Is
the common belief that if a little is good, then more must be better.
Although, many substances that provide beneficial effects to the body can be
harmful, or even deadly, in large amounts. Even water or oxygen can be
harmful or deadly in high amounts, or in the right circumstances.
Men who take high doses of vitamin supplements could be increasing their risk of lethal prostate cancer by nearly 30 per cent, say researchers.
A study of 48,000 men spanning more than two decades suggests popping too many vitamin pills can put them in danger of tumours that are more likely to be fatal.
The researchers linked high doses of vitamin C to an increased risk of lethal and advanced prostate cancer.
The results, by experts from Harvard School of Public Health in Boston, in the US, and the University of Oslo in Norway, are not the first to raise the alarm over the dangers of excess vitamin consumption.
Nearly a quarter of adults in the UK are estimated to take antioxidant supplements or multivitamins regularly in the hope that it will help protect them against illnesses such as heart disease and cancer. The market for such products is worth around half a billion pounds a year.
In recent years, high-dose vitamins have become popular, with people taking more in the belief that it is better for them.
For example, health food shops now sell vitamin C tablets in doses of 1,000mg each, but the body needs only about 40mg a day to keep cells healthy and promote healing.
In the latest research, the scientists set out to see if antioxidants in vitamin pills and food could reduce the chances of a prostate tumour.
From 1986 to 2008 they followed 48,000 men aged between 40 and 75. Every four years, the men completed food questionnaires designed to record their dietary habits.
The researchers followed them up to see which ones developed prostate cancer.
The results, published in the International Journal Of Cancer, show that total antioxidant intake – from foods or pills – neither increased nor decreased the risk of a tumour. Antioxidants fight the process, called oxidation, that destroys cells.
There was some suggestion antioxidants from coffee had a slightly protective effect.
But the most alarming finding was that men with the highest intake of antioxidants from vitamin pills were 28 per cent more likely to get lethal prostate cancer than those who took the lowest amount of pills or none.
Those with the highest intake of antioxidants from vitamin pills were 15 per cent more likely to get advanced prostate cancer – a tumour that spreads quickly beyond the prostate, reducing the chances of survival.
In a report the researchers said: ‘High intake of antioxidants from supplements was associated with increased risk for lethal and advanced prostate cancer.
'The main contributor is vitamin C, and this finding warrants further investigation.’
But the researchers stressed that, until more research is carried out, they cannot be sure that vitamin tablets actually cause cancer.
It may be that the cancer victims felt unwell for several months before their diagnosis and simply increased vitamin intake to try to ward off symptoms such as fatigue.
Dr Carrie Ruxton, of the Health Supplements Information Service, which is funded by supplements makers, said: ‘It is entirely possible that these men may have had prostate-related symptoms and fatigue long before diagnosis.
'The cancer may have had nothing to do with the supplements.’
Scientists found consuming large amounts of vitamin C made individuals 20 per cent more likely to develop the condition – which is a leading cause of blindness.
And regularly popping high-dose vitamin E tablets increased the chance of cataracts forming by 60 per cent.
The dangers are even greater for the elderly, with those over 65 nearly doubling their chances of damaging their vision if they took the supplements every day.
Researchers from the Karolinska Institute in Stockholm monitored 31,000 volunteers aged between 45 and 79. Nearly 3,000 of them went on to need treatment for their eyes.
The Swedish team discovered a strong link between those that developed cataracts and those who took high doses of vitamin C and E.
Eating a healthy vitamin-rich diet did not increase a patient’s chance of getting the condition.
It was originally thought the two vitamins would protect against cataracts because they are powerful antioxidants.
It was supposed that they would fight the process of oxidation, which destroys cells in much the same way as rust rots a car. However, it is now believed that, in large quantities, vitamin C may actually cause oxidation by upsetting the natural balance of proteins in the eye.
The human body does not make or store vitamin C, and gets its supply from fruit and vegetables. It only needs 40mg a day to keep cells healthy and promote healing. Vitamin E helps maintain the structure of cells and is found in foods such as nuts, seeds and cereals.
A man needs just 4mg a day and a woman should have 3mg. But tablets containing up to a hundred times this amount are also available in UK health food shops.
At high street chain Holland and Barrett a jar of 250 capsules can be bought for £8.99. Each pill contains 1,000mg of vitamin C.
Researchers stressed the dangers will only arise if the vitamins are taken in very large amounts. These were defined as 1,000mg a day of vitamin C and 100mg of vitamin E.
In a report on their findings, they said: ‘Our results further underscore the need to consider use of unregulated supplements with caution.’
However Professor Yit Yang, from the Royal College of Ophthalmologists, said: ‘It is not possible to establish from this study that vitamin C caused cataracts, as there may be other factors which were not accounted for.
‘In 2010, a randomised control trial designed to investigate specifically for causative effect of high-dose vitamin C did not find one.’
At the moment, nearly a quarter of adults in the UK regularly take antioxidant supplements or multivitamins.
They are relied on to help ward off a huge range of illnesses such as cancer and heart disease.
- Rutinbiofavonoids (vitamin P) factor K
- Factor Jfactor P Tyrosinase
- Ascorbinogen ascorbic acid
All of the above elements must be present in order for the body to absorb and benefit from the vitamin complex. Since synthetic ascorbic acid does not contain the full complex, your body must either gather the missing components from the body's reservoir, or simply eliminate the ascorbic acid from the body through the urine without benefit to the body.
You'll find ascorbic acid in all sorts of products, from vitamin C supplements to bottled tea drinks and fruit juices such as apple juice. The straightforward method to confirm its presence in a product is to simply read the ingredient label. However, as founder of AGM foods in Brisbane, Australia Alan Meyer found out, many times ascorbic acid can be found in foods even though it's not listed on the ingredient label.
Ascorbic acid is synthesized from corn syrup. So not only do we need to be concerned with its impact on intestinal flora, but with its potentially disastrous GMO corn-based origins. These days, if you cannot verify that any corn-based food that you consume is certified organic, you risk ingesting GMO corn, the health risks of which are well-known by knowledgeable NaturalNews readers.
So what is the solution to all this? The thing to do is avoid vitamin C supplements, pasteurized products, and pre-bottled teas and juices containing ascorbic acid. Get your vitamin C from natural, organic, uncooked fruits and vegetables. Some foods that contain the highest amounts of vitamin C are:
- Strawberries
- Citrus fruits
- Acerola Cherry (fresh or powdered forms)
- Black Currant
- Papaya
- Kiwi fruit
- Bell Pepper
- Guava
- Melons
- Brussel Sprouts
- Kale, chard, and spinach
- Broccoli
- Cauliflower
- Tomatoes
Again, remember to consume foods in their raw form. If heated, the natural vitamin C complex is destroyed.
