106 replies to this topic

[nowayout]

A negative study on megadosing of vitamin C in guinea pigs is summarized by MR at http://groups.google...9030de05f?hl=en. This was just mentioned on another thread but I thought it would be relevant to include here.

In this study, the megadosing guinea pigs had an earlier mortality than the lower-dosing ones.

Edited by andre, 27 May 2009 - 04:37 PM.

[nameless]

A negative study on megadosing of vitamin C in guinea pigs is summarized by MR at http://groups.google...9030de05f?hl=en. This was just mentioned on another thread but I thought it would be relevant to include here.

In this study, the megadosing guinea pigs had an earlier mortality than the lower-dosing ones.

That is an interesting study. Happen to know what that dosage equates to in humans?

This study, linked at the bottom of that guinea pig discussion, has a lot of good data in it:

http://www.ajcn.org/.../full/69/6/1086

[zawy]

Thanks, that's excellent work with the guinea pigs, showing 10% shorter lifespan on 20 g/day verses 350 mg/day when converted to 70 kg. That would be as bad as smoking or not exercising. 1% in water can very accurately be converted to human dose because the conversions should be based on calories, and persumably, water intake is directly proportional to calories. I believe humans are 2 L per day which would be 20 g/day. The 350 mg/day is based on weight and may need to be converted lower for humans by about a factor of 3. But that would indicate a dosage difference of 100 verses the reported 10-20 factor reported for the article. If would have been nice if they had also tested a buffer ascorbate since that much acid alone could cause the decrease in lifespan. Pauling too 18 g/day, but I am not sure what form he used. I used to take 15 g/day for a couple of years, but decided might be having a negative effect and dropped down alot. That report was published in 1977 and it would be interesting to see what pauling had to say about it. Here's a 1984 report that said mice survived
"up to" 20% longer on 1% in their water, 1,400 mg/kg, which converts exactly to my above estimated 20 g/d for humans if you use 1.4*70/5 = 19.6 g/d in humans based on calorie consumption. http://www.ncbi.nlm..../pubmed/6519438

Of course guinea pig applies much better than mice, even if they used mice that lacked the gene to convert glucose to ascorbic acid. The strain of mice appears to just be good for testing in cancer and may be more susceptable to it.

Edited by zawy, 27 May 2009 - 06:29 PM.

[zawy]

5 mg for a 1 kg guinea pig is really low (that's whats the thread says the study uses). Wiki says they "require" at least twice as much (10 mg for approx 1 kg guinea pig) and they sell a guinea pig supplement with 10 times as much. Another web site 5 times as much is needed. This last number seems about right and it would be 580 mg in humans. Using calorie correction, 1% in water for a guinea pig is about 850 mg/day, again that's about 20 g/day in humans. That would be 85 ml drinking water per day which sounds about right. 1 of those big vitamin C pills per day. Poor guinea pig. There would have to be a lot of exercise to excrete the acid.

Doing calorie correction may not be entirely correct for vitamin C since it's burned up a lot and has direct action on tissue (body weight). Calorie correction is usually best. Pauling and Stone used weight correction because it was very linear with weight "from a 100 gram mouse to a 70 kg goat". Although the numbers I've seen for mice and rats were low like the guinea pig needs, on the order of 1 to 3 g if doing just a weight conversion to humans. Divide by 5 or 6 if doing calorie conversion.

Edited by zawy, 27 May 2009 - 09:08 PM.

[nameless]

I'm pretty sure I read that Pauling used plain ascorbic acid. Although at 18 g/daily, I think that might burn some holes in people's stomachs (not literally, but it may feel like that).

Andre: what total amount of vitamin C do you consider optimal? I mean via food + supplement.

And for primates, what is considered their optimal C intake? I read that 2-3.5 grams/per 150 lbs is about right for apes. Do primates in zoos denied this amount develop heart disease?

[nowayout]

Andre: what total amount of vitamin C do you consider optimal? I mean via food + supplement.

No idea.

