JK, you're coming to this forum and quoting stuff from Merck?
'Nuff said.
The vitamin C and vitamin E exercise study is an interesting one. Since I started learning about nutrition, I've noted with interest the number of studies that come out claiming that vitamins are useless or bad for us, and they make headlines around the world. The newspapers don't publish the abstracts, or information about who funded the studies. One that I'm aware of, on vitamin E, used the L-chiral form, which is useless and possibly dangerous to the body. I'm not saying that any of these studies should be dismissed out of hand -- just that the details should be looked into before going along with brief summaries of abstracts, when the journalists have almost always not looked at the actual studies. (Less well publicised are the thousands of deaths occurring from FDA-approved medications. Strange, that.) So who is so interested in making yet another claim that vitamins are useless? Is someone's patent running out -- are they trying to head off competition? Questions worth asking. Vitamins C and E aren't big money-makers but pharmaceuticals, which we are told are safe and effective, are. (Sorry, up on my soap box.)
Anyone who wants to read more into this particular study can find an interesting discussion here. I found this person's comments interesting:
Quote
A fatal flaw in this study is the "hyperinsulinemic euglycemic clamp" test they used to determine "insulin sensitivity". Nothing is wrong with the test, it's just that you can't use it the same way on someone who has ingested vitamin C. This test involves giving someone insulin and then seeing how much glucose is needed to maintain blood sugar. More glucose required is a good sign that you are "insulin sensitive". The problem is that vitamin C makes you more sensitive to insulin, elevates glucose, reducing the need for sugar, which would make it appear as a negative outcome:
"These data indicate that elevated plasma AA delays the insulin response to a glucose challenge in normoglycemic adults, thereby prolonging the postprandial hyperglycemia."
Vitamin C is converted directly from glucose in 99.9% of animals and the two are transported similarly due to very similar structures. Someone on Vit C needs less insulin to maintain blood sugar. It can be used by diabetics to make them more sensitive to insulin so that they can reduce insulin needs by 2 units for each 1,000 mg Vit C taken (Dice and Daniel 1973). This indicates maybe 50% of diabetics could go without insulin if they took 10,000 mg Vit C/day. This is 1973 information. I doubt there is much "new information" out there to contradict or expand upon this. This is another example of how "new studies" should not be taken too seriously if they contradict the past 30 years of research. These 9 researchers from Harvard and Germany did not pay attention to what was published in 1973. Harvard BTW had the most ridiculous publications against nutritional supplements for decades. I would not be surprised if they are still saying you should never take supplements and only get nutrients from food. The last I read is that they agreed that 200 mcg/day selenium as a supplement reduced 50% of all cases of cancers in two huge studies but they still said not take it, but that you should wait until you get cancer to begin chemotherapy. My mouth just dropped open and its the last thing I read from their medical school newsletter.
The masses will never be aware of this argument agaist this study. Only the negative outcomes against vitamins, that contradict the past 50 years of research, will make the biggest news. The reason things like this make big news is the same reason it's usually wrong.
There are other arguments and things to consider that could negate the other findings of the paper. For example why not increase exercise rather than decreasing antioxidents. But I like the idea of a 1 hour oxidative stress every other day, so i may delay vit C after a workout. But I still do not know if that is a good idea or not. As a side note, I have seen 4,000 mg doses right after a "heat stress test" do amazingly good things in my elderly mother who likes to over-work in the yard. She can kill herself and be wiped out for 48 hours....if she doesn't follow it with 4,000 mg.
I'm surprised that the large body of work that Linus Pauling did on this vitamin, seems to be largely forgotten or ignored. NIMH claimed to have repeated one of his studies and declared that Pauling's results were invalid; NIMH was subsequently shown to have failed to follow Pauling's methodology, but the damage to his reputation was done:
From the reading I've done about this vitamin and Pauling's studies, I am quite happy to take large doses, and they have made a noticeable difference to me; though I am still poorly, I have gone from catching a cold/having a cold/fighting off a cold more than half the time, to almost never.
Personally I feel frustrated with repeated attempts to rubbish vitamins. If someone feels that vitamin C is interfering with their exercise, they can take it at other times of the day, though I don't know enough about biochemistry myself to be able to say exactly what is going on there.
