Is it Time to Focus on Defining Optimal Antioxidant Status?
Chronic inflammation and oxidative stress contribute to age-related disease. Having adequate antioxidant status helps maintain normal cell function, especially important in people who don’t eat enough fruit and vegetables, are overweight, and/or live a sedentary lifestyle. As summarized by Stephen Daniells on Oct 22, a depletion in plasma levels of antioxidants (in this case vitamin E) may play a role in age-related, non-communicable diseases.
Lambrecht and colleagues assessed markers of oxidation and inflammation in 42 obese, premenopausal women before and after a 30 min walk. The women were randomized to antioxidant supplementation or placebo and measurements were taken at baseline and after 8 weeks of use. The antioxidant capsules were a blend of fruit, vegetable and berry powders providing 7.5 mg beta-carotene, 200 mg vitamin C, 60 mg RRR-α-tocopherol, and 600 µg folate. The participants took 6 capsules daily. The authors report a reduction in markers of protein oxidation, oxidized LDL-cholesterol, total inflammation and TNF-α after supplementation relative to placebo. Similar to findings previously observed in trained men exercising at 70% VO2max, they report that walking at this intensity for 30 minutes does not generate oxidative stress in overweight women.
Avila and colleagues report that obese rats have higher levels of oxidative damage (superoxide dismutase and glutathione peroxidase) to lipids and proteins than lean rats. Obese rats were more likely to die when exposed to cardiovascular catecholamine stress (isoproterenol injection). Supplementation with a mixture of antioxidants (20 mg reseveratrol and 0.8 mg vitamin E per kg body weight) and fish oil (216 mg EPA and 40 mg DHA per kg body weight) for 2 months protected obese rats from extreme increases in markers of oxidative stress and inflammation when exposed to catecholamines. These changes in oxidative responses led to reduced mortality rates.
Antioxidants, such as vitamin E, resveratrol, vitamin C, are not magic bullets. Pharmacologic doses are not the answer. However, with a large percentage of people eating poorly, being sedentary, overweight and with elevated markers of inflammation and oxidative stress, health professionals need to understand the role of antioxidant status on health outcomes.
As Dr Manfred Eggersdorfer, DSM Nutritional Products, told Nathan Gray, “This is a wakeup call for new science on vitamin E. There is much left to learn. We must encourage young scientists to engage in new research on nutrient-gene interactions and to use novel biomarkers and analytical tools.”
Lambrecht M, Obermayer G, Steinbauer K, Cvirn G, Hofmann L, Ledinski G, Greilberger JF, Hallstroem S. 2013 Supplementation with a juice powder concentrate and exercise decrease oxidation and inflammation, and improve the microcirculation in obese women: randomised controlled trial data. 2013 Br J Nutr doi:10.1017/S0007224513001001
Avila PRM, Marques SO, Luciano TH, Vitto MF, Engelmann J, Souza DR, Pereira SV, Pinho RA, Lira FS, De Souza CT. Resveratrol and fish oil reduce catecholamine-induced mortality in obese rats: role of oxidative stress in the myocardium and aorta. 2013 Br J Nutr doi:10.1017/S0007114513000925