A summary measure of pro- and anti-oxidant exposures and risk of incident, sporadic, colorectal adenomas

Association between oxidative balance score and all-cause and cancer-specific mortality among cancer survivors

Background

The Oxidative Balance Score (OBS) represents a novel metric for assessing systemic oxidative stress, where elevated scores reflect increased antioxidant exposure. This study aims to explore the association between OBS and all-cause and cancer-specific mortality among cancer survivors.

Methods

An observational cohort study was conducted involving 4099 cancer survivors, utilizing data obtained from the National Health and Nutrition Examination Survey (NHANES) covering the years 1999 to 2018. The endpoints were established by cross-referencing data with the National Death Index (NDI). The OBS was developed based on dietary and lifestyle factors. Cox proportional hazards regression models were employed to examine the relationship between OBS and mortality risks. Restricted cubic spline was utilized to evaluate whether OBS exhibited a nonlinear association with the risk of death. Furthermore, Kaplan-Meier survival curves were generated to assess cumulative survival differences across various OBS outcomes.

Results

Over an average follow-up of 84.00 months, 1481 (26.29%) participants died, including 484 (8.9%) who died from cancer. In the fully adjusted model, multivariable Cox regression revealed that each unit increase in OBS was linked to a 1.8% decrease in all-cause mortality risk (HR 0.982, 95%CI 0.972-0.991) and a 2.6% decrease in cancer-specific mortality risk (HR 0.974, 95%CI 0.958-0.991). In the context of all-cause mortality, the risk of death was found to be significantly lower in quartiles Q2, Q3 and Q4 when compared to the OBS in quartile Q1. The hazard ratios (HRs) and 95% confidence intervals (CIs) for Q2, Q3 and Q4 were as follows: Q2 (HR 0.833, 95%CI 0.707-0.981), Q3 (HR 0.789, 95%CI 0.650-0.958) and Q4 (HR 0.699, 95%CI 0.579-0.844). Regarding cancer-specific mortality, the HRs and 95%CIs for Q2, Q3 and Q4 in comparison to Q1 were as follows: Q2 (HR 0.663, 95%CI 0.505-0.869), Q3 (HR 0.688, 95%CI 0.488-0.969) and Q4 (HR 0.595, 95%CI 0.435-0.815). Similar associations were noted when the dietary and lifestyle components of the OBS were analyzed separately.

Conclusion

The findings indicate that higher levels of OBS are associated with a decrease in all-cause and cancer-specific mortality among cancer survivors. Our findings may contribute to the refinement of lifestyle intervention recommendations for this population.

Association of oxidative balance score with incident cardiovascular disease in patients with type 2 diabetes: findings of the UK Biobank study

BACKGROUND & AIMS

To clarify how dietary and lifestyle factors work on diabetes-related cardiovascular disease (CVD), we investigated whether the increased risk of CVD in patients with type 2 diabetes mellitus (T2DM) could be offset by an increase in diet and/or lifestyle with antioxidant potential.

RESEARCH DESIGN AND METHODS

A total of 7,658 individuals from UK Biobank (UKB) with T2DM but no diagnosed CVD were included in this study. We screened combinations of 16 nutrients and/or 4 lifestyles to calculate the Oxidative Balance Score (OBS), dietary OBS (DOBS), and lifestyle OBS (LOBS). Cox proportional hazards (CPH) regression models and mediation statistical models were performed.

RESULTS

After adjusting for covariates, CPH regression models showed inverse associations between both OBS and LOBS and CVD. The highest tertile of LOBS was significantly associated with a lower risk of CVD compared to the lowest tertile, with hazard ratios and 95% CIs as follows: Atherosclerotic Cardiovascular Disease (ASCVD) 0.81 (0.68-0.97), Coronary Artery Disease (CAD) 0.79 (0.67-0.93), Atrial Fibrillation (AF) 0.56 (0.45-0.70) and CVD mortality 0.67(0.51-0.88). Correspondingly, the results of associations between the highest tertile of OBS and risks of CVDs above were ASCVD 0.80 (0.64-0.99), CAD 0.83(0.68-1.01), AF 0.73 (0.57-0.92) and CVD mortality 0.68 (0.50-0.92). No associations between DOBS and CVDs were observed [ASCVD 0.83 (0.66-1.05), CAD 0.86 (0.70-1.05), AF 0.77 (0.60-1.00), and CVD mortality 0.79 (0.57-1.10)]. These results were consistent in stratified analyses. Additionally, we identified a mediating role for C-reactive protein (CRP) and white blood cell count (WBC) in the observed relations, with indirect effect and mediation estimates as follows: CRP - 0.003 6.0% (OBS and CAD), -0.008 17.2%, -0.003 11.7%, and - 0.010 14.5% (OBS/DOBS/LOBS and CVD mortality); WBC - 0.006 14.3%, -0.006 12.6%, -0.006 13.4%, -0.005 23.3% (OBS and CVDs), -0.008 11.8%, -0.008 11.9%, -0.008 11.8%, and - 0.005 5.3% (LOBS and CVDs).

CONCLUSION

Sustained adherence to diets and lifestyles with high antioxidant potential may significantly reduce the risk of CVD in individuals with T2DM.

