Oil of Oregano

" Greek investigators, publishing in the Journal of Agriculture and Food Chemistry, determined that oil of wild oregano even destroyed human cancer cells. While spices may oxidize or destroy pathogens, amazingly, they also act as antioxidants for human cells, specifically for the fats of the human cell membranes."


Does olive oil protect against cancer? It might, depending on which one you choose, as Prevention learned when we put 22 of them to the test. Here's what we found-and what it may mean to your health

For years, scientists have puzzled over the hit-or-miss cancer-protective ability of olive oil. Studies suggest that it plays a key role in guarding Mediterranean people from cancer; their rates are half those of the US. Olive oil also seems to protect animals against deliberately induced cancers in the majority of lab studies. But not always. What's going on?
To find out, Prevention conducted its own investigation. We commissioned an independent laboratory to assess 22 olive oils, most of which we purchased in supermarkets, health food stores, and Italian specialty shops. (Two Greek oils were contributed by a leading cancer researcher.) SGS Control Services, Inc., of Memphis, which is certified to do gas chromatography fatty acid testing, checked the oils for three important nutrients: oleic acid and squalene, the two linked to olive oil's potential cancer-protecting power, and linoleic acid, a potent protector of the heart that has been shown to promote cancer in animal studies.

The results? Not all olive oils seem to have the same potential firepower to prevent cancer. And where do the best ones come from? You guessed it-the Mediterranean.

The Theory We Investigated

We looked at these three nutrients largely because of an article that appeared 2 years ago in the American Journal of Clinical Nutrition (vol 66 [supplement], 1997). Written by researcher Clement Ip, PhD, of the Roswell Park Cancer Institute in Buffalo, the article details the effects of different dietary fats on breast cancer.

When scientists talk about the great health benefits of olive oil, they mostly credit oleic acid, the monounsaturated fatty acid that is the predominant component of all olive oils. (Oleic acid is also found in meat, which is where most Americans get it-along with copious amounts of artery-clogging saturated fat, effectively negating its health benefits.)
Olive oil also contains squalene, a chemical recently found to protect against colon and other cancers in animal studies. But it also contains the potential cancer-promoter linoleic acid, a polyunsaturated fatty acid that is the main component of corn, sunflower, safflower, and soybean oils. All three exist in widely varying amounts in different olive oils. Linoleic acid, for instance, can be as low as 7% and as high as 20% in any given olive oil. Oleic acid can vary between 54 and 80%.
And that dramatic variation is at the core of Dr. Ip's intriguing theory for why there's so much conflicting data on olive oil. He suggests that the researchers who found no cancer-protective effect were probably using olive oils that were high in linoleic acid.

He carefully reviewed a number of animal research studies looking at breast cancer and found that a certain amount of linoleic acid is needed to help chemically induced breast cancer cells flourish.

Luckily, some olive oils have a higher percentage of oleic acid that theoretically may help cancel out linoleic's potential cancer-promoting effects. They're the ones that made our shopping list, along with the oils high in squalene, the newest and perhaps most promising of the potential anticancer nutrients. (See "Your Best-Buy Olive Oils")

Why All Olive Oils Aren't the Same

The differences between olive oils are enormous, says Leonard Cohen, PhD, a researcher and author of many published studies on the food/cancer connection. One reason why, he says, is that olive oil is produced in more than 20 different countries, including the US, and from a large number of different olive varieties, each possessing its own distinctive taste and physical characteristics.

Plus, the fatty acid content of olive oils varies to a much greater extent than other oils such as corn, safflower, peanut, and soybean. It depends on "which variety is being grown, which country it's grown in, the characteristics of the soil in that specific grove, the microclimate, the rainfall that year, and even the age of the tree-olive trees can live and produce fruit for centuries," says Dr. Cohen.

Unlike those other oils, olive oil isn't chemically processed-at least the virgin (first) pressing isn't. "Those other 'seed' oils are refined using solvents, chemicals, high heat, and even bleaches," explains Dr. Cohen. "With olive oil, you simply 'cold press' the olives, pit and all, which extracts the oil without using nutrient-robbing heat. Then you simply skim the oil off the top. As a result, this is the only really unprocessed oil. That may help account for its nutritional superiority and possible medical benefits."

Several years ago, Dr. Cohen tested the potency of various olive oils in preventing cancer in lab animals exposed to a carcinogen. The "better" the olive oil-the better the ratio of fatty acids it contained-the better the animals did against the cancer. A recent animal study also found that squalene was highly protective against colon cancer (Carcinogenesis, vol 19, 1998). "And the only real food source of squalene is olive oil-although it's also found in high amounts in sharks, oddly enough. Squalene may turn out to be the true anticancer element in olive oil," Dr. Cohen speculates.

Making Your Choice

Dr. Ip stresses that his paper and the studies it reported on concern tests on animals exclusively-and you can't necessarily translate those results to humans. There is population-based evidence that people in Mediterranean cultures have significantly lower levels of breast and other cancers, he notes-but olive oil is not the only important factor in their diet and lifestyle. Nor is linoleic acid always a bad guy. "There is very strong evidence that the linoleic acid in corn, sunflower, and safflower oil is very protective against heart disease," points out Dr. Ip.

Make no mistake, the scientific evidence on oleic acid, linoleic acid, and squalene -though very provocative-is also very preliminary. But if the threat of cancer runs through your genes and you want to err on the side of caution, change your oil. Limit your linoleic acid intake (less corn, sunflower, safflower, and soybean oils), and switch to an olive oil that's high in potentially cancer-protective oleic acid and squalene.

