Antioxidants prevent health-promoting effects of physical exercise in humans

jyb

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I'm ever so undecided about the pros/cons of supplemented antioxidants (or getting amounts far higher than from a normal diet). I read its good in disease and high oxidative stress, but then I also read its bad when healthy as it could disrupt endogenous production. Recents studies on fruit/vegetables seems to show no long term benefits of their antioxidants protection, in fact at least one study suggests DNA damage.

So I thought, what about fat soluble antioxidants, why would it be fundamentally different other than them being stored differently in the body? I'm also uncertain about Peat's view. I know he wrote how caffeine and endogenous uric acid are powerful antioxidants, but then I also read about excess uric acid being bad and how it suspiciously looks like a stress response to some foods like fructose to provide immediate protection (probably to protect against high fructose concentration in the portal vein before it reaches the liver, or maybe in the serum as a bit could leak), although that interpretation would support the idea that a little bit of uric acid as hormetic response is beneficial like in the study below. I think Wilfrid wrote a bit about too much uric acid becoming pro-oxidant, which reminds me a lot about caffeine.

Below is for antioxidants C and E. The part about moderate exercise improving insulin resistance is not new to this study, "moderate" being typically defined elsewhere as something like 30+ minutes of a light exercise in a day such as a decent walk.

So...should you really drink coffee every time you go through moderate stress? That's actually how I used to think last year: after the slightest hardship, including if I exercised, I drank coffee thinking it probably repaired everything so it was a good idea: constant feeding throughout the day of exogenous antioxidants.

For the reasons I mentioned, when discussing the merits of high-dose antioxidants let's leave the situation of obvious disease out of the discussion. I'm talking about *prevention*, not treatment.


Antioxidants prevent health-promoting effects of physical exercise in humans

Exercise promotes longevity and ameliorates type 2 diabetes mellitus and insulin resistance. However, exercise also increases mitochondrial formation of presumably harmful reactive oxygen species (ROS). Antioxidants are widely used as supplements but whether they affect the health-promoting effects of exercise is unknown. We evaluated the effects of a combination of vitamin C (1000 mg/day) and vitamin E (400 IU/day) on insulin sensitivity as measured by glucose infusion rates (GIR) during a hyperinsulinemic, euglycemic clamp in previously untrained (n = 19) and pretrained (n = 20) healthy young men. Before and after a 4 week intervention of physical exercise, GIR was determined, and muscle biopsies for gene expression analyses as well as plasma samples were obtained to compare changes over baseline and potential influences of vitamins on exercise effects. Exercise increased parameters of insulin sensitivity (GIR and plasma adiponectin) only in the absence of antioxidants in both previously untrained (P < 0.001) and pretrained (P < 0.001) individuals. This was paralleled by increased expression of ROS-sensitive transcriptional regulators of insulin sensitivity and ROS defense capacity, peroxisome-proliferator-activated receptor gamma (PPARγ), and PPARγ coactivators PGC1α and PGC1β only in the absence of antioxidants (P < 0.001 for all). Molecular mediators of endogenous ROS defense (superoxide dismutases 1 and 2; glutathione peroxidase) were also induced by exercise, and this effect too was blocked by antioxidant supplementation. Consistent with the concept of mitohormesis, exercise-induced oxidative stress ameliorates insulin resistance and causes an adaptive response promoting endogenous antioxidant defense capacity. Supplementation with antioxidants may preclude these health-promoting effects of exercise in humans.
 
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There's a whole hour of radio show where Ray Peat bashes the whole concept of "anti-oxidant"
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jyb

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Such_Saturation said:
There's a whole hour of radio show where Ray Peat bashes the whole concept of "anti-oxidant"
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I did not listen to that but I am aware things like caffeine and E clearly don't act just like antioxidants. But it does not address the problems raised by this study about high-dose E, which *can* act like an antioxidant.
 
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I think one thing is breaking free radical chains, one thing is preventing oxygen species production, but another is outright interfering with respiration (isoflavones, phenols).
 

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