A friend of mine got diagnosed with kidneystones today. She is extremely fit, lean, active and healthy. She does love her sweets though - she is the kind of girl that the normal girls (like me) envy - she can eat anything and not gain a gram.
Her doctor told her that the kidneystones are caused by excessive vitamin D - she takes her 5000IUD some times a week - and we do live above 60 deg latitude here. Ok, i have deep contempt for most doctors, so why should i be surprised? Im not. Im pissed. Because no blood was taken, no tests made, nobody knows her D(25)OH. And nobody cared to mention the number 1 cause of kidney stones - uric acid created by excess fructose in the diet.
This article is a good example of solid research in this field
"We documented 4902 incident kidney stones during a combined 48 years of
follow-up. The multivariate relative risks of kidney stones
significantly increased for participants in the highest compared to the
lowest quintile of total-fructose intake for all three study groups.
Free-fructose intake was also associated with increased risk.
Non-fructose carbohydrates were not associated with increased risk in
any cohort. Our study suggests that fructose intake is independently
associated with an increased risk of incident kidney stones."
This study was the first one performed on humans and they reported that the incidence of kidney stones in both men
and women was related to fructose consumption.
And kidney stones are the least of what may result from exess fructose consumption - heartdisease, metabolic syndrome, diabetes have been associated with elevated fructose consumption aswell.
ADDENDUM:
Vitamin D, Calcium and Kidney stones
I think i should also make it clear that a connection between vitamin D and kidney stones has been studied and dismissed in a Harvard study. They studied 45,616 men over 14 years for a total of 477,000
person-years of follow up. They found no increased risk of kidney stones
with vitamin D intake. They did find that the incidense of kidney stones can be related to low potassium, low magnesium, high refined carbohydrates, high sodas, and a high acid residue. Everything that can result from following a standard western diet. Today, humans live in a state of low-grade metabolic acidosis that leaches calcium from our bones, increases the amount of calcium in our urine, and causes kidney stones. However, at least two studies have linked kidney stones to latitude,
with an increasing incidence of stones at lower latitudes. One also
directly linked stones to sunlight. A Saudi Arabian study found kidney
stones were more common in the summer. We do know that kidney stone formation can be connected to dehydration - so wouldnt the logical connection be found there? Summer >>> dehydration?????
There is a very interesting connection between calcium and kidney stones as was found when scientists at Harvard decided to follow 92 731 women taking part in the Nurses Health Study in order to find out what affects the formation of kidney stones and what protects against it.
They found that calcium from dairy products protected from them, but calcium from supplements increased the risk of developing the kidney stones.
The nurses who consumed the most dietary calcium, primarily from dairy foods
such as milk, cheese and ice cream, were only 65 percent as likely to develop
kidney stones as the women who consumed the least dietary calcium.
At the same time, though, the nurses who took calcium supplements had a 20
percent greater risk of developing stones than women who didn't. The amount
of the supplements didn't seem to make any difference.
The other primary findings of the Nurses Health Study of kidney stones:
- Women who consumed the most sugar had higher rates of forming
kidney stones than other women.
- Those who consumed the most potassium
and fluid were less likely to develop kidney stones than others.
- Meat consumption didn't seem to have any effect on risk of stones
What my logic makes of that:
The calcium in dairy comes with fat and some vitamin D - therefore it is taken up into boneformation. The supplemented calcium doesnt - so it will gather in soft tissues and also in your bloodvesses forming kidney stones and plaque. Also vitamins C has been investigated as possible causes for kidney stones, but such proposals have been refuted.
What is fructose, why is it so dangerous?
From a biochemical perspective, fructose is a monosaccharide that is unique among other sugars. The difference is in the chemical build of the molecule. glucose, another monosacharide, for example is an "
aldose" whereas fructose is a
"ketose". A small but a significant difference where your liver is concerned.
where does one get that fructose from?