How Do They Taste?

Glad you asked. We wanted to know which of the top olive oils were the best tasting, so we enlisted Tom Ney, director of food marketing for Rodale and longtime Prevention chef/food guru, to stage a true olive oil tasting. It was held at the Rodale Food Center and conducted according to the standards of the International Olive Oil Council based in Madrid, Spain, using their grading system. Twelve tasters participated.

These oils finished high in both taste and lab tests (in order of their taste-test scores):

• Eden Selected Spanish ("zesty, buttery, assertive taste")
• St. Helena ("subtle, fruity, herbaceous, grapelike")
• Greek Gourmet ("fruity aroma, peppery finish, rich flavor")
• Spectrum Naturals ("subtle, delicate, fresh olive aroma")

What's "Extra" Virgin, Anyway?

You have to pass a test. Here's how it works, according to the International Olive Oil Council (IOOC) in Madrid, Spain:
Virgin refers to the entire first pressing of olives that have been handled correctly; specifically, the fruits are washed, crushed mechanically under cool conditions, and then the oil is separated out and (sometimes) filtered. No chemicals, high heat, or anything else that could affect the flavor, aroma, or nutritional quality is allowed.

Extra virgin is a designation applied to the highest quality virgin oils. It must have extremely low acidity and a high "organoleptic assessment"-its "sensorial attributes," as "perceived by a panel of 8 to 12 selected, trained tasters who are led by a panel supervisor." We're not making this up. The IOOC sets the rules and issues accreditation to the panels. To achieve extra virginhood, you need a score of 6.5 or better (on a scale of 0 to 9).
Fine virgin is an oil with a score of 5.5 or better.

Semifine or ordinary virgin is the lowest quality virgin oil that is deemed fit for consumption.

Refined olive oil doesn't make any of these grades and must be refined from other olive oils in order to be made usable. It's used to create regular old olive oil, a blend of refined oil and one of the higher classes of true virgin oil, usually fine or semifine.

PHOTO (COLOR): Go for the green: Extra virgin oils, especially those from California and Spain, contain the most nutrients linked to cancer prevention.


Most of the researchers we talked to felt that the ratio of oleic to linoleic acid in an olive oil is the best indicator of its cancer-protective abilities. That's because high levels of oleic acid may block out some of linoleic's less desirable effects on cancer cells. The larger the number, the more oleic acid an oil has in relation to its linoleic content.
That said, Mediterranean rules! As the chart below shows, olive oils from Spain, Italy, and Greece not only dominate the top 10, they also make up the entire top 5. And of those, one stands out: Eden Selected Spanish Extra Virgin scored high in oleic/linoleic ratio and finished among the top five oils with the highest squalene content. It also got top marks in our "taste test," making it our all-around best buy.

Some researchers think that squalene may be olive oil's real "secret ingredient," the main reason some oils seem to be able to block cancer's progress. The olive oils listed in red are also among the top 10 in squalene content. (We've listed their amounts in the squalene column.) 10 elsewhere, but it's the unequivocal leader in the squalene category, with 1.3%. The only thing higher is shark oil which, as you can imagine, doesn't taste as good tossed with pasta!

If you decide to shop for olive oils based on squalene levels, don't forget Venecia Extra Virgin, a Turkish oil (0.7), and SMS Extra Virgin (0.6), from Croatia. They tied for fourth and fifth respectively but didn't make it on the top 10 list.
Two of our oils were supplied by researcher Leonard Cohen, PhD, who got them from Greece. We included them to test the powerful Mediterranean connection. Unfortunately, they aren't available in the US.


1. Eden
Extra Virgin
(Spain) 13.87 0.8 $6.15/16 oz health food
($0.38/oz) stores

2. Atheya 13.36 0.5 N/A available
Extra Virgin only in
(Greece) Greece

3. Greek Gourmet 13.24 0.5 $7.79/17 oz health food
Extra Virgin $0.46/oz) stores

4. Bertolli Gentile 13.17 0.6 $5.49/17 oz supermarkets
Extra Virgin ($0.32/oz)

5. Bella Via 12.87 0.6 $9.99/17 oz health food
Organic ($0.58/oz) stores
Extra Virgin

6. Bionaturae 11.55 0.7 $10.99/17 oz health food
Organic ($0.64/oz) stores
Extra Virgin

7. Bertolli 11.35 0.5 $9.49/34 oz supermarkets
Extra ($0.27/oz)

8. Eleourgiki 10.90 0.5 N/A available
Extra only in
Virgin Greece

9. Spectrum
Extra Virgin
California) 10.82 0.9 N/A no longer

10. Pompeian 10.78 0.9 $4.79/16 oz
Extra Virgin ($0.29/oz) supermarkets

By Mike McGrath
Prevention contributing Editor Mike McGrath is also Organic Gardening magazine's editor-at-large.

See: http://www.colloidalsilversolutions.com/oreganoresearch.html

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Oil of Oregano cancer treatment.pdf117.74 KB

Epidemiological studies have shown the potential health benefits of olive oil, specifically in relation to cancer incidence. The negative modulating effect, probably protective, of high virgin olive oil diets on carcinogenesis have been experimentally demonstrated. There is evidence that olive oil influences different stages of carcinogenesis, hormonal levels, cell membrane composition, signal transduction pathways, gene expression, and the immune system. Either its main monounsaturated fatty acid, oleic acid, or the minor compounds may be responsible for its chemoprotective effects. Its bioactive compounds are emerging as potential agents in the treatment of cancer.