I'm a big fan of Vitamin C and feel much better when taking
it. In fact, it is really the only vitamin or mineral that
I megadose simply because I feel the RDA / AI is much too
low. I also am a cautious follower of the Pauling Theory, simply
because Vitamin C does some spectacular things at a megadose
level ( >= 1 gram/day). It's hard to argue with a
cheap supplement that can boost nitric oxide, improve weight loss, control cortisol, lower blood pressure, decrease inflammation, protect the brain - the list goes on and on. You can check out my links on 10+ Great Reasons
to Take Vitamin C and
Vitamin C and Erectile Dysfunction for more information.
CAUTION: In my link on Garlic and Erectile Dysfunction, I discuss how Vitamin C and garlic coupled together can dramatically increase nitric oxide and lower blood pressure. However, one should always consult with your doctor first if you have any medical condition or are on any medications. For example, lowering your blood pressure too much can have serious consequences.
In spite of all the praise I have for Vitamin C, a few cautions are in order. In my opinion, Vitamin C's track record is excellent, but a few potential "dangers" have been uncovered as well and I cover those below:
1. Blood Flow Reduction. One animal study showed that in some cases Vitamin C could possibly contribute to a loss of blood flow. This study basically demonstrated that Vitamin C could increase a key oxidant, peroxide, that is responsible for supplying blood flow to the muscles and expanding arteries. [15] In my link on Antioxidants and the Heart I discuss how free radicals, supposedly the villains, actually play crucial roles in our health. For example, nitric oxide is a free radical and dilates our arteries. Researchers are concerned that taking too many antioxidants, such as Vitamin C, could quench the body's requirement for these free radicals.
Now the rebuttal to this is that this study actually combined two antioxidants and thus may not really be a realistic scenario. In fact, as mentioned above, researchers have found that combining garlic and Vitamin C increases nitric oxide by three times! We have had guy on The Peak Testosterone Forum use this to cure their erectile dysfunction - that's how powerful it for some men. Nevertheless, it does beg the question as to whether we fully understand the complete impact of megadosing Vitamin C.
2. Loss of Exercise Benefits. Another disturbing study showed that 1000 mg daily of Vitamin C coupled with 235 mg daily of Vitamin E lowered key benefits of exercise. The researchers summarized by saying that "daily vitamin C and E supplementation attenuated increases in markers of mitochondrial biogenesis following endurance training." [18] Of course, some would argue that Vitamin C alone may not do the same and so it is too bad that the study did not also look at each supplement separately. Again, though, this shows that one can have too much of a good thing.
Do you know the foods and drinks that increase erection-boosting Nitric Oxide? Check out the Peak Erectile Strength Diet where I show you how to dramatically and naturally improve your erectile strength.
3. Increase Arterial Plaque?. And then came the real black eye: one study showed increased arterial thickness from Vitamin C. This study reported that those who took Vitamin C had 2.5 times the thickening of the arteries compared with those who took none. [3] This study has been criticized for being relatively small and one can't help but ask the question, "If Vitamin C causes such accelerated hardening of the arteries, why aren't its proponents dropping dead like flies?" Personally, I doubt that Vitamin C causes arterial thickness as this was a small and controversial study, and there are many studies showing that Vitamin C improves arterial health.
4. Increasing Nitrosamines. One can't help but wonder why Vitamin C does not fight cancer more effectively. After all, it is one of our body's most important antioxidants and it is used extensively throughout the immune system. It only stands to reason that it should help with cancer outcomes. The reason is very likely that Vitamin C very likely has a dark side: the journal Gut simulated conditions in the stomach and found that Vitamin C, when fat levels are low, actually inhibits the carcinogenic nitrosamine production but promotes nitrosamines when fat is present. [8] I'm not talking about fat as in overweight: I'm talking about fat in your meal. If you eat any fat in your meal - which almost every one in a modern society does - megadosing with Vitamin C will lead to a flood of carcinogenic nitrosamines and this may explain some of Vitamin C's questionable cancer results.
By the way, did you know that ascorbic acid is sometimes added to meats to lower nitrosamine production. The point is that there is data that shows the opposite of the above. As always, it's too bad there isn't more study work.
5. Raising Iron Absorption. Dr. Russell Blaylock and other recommend taking Vitamin C (in a "salt" or "Ester-C" form) in order to make sure that you do not increase iron absorption. Unfortunately, most men in Western societies consume too much iron and this associated with cardiovascular and neurological disease. Again, an easy solution is to take it on an empty stomach but not all men know about this.
6. Heart Disease. Let's start by looking at
Vitamin C and heart disease, which is the #1 killer of
men and the underlying cause of most erectile
dysfunction issues. Here the
studies have been decidedly mixed and some have
wondered if this means Vitamin C has some hidden negative property that
masks some of the good ones. In its favor, Vitamin C, and Vitamin E as
well, were
examined in a controlled study by Danish
researchers in 2000. Participants
were given 250 mg and 91 mg twice daily of
Vitamins C and E, respectively.
This study found that those on the Vitamins C
and E had decreased arterial
thickness, i.e. less plaque buildup from
arteriosclerosis. [1] The researchers
commented that "taking either vitamin separately
also resulted in a reduction in
plaque buildup but the combination of vitamins
worked best..." Similarly, a
large meta-analysis of nine cohorts found that
those who took supplemental
Vitamin C at megadose levels (> 700 mg) had
significantly reduced (25%)
cardiovascular issues compared to those who did
not take Vitamin C. [2]
So everything sounds like a "green light", right? Well, unfortunately, there have been a number of studies that have found that Vitamin C has no significant heart benefit. One of the biggest was The Physicians Health Study II of 14,000 male physicians run by a Harvard professor. In this study physicians were put on 500 mg Vitamin C and 400 IU Vitamin E daily. The researchers found that neither vitamin decreased cardiovascular events whatsoever. [17] Then came a study on postmenopausal women with diabetes that showed an increased cardiovascular risk with Vitamin C usage. [16] Critics point that 500 mg of Vitamin C is a fairly low dosage according to Pauling Theory.
Another researcher, Rory Collins, looked at not just heart disease during a huge five year study involving 20,000 people who took daily 600mg of vitamin E, 250mg of vitamin C and 20mg of beta-carotene. This study [7] in the prestigious journal Lancet found that there was no improvement in heart disease or cancer rates. Once again, Vitamin C looked like a questionable use of one's money. Again, some have criticized this study for only supplementing with 250 mg of Vitamin, but keep in mind that is roughly the Vitamin C found in five oranges.