Association between oxidative balance score and glaucoma in the National Health and Nutrition Examination Survey

Objective

To investigate the association between Oxidative Balance Score (OBS) and glaucoma risk.

Methods

Using data from the National Health and Nutrition Examination Survey (2005-2008), we analyzed 2,615 participants aged ≥40 years. OBS was calculated from 15 antioxidant and 5 pro-oxidant components, including dietary nutrients and lifestyle factors. Glaucoma was identified through self-reported diagnosis and retinal imaging. Survey-weighted logistic regression and restricted cubic splines (RCS) were used to assess associations.

Results

Higher OBS was associated with lower glaucoma risk (adjusted OR = 0.97, 95% CI: 0.94-1.00). Participants in the highest OBS quartile showed 51% lower odds of glaucoma compared to the lowest quartile (adjusted OR = 0.49, 95% CI: 0.27-0.90). The protective effect was more pronounced among middle-aged adults (40-60 years; OR = 0.90, 95% CI: 0.86-0.95) and males (OR = 0.93, 95% CI: 0.90-0.97).

Conclusion

Higher OBS were associated with lower glaucoma prevalence, particularly among middle-aged adults and males, suggesting potential benefits of maintaining oxidative balance in glaucoma prevention.

Relationship between oxidative balance indicators and Chronic Kidney Disease

INTRODUCTION

Chronic Kidney Disease (CKD) is a growing global health issue, affecting approximately 9.1% of the world's population. Oxidative stress is believed to play a key role in CKD development, with indicators such as the Oxidative Balance Score (OBS), Pro-Oxidant-Antioxidant Balance (PAB), and Total Antioxidant Capacity (TAC) being of particular interest. However, their association with CKD remains unclear.

METHODS

This study conducted a cross-sectional analysis using data from the National Health and Nutrition Examination Survey (NHANES) 2009-2018. A total of 18,951 participants were included after applying specific inclusion criteria. Logistic regression models and restricted cubic spline regression were employed to examine the associations between these oxidative balance indicators and CKD. Subgroup and interaction analyses were also conducted for further data analyses. Finally, ROC curve analysis was used to assess the predictive performance of these indicators for CKD risk.

RESULTS

After adjusting for various confounding factors, higher levels of OBS and PAB were significantly associated with a reduced risk of CKD (OR = 0.97, 95% CI: 0.96-0.99, P < 0.001; OR = 0.94, 95% CI: 0.92-0.97, P < 0.001, respectively). The ORs for the highest quartiles of OBS and PAB were 0.60 (95% CI: 0.49-0.75, P < 0.001) and 0.77 (95% CI: 0.63-0.94, P = 0.013), respectively. In contrast, TAC showed no significant association with CKD. ROC curve analysis further indicated that OBS had a superior predictive ability for CKD risk (AUC = 0.579) compared to PAB (AUC = 0.519) and TAC (AUC = 0.492).

CONCLUSION

The study suggests that oxidative balance indicators, particularly OBS and PAB, are inversely associated with CKD risk, while TAC showed no significant link. OBS demonstrated the strongest predictive ability among the indicators. These findings highlight the potential role of oxidative balance in CKD prevention. Further research is needed to confirm these associations in diverse populations and to explore the underlying mechanisms.

Oxidative balance score is associated with the risk of diabetic kidney disease in patients with type 2 diabetes mellitus: evidence from NHANES 2007-2018

Objective

The oxidative balance score (OBS) is a comprehensive measure of oxidative stress that is calculated from the combined prooxidant and antioxidant scores of 16 dietary components and four lifestyle factors. This study aimed to evaluate the relationship between OBS and the risk of diabetic kidney disease (DKD) in individuals with Type 2 diabetes mellitus (T2DM).

Methods

Data were obtained from the NHANES. A cross-sectional study was conducted using multiple logistic regression. Covariate effects of this relationship were also examined using subgroup analysis.

Results

We evaluated 3,669 T2DM participants, among whom DKD prevalence was 30.87%. In a fully adjusted logistic regression model, the risk of DKD among participants with OBS, lifestyle OBS, and dietary OBS in the highest quartile group was 0.50 times (95% CI: 0.39 to 0.65), 0.54 times (95% CI: 0.41-0.71), and 0.45 times (95% CI: 0.32-0.63), respectively, than that in the lowest quartile group, respectively. In addition, participants who scored in the top quartiles of OBS were more likely to possess higher levels of education and income. A stratified analysis demonstrated the robustness of these findings.

Conclusion

OBS negatively correlates with the risk of DKD among individuals with T2DM.

The association between oxidative balance score and sleep duration: a mediation analysis of a cross-sectional study

Study objectives

The Oxidative Balance Score (OBS), which reflects overall oxidation through diet and lifestyle, has been linked to sleep, but few studies have clarified this relationship. We investigated the association between OBS and sleep duration, and whether oxidative stress (OS) and inflammation mediate the underlying mechanisms.

Methods

Data were obtained from the National Health and Nutrition Examination Survey spanning the years 2007 to 2018. Multivariable logistic regression analyses were used to evaluate the association between OBS and the risk of sleep duration. Mediation analyses were conducted to investigate the role of OS and inflammatory markers.

