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Diabetes Developments - A blog on latest developments in diabetes by David Mendosa

Choosing Exercise or Antioxidants

May 13th, 2009 · 8 Comments

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Based on what I’ve read recently, some of which I have reported here, I’ve grown more and more wary of the wisdom of taking supplements. Few of the them seem to help.

And now comes a new study indicating that the two most common supplements can actually work against us. Those supplements are vitamins C and E.

It seems that we have a choice of exercising or taking large doses of those supplements. We know that exercise has lots of good effects like increasing our sensitivity to insulin, which is of great importance to all of us with diabetes.

We don’t really know whether taking antioxidants in pill form do much of anything for us. And now a small study that the Proceedings of the National Academy of Sciences just released online Monday before print seems to show that these fairly large doses of Vitamins C and E preclude the positive effects of exercise.

The doses weren’t all that big. The researchers divided 40 young men into a group that they gave 1000 mg of vitamin C and 400 mg of vitamin E each day and the other half as a control group that didn’t get the supplements. Half of each group had been exercising regularly and half hadn’t.

After the 4-week trial, the researchers found that the group taking the vitamins had no improvement in their insulin sensitivity and almost no activation of our natural defense mechanism against oxidative damage. Led by Dr. Michael Ristow, a nutritionist at Germany’s University of Jena, the researchers included Dr. C. Roland Kahn, president of the Joslin Diabetes Center in Boston.

“If people are trying to exercise, this is blocking the effects of insulin on the metabolic response,” Dr. Kahn told The New York Times. The effect “is really quite significant.”

This is a study limited to taking vitamins C and E as supplements. “Fruits and vegetables may exert health-promoting effects despite their antioxidant content and possibly due to other bio-active compounds,” the report says.

And they didn’t study the effects of other antioxidants when we exercise. But I’ve been taking 150 mg daily of a powerful antioxidant, coenzyme Q10.

It seems that I may have a choice of getting the benefits of exercise or of that antioxidant. I’m choosing to continue exercising and to get more help from it in controlling my blood glucose. I’ve surrendered the possible benefits of the antioxidant.

This is a mirror of one of my articles that Health Central published. You can navigate to that site to find my most recent articles.

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Posted in: Diabetes Medication, Exercise For Diabetes

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8 responses so far ↓

  • 1 marcus // Jun 19, 2009 at 12:15 am

    I don’t understand, so people who exercise and take the supplement did worse than those who just exercise?

  • 2 David Mendosa // Jun 19, 2009 at 6:59 am

    Dear Marcus,

    Thanks for your comment here and all your other recent and helpful comments on other posts.

    That does seem to be what they found, although they studied that only in rather large doses of Vitamins C and E.

    Best regards,

    David

  • 3 marcus // Jun 19, 2009 at 9:59 am

    Thanks, your website seems to be a great resource for people, good work.

  • 4 Doug Jewett // Sep 26, 2009 at 11:44 am

    In regards to Marcus’ question. Exercise may have beneficial effects by way of stress hormesis. Antioxidant supplements may blunt the effect of this beneficial level of stress. See recent papers by Mark Mattson (National Institute on Ageing) on the concept of hormesis. David, many thanks for alerting me to this important article.

  • 5 Marcus // Sep 27, 2009 at 7:35 pm

    Interesting, thanks for the response.

    Well I am becoming a scientist so I like to break things down and see what they really mean. Excercise has many beneficial effects, but only 2 of them seem to be measured in this study. So let the reader make sure they understand that point and that it means there could be other negative effects of combining excercise and antioxidants or there could be positive effects of combining the two.

    Of those two aspects studied here, only the first aspect that showed that there was no improvement in their insulin sensitivity is applicable. The second aspect about our natural defenses not bieng activated with the people taking antioxidants is expected because why would your body need to produce natural antioxidants when there already is a high level of antioxidants in the blood? So it seems doing both antioxidants and excercise at the same time could possibly be beneficial for people whose body has a hard time making enough natural antioxidants.

    However the first point about the insulin response not being improved can be a big deal especially for people with diabetes. And it looks like you comment Doug fits into this aspect that mabye the stress resopnse promotes insulin sensitivity, and this stress response can be blocked by antioxidants. Corrcet me if I’m wrong.

  • 6 Doug Jewett // Sep 29, 2009 at 6:53 pm

    Marcus. The original article should be available to the general public in a couple of months. I’m copying the abstract here for the time being:

    Authors Full Name
    Ristow, Michael. Zarse, Kim. Oberbach, Andreas. Kloting, Nora. Birringer, Marc. Kiehntopf, Michael. Stumvoll, Michael. Kahn, C Ronald. Bluher, Matthias.

    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 (PPARgamma), and PPARgamma coactivators PGC1alpha and PGC1beta 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.

  • 7 Doug Jewett // Sep 29, 2009 at 7:04 pm

    I found the following article on hormesis by Mark Mattson:

    pubmedcentral.nih.gov/articlerender.fcgi?artid=2612999

  • 8 Marcus // Sep 29, 2009 at 10:36 pm

    Thanks for making that abstract easily accessable

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