[zawy]

Here's an interesting study on guinea-pigs back in 1951. It says that only vitamin A has been found to vary directly from rats to horse based on body weight rather than surface area (approx. calorie consumption). Their work in guinea-pigs suggested that the same rule appeared to apply for vitamin C in guinea-pigs and they expressed confusion as to why the human recommendations were so low. They theorized either man made it himself (wrong) or had a special mechanism for preventing excretion (correct), eventhough they found none in the urine of the GP. So is the GP better than humans at keeping it? Their work showed as far as the adrenals and teeth growth were concerned, 7 mg/kg seemed to be adequate for the GP. (490 mg/70 kg). Concentration of vitamin C in adrenals was directly proportional to intake up to 7 mg/kg, but did not increase above there. It makes me wonder how many nutrients like vitamin A and vitamin C (according to Pauling) should be based strictly on body weight instead of calorie consumption. This would mean those converting rat and mouse data on resveratrol, vitamin D, or vitamin k to humans might be too low by a factor of 5 or 6. Navia and Hunt (1976) reported up to 25 mg/day was needed in some GPs which would be 1.8 g/d for humans if it was a heavy GP at 1 kg.

http://jn.nutrition....stract/47/4/503

Book with a summary of all GP vit C studies (and other nutrients)

http://www.nap.edu/o...d=4758&page=104

When based on calorie consumption, the vitamins required in GPs come out close to the DVs for humans. If the data on GP's is based on lifespan (optimum nutrition) and DV's are still biased towards "lack of disease", then you might want to multpily the GP values per calorie consumed by 3.4 to get a value for humans. This would be 70 IU/day vitamin E and 1,700 IU/day vitamin D in humans, and the B vitamins look more reasonable than DV's also. The minerals in GP also come out close to the DV's in humans when based on calorie consumption. So maybe vitamins should be based on body weight and minerals on calories consumed. Or, you can accept the DV's for vitamins and minerals to be perfectly accurate for optimum health in which case we can keep the simpler theory that both vitamins and minerals are based on calories consumed. If DV's were partially chosen based on animal data and if vitamins follow body weight rather than calories, then DV's for vitamins are biased low.

Edited by zawy, 28 May 2009 - 03:26 PM.

[stephen_b]

How oxidative stress may help prolong life.

Just stirrin' up the pot a little.

Edited by stephen_b, 29 May 2009 - 06:35 PM.

[VespeneGas]

if that speculation is true, it would go a long way toward explaining why so many of calorie restriction's benefits look like exercise's benefits.

[zawy]

If that's true, then periodic starvation (as is somewhat natural) may be best, like every other day and thentake a break a week, then starve for a week, then take a week break recovery and then every over day for 2 weeks. And if vit C creates excess H2O2 like some say, then a 4 g dose every morning might be as good as a short jog, in addition to fixing other problems by direct antioxidant effect.

I haven't had time to go through it all, but here is the vit C data in primates:

http://books.nap.edu...i...26&page=137

It's a great book that looks at all nutrients in primates if you think people are not being objective enough when looking at humans.

[Happy Gringo]

Could it be that Vitamin C blunts the effects of lactic acid, which has several exercise enhancing effects? I thought I had read about this before, but in searching, I can only find some reference to Eddy using intravenous vitamin C prior to cardiopulmonary bypass and it reducing lactic acid dehydrogenase, which I am not sure if this is the same as garden-variety lactic acid produced from exercise. However, another clue might be that:

Oral administration of vitamin C decreases muscle mitochondrial biogenesis and hampers training-induced adaptations in endurance performance
while lactic acid does the opposite. Here are a couple of things I found today about the importance of lactic acid and muscle adaptation:

Lactic acid as testosterone booster supplement
Lactic acid [structural formula shown below] is released during short, intensive bursts of activity. And after short, intensive exertion the body also produces more testosterone. So is there a relationship between the two phenomena? Yes, said the Taiwanese researchers we wrote about a few days ago. Testosterone producing Leydig cells work harder if they are if they are exposed to lactic acid, they discovered. And there’s another study along similar lines, done in 1997, which showed that giving lactic acid to non-active animals has the same effect.

