Oxidative Stress in Humans Training in a Cold, Moderate Altitude Environment and Their Response to a Phytochemical Antioxidant Supplement

Schmidt, M.; Askew, E. W.; Roberts, Donald E.; Prior, Ronald L.; Ensign, Wayne; Hesslink, Robert E.

doi:10.1580/1080-6032(2002)013[0094:osihti]2.0.co;2

Cited by 86 publications

(57 citation statements)

References 57 publications

(119 reference statements)

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“…Earlier studies have shown increased levels of oxidative stress associated with physical work at moderate altitude over a shorter period of time than our study, 11 -24 days (Araneda et al 2005;Chao et al 1999;Pfeiffer et al 1999;Schmidt et al 2002;Vasankari et al 1997), and 12 hypoxic training sessions during 6 weeks (Pialoux et al 2006). However, in those studies no sedentary control groups were investigated at altitude and the objective was mainly to investigate the influence of antioxidant supplementation.…”

Section: Discussionmentioning

confidence: 43%

“…In particular, it is known that exposure to altitude combined with exercise (Araneda et al 2005;Bailey et al 2001;Chao et al 1999;Pfeiffer et al 1999;Schmidt et al 2002), and even exposure to altitude in resting conditions (Bailey et al 2001), increases reactive oxygen species (ROS) levels/formation, especially in lung and blood. On the other hand, acute physical work per se is a contributor to oxidative stress where mitochondria represent the major source of free radicals (Bailey et al 2001;Bailey et al 2004;Sen 1995).…”

Section: Introductionmentioning

confidence: 99%

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Moderate altitude but not additional endurance training increases markers of oxidative stress in exhaled breath condensate

et al. 2009

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Oxidative stress occurs at altitude, and physical exertion might enhance this stress. In the present study, we investigated the combined effects of exercise and moderate altitude on redox balance in ten endurance exercising biathletes, and five sedentary volunteers during a 6 week stay at 2800 m. As a marker for oxidative stress, hydrogen peroxide (H 2 O 2 ) was analyzed by the biosensor measuring system Ecocheck TM , and 8-iso prostaglandin F2α (8-iso PGF2α) was determined by enzyme immunoassay in exhaled breath condensate (EBC). To determine the whole blood antioxidative capacity, we measured reduced glutathione (GSH) enzymatically using Ellman's reagent. Exercising athletes and sedentary volunteers showed increased levels of oxidative markers at moderate altitude, contrary to our expectations, there was no difference between both groups. Therefore, all subjects' data were pooled to examine the oxidative stress response exclusively due to altitude exposure. H 2 O 2 levels increased at altitude and remained elevated for 3 days after returning to sea level (p ≤ 0.05). On the other hand, 8-iso PGF2α levels showed a tendency to increase at altitude, but declined immediately after returning to sea level (p ≤ 0.001).Hypoxic exposure during the first day at altitude resulted in elevated GSH levels (p ≤ 0.05), that decreased during prolonged sojourn at altitude (p ≤ 0.001). In conclusion, a stay at moderate altitude for up to 6 weeks increases markers of oxidative stress in EBC independent of additional endurance training. Notably, this oxidative stress is still detectable 3 days upon return to sea level.

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Section: Discussionmentioning

confidence: 43%

Section: Introductionmentioning

confidence: 99%

Moderate altitude but not additional endurance training increases markers of oxidative stress in exhaled breath condensate

et al. 2009

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“…However, the lower the sum total of carotenoid plasma concentration is, the higher the plasma lipoperoxidation marker (6) is. Among the antioxidant complex supplements given to athletes highly exposed to oxidative stress -especially in extreme conditions such as cold or high altitude -those containing b-carotene or multiple carotenoids at nutritional doses fight lipoperoxidation with more efficiency in individuals with low initial antioxidant status (5,10,45) . The origin of free radical production influences the effect of ingested antioxidant vitamins and carotenoids.…”

Section: Carotenoidsmentioning

confidence: 99%

Does physical exercise modify antioxidant requirements?

Margaritis

Rousseau

2008

Nutr. Res. Rev.

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Physical training is known to induce a biochemical adaptive response which might require an increase in the ingestion and/or the absorption of micronutrients. A question that is still being raised is whether acute or chronic exercise modifies antioxidant requirements. First, the present review brings to light the most crucial studies on the topic. Second, it interprets the established relationships between antioxidant micronutrient intakes and the adaptive response of antioxidant systems. Finally, it exposes the major questions connected with antioxidant micronutrient requirements for athletes. To this effect, the training-load interaction with nutrition is taken into account. As oxidative stress cannot be avoided, the imbalance between oxidants and antioxidants can be alleviated to minimise oxidative damage and outcomes. There is growing evidence that one specific antioxidant cannot by itself prevent oxidative stress-induced damage, as direct adverse effects of supplementation are attributed to undesirable synergic effects. Other effects can be supposed that limit the endogenous adaptive effect of training. High doses of antioxidant supplements can minimise the effects of radical oxygen species themselves or generate pro-oxidant effects. Effects are only exhibited when nutritional status is deficient. There are no convincing effects of supplementation in well-trained athletes. Risk/benefit analysis emerges on evidence for an unknown risk of supranutritional intakes, a supposed impairment of adaptive effects and a still unknown long-term risk. Appropriate status can be achieved by a diversified and balanced diet, adapted to specific needs, by awareness of high-density food intakes (avoiding products containing a low density of micronutrients).

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“…Taken together, this evidence strongly suggests that combining ALA and VE is better than monotherapy. In parallel, the ALA-VE mixture has been combined with other dietary antioxidants, such as vitamin C, beta-carotene, and selenium, and evaluated under several conditions of exercise, experimental diabetes, cold, age and cancer, and promising results have also been obtained [46][47][48][49][50][51].…”

Section: Synergism Between Lipoate and Tocopherolmentioning

confidence: 99%

Therapeutic perspectives on the combination of α-lipoic acid and vitamin E

González-Pérez

González-Castañeda

2006

Nutrition Research

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Alpha-lipoic acid and vitamin E have synergistic effects, as determined in models of oxidant radical lesions. This review summarizes recent findings showing that the combination of alpha-lipoic acid plus vitamin E has beneficial effects in reducing oxidative damage in ischemic or other oxidationrelated pathological events. Both antioxidants are common in the normal human diet and side effects are very rare. Therefore, alpha-lipoic acid and vitamin E can counteract oxidative processes and could have an important role in clinical medicine.

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Oxidative Stress in Humans Training in a Cold, Moderate Altitude Environment and Their Response to a Phytochemical Antioxidant Supplement

Cited by 86 publications

References 57 publications

Moderate altitude but not additional endurance training increases markers of oxidative stress in exhaled breath condensate

Moderate altitude but not additional endurance training increases markers of oxidative stress in exhaled breath condensate

Does physical exercise modify antioxidant requirements?

Therapeutic perspectives on the combination of α-lipoic acid and vitamin E

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