Vitamin E and aerobic exercise: effects on physical performance in older adults

Long-term detraining reverses the improvement of lifelong exercise on skeletal muscle ferroptosis and inflammation in aging rats: fiber-type dependence of the Keap1/Nrf2 pathway

We investigated the effects of lifelong aerobic exercise and 8 months of detraining after 10 months of aerobic training on circulation, skeletal muscle oxidative stress, and inflammation in aging rats. Sprague-Dawley rats were randomly assigned to the control (CON), detraining (DET), and lifelong aerobic training (LAT) groups. The DET and LAT groups began aerobic treadmill exercise at the age of 8 months and stopped training at the 18th and 26th month, respectively; all rats were sacrificed when aged 26 months. Compared with CON, LAT remarkably decreased serum and aged skeletal muscle 4-hydroxynonenal (4-HNE) and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels. Superoxide dismutase 2(SOD2) levels were higher in the LAT group than in the CON group in skeletal muscle. However, DET remarkably decreased SOD2 protein expression and content in the skeletal muscle and increased malondialdehyde (MDA) level compared with LAT. Compared with LAT, DET remarkably downregulated adiponectin and upregulated tumor necrosis factor alpha (TNF-α) expression, while phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), and 70-kDa ribosomal protein S6 kinase (P70S6K) protein expression decreased, and that of FoxO1 and muscle atrophy F-box (MAFbX) proteins increased in the quadriceps femoris. Adiponectin and TNF-α expression in the soleus muscle did not change between groups, whereas that of AKT, mammalian target of rapamycin (mTOR), and P70S6K was lower in the soleus in the DET group than in that in the LAT group. Compared with that in the LAT group, sestrin1 (SES1) and nuclear factor erythroid 2-related factor 2 (Nrf2) protein expression in the DET group was lower, whereas Keap1 mRNA expression was remarkably upregulated in the quadriceps femoris. Interestingly, the protein and mRNA levels of SES1, Nrf2, and Keap1 in soleus muscle did not differ between groups. LAT remarkably upregulated ferritin heavy polypeptide 1(FTH), glutathione peroxidase 4(GPX4), and solute carrier family 7member 11 (SLC7A11) protein expression in the quadriceps femoris and soleus muscles, compared with CON. However, compared with LAT, DET downregulated FTH, GPX4, and SLC7A11 protein expression in the quadriceps femoris and soleus muscles. Long-term detraining during the aging phase reverses the improvement effect of lifelong exercise on oxidative stress, inflammation, ferroptosis, and muscle atrophy in aging skeletal muscle. The quadriceps femoris is more evident than the soleus, which may be related to the different changes in the Keap1/Nrf2 pathway in different skeletal muscles.

Review articles (Meta-Analyses) effects of walking on cognitive function in individuals with mild cognitive impairment: a systematic review and meta-analysis

BACKGROUND

Mild cognitive impairment (MCI) is the stage between the expected cognitive decline of normal aging and the more serious decline of dementia. Previous studies have shown that regular exercise can improve cognition and physical performance in older adults. Walking is a low-technology and low-cost exercise that has been proven to improve cognition and mobility in healthy elderly individuals. However, no systematic review or meta-analysis has explored whether walking can improve cognitive function in older adults with MCI. This study aimed to explore the effects of walking interventions on cognitive functions in individuals with MCI.

METHODS

In accordance with the PRISMA guidelines, MEDLINE, PubMed, SPORTDiscus, Cochrane Central Register of Controlled Trials, CINAHL, Web of Science, Airiti Library, and the National Digital Library of Theses and Dissertations in Taiwan were searched from inception to July 2023. Independent reviewers selected randomized clinical trials (RCT) that compared the effects of walking with no intervention or other exercises in individuals with MCI. The primary outcomes were cognitive functions, and the secondary outcome was walking endurance. Three reviewers independently conducted data extraction. The risk of bias was assessed using the Revised Cochrane Risk of Bias assessment tool.

RESULTS

Fourteen RCTs were included in this review. The quality of evidence in these studies was rated as good to excellent. The results of the meta-analysis showed that the individuals with MCI had no significant improvement in cognitive function but had significant improvement in the 6-min walk test (Mean Difference=23.70, p=0.008) after walking interventions compared to no intervention or other exercises.

CONCLUSION

Walking intervention has no significant improvement on cognitive functions in older adults with MCI. However, walking induces beneficial effects on aerobic capacity.

TRIAL REGISTRATION

This systematic review has the registration number CRD42021283753 on PROSPERO.

