthy are all the polyphenols it contains. In fact, I'd go so far as to say Michael (and other extremely health conscious individuals) wouldn't touch refined olive oil (without the polyphenols but with the MUFA) with a 10-foot pole - the polyphenols are that critical to EVOO's benefits. So if it's all about the polyphenols, why can't we get them without all the fat and calories of EVOO? It seems to me that we can, and in a form not much different in degree of refinement than EVOO. How you ask? Sure, we could eat olives. In fact store-bought olives have about 400mg/kg total polyphenols [1], higher than the minimum level Michael insists on for his high-quality, high-polyphenol EVOO (350 mg/kg). So if you aren't worried about the salt, store-bought olives might be a better option for getting your olive polyphenols, since kg-for-kg, calorie-for-calorie, and certainly dollar-for-dollar, they are a much better source of polyphenols. But before you go out and raid the antipasto bar at your local supermarket, one other potential shortcoming of olives is the fact that olives appears to maintain the same (or better) total polyphenol content as EVOO, the curing process used to debitter olives shifts which polyphenols are present. In particular, curing reduces the (bitter tasting) polyphenol oleuropein which is high in fresh olives (and high-quality EVOO), and replace it with two other derivative polyphenols, hydroxytyrosol and tyrosol. I'm not totally sure if this polyphenol shift is a step down or a step up, but it certain is a change, and most of the evidence for benefits of EVOO seem to point to the oleuropein (see below). So eating olives isn't the equivalent of eating EVOO, in terms of polyphenols (or salt or fat, obviously). So is there a better alternative to EVOO and olives that can provide the same (or higher) total polyphenol content, and in the same ratio as demonstrably healthy high-quality EVOO? Unfortunately, raw, uncured olives don't seem to be available, at least not on the biggest store in the world (Amazon). Anyone ever eaten them fresh off the tree? I bet they taste really bad. But there may be a better alternative, in the form of olive leaves and olive leaf tea. Now would be a good time for anyone who hasn't read it to check out my recent post to the cold exposure thread about how olive polyphenols turn white fat cells to brown/beige, increasing thermogenesis, insulin sensitivity, SIRT1 and AMPK as additional nice side effects. In short, olive polyphenols cured what ailed these white fat cells. But what really caught my attention about that study (PMID 27303302), was the method they used to obtain the olive polyphenols. They took fresh picked olive leaves, dried them, soaked them in hot (80 °C) water for 24 hours, strained out the leaf solids, and then concentrated the resulting liquid by removing much of the water. to create Olive Leaf Extract (OLE). In short, they made a tea from olive leaves, which they and others call Olive Leaf Extract (OLE). How do the polyphenols concentration and ratio in OLE compare with high-quality EVOO? The details are in that post, so I won't repeat them here. But to summarize, unlike cured olives, but like EVOO, Oleuropein was the most abundant polyphenol in OLE, along with (apparently) all the other major polyphenols in EVOO. So how much polyphenols are there in OLE? The authors of that study found their olive leaf tea concentrate (OLE) contained 40mg of total phenolics per gram. That equates to 40,000mg/kg (40g/kg) of polyphenols, or about two orders of magnitude higher concentration of polyphenols in the OLE than in Michael's top-notch olive oils or in cured olives themselves. So OLE, at least the way these researchers prepared it, is pretty potent stuff - a little goes a long way! So what about benefits of OLE vs. EVOO? As I discussed in detail in the cold exposure post above, OLE appears to boost BAT activity both in vitro and in vivo, just like EVOO. It looks like the polyphenol oleuropein, rich in EVOO and especially rich in OLE, is where the cardioprotective and neuroprotective effects come from [3]. LEF has a good review article with references to all the benefits of OLE and oleuropein, including improvements in blood pressure, arterial health, brain health, diabetes risk, cancer risk, and arthritis. But you might be saying - I like to eat whole foods, and olive leaf extract doesn't seem to qualify. Obviously EVOO, even of highest quality, isn't a whole food either. In fact, EVOO and OLE are quite similar, except the former has a lot more fat. And clearly green tea, coffee, or cocoa powder aren't whole foods either, but people around here generally consider them quite healthy. You may be saying by now "OK Dean, you've piqued my interest. How can I get my hands on some of this OLE stuff?" Not surprisingly, LEF and other nutraceutical vendors sells it in capsule form. For $0.36, one LEF OLE capsule contains 80mg of oleuropein among other polyphenols, the equivalent amount in about 200ml of the very highest quality EVOO, according to this table. That amount of high-quality EVOO will cost you about $8, and 1800 calories. Seems like a pretty good bargain to me... For those of you (like me) who'd rather not get your nutrition from pills if you can help it, you can buy dried olive leaves inexpensively in whole or powder form, for making tea. One benefit of being so busy posting about other topics, is that this post about OLE was delayed for a few days since I made the post over on the cold exposure thread which brought OLE to my attention. That gave me time to put my money where my mouth is, by ordering, receiving and testing out the Frontier organic whole olive leaf powder linked to above. All I can say is that if oleuropein is what makes EVOO and OLE bitter (and healthy), this stuff has a lot of oleuropein! Eating even a tiny pinch straight is not pleasant - to put it mildly. Fortunately as we saw above, it