|
My comments:
1. The title states Vitamin C linked to Hardening of Arteries. This is a conclusion statement with unfounded data and clarification. It could have just as easily stated Vitamin C
linked to Strengthening of Arteries.
2. The unpublished and not reviewed presentation states that thickening
occurred in the inner artery layer.
The news article writer then made a fatal pivotal claim yet unproven, i.e.
(assumption without clarification). --"Such thickening precedes atherosclerosis, physicians say." --Which physicians
say this thickening precedes a disease condition? (From further
information, it appears that ignorance rules the statement.) Thickening can mean strengthening of tissue,
i.e.. soft tissue such as arteries, veins and capillaries which are greatly enhanced by Vitamin C and
bioflavonoids and therefore resulting in protection from stroke or rupture and leakage of the
arterial walls. OR thickening may mean the laying down of plaque , i.e.. calcium in particular due to high oxidant activity and deterioration
or thinning of the cell wall, often a result of lack of vitamin C, which the article states "can help block the oxidation of
cholesterol", which is true.
3. The article relegates all previous scientific studies on Vitamin C and heart health as "based largely on a mixture of folk wisdom and over-extrapolated studies." I do find the very statement a true description of the author's article. It is an
over-extrapolation of a study with a specific result in mind. Meanwhile
Vitamin C remains one of the most studied nutrients in the United States
and internationally.
Why such poor writing and reporting?
1. The pharmaceutical industry has a desire to control the herb and vitamin market for protected profits and to make such nutrients available through doctor's prescriptions, as is now the case in
Germany and Norway. In fact no one can receive 500mg vitamin C tablets in Germany without a doctor's prescription.
This includes receiving it in the mail from overseas.
2. The subtle message is....The only authorities who can protect your health are doctors, and individuals who read books and take supplements to improve or maintain their health are incompetent and dangerous to themselves (even though these books are written by researchers and authorities on the actual subject).
3. Authors like to bash ideas and gain public exposure, even though the researchers plead with columnists not to distort their findings by equating speculations with facts and
doubling the problem by presenting information inaccurately and with prejudice.
Was this the case with this author or was he hired to do so?
4. More damage to the health industry is done by an outrageous headline. All the retractions and discussions that occur in the aftermath cannot possibly undue the damage. The weaker the industry, the cheaper to buy
it out by the rich multi-national pharmaceutical firms. That is happening right now, if you can't beat them, buy them out and get the
government to issue legislation that restricts access and availability. The health of the individual be damned!
5. Success is measured by the degree of fear and suspicion a well-placed and
badly written article generates. Even if the opposite is true of what is stated in a news item, the real battle is over the minds of
people in the marketplace. Once people are convinced they know nothing about their own health and give up all authority of it to a higher source, they become the well-led patient,
helpless victims, and very possibly one of the 108,000. (There were
108,000 documented deaths in 1998 due to doctor prescribed and hospital delivered pharmaceutical drugs.)
Regards, Michael
Following is the Linus Pauling Institute's response
to the recent article on
vitamin C and atherosclerosis:
(updated April 27, 2000)
Does vitamin C cause thickening of the arteries?
A widely-publicized study reported on March 2, 2000, by
Dr. James Dwyer and colleagues at an American Heart Association meeting in
San Diego suggested that vitamin C supplements may actually increase
thickening of the arteries, or atherosclerosis. Although the researchers
themselves called their findings "a surprise" and cautioned that
more experiments are needed to find out if vitamin C supplements are
harmful, the study was released to the news media, apparently without a
discussion of its limitations or putting it into the proper context of the
wealth of other research demonstrating the health benefits of vitamin C.
It was irresponsible to release this unconfirmed study without appropriate
background information, causing unnecessary and unjustified confusion and
fear among the public.