Results

A significant negative association was found between OBS and sleep duration (p < 0.01). Meanwhile, compared to participants in OBS tertile 1, the ORs (95% CIs) of incident short sleep duration were 0.78 (0.72-0.86) and 0.72 (0.67-0.79) (both p < 0.01) for OBS tertile 2 and 3, respectively. And the ORs (95% CIs) of incident long sleep duration were 0.83 (0.73, 0.95) and 0.66 (0.57, 0.75) (both p < 0.01) for OBS tertiles 2 and 3 after adjustment for multivariate variables. A linear relationship between OBS and short/long sleep duration (p for non-linearity = 0.69/0.94, both p < 0.01) were revealed. Mediation analysis showed absolute neutrophil count, serum total bilirubin mediated the association between OBS and short/long sleep duration with 5.72, 13.41% proportion of mediation, respectively (both p < 0.001).

Conclusion

OBS is negatively associated with sleep duration. OS and inflammatory biomarkers mediate the relationship.

Relationship between dietary oxidative balance score, anthropometric measurements and socioeconomic factors in women at low risk of cardiovascular disease

INTRODUCTION

The aim of this study was to investigate the relationship between the dietary oxidative balance score (OBS), an indicator of oxidative stress, anthropometric measures and socioeconomic factors in women at low risk of cardiovascular disease.

METHODS

The participants' 3-day dietary intake, demographic information, anthropometric measurements and blood pressure values were recorded, and the Framingham Risk Score (FRS) and OBS values were determined. Oxidative balance score consists of prooxidant and antioxidant scores. Prooxidant scores were calculated from red meat consumption, total iron and polyunsaturated fatty acid intake, alcohol and cigarette consumption parameters, while antioxidant scores were calculated by assessing cruciferous consumption, dietary total vitamin C, vitamin E, β-carotene, β-cryptoxanthin, β-carotene, β-cryptoxanthin, lycopene, lutein+zeaxanthin and selenium intake.

RESULTS

A total of 145 women were included in the study. Education level was associated with anthropometric measurements, income status with antioxidant and prooxidant scores, and exercise status with OBS (p<0.05). Weight, waist, hip, BMI, waist/hip, and waist/height ratio were significantly lower in subjects with low prooxidant score (p<0.05); there was no significant relationship between age, systolic, diastolic, FRS (p>0.05).

CONCLUSION

The study, conducted in healthy women, showed that dietary oxidative balance scoring is promising in preventing the development of CVD and reducing the burden of disease, and that prospective cohort studies should be conducted in this area.

Association between the oxidative balance score and estimated pulse wave velocity from the National Health and Nutrition Examination Survey (2005-2018)

BACKGROUND

No research report has been conducted to investigate the impact of oxidation balance score (OBS) on the estimated pulse wave velocity(ePWV).We aimed to examine the association between OBS and ePWV.

METHOD

We evaluated data for 13,073 patients from the National Health and Nutrition Examination Survey (NHANES). The exposure variable was OBS. The outcome variables was combination of ePWV and arterial stiffness.

RESULTS

We observed a significant negative correlation between OBS (Per 1SD increase) and ePWV in the gradually adjusted models. Based on the aforementioned results, a two-piecewise logistic regression adjusted model was subsequently employed to establish the association between OBS and elevated ePWV, and the inflection point was determined as 5. The increased risk of elevated ePWV (OR:0.70; 95%CI:0.51-0.94) gradually decreases with the increase of OBS on the left side of the inflection point; however, when OBS exceeds 5, this decrease in risk of elevated ePWV(OR:1.00; 95%CI:0.96-1.04) is no longer observed (P for log likelihood ratio test = 0.028).

CONCLUSIONS

There exists a significant association between OBS and ePWV in the context of American adults. Specifically, OBS exhibits a negative correlation with ePWV; however, when considering an elevated ePWV, a saturation effect is observed in relation to OBS.

Higher oxidative balance score was associated with decreased risk of erectile dysfunction: a population-based study

BACKGROUND

Erectile dysfunction (ED) is a prevalent condition that is thought to be significantly impacted by oxidative stress. The oxidative balance score (OBS) has been built to characterize the state of antioxidant/pro-oxidant balance. There is less known regarding the relationship of OBS with ED.

METHODS

This study conducted cross-sectional analyses on 1860 males who participated in the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2004. OBS was constructed by the 16 dietary components and 4 lifestyle factors. Self-reported ED was defined as men who indicated that they "never" or "sometimes" could achieve or keeping an erection adequate for satisfactory intercourse. Multivariate logistic regression models were applied to examine the association between OBS and the risk of ED.

RESULTS

Among 1860 participants, the median OBS was 20 (IQR 15-26), and OBS was lower in males with ED vs. those without ED (P = 0.001). The results of our analyses indicated a negative correlation between OBS and ED among male subjects. Specifically, each one-unit increase in the continuous OBS was relate to 3% reduction in the odds of ED after full adjustment. Moreover, when extreme OBS quartiles were compared, the adjusted odds ratio (95% confidence interval) for the 4th OBS category was 0.53 (0.32 to 0.88) after full adjustment (P for trend < 0.05). There was also statistical significance in the relationships between dietary/lifestyle OBS with ED, and the association between lifestyle OBS and ED may be even tighter. For each unit increase in lifestyle OBS, the odds of ED decreased by 11% after full adjustment.