Heres a list of fructose content%:
- apple juice 65%
- HFCS in sodas 55%
- table sugar 50%
- honey 38%
What does fructose do once in your body?
The way our body treats fructose is very different from the way it treats other sugars.
rofessor of endocrinology at the
University of California has been the leading forse behind making the ills of fructose public with his documentary "Sugar, the bitter truth", here are some main points i picked out from his work.
Lets pick that apart, shall we
Fructose and fat storage
My readers all know that highcarb/lowfat diets tend to increase triglyceride levels and promote weightgain, but the process of lipogenesis (production of fat cells)
doubles after consuming
fructose than after consuming glucose.
From the November 2004 issue of the American Journal of Clinical Nutrition:
"...ingestion
of large quantities of fructose has profound metabolic consequences
because it bypasses the regulatory step catalyzed by
phosphofructokinase. This allows fructose to flood the pathways in the
liver, leading to enhanced fatty acid synthesis, increased
esterification of fatty acids, and increased VLDL secretion, which may
raise serum triacylglycerols and ultimately raise LDL cholesterol
concentrations."
Why does this all happen?
This is what happens when carbohydrate (glucose) enters the body: blood glucose goes up and the glut-4-pathway is activated: >> NPY neurons of your hypothalamus signal the pancreas to release insulin>> insulin
stimulates the release of
leptin>> leptin suppresses ghrelin.
(all of that happens if your metabolism is not damaged and you are not insulinresistant - we are talking about healthy human metabolism here). As a result of this chain reaction your hunger is suppressed.
A study done in 2008 shows that in comparison with glucose, fructose
did not stimulate insulin output like this.
Fructose completely bypasses this system
and uses the glut-5 pathway - achieving a greatly downregulated insulin response. A blessing for the insuline resistan? Not so. It is only logical to think that the output of this chain reaction will be very different in case insulin-production is muted: ghrelin is not surpressed and you will continue feeling hungry.
The fact is that
fructose also leads to insulin resistance and as many of you know,
insulin resistance has been found to lead to weight gain. Fructose has been used in laboratory studies to create insulin resistance in rats.
"Although fructose does not stimulate insulin secretion in the short term (41),
the insulin resistance and obesity induced by long-term fructose
feeding in experimental animals induces compensatory hyperinsulinemia.
Blakely et al (93) showed significant increases in fasting serum insulin and fasting serum glucose concentrations in rats that consumed 15%
of energy as fructose"
Fructose and kidney disease
During the past decade, scientists have stared to associate fructoseconsumption with uric acid exess. It is a wellknown and longknown fact that elevations in uric acid can lead
to kidney stones. but these scientists found that high uric acid levels reduced nitric oxide
levels, and this, in turn, contributes to inflammation, cardiovascular disease, insulin resistance and "metabolic syndrome." after that more research has come out about the connection between
fructose and kidney disease and
Nakagawa T. et al 2006:
"Uric acid is strongly associated with cardiovascular and renal disease,
but is usually not considered to have a causal role. However, recent
experimental, epidemiological, and clinical studies provocatively
suggest that uric acid may contribute to the development of
hypertension, metabolic syndrome, and kidney disease in some patients.
Clinical studies are urgently needed to examine this important
possibility."
A University of Illinois study Nakamura et al 2008 explains further the toll fructose metabolism takes on our bodies, on our livers specifically
"In order for
fructose to be metabolized, the body has to create both fasted and fed
conditions. The liver is really busy when you eat a lot of fructose."
In this study, 24 rats were fed either a 63 percent glucose or
fructose diet four hours a day for two weeks; at the end of this period,
half the animals fasted for 24 hours before the scientists performed a
gene expression analysis; the other half were examined at the end of a
four-hour feeding.
Fructose feeding not only induced a broader range of genes than had
previously been identified, there were simultaneous increases in
glycogen (stored glucose) and triglycerides in the liver.
"To our surprise, a key regulatory enzyme involved in the breakdown
of glucose was about two times higher in the fructose-fed group than in
the glucose-fed group.