CAUTION: If you have a medical condition or are on any medications, please discuss any changes with your doctor first. Certain supplements, foods and even juices can alter absorption rates of certain medications for example. Play it safe.
REFERENCES:
1) Journal of Internal Medicine, 2000; 248 (5), 377-386
2) American Journal of Clinical Nutrition, Dec 2004, 80(6):1508-1520, December 2004 Antioxidant vitamins and coronary heart disease risk: a pooled analysis of 9 cohorts Paul Knekt, et al
3) Reported on March 2, 2000, by Dr. James Dwyer at an American Heart Association meeting in San Diego
7) The Lancet, 2002, 360(9347):1781-1782
8) Gut, 2007; 56:1678-1684, Published Online First: 4 September 2007, "Fat transforms ascorbic acid from inhibiting to promoting acid-catalysed N-nitrosation"
9) J Am Coll Nutr, 2005 Jun, 24(3):158-65
14) http://esciencenews.com/articles/2009/09/09/ study.reveals.new.role.vitamin.c.skin.protection
15) Experimental Physiology, Published Online: 21 Jul 2009, 94(9):961-971, "The effects of antioxidants on microvascular oxygenation and blood flow in skeletal muscle of young rats"
16) Am J Clin Nutr, Nov 2004, 80(5):1194-1200, "Does supplemental vitamin C increase cardiovascular disease risk in women with diabetes?"
17) JAMA, 2008 Nov 12, 300(18):2123-33, "Vitamins E and C in the prevention of cardiovascular disease in men: the Physicians' Health Study II randomized controlled trial.
18) J of Physiology, Published online before print Feb 3 2014, "Vitamin C and E supplementation hampers cellular adaptation to endurance training in humans: a double-blind randomized controlled trial"
Megadosing of vitamin C was made famous by the Linus Pauling Institute,
especially among cancer patients. The belief is that large amounts of
vitamin C can boost the immune system, destroy pathogens, and protect the body
from free radical damage safely because the excess vitamin C will be eliminated
from the body. Although, the use of massive doses of vitamin C for
therapy by the Linus Pauling Institute is done for very short periods of time,
up to a week. Even though short term megadosing of vitamin C may cause problems
in some people, the risk of adverse effects greatly increases with long term
use of excessive amounts of the vitamin.
Vitamin C does boost the immune system, and in does protect the body from some
free radical damage. And it is true that excess vitamin C can be
eliminated from the body. The practice of vitamin C megadosing does
present some safety issues.
A
severe deficiency of vitamin C can lead to a disease known as scurvy.
Symptoms of scurvy include connective tissue breakdown, causing bleeding,
muscle weakness, impaired wound healing, and nervous system disorders. It
is believed that megadosing of vitamin C for extended periods of time, then
drastically reducing the dose or going off cold turkey may lead to a condition
known as rebound scurvy. Rebound scurvy is believed to occur when the
body continues to excrete large amounts of vitamin C when megadoses are no
longer being supplemented. Although, very few cases of rebound scurvy
have been reported, and information about the cases have not been
well-documented.
Excessive vitamin C intake is also known to displace vitamin B12 from the body.
Vitamin B12 is essential for the maturation of blood cells. Deficiencies of B12
lead to a problem known as macrocytic anemia. This condition leads to the
formation of abnormally large red blood cells, with impaired ability to carry
oxygen. Decreased oxygen levels may cause fatigue, muscle weakness, shortness
of breath, and possibly heart arrhythmias.
Macrocytic anemia also leads to the formation of abnormally large white blood
cells with altered nuclei. White blood cells are an important component of the
immune system. Therefore, macrocytic anemia from B12 deficiency may impair
immune function.
B12
deficiencies may cause nerve damage leading to nerve pain and numbness, or loss
of some senses. Mental disturbances may also develop including depression,
dementia, paranoia, irritability, and delirium.
Vitamin C is a water soluble compound, which can be easily flushed from the
body. Although, vitamin C is a relatively unstable compound, and a
portion of excess ingested vitamin C breaks down into oxalic acid in the body.
Oxalic acid is beneficial to the body as well as detrimental. As vitamin C
breaks down in to oxalic acid, the oxalic acid actually serves as an
antioxidant to the vitamin C helping to prevent oxidative destruction of the
vitamin C. On the other hand, oxalic acid can bind with minerals forming
insoluble oxalates. Of particular importance is calcium oxalate, which can form
kidney stones. Studies have shown that oxalic stones, which make up 80% of
kidney stones, only formed in people with kidney diseases, but not in healthy
individuals at doses of 200mg daily. At 1,500mg daily intake there was only a
tiny rise in the incidence of oxalic stone formation. It is believed that the
insignificant rise is due to the fact that vitamin C is poorly absorbed by the
body. Therefore, the higher levels of vitamin C are not being absorbed, and
therefore are not converted in to oxalic acid.
Oxalic acid also binds with the
electrolytes sodium and potassium, and the mineral magnesium. Among other functions
of sodium and potassium is the regulation of heart rate. Magnesium serves a
multitude of important functions including maintaining normal blood pressure,
proper muscle function; including the heart, preventing muscle cramping, and
insulin production.
Oxalic acid is an irritant to the urinary tract. Irritation of the urinary
tract from oxalic acid can lead to urinary tract infections in sensitive
individuals.
There
is also concern that vitamin C may cause uric acid stones to form from excess
excretion of uric acid. Acidification of the urine with vitamin C increases the
ratio of uric acid to the more soluble sodium urate. For this reason, treatment
of uric acid stones includes alkalinizing the urine with sodium bicarbonate (baking
soda) or calcium citrate to increase sodium urate formation.
Excessive levels of vitamin C are contradicted in people suffering from kidney
stones, gout, cirrhosis, kidney diseases, and certain other disorders.
A
major concern of taking excessive doses of vitamin C is the fact that large
amounts of vitamin C can block copper absorption. Copper serves various
functions in the body including production of the antioxidant,
anti-inflammatory, and immune stimulating enzyme copper superoxide
dismutase. Copper is essential for the formation of collagen and elastin,
which give strength and elasticity to the tissues. Copper also plays a
role in the formation of neurotransmitters for proper nerve function. As a
factor in the production of melanin, copper helps to prevent graying of the
hair. In addition, copper helps to maintain proper levels of blood lipids
(fats), including cholesterol.
Decreased copper levels can lead to decreased collagen and elastin synthesis.