CONCLUSION

Higher OBS was associated with reduced risk of ED in U.S. males. These findings suggested that adopting an antioxidant-rich diet and engaging in antioxidant-promoting lifestyle behaviors may contribute to a lower incidence of ED. These results provided recommendations for a comprehensive dietary and lifestyle antioxidants for ED patients.

Association between oxidative balance score and hearing loss: a cross-sectional study from the NHANES database

Aim

The oxidative balance score (OBS), a composite score of dietary nutrients and lifestyles, reflects an individual's oxidative and antioxidant status. Evidence showed that oxidative stress levels were related to hearing loss. The relationship between OBS and hearing loss remains unclear. This study was to explore the association between OBS and hearing loss in adults.

Methods

In this cross-sectional study, data of participants aged 20-69 years who received hearing tests were extracted from the National Health and Nutrition Examination Survey (NHANES) database (2011-2012, 2015-2016). Hearing loss was defined as hearing threshold >25 dB in either ear. The OBS was composed of 16 dietary nutrients and 4 lifestyles. The covariates were screened using the backward stepwise regression analysis. The association of OBS and hearing loss was assessed with odds ratios (ORs) and 95% confidence intervals (CIs). Subgroups of age, gender, occupational noise exposure, recreational noise exposure, firearm noise exposure, and veteran status were further evaluated the associations. The importance ranking of OBS components was analyzed by the weighted random forest model.

Results

Of the total 3,557 adults, 338 (9.5%) suffered from hearing loss. High OBS levels were associated with lower odds of hearing loss (OR = 0.58, 95%CI: 0.41-0.82), after adjusting age, gender, race, hypertension, tinnitus, recreational noise exposure, and occupational noise exposure. Similar results were discovered in individuals aged50-59 years old (OR = 0.47, 95%CI: 0.24-0.93), aged 60-69 years old (OR = 0.31, 95%CI: 0.16-0.61), with female (OR = 0.44, 95%CI: 0.20-0.96), without occupational noise exposure (OR = 0.31, 95%CI: 0.16-0.62), recreational noise exposure (OR = 0.48, 95%CI: 0.30-0.76), firearm noise exposure (OR = 0.38, 95%CI: 0.19-0.77), and veteran status (OR = 0.57, 95%CI: 0.39-0.82). In OBS components, vitamin B12, total fat and physical activity were important for hearing loss.

Conclusion

Elevated OBS may be associated with hearing health in adults. Appropriate vitamin B12 supplementation, reduction of total fat intake, and increased physical activity may be beneficial to the prevention of hearing loss.

Oxidative balance score: a potential tool for reducing the risk of colorectal cancer and its subsites incidences

Background

The Oxidative Balance Score (OBS) is commonly used to assess oxidative stress and provides a comprehensive evaluation of dietary and lifestyle-related exposures. However, there is limited research on the association between OBS and colorectal cancer (CRC), its subsites, and complications. The objective of this study was to assess the relationship between OBS and the risk of CRC, its subsites, and common complications in a large prospective cohort study.

Methods

We included data from 175,808 participants in the UK Biobank data sample repository from 2006 to 2010. We evaluated OBS using a scoring system based on 22 dietary and lifestyle factors. Multiple adjustments, including multivariate Cox proportional hazard regression, gender stratification, subgroup analysis, and sensitivity analysis, were performed to fully explore the relationship between OBS and CRC, its subsites, and complications. The mediation analysis was conducted to investigate whether serum albumin, uric acid, and neutrophil levels mediate the relationship between OBS and CRC.

Results

After adjusting for potential confounding factors, a significant negative correlation was found between OBS and the risk of CRC and its subsites (proximal colon cancer, distal colon cancer, and rectal cancer). This correlation was particularly pronounced in male CRC patients. Serum albumin, uric acid, and neutrophil count, which are biomarkers, were found to have a significant mediating effect between OBS and CRC.

Conclusion

Our study suggests that higher exposure to antioxidants assessed through OBS (diet and lifestyle rich in antioxidants) may decrease the occurrence of CRC and its subsites.

Association between oxidative balance score and sarcopenia in older adults

Sarcopenia is a progressive skeletal muscle disease in which oxidative stress has been proposed as one of the primary markers. The oxidative balance score (OBS) represents the oxidative balance of a person's dietary pattern using the merged intake of anti-oxidants and pro-oxidants. Therefore, the present study assessed the association between OBS and sarcopenia in Iranian older adults. In the current study, 80 people with sarcopenia and 80 without it were considered the case and control groups, respectively. All controls were matched by sex with cases. To confirm sarcopenia, skeletal muscle mass index (SMI), handgrip strength (HGS) measurement, and gait speed were used. Also, body composition was measured by bioelectrical impedance analysis (BIA). A valid and reliable food frequency questionnaire (FFQ) was used to assess all participants' dietary intake of pro-oxidants and anti-oxidants. Conditional logistic regression was applied to assess the association between OBS and sarcopenia. In the bivariate model, we observed lower odds of sarcopenia in the second and last tertile of OBS in comparison to the first tertile (T) (T2 - odds ratio (OR) = 0.414, 95% confidence interval (CI) : 0.186-0.918 and T3 - OR = 0.101, 95% CI: 0.041-0.248). After adjusting for potential confounders, the association was not significant in second and last tertile of OBS in comparision to the first one. The present study's findings demonstrated that overcoming exposure to anti-oxidants over pro-oxidants, as illustrated by a higher OBS, is not related to lower odds of sarcopenia in older adults.

