| > Since, in my view, the
| > reduction of fasting insulin is possibly the most
| > important objective......
|
| I recall reading that TG/HDL is a surrogate marker for
| fasting insulin.  If it's an accurate measurement,
| then most of us should be in pretty good shape in the
| FI department due to our low triglycerides.

This excerpt is from The Anti-Aging Zone (Sears):

"Heart disease at the cellular level is caused by the death of heart muscle
cells that don't get enough oxygen.  Blocked arteries increase the
likelihood of decreased oxygen transfer, but 25% of heart disease deaths
occur in individuals who have no advanced atheroscleroic lesions in their
arteries.  These people die because of a spasm (i.e., a cramp) that
decreases or even stops blood flow to the muscle cells of the heart.  These
people also tend to have normal cholesterol levels.  This is not to say that
reducing cholesterol levels is not important, but only to point out that
cholesterol levels are not a gold standard for predicting heart attacks.  In
fact, it is estimated that nearly 50% of patients hospitalized with heart
disease have normal cholesterol levels.  If cholesterol is not such a great
predictor of implementing heart disease, then what is?

A study published in 1998 in the Journal of the American Medical Association
give some answers.  This study looked at traditional risk factors compared
to fasting insulin levels to see which was more predictive of developing
heart disease at the beginning of the study.  The results are shown in
Figure 14-2

[Figure 14 -2 is a graph that shows Cardiovascular Heart Disease Risk for
Various Blood Parameters on the x-axis and Relative Risk on the y-axis.  The
relative risk of heart disease is as follows:
insulin - ~5 times
triglycerides - ~2.75 times
LDL cholesterol - ~2.25 times
HDL cholesterol - ~1.5 times]

You can see from this figure that fasting insulin levels are more than twice
as predictive for the development of heart disease than LDL cholesterol,
which is currently considered the gold standard.  Yet, billions of dollars
are spent each year on drugs that reduce LDL cholesterol, and yet, the one
drug (i.e., the Zone diet) that can reduce fasting insulin levels is
ignored.

Notice also in figure 14-2 that triglycerides are also more predictive of
developing heart disease than LDL cholesterol levels are.  One of the first
signs of hyperinsulinemia is increased triglycerides.  As you have already
seen, both insulin and triglycerides drop dramatically on the Zone diet
within weeks.  Although HDL cholesterol by itself is a less powerful
predictor of future risk of heart disease than is LDL cholesterol, when you
multiply the increase in risk of elevated triglycerides by the increase in
risk of decreased HDL cholesterol, the result is only slightly behind
fasting insulin as a predictor of heart attacks.

This should not be too surprising since fasting triglyceride/HDL ratio is a
surrogate marker for fasting insulin.  One of the reasons why the fasting
triglyceride/HDL ratio is very predictive for heart disease may be due to
the formation of small dense atherogenic LDL particles that are very prone
to oxidation.  The higher the fasting triglyceride/HDL ratio, the greater
the proportion of the small, dense atherogenic LDL particles, and the
greater the risk of heart disease.

This is why any diet recommended for cardiovascular patients (or anyone for
that matter) that increases the fasting triglyceride/HDL cholesterol ratio
must be considered potentially dangerous.  How dangerous?  Researchers at
Harvard Medical School gave us a clue in a 1997 article in Circulation.
They took patients who had survived their first heart attacks (these are the
strong ones, since others died within the first 6 weeks) and then compared
them to matched patients who had no history of heart disease.  When they
looked at the triglyceride/HDL ratio to see how predictive it was, a
dramatic result was observed (see Figure 14 - 3)

[ Figure 14 - 3 is a graph which has TG/HDL ratio on the x-axis and Relative
Risk on the y-axis:
TG/HDL ratio                    Relative Risk
    1.4                                          ~1.0
    2.3                                          ~4.0
    3.3                                          ~6.0
    7.5                                          ~16.0]

The patients with the highest ratio of triglycerides/HDL cholesterol were 16
times more likely to have a heart attack than those with lower ratios.
Let's put this in perspective.  As I stated earlier, high cholesterol
increases the likelihood of a heart attack by a factor of 2.  And everyone
in medicine recommends lowering excessive cholesterol levels.  Smoking
increases the likelihood of a heart attack by a factor of 4.  And everyone
in medicine recommends that you stop smoking.  Yet a high triglyceride/HDL
ratio increases the likelihood of a heart attack by a factor of 16 and no
one does anything about it even though the drug is available today to reduce
that ratio.  What is that drug?  Its the Zone diet.

Much has been said about dietary fat as the cause of heart disease and
therefore its implication in accelerated aging.  Americans have come to
believe that fat intake must be reduced at all costs.  But is that really
so?  No, because fat has no direct effect on insulin.

This is why in 1997, a group of leading nutrition researchers wrote in the
New England Journal of Medicine that there is no persuasive data supporting
the hypothesis that a low-fat, high-carbohydrate diet has any long-term
benefit in treating obesity, heart disease, and cancer.  Why?  Because each
of those disease conditions is associated with hyperinsulinemia.  Fat has no
effect on insulin secretion, whereas carbohydrates have a major stimulatory
effect."

p 145 - 147

Rob