This in turn leads to bone loss, blood vessel weakness, poor wound healing, gum
disorders, tendon and ligament weakness, cartilage disorders, bruising, and
wrinkles. Disorders such as emphysema and diverticulitis also involve
loss of elastin in tissues.
The
risk of heart disease increases with copper deficiencies. This is most
likely due to weaker arterial walls, combined with increased inflammation,
increased oxidative damage, and elevated cholesterol levels.
Vitamin C is often touted as an immune stimulant, although excessive levels may
have the opposite effect. The enzyme copper superoxide dismutase (cu-SOD)
produces hydrogen peroxide in response to infections. Hydrogen peroxide serves
various functions, including activation of the immune system’s white blood
cells. White blood cells fight infections, and cancer cells within the body.
Therefore, declining levels of cu-SOD can have an adverse effect on the immune
system.
Inflammation has been shown to be a major contributor to the formation of
cancers. Another primary function of cu-SOD is to reduce inflammation. Copper
therefore may play a crucial role in other inflammatory diseases as well, such
as colitis, and arthritis.
As an
antioxidant, cu-SOD helps protect cells from free radical damage. The body
requires free radicals, such as hydrogen peroxide. Excessive levels of free
radicals have been implicated in various diseases though, including cancer.
Hemoglobin requires copper for its production. Therefore, copper deficiencies
can lead to anemia.
Copper is essential for the formation of thyroid hormones. Copper deficiencies
lead to hypothyroidism, although excessive levels suppress thyroid function.
This is especially true if zinc deficiencies are present since zinc promotes
thyroid function. Note that excessive levels of zinc can over stimulate the
thyroid.
As a
cofactor in neurotransmitter production, copper deficiencies can lead to
depression. High copper levels though have also been linked to depression, as
well as schizophrenia, ADHD symptoms, and other neurological disorders.
The
brain and spinal cord contain some of the highest levels of copper in the body.
Copper is not only essential for the formation of neurotransmitters, but also
for myelin, which insulates nerves so they do not “short circuit”.
Interestingly, the brain contains about 10 times the level of vitamin C as
found in the blood. Vitamin C actually has to be oxidized to cross the
blood-brain barrier. Oxidation converts the vitamin C in to dehydroascorbic
acid, which allows it to be transported in to the brain through sugar
receptors. There the dehydroascorbic acid is converted back in to ascorbic
acid, commonly known as vitamin C. Here the vitamin C helps prevent damage to
the myelin from free radicals, and aids in the conversion of dopamine to
norepinephrine.
Copper is essential for the proper regulation of histamine throughout the body.
High levels of histamine can lead to allergic responses, including asthma. In
the brain, histamine plays roles in mood, behavior, libido, addictions, and
sleep and wake cycles.
Despite all the benefits of copper, excess
levels of copper can be dangerous. Copper supplementation is not recommended in
most cases, although it should be combined with zinc if supplementing zinc. The
common ratio of zinc to copper in supplements is 50mg zinc to 2mg copper. Women
with excessive levels of estrogen would probably benefit more by taking zinc,
but not copper. Estrogen increases copper levels, and zinc antagonizes copper
helping to reduce the risk of copper toxicity.
Copper, which is displaced by excess vitamin C, is essential for the formation
of hemoglobin, which carries oxygen to the tissues, and removes carbon
dioxide. Iron is also essential for the formation of hemoglobin, and iron
absorption is increased by vitamin C. This all brings up an interesting
problem. If iron levels are increased by improved absorption from vitamin
C, but hemoglobin cannot be formed due to lack of copper, what happens to all
the iron being absorbed?
As
with copper, and vitamin C, iron is essential for the body and serves various
purposes. Although, as with copper and vitamin C, excess levels of iron
can be dangerous. And since the body has no efficient way of ridding itself of
excess iron, iron levels may easily build up to toxic levels.
As
iron accumulates in the body it is primarily stored in organs and glands, where
it can lead to organ failure and glandular damage. The heart, liver, and
pancreas are at the greatest risk of damage and failure from iron overload.
Side
effects of iron overload include heart disorders, diabetes, cirrhosis of the
liver, adrenal insufficiency, hypothyroidism, parathyroid damage resulting in
low blood calcium, pituitary gland dysfunction, atrophy of the testes and
ovaries, nervous system damage and disorders, arthritic disorders, graying or bronzing
of the skin, and decreased energy levels. Numerous microbes, and protozoa,
thrive with high iron levels. These include Candida, Listeria, Chlamydia,
Salmonella, Plasmodium, Staphylococcus, Streptococcus, Cryptococcus,
Campylobacter, Pseudomonas, Helicobacter pylori Escherichia coli, and numerous
others.
Iron overload is also known to increase
the risk of various cancers including liver cancer, Kaposi's sarcoma, breast
cancer, melanoma, and colon cancer. The increased risk of cancer is
probably due to the increased activity of cancer pathogens. For example,
human papilloma virus has been linked to several cancers including breast
cancer. Human herpes virus type 8 has been linked to the viral form of
Kaposi's sarcoma. Liver cancer has been linked to hepatitis viruses, and
aflatoxins from the fungus Aspergillusniger.
Arthritis may occur from iron overload due
to two factors. Oxidative destruction can lead to join damage. In addition,
certain forms of arthritis are triggered from pathogens. For example,
rheumatoid arthritis has been linked to an infection with a form of Chlamydia
bacteria.
Heart disease, due to iron overload, is
generally believed to result from oxidative damage to the arterial lining, and
to the heart muscle itself. There may be a secondary factor though.
Scientists have found a link between Chlamydia bacteria and arterial sclerosis,
which may lead to arrhythmias, angina, and heart attack.
Excess of levels of iron have also been
found in the brains of Alzheimer's patients. As with the excessive
aluminum levels found in the brains of Alzheimer's patients, that excessive
iron levels have not been proven to be a cause of Alzheimer's. Although,
it is hypothesized that the excessive level of iron may be causing oxidative
damage to the brain, leading to Alzheimer's disease.
Unfortunately the article
makes no mention of ascorbate's capability of dissolving calcium oxalate, the
material from which most kidney stones are comprised, to almost the same degree
as citrate is so capable. Renal function is complex, and I might as well add my
conjecture that repeated short-term periods of lactic acidosis are more
responsible for stones than ascorbate. Plus also factor in that some people are
SF's and some aren't, for reasons still not known, and things get real tough to
define and apply to entire populations.
Ascorbate increases human oxaluria and kidney stone risk.
