Effects of Intentional Weight Loss on Markers of Oxidative Stress, DNA Repair and Telomere Length - a Systematic Review

Abstract

Background: Altered levels of markers of oxidative stress, DNA repair, and telomere integrity have been detected in obese individuals and may underlie the pathogenesis of obesity-related diseases. However, whether or not such effects are reversed by intentional weight loss has not been systematically reviewed. Methods: A literature search in PubMed/Medline identified 2,388 articles of which 21 studies (randomized controlled trial (RCT) (n = 10) and non-randomized intervention studies (n = 11)) were classified as testing the effects of intentional weight loss on i) oxidative stress (n = 15), ii) DNA repair (n = 2), and iii) telomere length (n = 4). Results: Across a broad range of intervention designs, diet-, exercise-, surgery-, balloon-induced weight loss regimens decreased oxidative stress measures. Studies investigating DNA repair capacity or telomere length as endpoints after weight loss were less common in number and yielded null or inconsistent results, respectively. Conclusion: While this systematic review supports a role for intentional weight loss in reducing obesity-associated oxidative stress, it is not clear whether the effects are primary outcomes or secondary to improvement in obesity-associated insulin resistance and/or chronic inflammation. Although the lack of effect of intentional weight loss on DNA repair capacity might be anticipated given that oxidative stress is reduced, additional studies are needed. The inconsistent effects of weight loss on telomere length or DNA repair suggest the need for a re-assessment of intervention designs and assay methodology to definitively address this topic.

Impact of Weight Loss Strategies on Obesity‐Induced DNA Damage

“…Therefore, it is conceivable that the reduced activity of this repair system is causally related to oxidation of DNA bases in obese animals. Himbert et al . evaluated the literature regarding effects of weight loss on DNA repair functions and telomere lengths.…”

“…[44] Furthermore, a number of human investigations were published recently indicating that weight loss reduces obesity associated oxidative stress (for details see ref. [45]).…”

“…[46] Therefore, it is conceivable that the reduced activity of this repair system is causally related to oxidation of DNA bases in obese animals. Himbert et al [45] evaluated the literature regarding effects of weight loss on DNA repair functions and telomere lengths. The authors concluded that it is not clear at present whether the reduction of the body weight affects the repair capacity in humans in general and increases the telomere lengths.…”

Anthropometric and Dietary Factors as Predictors of DNA Damage in Obese Women

“…Furthermore, in obese patients, reduced energy intake and associated body weight loss was reported to reduce DNA damage [ 68 ]. However, a recently published systemic review showed the inconsistent effects of weight loss on telomere length and DNA repair [ 69 ]. Therefore, further studies are needed to establish the effect of weight loss on DNA damage and DNA repair.…”

Oxidative stress, telomeres and cellular senescence: What non-drug interventions might break the link?

“…In all of them telomere length was determined in either leukocytes or PBMC before and after the intervention. However, although the type of interventions described are known to impinge on oxidative-stress responses [78][79][80][81][82], only a few related telomere length measurements to changes in oxidative stressrelated parameters [62,64,65]. A brief description of these studies is summarized below.…”