Found the following. Until data is available it seems sensible to count
a gram of squalene as a gram of cholesterol for olive oil but not for
any other food.
-----------
Effects of trace components of dietary fat on cholesterol metabolism:
Phytosterols, oxysterols, and squalene
Nutrition Reviews, Nov 2002 by Ostlund, Richard E Jr, Racette, Susan B,
Stenson, William F
....
Similar to the situation in animal cells, squalene is usually only a minor
component of the nonsaponifiable materials of plants. It is estimated that the
average consumption of squalene in foodstuffs is only 28 mg/ day, a small
proportion of the cholesterol production rate of 1114 mg/day. However, dietary
squalene can vary remarkably and olive oil is a stark exception to the rule that
plant levels are generally low. Olive oil contains 200 to 700 mg squalene/100 g
oil. 7- to 300-fold more than other vegetable oils and up to 5000-fold more than
some vegetable foods . The efficiency of gastrointestinal squalene absorption
has been estimated at 42% in animals and 86% in humans, and dietary squalene
is found in postprandial lipoprotein fractions. Once absorbed, squalene
appears to be quantitatively converted to cholesterol. Some dietary squalene
is converted to cholesterol within the intestinal epithelium and may thereby
influence cholesterol absorption. The effect of long-term squalene feeding in
humans has not been investigated adequately. In a small study using purified
squalene (1 g/day) added to margarine, LDL cholesterol increased 17%, apo B
increased 14%, and fecal neutral sterols increased 9%. The incorporation of
labeled water into cholesterol was reported to be significantly lower after
olive oil consumption compared with other vegetable oils. This result would be
expected as compensation for increased unmeasured cholesterol synthesis from
unlabeled exogenous squalene. In a large study that used an undefined dietary
supplement containing squalene (presumably an extract of shark liver), there was
a 14% reduction in LDL cholesterol compared with placebo. It is unclear
whether the effect was due to squalene itself or to other components. Commercial
squalene supplements are often less than 50% pure.
Squalene content is potentially important in the interpretation of studies
involving olive oil administration. Based on the above data it is possible that
individuals consuming 50 g olive oil per day might have a squalene intake of 350
mg, an amount that could easily affect cholesterol metabolism because it is
would be equivalent to 350 mg of cholesterol, assuming similar efficiency of
absorption. Olive oil elevates serum cholesterol and LDL cholesterol relative to
other vegetable oils in controlled diet studies. However, it is not known
whether squalene is the active agent. Whether cholesterol derived from absorbed
squalene has effects similar to absorbed cholesterol is also not known. Because
many studies of monounsaturates were conducted with olive oil as the test
material, it would be important to define further the role of its squalene
component.
....
General fitness, health and nutrition · Public discussion
dietary squalene
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- General fitness, health and nutrition
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- 11 May 2005
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Another ludicrous "marker" study. What exactly are they saying? The
highest quality olive oil, which is the only kind woth consuming, is
high in squalene. The lowest quality, refined olive oil is used in
antioxidant experiments because it goes rancid so quickly. According
to these idiots, you should consume the lowest quality olive oil. If
they could show that high quality olive oil in a diet low in foods that
produce oxidative stress causes cholesterol levels to go considerably
higher than the Ancel Keys limit, which is 220, then it deserves
further study, but they are talking only about "markers," not about
actual mechanisms. Those familiar with biochemical mechanisms realize
(probably 99% of them, at least) that oxidative stress is the root
cause, and since squalene is such a good antioxidant, there is no
reason to avoid it, since it will protect your cholesterol from
becoming oxidized (as long as you don't eat cholesterol that is already
oxidized), so it does not matter if it raises cholesterol a few points.
In fact, that is good - protective against, cancer, shock, and
"bleeding" strokes, for example. The original anti-cholesterol
experiment, done in Russia in 1913 on rabbits, used pure oxidized
cholesterol, so the rabbits had major damage done to them.One should largely disregard "studies" that are done with "markers"
when there is no reason just to see what happens. In other words,
forget about cholesterol levels moving up a few points and just
determine who lived longer, and perhaps a higher quality of life as
well. If these guys were any more clueless, they would be cast in
another sequel to Dumb and Dumber. -
"montygram" <[email hidden]> schrieb im Newsbeitrag
news:[email hidden]...Quoted message said:
Another ludicrous "marker" study. What exactly are they saying? The
highest quality olive oil, which is the only kind woth consuming, is
high in squalene. The lowest quality, refined olive oil is used in
antioxidant experiments because it goes rancid so quickly. According
to these idiots, you should consume the lowest quality olive oil.Well, actually nobody said that in the text quoted.. nor did they advise to
stay away from squalene-rich foods.Quoted message said:
If
they could show that high quality olive oil in a diet low in foods that
produce oxidative stress causes cholesterol levels to go considerably
higher than the Ancel Keys limit, which is 220, then it deserves
further study, but they are talking only about "markers," not about
actual mechanisms. Those familiar with biochemical mechanisms realize
(probably 99% of them, at least) that oxidative stress is the root
cause, and since squalene is such a good antioxidant, there is no
reason to avoid it, since it will protect your cholesterol from
becoming oxidized (as long as you don't eat cholesterol that is already
oxidized), so it does not matter if it raises cholesterol a few points.
In fact, that is good - protective against, cancer, shock, and
"bleeding" strokes, for example. The original anti-cholesterol
experiment, done in Russia in 1913 on rabbits, used pure oxidized
cholesterol, so the rabbits had major damage done to them.I agree though, that this text does not say anything really important or
alarming.
What they say is: the body uses squalene to produce cholesterol.. ok. But is
this a risk factor?
How could it be.. cholesterol is an important factor in the human body and
has many different functions absolutely necessary for survival (hormones,
bile salts, cell membranes etc).
Besides that squalene is a secondary antioxidant and prevents other lipids
from oxidation by being oxidized itself.Total cholesterol doesn't say much.. LDL/HDL ratio makes more sense.
Quoted message said:
One should largely disregard "studies" that are done with "markers"
when there is no reason just to see what happens. In other words,This is pointless. You couldn't do many studies without markers.
Thing with markers is:
1) you have to understand them.. which means learning and exploring the
biochemistry that stands behind it.2) you have to know what you actually looked at and argue from there not
from what you thought you looked at.Quoted message said:
forget about cholesterol levels moving up a few points and just
determine who lived longer, and perhaps a higher quality of life as
well. If these guys were any more clueless, they would be cast in
another sequel to Dumb and Dumber.
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