"Lou" <lou(nospam)@411.com> wrote in message
news:[email hidden]...
Quoted message said:Lancet. 2001 Mar 3;357(9257):657-63. Related Articles, Links
Comment in:
Lancet. 2001 Jul 7;358(9275):71-2.Relation between plasma ascorbic acid and mortality in men and women in
EPIC-Norfolk prospective study: a prospective population study. European
Prospective Investigation into Cancer and Nutrition.Khaw KT, Bingham S, Welch A, Luben R, Wareham N, Oakes S, Day N.
Department of Public Health and Primary Care, Institute of Public Health,
University of Cambridge School of Clinical Medicine, UK.
[email hidden]BACKGROUND: Ascorbic acid (vitamin C) might be protective for several
chronic diseases. However, findings from prospective studies that relate
ascorbic acid to cardiovascular disease or cancer are not consistent. We
aimed to assess the relation between plasma ascorbic acid and subsequent
mortality due to all causes, cardiovascular disease, ischaemic heart
disease, and cancer. METHODS: We prospectively examined for 4 years the
relation between plasma ascorbic acid concentrations and mortality due to
all causes, and to cardiovascular disease, ischaemic heart disease, and
cancer in 19 496 men and women aged 45-79 years. We recruited individuals
by
Quoted message said:post using age-sex registers of general practices. Participants completed
a
Quoted message said:health and lifestyle questionnaire and were examined at a clinic visit.
They
Quoted message said:were followed-up for causes of death for about 4 years. Individuals were
divided into sex-specific quintiles of plasma ascorbic acid. We used the
Cox
Quoted message said:proportional hazard model to determine the effect of ascorbic acid and
other
Quoted message said:risk factors on mortality. FINDINGS: Plasma ascorbic acid concentration
was
Quoted message said:inversely related to mortality from all-causes, and from cardiovascular
disease, and ischaemic heart disease in men and women. Risk of mortality
in
Quoted message said:the top ascorbic acid quintile was about half the risk in the lowest
quintile (p<0.0001). The relation with mortality was continuous through
the
Quoted message said:whole distribution of ascorbic acid concentrations. 20 micromol/L rise in
plasma ascorbic acid concentration, equivalent to about 50 g per day
increase in fruit and vegetable intake, was associated with about a 20%
reduction in risk of all-cause mortality (p<0.0001), independent of age,
systolic blood pressure, blood cholesterol, cigarette smoking habit,
diabetes, and supplement use. Ascorbic acid was inversely related to
cancer
Quoted message said:mortality in men but not women. INTERPRETATION: Small increases in fruit
and
Quoted message said:vegetable intake of about one serving daily has encouraging prospects for
possible prevention of disease.PMID: 11247548 [PubMed - indexed for MEDLINE]
Interesting finding that the effect was "independent of supplement use".
It tends to reinforce the possibility that getting your vitamin C from the
diet is preferable to getting it from supplements, due to other qualities of
fruit and vegatables. Hence the ending recommendation.
Or, perhaps more accurately, the results simply reflect what we already
knew, that a diet rich in fruit and vegetables is healthy, and vitamin C
levels show the amount of fruit and vegetables ingested..
LOu, it is an utter waste of time taking massive doses of Vitamin C for
reasons other than the ones Eric has put. It is just not utilised. Here
is an ealrier post explaining why -----.
"The feet has been largely cut out from under Pauling's ideas on megavitamin
C. It always was extremely naive medically to assume that you only got
diarrhoea from a chemical substance when the body stopped consuming it, but
that is not the half of it.
Dr Andrew Weil, the alt.med guru, and one of the less flaky ones, recently
explained --
(Published: 8/5/99) Many of you have heard that I've reduced my recommended
dosage of vitamin C from 2,000 to 6,000 mg divided into three doses a day to
only 200 to 500 mg divided into two doses. I made the change after I
examined two recent studies that show lower levels of ascorbic acid more
than saturate the body's tissues, and thus are enough to protect against
cancer, heart disease and other chronic illnesses.
A review of clinical trials published in the April 21st issue of the Journal
of the American Medical Association concluded that 200 mg a day is the
maximum human cells can absorb, making anything above that level a waste.
The second study came from the Linus Pauling Institute (Pauling himself took
18,000 mg of C per day), published in the June issue of the American Journal
of Clinical Nutrition. It identified a similar dose, 120 to 200 mg, as the
optimal amount for reducing the risk of cardiovascular disease, cancer,
cataracts and other chronic conditions. I wouldn't worry if you've been
taking the higher dosages I've recommended in the past as vitamin C is water
soluble and anything not used by the body quickly passes out. In fact, I
still recommend higher dosages to those not getting at least five servings
of fruits and vegetables as part of their daily diet.
This is closer to original sources --
"New insights into the physiology and pharmacology of vitamin C
Sebastian J. Padayatty, Mark Levine
CMAJ 2001;164(3):353-5 [PDF]
When given orally, ascorbic acid is well absorbed at lower doses, but
absorption decreases as the dose increases. Thus, median bioavailability
following an oral dose is 87% for 30 mg, 80% for 100 mg, 72% for 200 mg and
63% for 500 mg. Less than 50% of a 1250-mg dose is absorbed, and most of the
absorbed dose is excreted in the urine.3,8 Ascorbic acid is not protein
bound, so it is filtered and reabsorbed by the kidneys in healthy subjects
but is lost in patients who have been hemodialyzed. Ascorbic acid begins to
appear in urine at doses above 100 mg/day, corresponding to a plasma
concentration of about 60 µmol/L, at which point plasma is 70% saturated and
circulating white blood cells are fully saturated. Decreased bioavailability
and renal excretion keep plasma vitamin C at less than 100 µmol/L, even with
an oral dose of 1000 mg. In men at steady state, a 30-mg daily intake
results in a mean plasma concentration of 9 µmol/L, 60 mg results in25
µmol/L, 100 mg in 56 µmol/L and 200 mg in 75 µmol/L. Thus, the
dose-concentration relationship is sigmoidal, with the steep portion of the
curve lying between 30 mg and 100 mg of oral vitamin C daily.3,8 Doses
greater than 500 mg daily contribute little to plasma or tissue stores.
Circulating white blood cells contain 10-30 times the plasma concentrations
of vitamin C."
At least our fish should be healthy, or are they a species that makes their
own Vitamin C?
Peter Moran
Reinforcing what ERic has said about larger doses of Vitamin C
Quoted message said:
(End of Abstract)My Take:
Note: "mortality due to all causes".
Just think of what higher levels induced via vitamin c supplementation
would
Quoted message said:provide.
I'm sticking to my 8 - 10 Grams of C a day. (For the last 11 years).
Lou