Cancer and Olive Oil |
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Articles and Questions about Cancer and Olive Oil answered by Dr. John Deane
Olive Oil
and a Greek diet lowers cancer
Olive
Oil is the Healthy Choice for Frying
Olive
Oil May Protect Against Colon Cancer
Olive Oil May
Protect Against Skin Cancer
Questions
from the Mailbag
Cancer
concerns
with Olive
Oil -
frying
Selected
References
Reproduction of articles: Copyright 12/14/07 The Olive Oil Source. All rights reserved for all countries. Content from this site may be reproduced with attribution and hyperlink to The Olive Oil Source.
Breast Cancer and Olive Oil
6/30/03 - M Solanas from the Department of Cell Biology in Barcelona reported in the International Journal of Oncology that olive oil slowed breast cancer in rats. A corn oil diet stimulated more cancers than a control diet while olive oil led to fewer and smaller tumors than the control diet. Solanas M - Int J Oncol - 01-Oct-2002; 21(4): 745-53
Cancer Concerns With Olive Oil
by John Deane M.D.
8/8/2001 - There was a deluge of mail from persons concerned about developing cancer from frying with olive oil. It is unknown where this latest food myth comes from but this sort of misinformation seems to spread like a computer virus. Perhaps it was the finding of contaminants in Spanish refined olive oil in early 2001 which prompted the concerns.
Polycyclic aromatic hydrocarbons are a group of chemicals which are formed when petroleum, petroleum products, coal, wood, cellulose, corn, or oil are burned. There are over 100 PAHs which have been studied. During oxidation and detoxification in the liver they are thought to form substances which damage DNA, starting a chain of events which could lead to cancer. A few of them have been classified by the EPA and The Department of Health and Human Services as carcinogenic to animals in studies and probably carcinogenic to humans.
A person's exposure at home to PAHs would likely be through tobacco smoke, wood smoke, vehicle exhausts, asphalt roads, coal, coal tar, wildfires, agricultural burning, waste incineration, creosote-treated wood products, cereals, grains, flour, bread, vegetables, fruits, meat, processed or pickled foods.
At work you could be exposed to PAHs in coal tar production plants, coking plants, bitumen and asphalt production plants, coal-gasification sites, smoke houses, aluminum production plants, coal tarring facilities, municipal trash incinerators and by inhaling engine exhaust. PAHs can also be found in the mining, oil refining, metalworking, chemical production, transportation, and the electrical industry.
Twenty years ago there was a food scare when PAHs were first being researched. They were found in meat and other foods which had been cooked at high temperatures, such as grilling and charring. The American Institute for Cancer Research recommends to avoid charring meat when grilling, pre-marinade, which somehow minimizes PAH formation, and minimize the amount of grilled meats consumed. (Grilled vegetables or fruit do not form PAHs).
Many foods naturally contain small quantities of PAHs. Olive oil, like other vegetable cooking oils, has been found to contain minute amounts of up to 17 PAHs such as benzanthracene and chrysene. Unripe olives tended to have more than ripe olives.
Burning any cooking oil can increase the amounts of PAHs. Oil of any kind which has been repeatedly heated to its smoking point will lose it's natural antioxidants and begin to accumulate free radicals and other cancer causing substances. Whether this has actually caused cancer in humans has never been proven. Commercial industrial kitchens which fry foods would be where this sort of thing might happen. It is unlikely that you would repeatedly fry at continuous high temperatures with the same oil at home. In commercial operations the oil is examined regularly with a rancidity test and discarded before it gets to a dangerous stage. Olive oil is typically not used in commercial kitchens as it is much too expensive. Cheaper oils like canola, corn or peanut oil are used instead. Extra virgin olive oil has fewer free fatty acids and more antioxidants which soak up free radicals. So heating it would produce fewer free radicals than a lower grade olive oil. It is unlikely that in home use olive oil or other cooking oils would be a significant source of PAHs.
Sometimes when people hear cancer, they panic and forget that we are surrounded by possible carcinogens, ranging from nearly every food we eat to sunlight. Although a substance we are exposed to is capable of causing cancer, the probability that this actually happens may be vanishingly small. Exposure to second hand cigarette smoke or going outside without sun block is probably thousands of times more likely to cause cancer than burning your cooking oil.
References:
Encyclopedia
Britannica
Kiritsakaas,
Apostolos, Olive Oil From the Tree
to the Table,
Agency
for Toxic Substances and Disease
Registry (ATSDR).
