Link: Vitamin supplements may cut benefits of exercise - health - 11 May 2009 - New Scientist

Free radicals aren't always the bad guys. It even seems that popping antioxidants to mop them up might reduce some of the beneficial effects of exercise.

Free radicals have long been thought to contribute to the ageing process, which is one reason why people take antioxidant supplements such as vitamin C or E.

However, other studies have hinted that taking antioxidants may hasten death through an unknown mechanism. One possibility is that they interfere with the beneficial effects of exercise, as there are hints that free radicals might be used by the body to prevent cellular damage after exercise.

To investigate further, Michael Ristow at the University of Jena in Germany and his colleagues recruited 40 volunteers, and asked half of them to take 1000 milligrams of vitamin C and 400 international units of vitamin E per day – equivalent to amounts in some vitamin supplements. They were also asked to exercise for 85 minutes a day, five days a week, for four weeks.

Muscle biopsies showed a two-fold increase in a marker of free radicals called TBARS (thiobarbituric acid-reactive substances) in those volunteers who didn't take antioxidants, but no increase in those who did take the supplements – suggesting that they were indeed mopping them up.
Lost benefits

Exercise is well known to have a beneficial effect on insulin resistance – a precursor condition to type 2 diabetes. However, when Ristow's team measured the effects of exercise on insulin sensitivity, they found no increase in those volunteers taking antioxidants, but a significant increase in those who didn't take the supplements.

"These data are fully in accord with recent work on the actions of reactive oxygen species in cells, although clearly at odds with the popular concept that dietary antioxidants are inevitably beneficial," says Malcolm Jackson at the University of Liverpool, UK, who was not involved in the research.

In fact, in this case, "antioxidants are preventing the health effects of exercise," adds Ristow, although he cautions that not all vitamin supplements contain such high doses of vitamin C and E.

These doses are also far higher than one would get from eating the recommended amount of fruit and vegetables, which do seem to have a positive effect on health – possibly because they contain other protective compounds. "Taking antioxidants cannot substitute for eating fruit and vegetables at all" says Ristow.

Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0903485106)

An interesting twist on the popular belief perhaps? Anyone got any comments?

Interesting read. I never would of guessed thought that.

Interesting! Kind of like how NSAIDs reduce benefits of exercise even though they help with pain.

Really interesting. I've been taking 1000mg of vitamin c and have been researching on the dosage on vitamin e, all because i'm losing weight and people have told me that both these can help in free radicals and also to help in stretch marks once i lose weight. But i did notice that, for past few weeks i've not seen much difference in my muscle growth. Maybe this might be the answer!

Do you guys think that the vitamins dosage in multivits are enough and beneficial?

I'm taking mega men from GNC.

With regards to the possibility that antioxidants could potentially hasten death, I think the unknown mechanism mentioned is related to the fact that the "free radicals" described (molecules like hydrogen peroxide, superoxide etc.) in low amounts act in cellular signalling pathways, such as the activation of proteins like AMPK, which is a key molecule to insulin sensitivity (and one of the targets of anti-diabetic treatment).

Anyway, I realise this isn't really specific to the exercise based benefits you guys are talking about, but I thought I'd provide a small link in the "unknown mechanism" described, even if it isn't fully elucidated yet. I'm pretty interested in this side of research, if any of you guys are, feel free to give me a shout. Cheers.

Originally Posted by Delita420

Interesting! Kind of like how NSAIDs reduce benefits of exercise even though they help with pain.

On hypertrophy, not exercise in general.

Originally Posted by Rodja

On hypertrophy, not exercise in general.

Yeah, but the evidence still isn't very convincing or sufficiently supported. While i think that chronic NSAID use may play a bigger factor, i'm not convinced the occasional use of an NSAID is hampering muscle gains to any significant degree. More studies need to be done to prove it either way.

Originally Posted by Trauma1

Yeah, but the evidence still isn't very convincing or sufficiently supported. While i think that chronic NSAID use may play a bigger factor, i'm not convinced the occasional use of an NSAID is hampering muscle gains to any significant degree. More studies need to be done to prove it either way.

I agree. It is more of an chronic issue than an acute issue. That being said, I try not to dose any NSAIDs unless absolutely necessary.

Originally Posted by Rodja

I agree. It is more of an chronic issue than an acute issue. That being said, I try not to dose any NSAIDs unless absolutely necessary.

Yeah i agree. Some people eat them like candy. Little do they know what this is doing to them on the inside.

Originally Posted by Trauma1

Yeah i agree. Some people eat them like candy. Little do they know what this is doing to them on the inside.

It's sad that they don't realize that much inflammation is a horrible thing. Another sign that metabolic syndrome is growing.

I was actually thinking about this the other day. I don't remember why though...

It's like everything in the body I guess...there needs to be balance.

Meh....

I've been taking vit C 1-2g a day and 3 NP EGCG pills daily and my gains have and are still going strong. I've been using this for months if not years(EGCG). So accumulative affects are not a factor for me, unless of course we're talking years of use???

I've also been using Bio-Mend the last 3 weeks.

I need to see a few more studies all confirming the above before I believe it.

I'd agree about moderation tho. But for me, if it's not broke, why fix it?

Antioxidants prevent health-promoting effects
of physical exercise in humans

Michael Ristowa,b,1,2, Kim Zarsea,2, Andreas Oberbachc,2, Nora Klo¨ tingc, Marc Birringera, Michael Kiehntopfd,
Michael Stumvollc, C. Ronald Kahne, and Matthias Blu¨ herc,2

aDepartment of Human Nutrition, Institute of Nutrition, University of Jena, Jena D-07743, Germany; bGerman Institute of Human Nutrition,
Potsdam-Rehbru¨ cke D-14558, Germany; cDepartment of Medicine, University of Leipzig, Leipzig D-04103, Germany; dInstitute of Clinical Chemistry and
Laboratory Medicine, University of Jena, Jena D-07743, Germany; and eResearch Division, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215
Contributed by C. Ronald Kahn, March 31, 2009 (sent for review March 14, 2009)

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, peroxisomeproliferator-
activated receptor gamma (PPAR), and PPAR coactivators
PGC1 and PGC1 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.