|Image 1: If you add some reactive oxygen species to this mitochondrium, this will trigger beneficial, (mito-)hormetic adaptations, that could be blunted by too many antioxidants.|
The hormetic benefits of inflammation
According to the mitohormesis hypothesis, the beneficial effects of exercise on health, in general, and glucose metabolism, in particular, are at least partly mediated by an increase in reactive oxygen species, which triggers downstream "hormetic" adaptation processes which result in increased oxidative capacity and insulin sensitivity, as well as a reduction in total inflammation (cf. previous posts on the work of S. Schmeisser and M. Ristow from the Department of Human Nutrition at the University of Leipzig. If this theory held true, or let's be more specific, if this theory which is largely based on observations in metabollically derranged, i.e. obese and/or type II diabetic subjects, was applicable to healthy people and athletes, as well, this could mean that the multi-vitamin, the vitamin C pills, the alpha-tocopherol (vitamin E) and all the other little helpers you have been taking religiously to increase your exercise performance would actually have hampered, not promoted your muscle gains, fat loss and whatever else you may have had in mind, when you hit the gym, the road, the field, the court or the green ;-)
|Figure 1: Neither the high-dose supplementation protocol in rodents (HED: Human Equivalent Dose for 80kg), nor the moderate dose protocol in humans did block any of the measured beneficial adaptations to exercise in the studies by Higashida (2011) and Yfanti. (2011), respectively.|
|Figure 2: Serum vitamin C and vitamin E levels (µmol/L) in 21 subjects before, at the beginning and after 12 weeks of 5x a week strenuous cycling exercise with and without supplemental vitamin C & E (adapted from Yfanti. 2011)|
[...] the present study showed that combined supplementation with vitamins C and E before and during 12 weeks of supervised, strenuous bicycle exercise training of a frequency of 5 days/week had no effect on maximal oxygen consumption, maximal power output, workload at lactate threshold, glycogen content, and CS and β-HAD activity in muscle.In other words, supplementing with "reasonable" amounts of vitamin C and vitamin E had absolutely NO EFFECT (!) on the exercise induced metabolic adaptations or performance increases - that does yet also imply that taking anti-oxidants is of little benefit as long as the minimal dietary requirements are met... and if you still insist to poor money down the literally rat hole, you may be interested to hear that (assuming that the results from Higashida's rat study translate to humans), even 10g of vitamin C and 3000IU of vitamin E a day probably would not really make a difference - as long as you train heavy enough.
|Figure 4: Exercise induced changes in GLUT-4 expression (arbitrary units) and 2DG transport (µmol/ml/20min) in rats subjected to 8 weeks of high dose antioxidant supplementation and 6days/week swimming exercise in the last 3 weeks (data adapted fro Higashida. 2011)|
|Figure 5: Exercise induced changes in MDA, SOD and PGC-1α in rats subjected to 8 weeks of high dose antioxidant supplementation and 6days/week swimming exercise in the last 3 weeks (data adapted fro Higashida. 2011)|
Now, I a confused and don't know what to believe
So what does all that tell us? Well, we can now be relatively certain that supplementing with vitamin C and vitamin E is a waste of time and money for most of us. What we still cannot say for sure, though is why the Ristow study from 2009, which even made it to mainstream media news, found detrimental effects of supplementing with 1g of vitamin C and 400IU of vitamin E on the adaptive response to 4 weeks of 5days/week 20min steady state aerobic training + 45 minute circuit training + 20 min warm up + cool down (Ristow. 2009), while the Yfanti study, with 500mg of vitamin C and 400IU of vitamin E did not find any effects of supplementation...
|Figure 6: Exercise protocol that was used in the Yfanti study.|
All that being said, it appears that all is coming back to what I have been writing (and also saying on SHR) several times before: Controlled oxidation is likely to be beneficial. It's like the fire in the oven that keeps you warm - the one you carefully take care of, in order to prevent your whole house to catch fire... if you are a marathon runner, the latter can happen pretty quickly and you will need (tons of ;-) antioxidants and even that will probably not suffice. If you are the housewife on the treadmill, who walks at 5km/h for 20min two times a week, on the other hand, even a few milligrams of vitamin C and a few units of vitamin E will blunt the little oxidative "damage" that you do and your "efforts" to increase your insulin sensitivity or whatever your intentions may be will be sabotaged by your vitamin supplements.