Dr. Dwyer reported that subjects taking 500 milligram
supplements of vitamin C daily for at least a year had a rate of
thickening of the carotid artery wall 2.5 times greater than subjects who
did not take supplements. However, these results directly conflict with a
much larger and better controlled study published in 1995 in the American
Heart Association journal Circulation, which found significantly reduced
carotid artery wall thickness in people over 55 years old who consumed
daily amounts of vitamin C greater than about 1,000 mg compared to those
consuming less than 88 mg. Interestingly, this study used the same
study design and methods to measure artery wall thickness as Dwyer, but
was based on over 11,000 subjects and had undergone rigorous peer-review
before publication. Dwyer’s study was based on 573 subjects and was
presented as an abstract without prior peer-review.
If Dwyer’s results were indeed true, those people who
take vitamin C supplements should die of heart attacks and strokes at a
much greater rate than non-supplement users. However, there is no
scientific evidence to support this concept. Many epidemiological studies
and some clinical trials have suggested that dietary intake or
supplementation of vitamin C is associated with a reduced risk of heart
disease and stroke. For example, a large epidemiological study published
in 1992 showed a risk reduction for heart disease of 45% in men and 25% in
women consuming greater than 50 mg of vitamin C daily from the diet plus
regular supplements, corresponding to a total vitamin C intake of about
300 mg per day. Although this study indicated that vitamin C supplements
provide cardiovascular benefits above and beyond the vitamin C obtained
from the diet, two other large epidemiological studies published in 1996
found no effect on heart disease risk in people who take regular vitamin C
supplements. Importantly, not a single epidemiological study or
clinical trial has found an increased risk of heart attacks or strokes in
people taking vitamin C supplements.
Over twenty clinical studies since 1996, published
primarily in Circulation, have consistently found beneficial effects of
vitamin C—administered either orally or by intra-arterial infusion—on
the relaxation of arteries, or vasodilation. Impaired vasodilation is an
important risk factor for angina, heart attacks, and strokes. Vasodilation
in patients with heart disease is significantly improved following daily
supplementation with 500 mg of vitamin C for thirty days and is comparable
to vasodilation seen in healthy people.
Beneficial effects of vitamin C supplements leading to
normalization of vasodilation have also been observed in patients with
angina, heart failure, high cholesterol levels, hypertension, diabetes,
high homocysteine levels, and in smokers. Additionally, a recent
study in Lancet demonstrated that 500 mg of vitamin C given daily for
thirty days lowers blood pressure in patients with mild to moderate
hypertension. High blood pressure is a major risk factor for heart disease
and strokes. The salubrious effects of vitamin C were comparable to those
derived from conventional anti-hypertensive medications.
There is another important limitation of the study
reported by Dwyer and colleagues. Because this is an epidemiological
study, the observed associations between vitamin C intake and carotid
atherosclerosis do not prove a causal relationship and may be confounded
by unmeasured risk factors or imperfect statistical adjustment of the
data. In other words, there may have been differences in diet or lifestyle
that better explain the results of the study. Furthermore, the vitamin C
intakes were estimated from 24-hour recall and dietary questionnaires,
relatively imprecise methods to assess vitamin C status in the body.
Although blood levels of vitamin C were reported—a more reliable measure
of the body’s vitamin C status—they were not compared to artery wall
thickness.
People taking vitamin C supplements should continue to
do so, as the known health benefits of vitamin C far outweigh alleged,
unconfirmed risks. There is no scientific evidence that vitamin C
supplements increase the risk of heart attacks or strokes. Daily vitamin C
supplements of 500 mg have been shown to normalize vasodilation and lower
blood pressure, mitigating two major cardiovascular risk factors.
Back to Top
Next are letters from two other experts on vitamin
C.....
From: "Dr. Bill Misner, Ph.D."
I received this posting yesterday and thought the endurance list
would be interested. It appears partly to explain why Vitamin C
was attacked again by the news media, not by real scientists...
A similar Vitamin C bashing took place 6-8 months ago claiming vitamin C caused DNA damage, but later we discovered the
DNA damage occurred in mishandling by graduate research lab technicians, when they transferred the DNA from one media to another. (my
emphasis)
We have been in contact with Professor James Dwyer of
the USC Medical School, one of the principal researchers. As expected, this research seems to be good news for
elderly vitamin C takers whose carotid arteries have
"thinned" with age. There is no evidence of occlusion (or clogging), contrary to the media reports.
