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By Nancy Appleton, Ph.D.
The consumption of fructose (corn syrup) has risen considerably in the general
population within recent years. In 1980 the average person ate 39 pounds
of fructose and 84 pounds of sucrose. In 1994 the average person ate 66
pounds of sucrose and 83 pounds of fructose. This 149 pounds is approximately
19% of the average person's diet.
This increase is due to several factors. There was a decreased
use of cane and beet sugar (sucrose) in processed foods and a wide spread
use of corn syrup due to economics. Corn is much cheaper and twice as sweet
as table sugar. It is absorbed only 40% as quickly as glucose and causes
only a modest rise in blood sugar.
A few years ago the medical community revealed that there
was good news for diabetics. Many people had previously known that table
sugar (sucrose) was not a healthy food for diabetics because it raised their
blood sugar levels above normal.
Since diabetics have a hard time maintaining healthy blood
sugar levels, doctors counseled diabetics not to eat sugar. The new revelation
was that diabetics could eat fructose because fructose did not raise their
blood sugar level extremely high. So far so good, but there is more.
Many doctors were recommending fructose instead of glucose.
Today fructose is not only being used by some diabetics but it is used for
a variety of foods, drinks and confectionery around the world. It is used
for candies for diabetics, desserts for weight watchers, drinks for the
sportsman and jelly for the health conscious.
The medical community recommended it because of a low
increase in glucose in the blood. The scientists did not look at other factors
in the body when a person eats sugar. Let's look at some of these factors
now.
- Fructose has no enzymes, vitamins, and minerals and
robs the body of its micronutrient treasures in order to assimilate itself
for physiological use.
Fructose browns food more readily (Maillard reaction)
than with glucose. This may seem like a good idea, but it is not.
The Maillard reaction, a browning reaction, happens
with any sugar. With fructose it happens seven times faster with than
glucose, results in a decrease in protein quality and a toxicity of
protein in the body.
This is due to the loss of amino acid residues and
decreased protein digestibility. Maillard products can inhibit the uptake
and metabolism of free amino acids and other nutrients such as zinc
and some advanced Maillard products have mutagenic and/or carcinogenic
properties. The Maillard reactions between proteins and fructose, glucose,
and other sugars may play a role in aging and in some clinical complications
of diabetes.
- Research showed that in subjects that had healthy glucose
tolerance and those that had unhealthy glucose tolerance, fructose caused
a general increase in both the total serum cholesterol and in the low
density lipoproteins (LDL) in most of the subjects. This puts a person
at risk for heart disease.
- Another study showed that the very low density lipoproteins
(VLDL) increased without an apparent change in high density lipoproteins
(HDL). The VLDL and the LDL should be as low as possible and the HDL should
be as high as possible.
- There is a significant increase in the concentration
of uric acid that is dependent on the amount of fructose digested. After
glucose no significant change occurs. An increase in uric acid can be
an indicator of heart disease.
- Fructose
ingestion in humans results in increases in blood lactic acid, especially
in patients with preexisting acidotic conditions such as diabetes, postoperative
stress, or uremia. The significance to human health is that extreme elevations
cause metabolic acidosis and can result in death.
- Fructose is absorbed primarily in the jejunum and metabolized
in the liver. Fructose is converted to fatty acids by the liver at a greater
rate than is glucose. When consumed in excess of dietary glucose, the
liver cannot convert all of the excess of fructose in the system and it
may be malabsorbed. What escapes conversion and being absorbed into the
cells may be thrown out in the urine. Diarrhea can be a consequence.
- Fructose
interacts with oral contraceptives and elevates insulin levels in women
on "the pill."
- Fructose reduced the affinity of insulin for its receptor.
This is the first step for glucose to enter a cell and be metabolized.
As a result, the body needs to pump out more insulin, to handle the same
amount of glucose.
- Fructose consistently produced higher kidney calcium
concentrations than did glucose in a study with rats. Fructose generally
induced greater urinary concentrations of phosphorus and magnesium and
lowered urinary pH compared with glucose.
The balance of minerals in the body is very important
for the function of vitamins, enzymes and other body function. When
the minerals are out of the right relationship, the body chemistry suffers.
The presence of diarrhea might be the cause of decreased absorption
of minerals.
- Fructose-fed
subjects lose minerals. They had higher fecal excretions of iron and magnesium
than did subjects fed sucrose. Apparent iron, magnesium, calcium, and
zinc balances tended to be more negative during the fructose feeding period
as compared to balances during the sucrose feeding period.
- A study of 25 patients with functional bowel disease
showed that pronounced gastrointestinal distress may be provoked by malabsorption
of small amounts of fructose.
- Many times
fructose and sorbitol are substituted for glucose in parenteral nutrition
(intervenious feeding, IV). This can have severe consequences with people
with hereditary fructose intolerance, a congenital disorder affecting
one in 21,000. A European doctor declared: "Fructose and sorbitol containing
infusion fluids have no further place in our hospital pharmacies."
- There
is significant evidence that high sucrose diets may alter intracellular
metabolism, which in turn facilitates accelerated aging through oxidative
damage. Scientists found that the rats given fructose had more undesirable
cross?linking changes in the collagen of their skin than in the other
groups.
These changes are also thought to be markers for aging.
The scientists say that it is the fructose molecule in the sucrose,
not the glucose, which plays the larger problem.
- Fructose is not metabolized the same as other sugars.
Instead of being converted to glucose which the body uses, it is removed
by the liver.
- Because it is metabolized by the liver, fructose does
not cause the pancreas to release insulin the way it normally does. Fructose
converts to fat more than any other sugar. This may be one of the reasons
Americans continue to get fatter.
Fructose raises serum triglycerides significantly.
As a left-handed sugar, fructose digestion is very low. For complete
internal conversion of fructose into glucose and acetates, it must rob
ATP energy stores from the liver.
- Fructose inhibits copper metabolism. A deficiency in
copper leads to bone fragility, anemia, defects of the connective tissue,
arteries, and bone, infertility, heart arrhythmias, high cholesterol levels,
heart attacks, and an inability to control blood sugar levels.
It seems that the magnitude of the deleterious effects
varies depending on such factors as age, sex, baseline glucose, insulin,
and triglyceride concentrations, the presence of insulin resistance, and
the amount of dietary fructose consumed.
Some people are more sensitive to fructose. They include
hypertensive, hyperinsulinemic, hypertriglyceridemic, non?insulin dependent
diabetic people, people with functional bowel disease and postmenopausal
women.
There is a continuing increase in sugar consumption in
the United States. We now eat 153 pounds of sugar per person per year.
This increase is mostly in the form of fructose. From
the research presented, it seems that this increase is going to have a negative
influence on our health.
Nancy Appleton, Ph.D. is a clinical nutritionist, researcher,
lecturer, and author of Lick the Sugar, Healthy Bones, Heal Yourself
With Natural Foods and the Curse Of Louis Pasteur and her new book Lick
the Sugar Habit Sugar Counter.
Her website is www.NancyAppleton.com.
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