Redox Signaling and Sarcopenia: Searching for the Primary Suspect

Sarcopenia, the age-related decline in muscle mass and function, derives from multiple etiological mechanisms. Accumulative research suggests that reactive oxygen species (ROS) generation plays a critical role in the development of this pathophysiological disorder. In this communication, we review the various signaling pathways that control muscle metabolic and functional integrity such as protein turnover, cell death and regeneration, inflammation, organismic damage, and metabolic functions. Although no single pathway can be identified as the most crucial factor that causes sarcopenia, age-associated dysregulation of redox signaling appears to underlie many deteriorations at physiological, subcellular, and molecular levels. Furthermore, discord of mitochondrial homeostasis with aging affects most observed problems and requires our attention. The search for the primary suspect of the fundamental mechanism for sarcopenia will likely take more intense research for the secret of this health hazard to the elderly to be unlocked.

Can vitamin E supplementation affect obesity indices? A systematic review and meta-analysis of twenty-four randomized controlled trials

BACKGROUND

Several mechanisms have been proposed for the effect of vitamin E on weight loss. Yet various interventional studies with wide ranges of doses and durations have reported contradictory results.

METHODS

Cochrane Library, PubMed, Scopus, and Embase databases were searched up to December 2020. Meta-analysis was performed using random-effect method. Effect size was presented as weighted mean difference (WMD) and 95% confidence interval (CI). Heterogeneity was evaluated using the I² index. In order to identification of potential sources of heterogeneity, predefined subgroup and meta regression analyses was conducted.

RESULTS

A total of 24 studies with 33 data sets were included. There was no significant effect of vitamin E on weight (WMD: 0.15, 95% CI: -1.35 to 1.65, P = 0.847), body mass index (BMI) (WMD = 0.04, 95% CI: -0.29 to 0.37, P = 0.815), and waist circumference (WC) (WMD = -0.19 kg, 95% CI: -2.06 to 1.68, P = 0.842), respectively. However, subgroup analysis revealed that vitamin E supplementation in studies conducted on participants with normal BMI (18.5-24.9) had increasing impact on BMI (P = 0.047).

CONCLUSION

There was no significant effect of vitamin E supplementation on weight, BMI and WC. However, vitamin E supplementation might be associated with increasing BMI in people with normal BMI (18.5-24.9).

Antioxidants and Exercise Performance: With a Focus on Vitamin E and C Supplementation

Antioxidant supplementation, including vitamin E and C supplementation, has recently received recognition among athletes as a possible method for enhancing athletic performance. Increased oxidative stress during exercise results in the production of free radicals, which leads to muscle damage, fatigue, and impaired performance. Despite their negative effects on performance, free radicals may act as signaling molecules enhancing protection against greater physical stress. Current evidence suggests that antioxidant supplementation may impair these adaptations. Apart from athletes training at altitude and those looking for an immediate, short-term performance enhancement, supplementation with vitamin E does not appear to be beneficial. Moreover, the effectiveness of vitamin E and C alone and/or combined on muscle mass and strength have been inconsistent. Given that antioxidant supplements (e.g., vitamin E and C) tend to block anabolic signaling pathways, and thus, impair adaptations to resistance training, special caution should be taken with these supplements. It is recommended that athletes consume a diet rich in fruits and vegetables, which provides vitamins, minerals phytochemicals, and other bioactive compounds to meet the recommended intakes of vitamin E and C.

The effects of vitamin C and E on exercise-induced physiological adaptations: a systematic review and Meta-analysis of randomized controlled trials

We conducted a systematic review and meta-analysis of randomized controlled trials examining the effect of vitamin C and/or E on exercise-induced training adaptations. Medline, Embase and SPORTDiscus databases were searched for articles from inception until June 2019. Inclusion criteria was studies in adult humans where vitamin C and/or E had to be consumed alongside a supervised exercise training program of ≥4 weeks. Nine trials were included in the analysis of aerobic exercise adaptations and nine for resistance training (RT) adaptations. Vitamin C and/or E did not attenuate aerobic exercise induced improvements in maximal aerobic capacity (V ̇ O2max) (SMD -0.14, 95% CI: -0.43 to 0.15, P = 0.35) or endurance performance (SMD -0.01, 95% CI: -0.38 to 0.36, P = 0.97). There were also no effects of these supplements on lean mass and muscle strength following RT (SMD -0.07, 95% CI: -0.36 to 0.23, P = 0.67) and (SMD -0.15, 95% CI: -0.16 to 0.46, P = 0.35), respectively. There was also no influence of age on any of these outcomes (P > 0.05). These findings suggest that vitamin C and/or E does not inhibit exercise-induced changes in physiological function. Studies with larger sample sizes and adequate power are still required.