The study also suggests that a protein called carbohydrate response
element binding protein is responsible for the fructose effect on
certain genes that trigger the production of fat"
Fructose and gout
We have all heard the doctors say that gout is a lifestyle disease induces by overconsumption of meatproducts more abundant inthe diets of the well-off. If only it were so, your normal nutritionists with the lowfat/no red meat dogma should have cured the world of gout by now if that were so easy. It is true that uric acid is a breakdown product of the purines, adenine and guanine.
These compounds are found in relatively high amounts in meat, but the causes of gout are a bit more complex than that:
Gout is triggered by the presence of crystals of uric acid in your
joints. Many people with gout have high levels of
uric acid in their blood stream. But not all! Some people with gout do
not have high levels of uric acid in their blood.
Enter fructose: homo sapiens have no enzyme-system to
break down fructose polymers. The only sources of fructose we can use up to a limit
are the simple sugar in fruit or honey and as the molecule combined with
glucose as sucrose in table sugar. Drenching your body with
fructose is a recent novelty we havent simply had time to adapt to. What happens when you drench you metabolism with fructose? The first step in the fructose metabolism patway is conversion to fructose-1-phosphate. Drink a 1,5 litre of cola and you will get 100gm of fructose in your liver. This
will require a large input of phosphate to for the fructose-1-phosphate,
leaving very little for the generation of adenosine tri phosphate (ATP, the primary energy currency of our cells) to be made. A lack of ATP triggers
activity of the degradation system for adenine and the production of,
guess what, uric acid! Wellcome gout, and no steakeating fest was necessary.
Gout has been previously connected to fructose in
older men but now also in
younger women.
Fructose, inflammation and autoimmune disease
Fructose is the most potent reducing sugar in the human diet and if fructose makes its way into the body intact it
is capable of interacting with the amino acid chains of tissue
proteins. That reaction is known as
glycation. Glycation of proteins can alter their function and change the structure
of proteins, which can cause them to be recognized by the immune system
as "foreign" thus inucing an autoimmune attack. Glycated proteins have been shown to be one of causes for
atherosclerosis and in the end-organ damage seen in diabetics. Fortunately, most of the fructose we eat is
converted to glucose in the intestinal wall or in the liver before it
reaches the blood-circulation. Consumption of very
large amounts of fructose (large sodas, overindulging in fructosecontaining sweets, dried fruit etc) overwhelms the fructose-metabolizing capacity of the liver, resulting in the spillage of fructose
into the bloodstream.
In recent
studies it has been confirmed that fructose consumption in the range of the SAD (standard american diet) induces inflammatory state in the vascular
and endothelila cells and decreases intracellular ATP production.
Fructose and cardiovascular disease
Kimber Stanhope of the University of California says in this
study that the Dietary Guidelines for Americans 2010
suggest an upper limit of 25 percent or less of daily calories consumed
as added sugar. In this study, researchers examined 48 adults ages 18-40 and compared
the effects of consuming 25 percent of one's daily calorie requirement
as glucose or fructose on risk factors for
cardiovascular disease. The study, published in the Journal of Clinical Endocrinology &
Metabolism, found that within two weeks, study participants consuming
fructose or high-fructose corn syrup, but not glucose, exhibited
increased concentrations of low-density lipoprotein, "bad" cholesterol,
as well as triglycerides and apolipoprotein-B -- a protein that can lead
to plaques that cause vascular disease.
"Our findings demonstrate that several factors associated with an
elevated risk for cardiovascular disease were increased in individuals
consuming 25 percent of their calories as fructose or high fructose corn
syrup, but consumption of glucose did not have this effect," Stanhope
says.