doesn't take much. I'm now adding just a pinch per day of olive leaf powder to my coffee/tea/cacao concoction, which has enough flavors in it that I don't even notice the OLE's unpleasant taste. Plus by cold brewing it overnight, warm brewing it briefly in the morning, and filtering the heck out of it, I'm eliminating any nastiness left in the solids. The powder I purchased are supposed to be from organic olive leaves, but who knows... Just like with cadmium from the soil in cacao, lead in tea leaves etc. In summary, if you are interested in the benefits of the highest quality olive oil, without the financial or calorie burden, you might seriously consider olive leaf extract or olive leaf tea as alternatives. I'm curious, has anyone else tried olive leaf products, and if so (or even if not), what do you think? --Dean --------- [1] J Agric Food Chem. 2004 Feb 11;52(3):479-84. Effect of cultivar and processing method on the contents of polyphenols in table olives. Romero C(1), Brenes M, Yousfi K, García P, García A, Garrido A. Author information: (1)Food Biotechnology Department, Instituto de la Grasa (CSIC), Avenida Padre García Tejero 4, Seville, Spain. Full text: http://sci-hub.cc/10.1021/jf030525l Polyphenols were determined by HPLC in the juice and oil of packed table olives. The phenolic compositions of the two phases were very different, hydroxytyrosol and tyrosol being the main polyphenols in olive juice and tyrosol acetate, hydroxtyrosol acetate, hydroxytyrosol, tyrosol, and lignans (1-acetoxypinoresinol and pinoresinol) in oil. The type of processing had a marked influence on the concentration of polyphenols in olive juice and little on the content in oil. The analyses carried out on 48 samples showed that turning color olives in brine had the highest concentration in polyphenols ( approximately 1200 mg/kg), whereas oxidized olives had the lowest ( approximately 200 mg/kg). Among olive cultivars, Manzanilla had a higher concentration than Hojiblanca and Gordal. The type of olive presentation also influenced the concentration of polyphenols in olives, decreasing in the order plain > pitted > stuffed. The results obtained in this work indicate that table olives can be considered a good source of phenolic antioxidants, although their concentration depends on olive cultivar and processing method. PMID: 14759136 ----------- [2] J Agric Food Chem. 2012 Jul 25;60(29):7081-95. doi: 10.1021/jf3017699. Epub 2012 Jul 11. Factors influencing phenolic compounds in table olives (Olea europaea). Charoenprasert S(1), Mitchell A. Author information: (1)Department of Food Science and Technology, University of California, One Shields Avenue, Davis, California 95616, United States. The Mediterranean diet appears to be associated with a reduced risk of several chronic diseases including cancer and cardiovascular and Alzheimer's diseases. Olive products (mainly olive oil and table olives) are important components of the Mediterranean diet. Olives contain a range of phenolic compounds; these natural antioxidants may contribute to the prevention of these chronic conditions. Consequently, the consumption of table olives and olive oil continues to increase worldwide by health-conscious consumers. There are numerous factors that can affect the phenolics in table olives including the cultivar, degree of ripening, and, importantly, the methods used for curing and processing table olives. The predominant phenolic compound found in fresh olive is the bitter secoiridoid oleuropein. Table olive processing decreases levels of oleuropein with concomitant increases in the hydrolysis products hydroxytyrosol and tyrosol. Many of the health benefits reported for olives are thought to be associated with the levels of hydroxytyrosol. Herein the pre- and post-harvest factors influencing the phenolics in olives, debittering methods, and health benefits of phenolics in table olives are reviewed. PMID: 22720792 --------- [3] Saudi Pharm J. 2010 Jul;18(3):111-21. doi: 10.1016/j.jsps.2010.05.005. Epub 2010 May 31. Cardioprotective and neuroprotective roles of oleuropein in olive. Omar SH(1). Author information: (1)College of Pharmacy, Qassim University, P.O. Box 31922, Buraidah-51418, Saudi Arabia. Traditional diets of people living in the Mediterranean basin are, among other components, very rich in extra-virgin olive oil, the most typical source of visible fat. Olive is a priceless source of monounsaturated and di-unsaturated fatty acids, polyphenolic antioxidants and vitamins. Oleuropein is the main glycoside in olives and is responsible for the bitter taste of immature and unprocessed olives. Chemically, oleuropein is the ester of elenolic acid and 3,4-dihydroxyphenyl ethanol, which possesses beneficial effects on human health, such as antioxidant, antiatherogenic, anti-cancer, anti-inflammatory and antimicrobial properties. The phenolic fraction extracted from the leaves of the olive tree, which contains significant amounts of oleuropein, prevents lipoprotein oxidation. In addition, oleuropein has shown cardioprotective effect against acute adriamycin cardiotoxicity and an anti-ischemic and hypolipidemic activities. Recently, oleuropein has shown neuroprotection by forming a non-covalent complex with the Aβ peptide, which is a key hallmark of several degenerative diseases like Alzheimer and Parkinson. Thus, a large mass of research has been accumulating in the area of olive oil, in the attempt to provide evidence for the health benefits of olive oil consumption and to scientifically support the widespread adoption of traditional Mediterranean diet as a model of healthy eating. These results provide a molecular basis for some of the benefits potentially coming from oleuropein consumption and pave the way to further studies on the possible pharmacological use of oleuropein to prevent or to slow down the cardiovascular and neurodegenerative diseases. PMCID: PMC3730992 PMID: 23964170