Oxidative balance score was negatively associated with the risk of metabolic syndrome, metabolic syndrome severity, and all-cause mortality of patients with metabolic syndrome

Background

The oxidative balance score (OBS), an encompassing scoring mechanism for assessing oxidative stress, is formulated based on nutritional and lifestyle components. The emergence of metabolic syndrome (MetS) is intricately linked to oxidative stress. Nonetheless, the correlation between OBS and MetS displays variability within distinct cohorts.

Objective

We worked on the relationships between OBS and the risk of MetS, MetS severity, and all-cause mortality of MetS patients.

Methods

A total of 11,171 adult participants were collected from the U.S. National Health Examination Survey (NHANES) 2007-2018. Employing survey-weighted logistic models, we evaluated the relationship between OBS and MetS risk. Furthermore, survey-weighted linear models were utilized to investigate the connection between OBS and MetS severity. Among the participants, 3,621 individuals had their survival status recorded, allowing us to employ Cox proportional hazards regression models in order to ascertain the association between OBS and the all-cause mortality within the subset of individuals with MetS. The OBS (where a higher OBS signified an increased prevalence of anti- or pro-oxidant exposures) weighed the 20 factors, while the MetS severity score weighed the five factors.

Results

After multivariable adjustment, individuals with elevated OBS were found to exhibit a decreased susceptibility to MetS [odds ratio (OR) 0.95; 95% CI 0.94-0.96]. The adjusted OR was 0.42 (95% CI 0.33-0.53) for MetS risk in the fourth OBS quartile compared with those in the first OBS quartile (P for trend < 0.001). A one-unit increase in OBS was linked to a 3% reduction in MetS severity score by 3% (mean difference, -0.03; 95% CI, -0.04 to -0.03). Moreover, increased OBS correlated with decreased hazard of all-cause mortality risk among MetS subjects (adjusted hazard ratio, 0.95; 95% CI, 0.93-0.98). These associations retained their strength even subsequent to the introduction of sensitivity analyses. There existed a statistically significant negative correlation between diet/lifestyle OBS and both MetS risk as well as MetS severity.

Conclusions

An inverse correlation was observed between OBS and the susceptibility to MetS, MetS severity, and all-cause mortality of MetS patients. Health outcomes for MetS patients were positively related to antioxidant diets and lifestyles.

Oxidative balance score and risk of cancer: a systematic review and meta-analysis of observational studies

BACKGROUND

The oxidative balance score (OBS) has been utilized to assess the overall pro- and antioxidant exposure status in various chronic diseases. The current meta-analysis was carried out to pool the association between OBS and the risk of cancer.

METHODS

We systematically searched the Web of Science, PubMed, Scopus, Embase, and Google Scholar up to August 2023. All observational studies which evaluated the association of OBS with the risk of cancers were included. There was no time of publication or language restrictions. Heterogeneity between studies was assessed using the Chi-square-based Q-test and the I2. A random-effects model meta-analysis was conducted to estimate the pooled effect sizes. Possible sources of heterogeneity were explored by subgroup and meta-regression analysis.

RESULTS

Totally, 15 studies (9 case-control and 6 cohorts) were eligible for meta-analysis. Random effect model meta-analysis of case-control studies showed that higher OBS significantly decreases the odds of cancers (pooled OR: 0.64, 95% CI: 0.54, 0.74). In the cohort studies, the association of OBS with the risk of cancers was not significant (pooled HR: 0.97, 95% CI: 0.80,1.18). The subgroup analysis showed that cancer type and gender were the potential sources of heterogeneity.

CONCLUSION

Our results show an inverse and significant association between higher OBS and odds of colorectal cancers in case-control and cohort studies. In the case of prostate cancer in cohort studies, our results did not align with the hypothesis. Considering the importance of diet and antioxidant balance in the conditions of malignancy, it is suggested to conduct more comprehensive studies with standard measurement methods to obtain conclusive results.

Association of the Oxidative Balance Score and Cognitive Function and the Mediating Role of Oxidative Stress: Evidence from the National Health and Nutrition Examination Survey (NHANES) 2011-2014

BACKGROUND

Oxidative stress is possibly related to cognitive function decline. The oxidative balance score (OBS) that combines pro- and antioxidant components from diet and lifestyle has been reported to be associated with age-related diseases.

OBJECTIVES

We aimed to investigate the association between OBS and cognitive function in older adults and explore whether oxidative stress mediated this relationship.

METHODS

A total of 1745 adults aged ≥60 y were included in the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Cognitive function was measured using 4 tests: the immediate recall test, delayed recall test, animal fluency test (AFT), and digital symbol substitution test (DSST). Weighted multivariate linear regression and restricted cubic splines (RCS) analyses were used to evaluate the association between OBS and cognitive function, and mediation analysis was used to test the indirect effect of oxidative stress indicators on the association.