Lactic acid also increases muscle mitochondria, from the New York Times:

Lactic Acid Is Not Muscles' Foe, It's Fuel

By GINA KOLATA
Published: May 16, 2006
Everyone who has even thought about exercising has heard the warnings about lactic acid. It builds up in your muscles. It is what makes your muscles burn. Its buildup is what makes your muscles tire and give out.

Coaches and personal trainers tell athletes and exercisers that they have to learn to work out at just below their "lactic threshold," that point of diminishing returns when lactic acid starts to accumulate. Some athletes even have blood tests to find their personal lactic thresholds.

But that, it turns out, is all wrong. Lactic acid is actually a fuel, not a caustic waste product. Muscles make it deliberately, producing it from glucose, and they burn it to obtain energy. The reason trained athletes can perform so hard and so long is because their intense training causes their muscles to adapt so they more readily and efficiently absorb lactic acid.

The notion that lactic acid was bad took hold more than a century ago, said George A. Brooks, a professor in the department of integrative biology at the University of California, Berkeley. It stuck because it seemed to make so much sense.

"It's one of the classic mistakes in the history of science," Dr. Brooks said.

Its origins lie in a study by a Nobel laureate, Otto Meyerhof, who in the early years of the 20th century cut a frog in half and put its bottom half in a jar. The frog's muscles had no circulation — no source of oxygen or energy.

Dr. Myerhoff gave the frog's leg electric shocks to make the muscles contract, but after a few twitches, the muscles stopped moving. Then, when Dr. Myerhoff examined the muscles, he discovered that they were bathed in lactic acid.

A theory was born. Lack of oxygen to muscles leads to lactic acid, leads to fatigue.

Athletes were told that they should spend most of their effort exercising aerobically, using glucose as a fuel. If they tried to spend too much time exercising harder, in the anaerobic zone, they were told, they would pay a price, that lactic acid would accumulate in the muscles, forcing them to stop.

Few scientists questioned this view, Dr. Brooks said. But, he said, he became interested in it in the 1960's, when he was running track at Queens College and his coach told him that his performance was limited by a buildup of lactic acid.

When he graduated and began working on a Ph.D. in exercise physiology, he decided to study the lactic acid hypothesis for his dissertation.

"I gave rats radioactive lactic acid, and I found that they burned it faster than anything else I could give them," Dr. Brooks said.

It looked as if lactic acid was there for a reason. It was a source of energy.

Dr. Brooks said he published the finding in the late 70's. Other researchers challenged him at meetings and in print.

"I had huge fights, I had terrible trouble getting my grants funded, I had my papers rejected," Dr. Brooks recalled. But he soldiered on, conducting more elaborate studies with rats and, years later, moving on to humans. Every time, with every study, his results were consistent with his radical idea.

Eventually, other researchers confirmed the work. And gradually, the thinking among exercise physiologists began to change.

"The evidence has continued to mount," said L. Bruce Gladden, a professor of health and human performance at Auburn University. "It became clear that it is not so simple as to say, Lactic acid is a bad thing and it causes fatigue."

As for the idea that lactic acid causes muscle soreness, Dr. Gladden said, that never made sense.

"Lactic acid will be gone from your muscles within an hour of exercise," he said. "You get sore one to three days later. The time frame is not consistent, and the mechanisms have not been found."

The understanding now is that muscle cells convert glucose or glycogen to lactic acid. The lactic acid is taken up and used as a fuel by mitochondria, the energy factories in muscle cells.

Mitochondria even have a special transporter protein to move the substance into them, Dr. Brooks found. Intense training makes a difference, he said, because it can make double the mitochondrial mass.

It is clear that the old lactic acid theory cannot explain what is happening to muscles, Dr. Brooks and others said.

Yet, Dr. Brooks said, even though coaches often believed in the myth of the lactic acid threshold, they ended up training athletes in the best way possible to increase their mitochondria. "Coaches have understood things the scientists didn't," he said.

Through trial and error, coaches learned that athletic performance improved when athletes worked on endurance, running longer and longer distances, for example.

