Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Vitamin Supplements Block Beneficial Effect of Exercise on Diabetes Risk

Research Examines Adverse Effects of Antioxidants

Type 2 diabetes is a highly prevalent disease that promotes multiple conditions, including stroke, heart attacks, kidney failure and blindness. Physical exercise is known to prevent type 2 diabetes, and a related condition named insulin resistance.

On the other hand, exercise also induces formation of free radicals, a form of very active oxygen, producing oxidative stress, which, if it persists for long periods of time, is commonly thought to be harmful. Accordingly, athletes, as well as non-athletes, consume antioxidant supplements to ameliorate the presumably harmful side-effects of oxidative stress. Moreover, a significant percentage of the general population uses antioxidant supplements on a daily basis in hopes to prevent other kinds of oxidative tissue damage and thereby improve health and longevity. The most commonly used anti-oxidants are vitamins C and E.

A study published today in the "Proceedings of the National Academy of Sciences" (PNAS) suggests that vitamin C and E supplements may actually be harmful, at least in regards to diabetes risk and glucose metabolism. According to this study, the health-promoting effects of exercise require the formation of oxidative stress during sports and if this is blocked, some of these effects do not occur. In the particular study, the intake of antioxidants during a four-week exercise training class abolished the effects of exercise to improve insulin sensitivity and glucose metabolism which would help prevent diabetes, while those individuals not taking the antioxidants had major benefits in terms of metabolism from exercise.

Dr. Michael Ristow, lead-author of the study which was published by a team of researchers from Leipzig and Jena Universities (both Germany) and Harvard Medical School, points out: "Exercise causes repeated boosts of free radicals, which - according to our results - induce a health-promoting adaptive response in humans. Subsequently, our body activates molecular defense systems against stress, and metabolizes carbohydrates more efficiently, both of which prevents diabetes, and possibly other diseases. Blocking these boosts of free radicals by antioxidants accordingly blocks the health promoting effects of exercise." He further says that "short-term doses of free radicals may act like a vaccine, helping the body to defend itself from chronic stressors more efficiently by inducing a long-term adaptive response".

Dr. C. Ronald Kahn, a collaborating author from the Joslin Diabetes Center and Harvard Medical School, noted: "This is a very important study for the millions of people at risk for type 2 diabetes. Exercise is a proven way to improve insulin action and reduce diabetes risk, but clearly this beneficial effect can be largely blocked by taking these very commonly used vitamin supplements. We need larger studies to fully assess this effect, but in the meantime, individuals at risk for diabetes and maybe even some with type 2 diabetes itself, need to think carefully about the use of these vitamin supplements, especially if they exercise regularly to improve there health."

Original Publication:
Ristow, M., Zarse, K., Oberbach, A., Klöting, N., Birringer, M., Kiehntopf, M., Stumvoll, M., Kahn, C. R., Blüher, M.: Antioxidants Prevent Health-Promoting Effects of Physical Exercise in Humans. Proceedings of the National Academy of Sciences of the United States of America (PNAS), early edition:
Prof. Dr. Michael Ristow, M.D., Dept. for Human Nutrition, Institute for Nutrition, University of Jena, Germany; tel. +49-3641-949630, e-mail:; additional material at:


Prof. Dr. C. Ronald Kahn, M.D., Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA; tel. +1-617-732-2635, e-mail:

Manuela Heberer | idw
Further information:

More articles from Health and Medicine:

nachricht NIH scientists describe potential antibody treatment for multidrug-resistant K. pneumoniae
14.03.2018 | NIH/National Institute of Allergy and Infectious Diseases

nachricht Researchers identify key step in viral replication
13.03.2018 | University of Pittsburgh Schools of the Health Sciences

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Physicists made crystal lattice from polaritons

20.03.2018 | Physics and Astronomy

Mars' oceans formed early, possibly aided by massive volcanic eruptions

20.03.2018 | Physics and Astronomy

Thawing permafrost produces more methane than expected

20.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>