RESULTS

The OBS was positively associated with AFT, DSST, and global cognitive function in older adults, and the beta estimates (95% CI) were 0.015 (0.008, 0.034), 0.009 (0.002, 0.025), and 0.030 (0.024, 0.074), moreover, RCS results suggested an approximately linear dose-response relationship between the OBS and these 3 tests. The highest quartiles of these 3 tests were also significantly correlated with OBS. Albumin, uric acid, and serum 25(OH)D concentrations were significant mediators of the relationship between OBS and cognitive function, and the overall mediation effect proportion was 36% when included in 1 model.

CONCLUSIONS

OBS was positively correlated with cognitive function in older adults, and albumin, uric acid, and serum 25(OH)D concentrations could be the driving mediators of the association. The findings emphasize the importance of a healthy, antioxidant diet and lifestyle that contribute to cognitive function. J Nutr 20xx;x:xx.

Oxidative balance score and dietary phytochemical index can reduce the risk of colorectal cancer in Iranian population

BACKGROUND

No previous study has assessed the association between oxidative balance score (OBS) and dietary phytochemical index (DPI) with colorectal cancer (CRC) simultaneously. Therefore, this study investigated the association between OBS and DPI with the odds of CRC among the Iranian population.

METHODS

This hospital-based age and sex-matched case-control study was conducted between September 2008 and January 2010 (142 controls and 71 cases were entered for analysis). New diagnosed CRC cases were selected from the Cancer Institute, Imam Khomeini Hospital of Tehran. Dietary intakes were determined by a semi-quantitative food frequency questionnaire (FFQ). Then, dietary indices were calculated by food items and nutrient intake. Logistic regression was utilized for assessing the tertiles of OBS and DPI.

RESULTS

In multivariate analysis, OBS was associated with a 77% reduction in CRC odds in the last tertile than the first tertile (odds ratio (OR) = 0.23, confidence interval (CI): 0.07-0.72, P_trend = 0.017). Also, we found a 64% reduction in CRC odds in the last tertile of DPI compared to the first tertile (OR = 0.36, CI: 0.15-0.86, P_trend = 0.015).

CONCLUSIONS

A diet rich in phytochemicals and anti-oxidants, including fruits and vegetables (citrus fruits, colored berries, and dark-green leafy vegetables) and whole grains, may reduce the CRC odds.

Association between Hypertension and Stroke Recurrence as Modified by Pro-oxidant-Antioxidant Balance: A Multi-Center Study

BACKGROUND

Hypertension and oxidative stress are involved in the pathophysiological mechanism of stroke. We aimed to investigate the modification impact of the pro-oxidant-anti-oxidant balance (PAB) on the association between hypertension and stroke recurrence (SR).

METHODS

A cross-sectional design was conducted from December 2019 to December 2020 in 951 stroke patients in six hospitals across Vietnam. Hypertension was defined using antihypertensive medication or systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg. PAB was estimated using weighting methods based on smoking, drinking, and overweight/obesity with pro-oxidant capacity, diet quality, fruit intake, vegetable intake, and physical activity with antioxidant capacity. The higher PAB scores indicated a beneficial balance shifting toward antioxidant dominance. SR was diagnosed by neurologists. Moreover, sociodemographic and health conditions were included as covariates. Multiple logistic regression analyses were used to explore the associations and interactions.

RESULTS

The hypertension and SR proportions were 72.8% and 17.5%, respectively. hypertension was associated with an increased SR likelihood (odds ratio (OR) = 1.93; p = 0.004), whereas a higher PAB score was associated with a lowered SR likelihood (OR = 0.87; p = 0.003). Moreover, hypertension interacting with every one-point increment of PAB was associated with a lowered SR likelihood (OR = 0.83; p = 0.022).

CONCLUSIONS

The harmful impact of hypertension on SR could be alleviated by PAB. The interplay of health behaviors should be highlighted in the intervention strategies for stroke prevention.

Association of oxidative balance score and lung health from the National Health and Nutrition Examination Survey 2007-2012

Background

Oxidative stress is associated with outcomes of chronic lung disease. The oxidative stress-related exposures of diet and lifestyle can be evaluated by the oxidative balance score (OBS), and higher OBS scores indicate more significant antioxidant exposures. But the relationship between OBS and lung health is unknown.

Purpose

The aim of this study was to explore the association between OBS and lung health (respiratory symptoms, chronic lung disease, and lung function).

Methods

A series of models, including weighted linear models, weighted logistic regression, and weighted multinomial logistic regression, were performed to assess the associations of OBS with respiratory symptoms, chronic lung disease, and lung function. The models adjusted by age, race/ethnicity, gender, educational background, poverty-to-income ratio, and dietary energy were also performed.

Results

Cross-sectional data of 5,214 participants from the National Health and Nutrition Examination Survey for the years 2007-2012 were analyzed. For every one-unit increase in OBS, the odds of wheezing/chronic bronchitis decreased by 6%. Increased OBS was associated with higher percent-predicted forced expiratory volume in one second (FEV1) (adjusted mean difference (MD), 0.21%; 95% CI: 0.10-0.32) and percent-predicted forced vital capacity (FVC) (adjusted MD, 0.15%; 95% CI: 0.07-0.24). A significantly lower risk of wheezing/chronic bronchitis was found in participants in the second/third/fourth OBS quartile compared to those in the first OBS quartile (all P for trend < 0.05). Moreover, higher percent-predicted FEV1 and FVC were also found in the third quartile and fourth quartile (all P for trend < 0.05). Furthermore, both dietary and lifestyle components were tightly related to pulmonary outcomes. Many associations were maintained after stratified by sex or after sensitivity analyses.