Department of Food Science and Human
Nutrition, Washington State University, Spokane, WA,
USA. massey@wsu.edu
Currently,
the recommended upper limit for ascorbic acid (AA) intake is 2000 mg/d.
However, because AA is endogenously converted to oxalate and appears to
increase the absorption of dietary oxalate, supplementation may increase the
risk of kidney stones. The effect of AA supplementation on urinary oxalate was
studied in a randomized, crossover, controlled design in which subjects
consumed a controlled diet in a university metabolic unit. Stoneformers (n =
29; SF) and age- and gender-matched non-stoneformers (n = 19; NSF) consumed
1000 mg AA twice each day with each morning and evening meal for 6 d (treatment
A), and no AA for 6 d (treatment N) in random order. After 5 d of adaptation to
a low-oxalate diet, participants lived for 24 h in a metabolic unit, during
which they were given 136 mg oxalate, including 18 mg 13C2 oxalic acid, 2 h
before breakfast; they then consumed a controlled very low-oxalate diet for 24
h. Of the 48 participants, 19 (12 stoneformers, 7 non-stoneformers) were
identified as responders, defined by an increase in 24-h total oxalate
excretion > 10% after treatment A compared with N. Responders had a greater
24-h Tiselius Risk Index (TRI) with AA supplementation (1.10 +/- 0.66 treatment
A vs. 0.76 +/- 0.42 treatment N) because of a 31% increase in the percentage of
oxalate absorption (10.5 +/- 3.2% treatment A vs. 8.0 +/- 2.4% treatment N) and
a 39% increase in endogenous oxalate synthesis with treatment A than during
treatment N (544 +/- 131 A
vs. 391 +/- 71 micromol/d N). The 1000 mg AA twice each day increased urinary
oxalate and TRI for calcium oxalate kidney stones in 40% of participants, both
stoneformers and non-stoneformers.
Cancer-causing Compound Can Be Triggered By Vitamin C
Date:
March 13, 2007
Source:
Brown University
Summary:
Chromium
6, the cancer-causing compound that sparked the legal crusade by Erin
Brockovich, can be toxic in tiny doses. Brown University scientists have
uncovered the unlikely culprit: vitamin C. In new research, the Brown
team shows that when vitamin C reacts with even low doses of chromium 6
inside human cells, it creates high levels of cancer-causing DNA damage
and mutations.
Chromium
6, the cancer-causing compound that sparked the legal crusade by Erin
Brockovich, can be toxic in tiny doses. Brown University scientists have
uncovered the unlikely culprit: vitamin C. In new research, the Brown
team shows that when vitamin C reacts with even low doses of chromium 6
inside human cells, it creates high levels of cancer-causing DNA damage
and mutations.
Even miniscule amounts of chromium 6 can cause cancer. Blame that do-gooder nutrient, vitamin C.
Brown University researchers have discovered that naturally occurring vitamin C reacts inside human lung cells with chromium 6, or hexavalent chromium, and causes massive DNA damage. Low doses of chromium 6, combined with vitamin C, produce up to 15 times as many chromosomal breaks and up to 10 times more mutations – forms of genetic damage that lead to cancer – compared with cells that lacked vitamin C altogether.
This finding is startling, said Anatoly Zhitkovich, an associate professor of medical science at Brown who oversaw the experiments. Outside cells, Zhitkovich said, vitamin C actually protects against the cellular damage caused by hexavalent chromium, the toxic chemical that starred as the villain in the true-to-life Hollywood drama, Erin Brockovich. In fact, vitamin C has been used as an antidote in industrial accidents and other instances when large amounts of chromium are ingested.
Vitamin C works protective wonders because it is a powerful antioxidant, blocking cellular damage from free radicals. Specifically, the vitamin rapidly “reduces,” or adds electrons, to free radicals, converting them into harmless molecules. This electron transfer from vitamin C to chromium 6 produces chromium 3, a form of the compound that is unable to enter cells.
But what happens when chromium and vitamin C come together inside cells? Because vitamin C isn’t found in cells grown in a lab, Zhitkovich and his team conducted experiments using human lung cells supplemented with vitamin C. They learned that when vitamin C is present, chromium reduction has a very different effect. Cellular vitamin C acted as a potent toxic amplifier, sparking significantly more chromosomal breaks and cellular mutations.
“When we increased the concentration of vitamin C inside cells, we saw progressively more mutations and DNA breaks, showing how seemingly innocuous amounts of chromium can become toxic,” Zhitkovich said. “For years, scientists have wondered why exposure to small amounts of hexavalent chromium can cause such high rates of cancer. Now we know. It’s vitamin C.”
Hexavalent chromium is used to plate metals and to make paints, dyes, plastics and inks. As an anticorrosive agent, it is also added to stainless steel, which releases hexavalent chromium during welding. Hexavalent chromium causes lung cancer and is found in 40 percent of Superfund sites nationwide. This is the toxic metal, found in drinking water in a small California town, that Erin Brockovich campaigned against, successfully winning residents a record settlement of $333 million in 1996.
Zhitkovich said his team’s research, published in Nucleic Acids Research, might have policy implications. When combined with vitamin C, chromium 6 caused genetic damage in cells in doses four times lower than current federal standards, Zhitkovich said. If additional research backs these findings, he said federal regulators might want to lower exposure standards.
Zhitkovich is part of a major Brown research initiative, the Superfund Basic Research Program, which addresses the health and environmental concerns created by hazardous waste contamination. As part of this program, funded by the National Institute of Environmental Health Sciences, Zhitkovich is conducting basic research that may result in a medical test that assesses DNA damage from hexavalent chromium.
Former Brown graduate student Mindy Reynolds was lead author of the journal article. Brown research assistant Lauren Stoddard and postdoctoral research associate Ivan Bespalov also took part in the research.
The National Institutes of Health funded the work.
Brown University researchers have discovered that naturally occurring vitamin C reacts inside human lung cells with chromium 6, or hexavalent chromium, and causes massive DNA damage. Low doses of chromium 6, combined with vitamin C, produce up to 15 times as many chromosomal breaks and up to 10 times more mutations – forms of genetic damage that lead to cancer – compared with cells that lacked vitamin C altogether.
This finding is startling, said Anatoly Zhitkovich, an associate professor of medical science at Brown who oversaw the experiments. Outside cells, Zhitkovich said, vitamin C actually protects against the cellular damage caused by hexavalent chromium, the toxic chemical that starred as the villain in the true-to-life Hollywood drama, Erin Brockovich. In fact, vitamin C has been used as an antidote in industrial accidents and other instances when large amounts of chromium are ingested.
