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Complementary and Alternative
Medicine: Fair and Balanced
composition in dietary oils compared
oil is higher in monounsaturated fats than other dietary oils, making
it more healthy than some. But as a fat, its use should be limited.
By John Russo Jr./Vicus.com
(18 Oct. 2000) -- The Lyon
Diet Heart Study showed that the so-called Mediterranean diet
was associated with a lower risk of a second heart attack in people
who had a previous myocardial infarction. Other cardiovascular
conditions (unstable angina, stroke, heart failure, pulmonary or
peripheral embolism) and even hospitalizations for cardiovascular
disease were also reduced (de Lorgeril, et al., 1999).
A key component in the Mediterranean diet is olive oil, along with
a high consumption of plant-based foods and a low consumption of red
meat. According to a recent study (Trichopoulou, et al.,
2000), olive oil is more beneficial against cancer than other forms of
This study also estimates that up to 25% of the incidence of
colorectal cancer (also see Stoneham, et al., 2000),
approximately 15% of the incidence of breast cancer, and approximately
10% of the incidence of prostate, pancreas and endometrial cancer
could be prevented if the populations of highly developed Western
countries could shift to the traditional healthy Mediterranean diet.
The health benefits and characteristics of olive oil are the topic
of this article.
The distinct taste and types of olive oil
One of the main reasons to cook with olive oil is to benefit from
the flavor it adds. Cooking with olive oil is like cooking with
wine. Never use a wine or olive oil that does not taste good to you.
An inferior one will leave an aftertaste.
You'll understand the difference if you do a
taste test and compare the "pure" to the "extra-virgin" olive oil.
There are many olive oils available. They all share the high level
of monounsaturated fats, but differ in other ways. Table
1 provides a summary of the most common types of olive
Olive oil vs. other cooking oils
Fats should contribute no more than 30% of the calories in a diet.
The majority of calories from fat should come from monounsaturated
fats, as they have been shown to lower LDL ("bad") cholesterol
(Kris-Etherton, et al., 1999; Williams, et al.,
1999; Aro, et al., 1998).
Polyunsaturated fats should be used in moderation. Saturated fats
should be avoided. They come from animal meats, dairy products and
tropical oils such as coconut and palm oil. As noted throughout the
literature, consumption of saturated fats has been shown to raise LDL
2 shows how olive oil compares with other cooking oils
in the percentage of fat from monounsaturated, polyunsaturated and saturated
Benefits and characteristics of extra virgin olive oil
Extra virgin olive oil is a unique dietary lipid, according to
Visioli and Galli (2000), in the sense that it is not extracted from
seeds by means of solvents. Rather, it is obtained from the whole
fruit (drupe), by using the cold-press technique, which does not alter
the chemical nature of the drupe or that of the resulting oil.
According to a study published in The Lancet in
October 2000 (Owen, et al.), high consumption of
extra-virgin olive oils, which are particularly rich in phenolic
antioxidants (as well as squalene and oleic acid), should afford
considerable protection against cancer (colon,
breast, skin), coronary
heart disease and aging by inhibiting oxidative stress. It is the
unique profile of the phenolic fraction, along with high intakes of
squalene and the monounsaturated fatty acid, oleic acid, which are
believed to confer the extra-virgin oil's health-promoting properties.
Extra virgin olive oil is graded by acidity. Lower acidity is
associated with a higher quality product because acidity affects the
taste and the aroma of the oil. Extra virgin olive oils are permitted
to have a maximum acidity of 1%, but the top-quality oils tend to have
less than 0.5% acidity. Virgin oil, by comparison, can have up to 3%
Olive oil or pure olive oil, in contrast to extra virgin oil, is
chemically treated, heated and filtered to reduce its acidity. Ugo
Erasmus, in his book Fats That Heal, Fats That Kill: The
Complete Guide to Fats, Oils, Cholesterol and Human Health, notes
that this manufacturing process alters an oil's characteristics. In
fact, heating during processing or in cooking destroys the beneficial
compounds in most oils, including olive oil.
The color of extra virgin olive oil ranges from a pale yellow to
bright green. Usually, the deeper the color, the more intense the
flavor. It should taste sweet, with a little "edge" to
As an additional note, bottling olive oil in plastic can be
detrimental to its quality. The oil can capture the chemicals from the
plastic and air can seep in, causing rancidity. The ideal packaging
for olive oil should be dark glass, which prevents exposure to light,
a basic cause of quality deterioration. Olive oil should not be stored
in the refrigerator.
Russo Jr., PharmD, is senior vice president of medical
communications at Vicus.com. He is a pharmacist and medical writer
with more than 20 years of experience in medical education.
Aro A, Pietinen P, et al. Effects of reduced-fat
diets with different fatty acid compositions on serum lipoprotein
lipids and apolipoproteins. Public Health Nutr. 1998
de Lorgeril M, Salen P, et al. Mediterranean diet,
traditional risk factors, and the rate of cardiovascular complications
after myocardial infarction: final report of the Lyon Diet Heart
Study. Circulation. 1999 Feb; 99(6):779-85.
Erasmus U. Fats That Heal, Fats That Kill: The Complete
Guide to Fats, Oils, Cholesterol and Human Health. Burnaby,
British Columbia, Canada: Alive Books; 1993.
Kris-Etherton PM, Pearson TA, et al. High-monounsaturated
fatty acid diets lower both plasma cholesterol and triacylglycerol
concentrations. Am J Clin Nutr. 1999 Dec;
Owen RW, Giacosa A, et al. Olive-oil consumption
and health: the possible role of antioxidants. Lancet Oncol. 2000
Stoneham M, Goldacre M, et al. Olive oil, diet and
colorectal cancer: an ecological study and a hypothesis. J
Epidemiol Community Health. 2000 Oct; 54(10):756-760.
Trichopoulou A, Lagiou P, et al. Cancer and
Mediterranean dietary traditions. Cancer Epidemiol Biomarkers
Prev. 2000 Sep; 9(9):869-73.
Visioli F, Galli C. Olive oil: more than just oleic acid. Am
J Clin Nutr. 2000 Sep; 72(3):853.
Williams CM, Francis-Knapper JA, et al. Cholesterol
reduction using manufactured foods high in monounsaturated fatty
acids: a randomized crossover study. Br J Nutr. 1999