Conclusion

Oxidative balance score was negatively correlated with the diagnosis of chronic bronchitis/wheezing/restrictive spirometry pattern and positively correlated with percent-predicted FVC and FEV1. It seems that the higher the OBS score, the better the pulmonary outcomes. The findings highlight the importance of adherence to an antioxidant diet and lifestyle and that it contributes to lung health.

Bulky Adducts in Clustered DNA Lesions: Causes of Resistance to the NER System

The nucleotide excision repair (NER) system removes a wide range of bulky DNA lesions that cause significant distortions of the regular double helix structure. These lesions, mainly bulky covalent DNA adducts, are induced by ultraviolet and ionizing radiation or the interaction between exogenous/endogenous chemically active substances and nitrogenous DNA bases. As the number of DNA lesions increases, e.g., due to intensive chemotherapy and combination therapy of various diseases or DNA repair impairment, clustered lesions containing bulky adducts may occur. Clustered lesions are two or more lesions located within one or two turns of the DNA helix. Despite the fact that repair of single DNA lesions by the NER system in eukaryotic cells has been studied quite thoroughly, the repair mechanism of these lesions in clusters remains obscure. Identification of the structural features of the DNA regions containing irreparable clustered lesions is of considerable interest, in particular due to a relationship between the efficiency of some antitumor drugs and the activity of cellular repair systems. In this review, we analyzed data on the induction of clustered lesions containing bulky adducts, the potential biological significance of these lesions, and methods for quantification of DNA lesions and considered the causes for the inhibition of NER-catalyzed excision of clustered bulky lesions.

Lifestyle-based oxidative balance score and its association with cardiometabolic health of the community-dwelling elderly: A cross-sectional secondary analysis

Background

Cardiometabolic diseases, the main disease burden in older adults, are largely caused by oxidative stress resulting from lifestyle factors. This study investigated the relationship between lifestyle-based oxidative balance scores and cardiometabolic health among the community-dwelling elderly.

Methods

This work conducted a secondary analysis of previous cross-sectional research data and constructed a lifestyle-based oxidative balance score (LOBS) including 4 components (higher scores were considered more antioxidant). Linear regression models and logistic regression models were used to evaluate the associations with cardiometabolic biomarkers and the number of cardiometabolic risk factors. Besides, we investigated whether these associations differed by covariates.

Results

A total of 710 individuals (60.99% female, median age 70.0 years) were recruited. The inverse associations of LOBS with SBP and TG and the positive association with HDLC were statistically significant in both linear and logistic regression models. In contrast, an inverse association of LOBS with DBP was significant only in the linear regression model (all P < 0.05). The associations of LOBS with TG and HDLC were not affected by age, gender, or socioeconomic level. A significant inverse association was observed between LOBS and the number of cardiometabolic risk factors. Compared with the lowest LOBS, the ORs for more cardiometabolic risk factors in the second and third intervals were 0.577 (0.422, 0.788) and 0.460 (0.301, 0.703) (both P < 0.001).

Conclusion

In summary, this study shows that antioxidant-predominant lifestyle exposure yields a better cardiometabolic health status. We recommend that general practitioners should offer comprehensive healthy lifestyle management to community-dwelling elderly.

Adherence to Oxidative Balance Scores is Associated with a Reduced Risk of Breast Cancer; A Case-Control Study

We aimed to examine whether anthropometric indices, dietary factors, and nutrient intakes of women with and without breast cancer (BrCa) are associated with the oxidative balance score (OBS). This case-control study was carried out among 253 patients with BrCa and 267 healthy subjects aged >18 years. The OBS was calculated by using the following 13 dietary and non-dietary anti- and prooxidant components: dietary antioxidants (selenium, fiber, β-carotene, vitamin D, vitamin C, vitamin E, and folate), dietary prooxidants (iron and saturated and polyunsaturated fatty acids), and nondietary anti- (physical activity) and prooxidants (smoking and obesity). The binary logistic regression was used to determine the association OBS with BrCa. After adjusting for potential confounders in the final model, there was evidence that the odds of BrCa decreased with increasing categories of the OBS (OR = 0.53, 95% CI 0.28 - 0.98; P-trend = 0.021). When we made stratified analysis by menopausal status, OBS was inversely associated with odds of BrCa in premenopausal women after adjusting for potential confounders. No significant association was found between OBS and odds of BrCa among post-menopausal women. Our data suggest that OBS scores were associated with decreased BrCa risk in the overall population.