Uric acid promotes gout, but also hypertension and
cardiovascular disease. Fructose consumption raises uric acid levels in the body and there are many
studies which show uric acid is linked to heart disease:
This
Baylor College of Medicine study says:
The association between uric acid and cardiovascular disease was largely
ignored until the mid-1950s and early 1960s, when it was rediscovered.2,3
Since then, a number of epidemiologic studies have reported a relation
between serum uric acid levels and a wide variety of cardiovascular
conditions, including hypertension,2 metabolic syndrome,4 coronary artery disease,5 cerebrovascular disease,6 vascular dementia,7 preeclampsia,8 and kidney disease.9,10
The relation between uric acid and cardiovascular disease is observed
not only with frank hyperuricemia (defined as more than 6 mg per
deciliter [360 μmol per liter] in women and more than 7 mg per deciliter
[420 μmol per liter] in men) but also with uric acid levels considered
to be in the normal to high range (>5.2 to 5.5 mg per deciliter [310
to 330 μmol per liter]).11-13
Fructose and erectile dysfunction
One of the many side-effects of fructose consumption is a massive
decrease in nitric oxide production (as discussed above).
Erectile problems stem from diminished nitric oxide (NO) production, poor blood pressure, hormones, low testosterone, or stress. Successful penile erection requires the relaxation of blood vessels
within the penis' tissue. This relaxation and resulting
engorgement of blood is triggered by a gaseous chemical our bodies
produce, called nitric oxide (NO). Overconsumption of fructose raises uric acid which significantly lowers the body`s ability to produce NO.
Fructose and ageing
Just in case you haven`t been convinced to stay away from the fruit juice by now, then
here is another reason. Fructose may be causing your body to
age faster through a process known as glycation.As mentioned earlier, fructose is the most reactive of all monosaccharides.
Glycation is a process where a sugar molecule binds itself to a protein molecule or
a lipid molecule. The resulting molecules are called Advance Glycation
Endproducts or AGEs for short. These AGEs are implicated in
diabetes, muscular degeneration, cataracts, and both weakening and
stiffening of collagen. Collagen is the stuff that keeps the skin supple and your blood vessels elastic. When your collagen hardens
and weakens, you start accumulating wrinkles and your blood pressure starts
to rise.
Your body is able to get rid of AGEs, through your kidneys and autophagy processes, but never as
fast as they are formed. The kidneys can be overloaded
by the AGE accumulation resulting in kidneys failure. This is a common problem with diabetics who often
have excessive AGEs due to excessive glucose in their blood.
This study, published in the Journal of Nutrition already in 1998 concludes:
This study demonstrates that long-term fructose feeding accelerates
aging as expressed by changes in various age-related markers
measured in collagen from skin and bones. The focus
on collagen is warranted because collagen is present ubiquitously,
accounts
for as much as 30% of body proteins, mainly in the
extracellular matrix, and provides the basic functional properties of
most
vulnerable tissues such as renal basement membrane,
the cardiovascular system and retinal capillaries. In addition,
collagen
has a long half-life that allows the accumulation
of nutritional and age-related lesions. Glycation can affect both
biochemical,
mechanical and physiologic functioning of collagen.
The deleterious effects of glycation on collagen play a significant
role
in the pathogenesis of the aging process and the
late complications of diabetes (Paul and Bailey 1996).
Ok, i give up, if you werent convinced by now, go and continue with your fruitjuices, honey and agave nectar. Im tired now. Over and out.
Ok, ok just one more
Fructose and cancer
We in the paleocommunity are aware that glucose
is used in the cancercells for energy as they have disfunctioning
mitochondria and cant produce ATP as normal cells do.
At the University of
California they made a study looking into cancercell proliferation and they published their findings in the Journal of Cancer Research:
"These findings show that cancer cells can readily
metabolize fructose to increase proliferation," Dr. Anthony
Heaney of UCLA's Jonsson Cancer Center and colleagues wrote.
"They have major significance for cancer patients
given dietary refined fructose consumption, and indicate that
efforts to reduce refined fructose intake or inhibit
fructose-mediated actions may disrupt cancer growth."
Im going home, enjoy the weekend everybody