Inter-individual differences in weight change following exercise interventions: a systematic review and meta-analysis of randomized controlled trials

Previous reports of substantial inter-individual differences in weight change following an exercise intervention are often based solely on the observed responses in the intervention group. Therefore, we aimed to quantify the magnitude of inter-individual differences in exercise-mediated weight change. We synthesized randomized controlled trials (RCTs) of structured, supervised exercise interventions. Fourteen electronic databases were searched for relevant studies published up to March 2017. Search terms focused on structured training, RCTs and body weight. We then sifted these results for those RCTs (n = 12, 1500 participants) that included relevant comparator group data. Standard deviations (SDs) of weight change were extracted, thereby allowing the SD for true inter-individual differences in weight loss to be calculated for each study. Using a random effects meta-analysis, the pooled SD (95% CI) for true individual responses was 0.8 (-0.9 to 1.4) kg. The 95% prediction interval (based on 2SDs) for true inter-individual responses was -2.8 to 3.6 kg. The probability (% chance) that the true individual response variability would be clinically meaningful (>2.5 kg) in a future study in similar settings was 23% ('unlikely'). Therefore, we conclude that evidence is limited for the notion that there are clinically important individual differences in exercise-mediated weight change.

No association between vitamin C and E supplementation and grip strength over 5 years: the Colaus study

PURPOSE

To assess the cross-sectional and longitudinal association between self-reported vitamin C + E dietary supplementation and markers of grip strength and frailty in community-dwelling Swiss adults.

METHODS

Population-based study including 3277 participants (1722 women) aged 40-80 years at baseline. The associations between vitamin C + E dietary supplementation and grip strength were examined cross-sectionally and after a follow-up of 5.2 years on average.

RESULTS

There were 253 (7.7%) self-reported vitamin C + E supplement users. Female users had significantly lower grip strength than non-users (average ± standard deviation: 24.3 ± 6.1 versus 25.6 ± 6.1 kg, respectively). However, the association disappeared after multivariate adjustment (24.7 ± 0.5 versus 25.6 ± 0.1 kg, for users versus non-users, respectively). No differences were found in men regarding grip strength. No differences were found in the highest quintile of grip strength or prevalence of low grip strengthin in users versus non-users during cross-sectional analysis for both genders. After 5.2 years of follow-up, no associations were found between vitamin C + E supplementation and change in grip strength for raw values (difference between baseline and follow-up: 1.2 ± 5.0 versus 0.4 ± 5.2 kg for female and 0.6 ± 6.5 versus 1.1 ± 6.8 kg for male users and non-users, respectively) or after multivariable adjustment (1.2 ± 0.5 versus 0.4 ± 0.1 kg for female and 0.6 ± 0.8 versus 1.1 ± 0.2 kg for male users and non-users, respectively) when taking baseline vitamin C + E supplementation into account. No association was also found for incidence of low grip strength.

CONCLUSION

In a sample of community-dwelling Swiss adults, vitamin C + E supplementation neither improved grip strength nor prevented low-grip strength over a 5-year period.

The antioxidant requirement for plasma membrane repair in skeletal muscle

Vitamin E (VE) deficiency results in pronounced muscle weakness and atrophy but the cell biological mechanism of the pathology is unknown. We previously showed that VE supplementation promotes membrane repair in cultured cells and that oxidants potently inhibit repair. Here we provide three independent lines of evidence that VE is required for skeletal muscle myocyte plasma membrane repair in vivo. We also show that when another lipid-directed antioxidant, glutathione peroxidase 4 (Gpx4), is genetically deleted in mouse embryonic fibroblasts, repair fails catastrophically, unless cells are supplemented with VE. We conclude that lipid-directed antioxidant activity provided by VE, and possibly also Gpx4, is an essential component of the membrane repair mechanism in skeletal muscle. This work explains why VE is essential to muscle health and identifies VE as a requisite component of the plasma membrane repair mechanism in vivo.

Controversies of antioxidant vitamins supplementation in exercise: ergogenic or ergolytic effects in humans?

The aim of this commentary was to discuss the last studies regarding the effect of antioxidant vitamins supplementation on oxidative stress in exercise in humans. The inclusion criteria encompassed published studies done in adult males and females between 2006 and 2013. The keywords used in the search engine were: endurance athlete, diet, oxidative stress, physical activity, diet, nutrition, antioxidant, antioxidant status, vitamin C, vitamin A, vitamin E, β-carotene and combinations. Twelve studies were identified and organized according to the methodology and results of supplementation: ergogenic, ergolytic, partial or no difference between groups. The results of these studies showed no effect on physiological parameters and activity of antioxidant enzymes (n = 07), better response of the placebo treatment (ergolytic effect; n = 02), partial results (n = 01) and ergogenic results of antioxidant supplementation (n = 02). It is concluded that supplementation with antioxidant vitamins has controversial effects to oxidative damage induced by endurance exercise. The discordances among the studies are presented and discussed.