Vitamin C works protective wonders because it is a powerful antioxidant, blocking cellular damage from free radicals. Specifically, the vitamin rapidly “reduces,” or adds electrons, to free radicals, converting them into harmless molecules. This electron transfer from vitamin C to chromium 6 produces chromium 3, a form of the compound that is unable to enter cells.
But what happens when chromium and vitamin C come together inside cells? Because vitamin C isn’t found in cells grown in a lab, Zhitkovich and his team conducted experiments using human lung cells supplemented with vitamin C. They learned that when vitamin C is present, chromium reduction has a very different effect. Cellular vitamin C acted as a potent toxic amplifier, sparking significantly more chromosomal breaks and cellular mutations.
“When we increased the concentration of vitamin C inside cells, we saw progressively more mutations and DNA breaks, showing how seemingly innocuous amounts of chromium can become toxic,” Zhitkovich said. “For years, scientists have wondered why exposure to small amounts of hexavalent chromium can cause such high rates of cancer. Now we know. It’s vitamin C.”
Hexavalent chromium is used to plate metals and to make paints, dyes, plastics and inks. As an anticorrosive agent, it is also added to stainless steel, which releases hexavalent chromium during welding. Hexavalent chromium causes lung cancer and is found in 40 percent of Superfund sites nationwide. This is the toxic metal, found in drinking water in a small California town, that Erin Brockovich campaigned against, successfully winning residents a record settlement of $333 million in 1996.
Zhitkovich said his team’s research, published in Nucleic Acids Research, might have policy implications. When combined with vitamin C, chromium 6 caused genetic damage in cells in doses four times lower than current federal standards, Zhitkovich said. If additional research backs these findings, he said federal regulators might want to lower exposure standards.
Zhitkovich is part of a major Brown research initiative, the Superfund Basic Research Program, which addresses the health and environmental concerns created by hazardous waste contamination. As part of this program, funded by the National Institute of Environmental Health Sciences, Zhitkovich is conducting basic research that may result in a medical test that assesses DNA damage from hexavalent chromium.
Former Brown graduate student Mindy Reynolds was lead author of the journal article. Brown research assistant Lauren Stoddard and postdoctoral research associate Ivan Bespalov also took part in the research.
The National Institutes of Health funded the work.
Story Source:
The above story is based on materials provided by Brown University. Note: Materials may be edited for content and length.
The above story is based on materials provided by Brown University. Note: Materials may be edited for content and length.
March 2, 2000. Taking vitamin C supplements could
speed up hardening of the arteries, according to a study of "573 outwardly
healthy middle-aged men and women who work for an electric utility in Los
Angeles." Those taking vitamin C supplements showed "accelerated
thickening of the walls of the big arteries in their necks....the more
they took, the faster the buildup," according to the (now defunct)
Nando Times.
Do high doses of vitamin C raise prostate cancer risk? Study shows popping too many supplements could give men tumours
- Study of followed the health of 48,000 men aged 40-75 over 22 years
- It found that men who take large amounts of supplements risk disease
- The chance of developing prostate cancer increased by 28 per cent
- The finds were published in the International Journal of Cancer
Men who take high doses of vitamin supplements could be increasing their risk of lethal prostate cancer by nearly 30 per cent, say researchers.
A study of 48,000 men spanning more than two decades suggests popping too many vitamin pills can put them in danger of tumours that are more likely to be fatal.
The researchers linked high doses of vitamin C to an increased risk of lethal and advanced prostate cancer.
The results, by experts from Harvard School of Public Health in Boston, in the US, and the University of Oslo in Norway, are not the first to raise the alarm over the dangers of excess vitamin consumption.
Nearly a quarter of adults in the UK are estimated to take antioxidant supplements or multivitamins regularly in the hope that it will help protect them against illnesses such as heart disease and cancer. The market for such products is worth around half a billion pounds a year.
In recent years, high-dose vitamins have become popular, with people taking more in the belief that it is better for them.
For example, health food shops now sell vitamin C tablets in doses of 1,000mg each, but the body needs only about 40mg a day to keep cells healthy and promote healing.
In the latest research, the scientists set out to see if antioxidants in vitamin pills and food could reduce the chances of a prostate tumour.
From 1986 to 2008 they followed 48,000 men aged between 40 and 75. Every four years, the men completed food questionnaires designed to record their dietary habits.
The researchers followed them up to see which ones developed prostate cancer.
The results, published in the International Journal Of Cancer, show that total antioxidant intake – from foods or pills – neither increased nor decreased the risk of a tumour. Antioxidants fight the process, called oxidation, that destroys cells.
There was some suggestion antioxidants from coffee had a slightly protective effect.
But the most alarming finding was that men with the highest intake of antioxidants from vitamin pills were 28 per cent more likely to get lethal prostate cancer than those who took the lowest amount of pills or none.
Those with the highest intake of antioxidants from vitamin pills were 15 per cent more likely to get advanced prostate cancer – a tumour that spreads quickly beyond the prostate, reducing the chances of survival.
In a report the researchers said: ‘High intake of antioxidants from supplements was associated with increased risk for lethal and advanced prostate cancer.
'The main contributor is vitamin C, and this finding warrants further investigation.’
But the researchers stressed that, until more research is carried out, they cannot be sure that vitamin tablets actually cause cancer.
It may be that the cancer victims felt unwell for several months before their diagnosis and simply increased vitamin intake to try to ward off symptoms such as fatigue.
Dr Carrie Ruxton, of the Health Supplements Information Service, which is funded by supplements makers, said: ‘It is entirely possible that these men may have had prostate-related symptoms and fatigue long before diagnosis.
'The cancer may have had nothing to do with the supplements.’
How vitamin pills 'can raise risk of cataracts' as hidden danger of everyday supplements is revealed
Taking vitamin pills in high doses can significantly increase the risk of cataracts, a study has shown.Scientists found consuming large amounts of vitamin C made individuals 20 per cent more likely to develop the condition – which is a leading cause of blindness.
And regularly popping high-dose vitamin E tablets increased the chance of cataracts forming by 60 per cent.
The dangers are even greater for the elderly, with those over 65 nearly doubling their chances of damaging their vision if they took the supplements every day.
Researchers from the Karolinska Institute in Stockholm monitored 31,000 volunteers aged between 45 and 79. Nearly 3,000 of them went on to need treatment for their eyes.
The Swedish team discovered a strong link between those that developed cataracts and those who took high doses of vitamin C and E.
Eating a healthy vitamin-rich diet did not increase a patient’s chance of getting the condition.
