Wonders of an Olive Tree
Olive trees have
the ability to live up to thousands of years old. They often rejuvenate
themselves after being burned or even cut to the ground. Due to
pathogen-fighting and age-defying properties found in olive trees, there is good
reason to believe that olive enthusiasts might also live a longer life.
Olive Oil
Overview
Olive oil
consists of monounsaturated fatty acids, which promote the good HDL blood
cholesterol while inhibiting the harmful LDL blood cholesterol. There is no
cholesterol in olive oil itself. Studies have found that olive oil
significantly reduces the risk of stroke, stomach cancer, heart disease, heart
attacks, and other cancers. Olive oil seems to also protect the bones, joints,
skin, liver and heart.
Olive
oil in the Mediterranean diet
In the 1960s, it was found that the people of Greece (Crete) consumed a great
deal of salt and fat (but also a lot of plant foods). They were living longer
than the Japanese, who were also eating a lot of salt but whose diet was low in
fat and lower in plant foods.
The people of Crete lived longer because they had lower rates of stroke,
stomach cancer, heart disease and other cancers. Researchers also noticed that
people living in countries around the Mediterranean had a lower incidence of
heart disease, despite their high intake of mono-unsaturated fats, such as
olive oil. This led to investigations into what is known as 'the Mediterranean
diet', of which olive oil is a major part.
Research supports the health benefits of olive oil
Recent studies into the health benefits of olive oil have found that it can
lower the risk of coronary heart disease by reducing blood cholesterol levels.
According to one study, a person's risk of fatal heart attack is halved in just
two to four years once they switch to 'the Mediterranean diet', which includes
using olive oil as the main dietary fat, increasing vegetable intake, and
limiting meat and dairy foods. Research has also found that olive oil may
influence body fat distribution, with less fat stored around the stomach.
Dietary fats
There are three types of fat: saturated, polyunsaturated and mono-unsaturated
(these terms describe the type of chemical bonding between the atoms). Each
type consists of fatty acids, which are chains of carbon and hydrogen atoms, in
varying combinations. Both polyunsaturated and mono-unsaturated fats can lower
blood cholesterol levels. Olive oil is a mono-unsaturated fat.
Types of olive oil
Generally, olive oil is extracted by pressing or crushing olives. Olive oil
comes in different varieties, depending on the amount of processing involved.
Varieties include:
- Extra virgin - considered the best; this
oil comes from the first pressing of the olives
- Virgin - from the second pressing
- Pure - undergoes some processing,
such as filtering and refining
- Extra light - undergoes considerable
processing and only retains a very mild olive flavour.
Blood
cholesterol and atherosclerosis
Low density lipoprotein cholesterol (LDL) is considered the 'bad' cholesterol.
This is because it can stick to artery walls and cause atherosclerosis, which
increases the risk of coronary heart disease and stroke.
Studies into LDL cholesterol have suggested that oxidation is an important step
in the development of atherosclerosis. It seems that mono-unsaturated fats
reduce the capacity of LDL cholesterol to oxidise, which may explain the
protective properties of olive oil. However, extra virgin olive oil also
contains around 40 antioxidant phytochemicals. Antioxidants have been associated
with reduced oxidation of LDL cholesterol, so perhaps these phytochemicals are
the factors responsible for the health benefits.
Blood fats
Once a fatty meal is eaten, it takes the liver around six to 12 hours to scour
dietary fats from the blood and change them into compounds such as LDL and HDL
(high density lipoprotein) cholesterol.
There is evidence that this six to 12 hour period may be a crucial contributing
factor in atherosclerosis. Mono-unsaturated fats like olive oil are cleared
from the blood much faster than saturated fats, and this reduces the window of
opportunity for the development of atherosclerosis. Mono-unsaturated fats also
help to prevent the blood from becoming sticky after a fatty meal and forming
dangerous clots.
Researchers compared the weight loss results from one group of people,
following 'the Mediterranean diet', to another group who were sticking to low
fat and high carbohydrate diets. They found that those following the
Mediterranean diet shed excess pounds from both the upper and lower body, but
the other group mainly lost fat from the lower body. People who store their
body fat around the waist and abdomen ('apple shaped') have a higher risk of
heart disease than those people who carry their weight at the hips and thighs ('pear
shaped').
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