That, it turns out, increased the mass of their muscle mitochondria, letting them burn more lactic acid and allowing the muscles to work harder and longer.

Just before a race, coaches often tell athletes to train very hard in brief spurts.

That extra stress increases the mitochondria mass even more, Dr. Brooks said, and is the reason for improved performance.

And the scientists?

They took much longer to figure it out.

"They said, 'You're anaerobic, you need more oxygen,' " Dr. Brooks said. "The scientists were stuck in 1920."

-----------------------------------------------------------------------------------------------------------------------------------------
Anyway, I think I'll continue 1 gram at 7:30 AM to blunt cortisol, and then exercising at 2:30 to hopefully have the levels down enough to not blunt adaptation. I read that vitamin c orally has a 2-3 hour half life...

Edited by Happy Gringo, 15 June 2009 - 01:12 PM.

[stephen_b]

This post in 2006 talked about the study "Physical training and metabolic supplementation reduce spontaneous atherosclerotic plaque rupture and prolong survival in hypercholesterolemic mice" (PMID 16801544):

Moderate physical exercise (PE) combined with metabolic treatment (MT) (antioxidants and l-arginine) are well known to reduce atherosclerotic lesion formation in hypercholesterolemic mice. However, the long-term beneficial effects on unstable atheroma remain poorly understood. We started early PE training in large groups of 6-week-old hypercholesterolemic mice (by graduated swimming) alone or in combination with nutritional supplementation (1.0% vitamin E added to the chow and 0.05% vitamin C and 6% l-arginine added to the drinking water). Inactive controls did not receive PE. The spontaneous development of atherosclerotic plaque rupture (associated with advanced atherosclerosis) and survival rates were evaluated. Moderate PE elicited an increase in plasma levels of nitric oxide. Early combined treatment with PE and MT in the hypercholesterolemic mice significantly reduced lesions (also detected noninvasively at 10 months) and spontaneous atherosclerotic plaque rupture and prolonged survival more effectively than each intervention alone. Thus, early concerted actions of MT and PE improve the natural history of atherosclerotic lesions and reduce the plaque instability in hypercholesterolemic mice.

Granted, a far cry from healthy humans. The study discussed in this thread used E and C but no l-arginine. It does make me wonder if not having the l-arginine in the mix might have thrown off the results.

StephenB

[mikeinnaples]

I switched to take antioxidants in the morning as I exercise in the evening. This is pure ancedote, but I have been able to get over some levels in weight training that I have been stuck at for quite some time.

[Sillewater]

Another anecdote:

I ran out of Vitamin E (FamilE) and Vitamin C (1g/day time-released) a couple of weeks ago and I have seen incredible gains in strength since.

[Aeropsia]

This is total hysterical invented misinterpreted hypothetical-misapprehension BS!

Back when I was working out 2-4 times per week, I was also continuing the mega-dosing of antioxidants (and other supplements) I had started when I was 18 and had read Pearson/Shaw's seminal "Life Extension" ... it certainly did not prevent me from making rapid, gains in mass and definition and aerobic capacity.

I am sure there are hundreds of thousands if not millons of people who are simultaneous supplment (including mega-dose antioxidants) AND gym junkies who will give you their personal testimony that the antioxidants never stopped THEM from seeing the benefits of exercise and looking 1000% better than 99% of every other person they pass in the street.

Poppycockl!!!

But the study is talking about insulin sensitivity, not muscle mass gain, right?

Edited by Aeropsia, 18 October 2010 - 04:24 AM.

[Nate-2004]

Here a couple more "recent" articles from 2014 and 2012:

 

http://joshmitteldor...ts-of-exercise/

 

http://joshmitteldor...tment-or-worse/

 

I'm done with taking anything antioxidant at this point. I kind of wish I hadn't done the whole C60 thing.

 

I'm not sure why I didn't find these when researching the topic early last year.

 

 

Edited by Nate-2004, 04 January 2017 - 08:28 PM.

[jack black]

Good info, thanks for posting.

Now, how do we reconsilate it with Linus Pauling therapy?

Edited by jack black, 05 January 2017 - 01:50 PM.