It was originally thought the two vitamins would protect against cataracts because they are powerful antioxidants.
It was supposed that they would fight the process of oxidation, which destroys cells in much the same way as rust rots a car. However, it is now believed that, in large quantities, vitamin C may actually cause oxidation by upsetting the natural balance of proteins in the eye.
The human body does not make or store vitamin C, and gets its supply from fruit and vegetables. It only needs 40mg a day to keep cells healthy and promote healing. Vitamin E helps maintain the structure of cells and is found in foods such as nuts, seeds and cereals.
A man needs just 4mg a day and a woman should have 3mg. But tablets containing up to a hundred times this amount are also available in UK health food shops.
At high street chain Holland and Barrett a jar of 250 capsules can be bought for £8.99. Each pill contains 1,000mg of vitamin C.
In a report on their findings, they said: ‘Our results further underscore the need to consider use of unregulated supplements with caution.’
However Professor Yit Yang, from the Royal College of Ophthalmologists, said: ‘It is not possible to establish from this study that vitamin C caused cataracts, as there may be other factors which were not accounted for.
‘In 2010, a randomised control trial designed to investigate specifically for causative effect of high-dose vitamin C did not find one.’
At the moment, nearly a quarter of adults in the UK regularly take antioxidant supplements or multivitamins.
They are relied on to help ward off a huge range of illnesses such as cancer and heart disease.
Synthetic vitamin C, or ascorbic acid, kills beneficial probiotic bacteria in the gut
(NaturalNews) Most people nowadays are well informed about the numerous health benefits of vitamin C, and find ways to incorporate it in their diets, either by taking supplements or eating more foods that contain the vitamin. While the many benefits of vitamin C are well-documented, such as its ability to boost the immune system, there are less well known facts about the synthetic version of vitamin C, or ascorbic acid. Ascorbic acid, the synthesized version of vitamin C, has been proven to kill bacteria effectively, which makes it effective in killing parasites and infections. Unfortunately, it does not differentiate between the good and bad bacteria in the gut, and wipes out good bacteria in the gut which is mandatory for vibrant health.Ascorbic acid defined
Synthetic vitamin C, or ascorbic acid, is not found in nature. It does not grow naturally in plants or trees and cannot be grown on a farm. It can only be made in a lab. Contrary to popular belief, ascorbic acid and vitamin C are not the same thing. Ascorbic acid is not a complete vitamin, but really only the outer layer of the complete complex known as vitamin C. The complete complex of vitamin C as found in natural food sources is composed of these elements:- Rutinbiofavonoids (vitamin P) factor K
- Factor Jfactor P Tyrosinase
- Ascorbinogen ascorbic acid
All of the above elements must be present in order for the body to absorb and benefit from the vitamin complex. Since synthetic ascorbic acid does not contain the full complex, your body must either gather the missing components from the body's reservoir, or simply eliminate the ascorbic acid from the body through the urine without benefit to the body.
You'll find ascorbic acid in all sorts of products, from vitamin C supplements to bottled tea drinks and fruit juices such as apple juice. The straightforward method to confirm its presence in a product is to simply read the ingredient label. However, as founder of AGM foods in Brisbane, Australia Alan Meyer found out, many times ascorbic acid can be found in foods even though it's not listed on the ingredient label.
The microbe-neutralizing properties of ascorbic acid and its source of origin
Mr. Meyer had been following a recipe to make a fermented apple drink. The recipe called for pure apple juice, so he bought a bottle of organic apple juice. After running some tests on his concoction, he found that the apple juice had killed the friendly microbes in it even though according to ingredient label on the bottle there was nothing in the juice but organic apples. He ran the process again to confirm that it wasn't just a fluke and sure enough the microbes were destroyed once more. After calling the company he found out that they were indeed adding ascorbic acid to the juice as a preservative to kill off bacteria. Unfortunately, ascorbic acid doesn't just kill harmful bacteria, but also kills beneficial bacteria. Ascorbic acid has the same effect in our bodies as it does in juice.Ascorbic acid is synthesized from corn syrup. So not only do we need to be concerned with its impact on intestinal flora, but with its potentially disastrous GMO corn-based origins. These days, if you cannot verify that any corn-based food that you consume is certified organic, you risk ingesting GMO corn, the health risks of which are well-known by knowledgeable NaturalNews readers.
The real vitamin C solution
Naturally-occurring vitamin C is found in many fruits and vegetables. Vitamin C has the curious habit of breaking down when heated. This means that when food is heated, the vitamin breaks down and becomes useless. Since pasteurization is a form of heating (boiling to kill bacteria), any pasteurized beverage therefore becomes void of natural vitamin C complex. Ascorbic acid was therefore invented as a synthetic replacement of the natural form of vitamin C which is destroyed by heat. Unfortunately, ascorbic acid simply cannot replace the real, natural vitamin complex. Add to that the bacteria-neutralizing behavior of ascorbic acid which destroys health-critical beneficial microbes, and you have a substance which we'd all be better off to avoid as health-minded individuals.So what is the solution to all this? The thing to do is avoid vitamin C supplements, pasteurized products, and pre-bottled teas and juices containing ascorbic acid. Get your vitamin C from natural, organic, uncooked fruits and vegetables. Some foods that contain the highest amounts of vitamin C are:
- Strawberries
- Citrus fruits
- Acerola Cherry (fresh or powdered forms)
- Black Currant
- Papaya
- Kiwi fruit
- Bell Pepper
- Guava
- Melons
- Brussel Sprouts
- Kale, chard, and spinach
- Broccoli
- Cauliflower
- Tomatoes
Again, remember to consume foods in their raw form. If heated, the natural vitamin C complex is destroyed.
The Dangers of Vitamin C?
I'm a big fan of Vitamin C and feel much better when taking
it. In fact, it is really the only vitamin or mineral that
I megadose simply because I feel the RDA / AI is much too
low. I also am a cautious follower of the Pauling Theory, simply
because Vitamin C does some spectacular things at a megadose
level ( >= 1 gram/day). It's hard to argue with a
cheap supplement that can boost nitric oxide, improve weight loss, control cortisol, lower blood pressure, decrease inflammation, protect the brain - the list goes on and on. You can check out my links on 10+ Great Reasons
to Take Vitamin C and
Vitamin C and Erectile Dysfunction for more information.
CAUTION: In my link on Garlic and Erectile Dysfunction, I discuss how Vitamin C and garlic coupled together can dramatically increase nitric oxide and lower blood pressure. However, one should always consult with your doctor first if you have any medical condition or are on any medications. For example, lowering your blood pressure too much can have serious consequences.