1995. Toxicological profile for
polycyclic aromatic hydrocarbons
(PAHs). Atlanta, GA: U.S. Department
of Health and Human Services, Public
Health Service
Olive Oil and Skin Cancer
8/13/2001 - A Japanese researcher has found that hairless mice exposed to damaging doses of sunlight then soothed with olive oil developed fewer skin cancers. We don't know if people's skin will react the same as hairless mice but its a good bet that the antioxidants in olive oil could prevent cancer in humans too. Sunlight causes damage to DNA and creates free radicals which cause oxidative damage. Olive oil has polyphenols and other natural antioxidants which could prevent the type of damage which leads to cancer. Cheaper refined olive oil didn't seem to help the mice as much as fresh, extra virgin olive oil. The utility of this study is unclear as no amount of olive oil would undo all the damage caused by the sun. A wiser course would be to avoid the sun, use a hat and sunscreens and save the olive oil for a salad.
Olive Oil and a Greek diet lowers cancer
Oliver Spits
Sausalito, California - An article from the September issue of Hippocrates magazine summarized the findings from a new study out of the University of Ste.-Etienne. 605 men and women who had suffered a heart attack were put on one of two diets. One was the American Heart Association's (AHA) diet which permitted meat, cream and butter. "The other half ate like Greeks, consuming less of those items and more fruits, vegetables, cereals, beans, and fish, as well as olive oil and a canola oil margarine". The study was designed to look at the effect of diet on heart disease but found that after four years the "Greek" group had less cancer, just two new cases of cancer verses 12 in the AHA diet group. This is a small study and needs to be followed up with a much bigger one, but the results are very surprising.
Olive Oil May Protect Against Colon Cancer
by John Deane M.D.
Animal studies have show that dietary fats increase the development of colon tumors. Colon cancer is the second most common cause of cancer death in Americans. The fact that the Western diet is high in fats and Americans have a much higher risk of colon cancer than people in the rest of the world seems to be related. But different fats have different effects. Doctors in the department of Gastroenterology, University Hospital in Barcelona decided to test olive oil to see if it could safeguard against colon cancer compared to other oils. It is well know that olive oil seems to confer several healthful benefits to Southern Europeans. Investigators studied the effects of a diet rich in safflower, fish oil or olive oil on rats which had been given a chemical which accelerates cancer in the bowel. After five months, twice as many rats in the safflower group had developed tumors as the rats in the other two groups. It is not known what specific property of olive oil lowers the incidence of bowel tumors. Olive Oil is an n9 fatty acid with a different structure from safflower and fish oil. Dietary olive oil was shown to help prevent colon cancer development. The study authors postulated that these effects may be partly due to a lowering of inflammation chemicals made in the gut. Olive Oil has been shown to have anti-inflammatory effects in several other studies. Studies also suggest that olive oil can decrease the incidence of breast cancer.
Bartoli R, Fernandez-Banares F, Navarro E, Castella E, Mane J, Alvarez M, Pastor C, Cabre E, Gassull MA
Department of Gastroenterology, Hospital Universitari Germans Trias i Pujol, Carretera del Canyet s/n, 08916 Badalona, Spain.
Olive Oil is the Healthy Choice for Frying
by John Deane M.D.
San Rafael - Heating olive oil to frying temperatures ruins its delicate flavor but can also decrease the amount of healthful antioxidants and create hazardous aldehydes. The same is true for any oil. In a study at Ankara University in Turkey, investigators examined the effect of heating olive oil, sunflower oil and soy oil to 180 degrees C. Olive oil fared the best. It retained its natural antioxidant defense potential and formed the fewest potentially cancer causing aldehydes. For more information contact Ankara University, Medical Faculty, Department of Biochemistry, Turkey. durak@pallas.dialup.ankara.edu.tr 1/2000
| Olive oil is an integral
part of the "Mediterranean diet" which is associated with sensible
tasty portions and slower, more enjoyable eating. People who eat a
"Mediterranean diet" have been shown to have a remarkable variety
of health benefits. Olive oil can quickly satisfy hunger and lead
to fewer total calories ingested at mealtime. Studies suggest that
olive oil decreases rates of cardiovascular disease and cancer. It
is unclear if any single component of olive oil is responsible for
these health benefits or if it is a combination of olive oil and a
diet high in vegetables, fruit and fish.
Extra virgin olive oil is one of the few oils that can be eaten without chemical processing. (Nearly every other vegetable oil has been detoxified and refined with steam and solvents). Fresh pressed olive oil can be eaten immediately and retains the natural flavors, vitamins, minerals, antioxidants, and other healthy products of the ripe olive fruit. Most doctors advocate lowering total fat and calories in your diet, and substituting butter, margarine and tropical oils with healthy fats like olive oil. |