(my emphasis)
Here is what we have confirmed with Dr. Dwyer:
1. There is no paper as we suspected. (The USC
team's paper is in "peer review" and not available.)
2. The USC team used a new "B-mode" imaging technique
which is still undergoing clinical trial for accuracy at the NIH.
3. This B-mode imaging technique has three indicators. The USC team only studied one; carotid arterial "thickening"
or "IMT". (Dr. Dwyer tells us there will be no reference in
their paper to the other two occlusion indicators; plaque
index and velocity ratio.)
4. According to correspondence, Dr. Dwyer and the USC team
is unaware that arteries might get thicker with increased
vitamin C intake, and that this is entirely predicted by theory. (Increased Vitamin C stimulates collagen production, but this is
not well taught or well known in medical school.)
5. Last year, the same USC research team (Dwyers, et. al)
wrote a paper with the OPPOSITE findings. Last year they
found that stress (some would say a vitamin C deficiency)
leads to early atherosclerosis in men (March 1999).
Bottom line: There is no evidence of occlusion, only thickening.
Now we need your help repairing the damage caused by the premature release of this unpublished research. Millions of
people are now afraid of vitamin C. Please help spread the
word. We will post more information as it becomes available at: http://www.vitamincfoundation.org
Back to Top
Here is another letter from a highly respected
physician in the SF Bay Area
Dr. Cathcart the leading expert on treating people with high doses of vitamin C says,
"My experience with 25,000 patients since 1969 indicates that
this charge is ridiculous. I know that follow-up is not perfect in
private practice but I have had no patient who had a good heart
when I first saw them and who took massive doses of C who ever
developed heart problems. I have to add that I advise all my patients
to avoid sugar, chemicals, and highly process foods, and put them
on a number of other nutrients.
"If it turns out that there is thickening of the carotid, I think it
is
reversing the thinning that occurs with aging. It is interesting that
the effect is so dramatic in the reversing of the effect on smokers.
I have to congratulate you at the Vitamin C Foundation on unveiling
the other two findings that could have been measured which were not reported.
"Probably the finding that C helped would not be publishable."
Sincerely,
Robert Cathcart, MD
March 10, 2000
Back to Top
Here is more information on the technique used for the USC experiments.
Here is some technical information on the B-mode imaging
process. Note there are three measures, yet the USC paper
will only mentions one. The missing two measures are used to
infer occlusion.
Detailed B-mode images of the right and left common carotid
artery, common carotid bifurcation, and the first centimeter of
the internal carotid artery are obtained. Selected images are
digitized for later measurement of intima-media thickness. After
imaging, the sonographer obtains pulsed wave Doppler measures
of blood flow velocity at the mid common (2 cm proximal to the
carotid bulb) and in the internal carotid artery at the point of
highest velocity distal to the flow divider. These are used to calculate the degree to which plaque may be interfering with blood
flow.
The scanning and reading protocols result in three primary carotid
disease measures:
1. average wall intima-media thickness ;
2. a measure of degree of focal plaque called the plaque index;
3. and the velocity ratio, a determination of whether or not
plaque is interfering with blood flow in the internal carotid artery.
Again, the USC team's report will only concern arterial thickness. The occlusion indicators are not reported for reasons unknown.
Owen R. Fonorow
The Vitamin C Foundation
www.vitaminCfoundation.org
'til next time, Michael
|
Disclaimer:
The information contained in Michael's Notes is based on the
personal experiences and research of the author, Michael
LeVesque. It has not been evaluated by the Food and Drug
Administration. It is intended for educational purposes, and
is not meant to diagnose, treat, cure, or prevent any disease, or
to prescribe or replace medical care. Due to biological
individuality, each person is unique and should check with a qualified health professional regarding
the appropriateness of any product. It is always wise to
seek more than one opinion. |
Back to Top |