In spite of all the praise I have for Vitamin C, a few cautions are in order. In my opinion, Vitamin C's track record is excellent, but a few potential "dangers" have been uncovered as well and I cover those below:
1. Blood Flow Reduction. One animal study showed that in some cases Vitamin C could possibly contribute to a loss of blood flow. This study basically demonstrated that Vitamin C could increase a key oxidant, peroxide, that is responsible for supplying blood flow to the muscles and expanding arteries. [15] In my link on Antioxidants and the Heart I discuss how free radicals, supposedly the villains, actually play crucial roles in our health. For example, nitric oxide is a free radical and dilates our arteries. Researchers are concerned that taking too many antioxidants, such as Vitamin C, could quench the body's requirement for these free radicals.
Now the rebuttal to this is that this study actually combined two antioxidants and thus may not really be a realistic scenario. In fact, as mentioned above, researchers have found that combining garlic and Vitamin C increases nitric oxide by three times! We have had guy on The Peak Testosterone Forum use this to cure their erectile dysfunction - that's how powerful it for some men. Nevertheless, it does beg the question as to whether we fully understand the complete impact of megadosing Vitamin C.
2. Loss of Exercise Benefits. Another disturbing study showed that 1000 mg daily of Vitamin C coupled with 235 mg daily of Vitamin E lowered key benefits of exercise. The researchers summarized by saying that "daily vitamin C and E supplementation attenuated increases in markers of mitochondrial biogenesis following endurance training." [18] Of course, some would argue that Vitamin C alone may not do the same and so it is too bad that the study did not also look at each supplement separately. Again, though, this shows that one can have too much of a good thing.
Do you know the foods and drinks that increase erection-boosting Nitric Oxide? Check out the Peak Erectile Strength Diet where I show you how to dramatically and naturally improve your erectile strength.
3. Increase Arterial Plaque?. And then came the real black eye: one study showed increased arterial thickness from Vitamin C. This study reported that those who took Vitamin C had 2.5 times the thickening of the arteries compared with those who took none. [3] This study has been criticized for being relatively small and one can't help but ask the question, "If Vitamin C causes such accelerated hardening of the arteries, why aren't its proponents dropping dead like flies?" Personally, I doubt that Vitamin C causes arterial thickness as this was a small and controversial study, and there are many studies showing that Vitamin C improves arterial health.
4. Increasing Nitrosamines. One can't help but wonder why Vitamin C does not fight cancer more effectively. After all, it is one of our body's most important antioxidants and it is used extensively throughout the immune system. It only stands to reason that it should help with cancer outcomes. The reason is very likely that Vitamin C very likely has a dark side: the journal Gut simulated conditions in the stomach and found that Vitamin C, when fat levels are low, actually inhibits the carcinogenic nitrosamine production but promotes nitrosamines when fat is present. [8] I'm not talking about fat as in overweight: I'm talking about fat in your meal. If you eat any fat in your meal - which almost every one in a modern society does - megadosing with Vitamin C will lead to a flood of carcinogenic nitrosamines and this may explain some of Vitamin C's questionable cancer results.
By the way, did you know that ascorbic acid is sometimes added to meats to lower nitrosamine production. The point is that there is data that shows the opposite of the above. As always, it's too bad there isn't more study work.
5. Raising Iron Absorption. Dr. Russell Blaylock and other recommend taking Vitamin C (in a "salt" or "Ester-C" form) in order to make sure that you do not increase iron absorption. Unfortunately, most men in Western societies consume too much iron and this associated with cardiovascular and neurological disease. Again, an easy solution is to take it on an empty stomach but not all men know about this.
| Can't figure out the cause of your E.D.? Check out these 15 Natural Cures. |
| Combine supplements for max erectile strength? Go with This Approach. |
So everything sounds like a "green light", right? Well, unfortunately, there have been a number of studies that have found that Vitamin C has no significant heart benefit. One of the biggest was The Physicians Health Study II of 14,000 male physicians run by a Harvard professor. In this study physicians were put on 500 mg Vitamin C and 400 IU Vitamin E daily. The researchers found that neither vitamin decreased cardiovascular events whatsoever. [17] Then came a study on postmenopausal women with diabetes that showed an increased cardiovascular risk with Vitamin C usage. [16] Critics point that 500 mg of Vitamin C is a fairly low dosage according to Pauling Theory.
Another researcher, Rory Collins, looked at not just heart disease during a huge five year study involving 20,000 people who took daily 600mg of vitamin E, 250mg of vitamin C and 20mg of beta-carotene. This study [7] in the prestigious journal Lancet found that there was no improvement in heart disease or cancer rates. Once again, Vitamin C looked like a questionable use of one's money. Again, some have criticized this study for only supplementing with 250 mg of Vitamin, but keep in mind that is roughly the Vitamin C found in five oranges.
CAUTION: If you have a medical condition or are on any medications, please discuss any changes with your doctor first. Certain supplements, foods and even juices can alter absorption rates of certain medications for example. Play it safe.
REFERENCES:
1) Journal of Internal Medicine, 2000; 248 (5), 377-386
2) American Journal of Clinical Nutrition, Dec 2004, 80(6):1508-1520, December 2004 Antioxidant vitamins and coronary heart disease risk: a pooled analysis of 9 cohorts Paul Knekt, et al
3) Reported on March 2, 2000, by Dr. James Dwyer at an American Heart Association meeting in San Diego
7) The Lancet, 2002, 360(9347):1781-1782
8) Gut, 2007; 56:1678-1684, Published Online First: 4 September 2007, "Fat transforms ascorbic acid from inhibiting to promoting acid-catalysed N-nitrosation"
9) J Am Coll Nutr, 2005 Jun, 24(3):158-65
14) http://esciencenews.com/articles/2009/09/09/ study.reveals.new.role.vitamin.c.skin.protection
15) Experimental Physiology, Published Online: 21 Jul 2009, 94(9):961-971, "The effects of antioxidants on microvascular oxygenation and blood flow in skeletal muscle of young rats"
16) Am J Clin Nutr, Nov 2004, 80(5):1194-1200, "Does supplemental vitamin C increase cardiovascular disease risk in women with diabetes?"
17) JAMA, 2008 Nov 12, 300(18):2123-33, "Vitamins E and C in the prevention of cardiovascular disease in men: the Physicians' Health Study II randomized controlled trial.
18) J of Physiology, Published online before print Feb 3 2014, "Vitamin C and E supplementation hampers cellular adaptation to endurance training in humans: a double-blind randomized controlled trial"
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