Physical rehabilitation for older people in long-term care

BACKGROUND

The worldwide population is progressively ageing, with an expected increase in morbidity and demand for long-term care. Physical rehabilitation is beneficial in older people, but relatively little is known about effects on long-term care residents. This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To evaluate the benefits and harms of rehabilitation interventions directed at maintaining, or improving, physical function for older people in long-term care through the review of randomised and cluster randomised controlled trials.

SEARCH METHODS

We searched the trials registers of the following Cochrane entities: the Stroke Group (May 2012), the Effective Practice and Organisation of Care Group (April 2012), and the Rehabilitation and Related Therapies Field (April 2012). In addition, we searched 20 relevant electronic databases, including the Cochrane Central Register of Controlled Trials (The Cochrane Library, 2009, Issue 4), MEDLINE (1966 to December 2009), EMBASE (1980 to December 2009), CINAHL (1982 to December 2009), AMED (1985 to December 2009), and PsycINFO (1967 to December 2009). We also searched trials and research registers and conference proceedings; checked reference lists; and contacted authors, researchers, and other relevant Cochrane entities. We updated our searches of electronic databases in 2011 and listed relevant studies as awaiting assessment.

SELECTION CRITERIA

Randomised studies comparing a rehabilitation intervention designed to maintain or improve physical function with either no intervention or an alternative intervention in older people (over 60 years) who have permanent long-term care residency.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed risk of bias and extracted data. We contacted study authors for additional information. The primary outcome was function in activities of daily living. Secondary outcomes included exercise tolerance, strength, flexibility, balance, perceived health status, mood, cognitive status, fear of falling, and economic analyses. We investigated adverse effects, including death, morbidity, and other events. We synthesised estimates of the primary outcome with the mean difference; mortality data, with the risk ratio; and secondary outcomes, using vote-counting.

MAIN RESULTS

We included 67 trials, involving 6300 participants. Fifty-one trials reported the primary outcome, a measure of activities of daily living. The estimated effects of physical rehabilitation at the end of the intervention were an improvement in Barthel Index (0 to 100) scores of six points (95% confidence interval (CI) 2 to 11, P = 0.008, seven studies), Functional Independence Measure (0 to 126) scores of five points (95% CI -2 to 12, P = 0.1, four studies), Rivermead Mobility Index (0 to 15) scores of 0.7 points (95% CI 0.04 to 1.3, P = 0.04, three studies), Timed Up and Go test of five seconds (95% CI -9 to 0, P = 0.05, seven studies), and walking speed of 0.03 m/s (95% CI -0.01 to 0.07, P = 0.1, nine studies). Synthesis of secondary outcomes suggested there is a beneficial effect on strength, flexibility, and balance, and possibly on mood, although the size of any such effect is unknown. There was insufficient evidence of the effect on other secondary outcomes. Based on 25 studies (3721 participants), rehabilitation does not increase risk of mortality in this population (risk ratio 0.95, 95% CI 0.80 to 1.13). However, it is possible bias has resulted in overestimation of the positive effects of physical rehabilitation.

AUTHORS' CONCLUSIONS

Physical rehabilitation for long-term care residents may be effective, reducing disability with few adverse events, but effects appear quite small and may not be applicable to all residents. There is insufficient evidence to reach conclusions about improvement sustainability, cost-effectiveness, or which interventions are most appropriate. Future large-scale trials are justified.

Antioxidant supplementation during exercise training: beneficial or detrimental?

High levels of reactive oxygen species (ROS) produced in skeletal muscle during exercise have been associated with muscle damage and impaired muscle function. Supporting endogenous defence systems with additional oral doses of antioxidants has received much attention as a noninvasive strategy to prevent or reduce oxidative stress, decrease muscle damage and improve exercise performance. Over 150 articles have been published on this topic, with almost all of these being small-scale, low-quality studies. The consistent finding is that antioxidant supplementation attenuates exercise-induced oxidative stress. However, any physiological implications of this have yet to be consistently demonstrated, with most studies reporting no effects on exercise-induced muscle damage and performance. Moreover, a growing body of evidence indicates detrimental effects of antioxidant supplementation on the health and performance benefits of exercise training. Indeed, although ROS are associated with harmful biological events, they are also essential to the development and optimal function of every cell. The aim of this review is to present and discuss 23 studies that have shown that antioxidant supplementation interferes with exercise training-induced adaptations. The main findings of these studies are that, in certain situations, loading the cell with high doses of antioxidants leads to a blunting of the positive effects of exercise training and interferes with important ROS-mediated physiological processes, such as vasodilation and insulin signalling. More research is needed to produce evidence-based guidelines regarding the use of antioxidant supplementation during exercise training. We recommend that an adequate intake of vitamins and minerals through a varied and balanced diet remains the best approach to maintain the optimal antioxidant status in exercising individuals.

Effects of resistance and aerobic exercise on physical function, bone mineral density, OPG and RANKL in older women

This study compared the effects of a resistance training protocol and a moderate-impact aerobic training protocol on bone mineral density (BMD), physical ability, serum osteoprotegerin (OPG), and receptor activator of nuclear factor kappa B ligand (RANKL) levels. Seventy-one older women were randomly assigned to resistance exercise (RE), aerobic exercise (AE) or a control group (CON). Both interventions were conducted 3 times per week for 8 months. Outcome measures included proximal femur BMD, muscle strength, balance, body composition, serum OPG, and RANKL levels. Potential confounding variables included dietary intake, accelerometer-based physical activity (PA), and molecularly defined lactase nonpersistence. After 8 months, only RE group exhibited increases in BMD at the trochanter (2.9%) and total hip (1.5%), and improved body composition. Both RE and AE groups improved balance. No significant changes were observed in OPG and RANKL levels, and OPG/RANKL ratio. Lactase nonpersistence was not associated with BMD changes. No group differences were observed in baseline values or change in dietary intakes and daily PA. Data suggest that 8 months of RE may be more effective than AE for inducing favourable changes in BMD and muscle strength, whilst both interventions demonstrate to protect against the functional balance control that is strongly related to fall risk.

Elements in sera of elite taekwondo athletes: effects of vitamin E supplementation

Many researchers have emphasized the relation between nutrition and development and sustaining performance. Two methods are commonly employed to identify the interaction between physical activity and nutrition. The first consists of administering food with a variety of contents to people engaged in physical activity and observing their performance responses, and the other is concerned with determining the effects of physical activity on nutrition. Therefore, it can be said that there has been a growing interest in the explorations into the relation between exercise and vitamins, minerals, and elements. The present study reports the effects of 6 weeks administration of 300 mg/day vitamin E on the distribution of serum elements in elite taekwondo athletes. Seven male athletes, mean ages 22.1 ± 0.5 years weighing on average 66.4 ± 2.4 kg were included in the study. The athletes had been practicing taekwondo for 10-12 years. Resting blood samples were collected in duplicate before and after supplementation for determination of serum levels of cobalt, boron, cadmium, chromium, nickel, manganese, sulfur, copper, iron, zinc, phosphorus, sodium, potassium, and calcium. Supplementation resulted in significant increases of all elements relative to values before supplementation (p < 0.001), with the exception of boron and sulfur, which remained without change. The results of the present study demonstrate that vitamin E supplementation crucially influences the element and mineral metabolism in elite athletes.

Effect of vitamin E supplementation with exercise on cognitive functions and total antioxidant capacity in older people

OBJECTIVE

We investigated the effects of six months vitamin E administration on cognition evaluated by event-related potentials in exercising older subjects.

DESIGN

Randomised controlled trial.

SETTING

Retirement home in Antalya, Turkey.

PARTICIPANTS

Fifty-seven adults aged 60-85 years were randomly assigned to one of four groups: sedentary control (C), vitamin E (V), exercise training (E) and vitamin E under training (EV).

INTERVENTION

V and EV groups were received vitamin E at a dose of 900 IU/day P.O. for 6 months. Trained groups were subjected to walking exercise involved 3 sessions per week for 6 months. Walking duration was gradually increased during 8 weeks, and stayed constant until the end of training period. Participants were begun walking at % 70 heart rate reserve for 20 min/day at the first two weeks, and walking duration was increased by 5 minutes/day of each week until subjects were reached a level of 50 min/day by week 8.

MEASUREMENTS

Plasma vitamin E concentration, total antioxidant capacity and two parameters of event-related potentials namely P3 latency and amplitude were performed on all study groups both before and after training.

RESULTS

Significant improvement in P3 latency was found in exercising groups. However, no significant differences were found between vitamin and other groups for P3 latency. Amplitude measurements were found unaltered among all groups.

CONCLUSION

We concluded that although six months training results improvement in P3 latency, vitamin E supplementation does not affect cognitive function evaluated by event-related potentials in older subjects.