Early Prediction for Prediabetes and Type 2 Diabetes Using the Genetic Risk Score and Oxidative Stress Score

We aimed to use a genetic risk score (GRS) constructed with prediabetes and type 2 diabetes-related single nucleotide polymorphisms (SNPs) and an oxidative stress score (OSS) to construct an early-prediction model for prediabetes and type 2 diabetes (T2DM) incidence in a Korean population. The study population included 549 prediabetes and T2DM patients and 1036 normal subjects. The GRS was constructed using six prediabetes and T2DM-related SNPs, and the OSS was composed of three recognized oxidative stress biomarkers. Among the nine SNPs, six showed significant associations with the incidence of prediabetes and T2DM. The GRS was profoundly associated with increased prediabetes and T2DM (OR = 1.946) compared with individual SNPs after adjusting for age, sex, and BMI. Each of the three oxidative stress biomarkers was markedly higher in the prediabetes and T2DM group than in the normal group, and the OSS was significantly associated with increased prediabetes and T2DM (OR = 2.270). When BMI was introduced to the model with the OSS and GRS, the area under the ROC curve improved (from 69.3% to 70.5%). We found that the prediction model composed of the OSS, GRS, and BMI showed a significant prediction ability for the incidence of prediabetes and T2DM.

Oxidative Balance Scores (OBSs) Integrating Nutrient, Food and Lifestyle Dimensions: Development of the NutrientL-OBS and FoodL-OBS

Oxidative Balance Scores (OBS) are tools that allow us to assess the individual’s antioxidant state by ranking both antioxidant and pro-oxidant components of dietary and lifestyle factors. Our aim was to develop novel OBSs accounting for either the global supply of nutrient antioxidants in the diet, or the intake of antioxidant-rich foods, in combination with lifestyle factors. Pro-oxidant factors were also considered. Within two centers of the Spanish European Prospective Investigation into Cancer and Nutrition (EPIC) study, EPIC-Granada and EPIC-Gipuzkoa (N = 14,756 participants), we developed the Nurient, Food and Lifestyle OBS (NutrientL-OBS and FoodL-OBS), and their simplified versions (solely with dietary or lifestyle factors, the Nutrient-OBS, Food-OBS and L-OBS). Their antioxidant potential was evaluated considering their relationship with: (i) 20 scores of adherence to the Mediterranean Diet (MD); and, (ii) 25 biomarkers of antioxidant nutrients (ascorbic acid, β-carotene, etc.), inflammation (CRP, TNF-alpha, etc.) and oxidative stress (uric acid), among 210 participants. Spearman correlation and multivariate linear regression analyses were applied to analyze these associations. Some statistically significant relationships were encountered between the NutrientL-OBS and the FoodL-OBS with the MD scores, and with ascorbic acid (per one-unit increase in OBS: β = 0.012 and 0.015; p = 0.022 and 0.008, respectively) and CRP (per one-unit increase in both OBS: β = −0.02; p = 0.02); the latter appeared to be restricted to the OBS´s lifestyle components. In conclusion, the NutrientL- and FoodL-OBSs and their sub-versions are related to antioxidant-rich dietary patterns and to biomarkers of antioxidant nutrient intake and inflammation, supporting that these tools are valid to assess the individual´s oxidative/antioxidant status.

Recognition and removal of clustered DNA lesions via nucleotide excision repair

Clustered damage of DNA consists of two or more lesions located within one or two turns of the DNA helix. Clusters consisting of lesions of various structures can arise under the influence of strong damaging factors, especially if the cells have a compromised repair status. In this work, we analyzed how the presence of an analog of the apurinic/apyrimidinic site - a non-nucleoside residue consisting of diethylene glycol phosphodiester (DEG) - affects the recognition and removal of a bulky lesion (a non-nucleoside site of the modified DNA strand containing a fluorescein residue, nFlu) from DNA by a mammalian nucleotide excision repair system. Here we demonstrated that the efficiency of nFlu removal decreases in the presence of DEG in the complementary strand and is completely suppressed when the DEG is located opposite the nFlu. By contrast, protein factor XPC-RAD23B, which initiates global genomic nucleotide excision repair, has higher affinity for DNA containing clustered damage as compared to DNA containing a single bulky lesion; the affinity of XPC strengthens as the positions of DEG and nFlu become closer. The changes in the double-stranded DNA's geometry caused by the presence of clustered damage were also assessed. The obtained experimental data together with the results of molecular dynamics simulations make it possible to get insight into the structural features of DNA containing clustered lesions that determine the efficiency of repair. Speaking more broadly, this study should help to understand the probable fate of bulky adduct-containing clusters of various topologies in the mammalian cell.

Association of Oxidative Balance Score with the Metabolic Syndrome in a Sample of Iranian Adults

OBJECTIVE

We aimed to assess the association of the oxidative balance score (OBS) with metabolic syndrome (MetS) in adults.

DESIGN

A population-based cross-sectional study Setting. Health centers from five districts in Tehran, Iran.

METHODS

We recruited 847 participants with an age range of 18-65 years. Dietary intake was assessed by a semiquantitative food frequency questionnaire with 168 items. The OBS was calculated by using the following 13 dietary and nondietary anti- and prooxidant components: dietary antioxidants (selenium, fiber, β-carotene, vitamin D, vitamin C, vitamin E, and folate), dietary prooxidants (iron and saturated and polyunsaturated fatty acids), and nondietary anti- (physical activity) and prooxidants (smoking and obesity). The odds ratio (OR) and 95% confidence interval (CI) of the MetS and its components across tertiles of the OBS were calculated by logistic regression analysis, controlling for age, sex, energy intake, occupation, and educational level.

RESULTS

The range of OBS was between 16 and 39. Being in the top versus the bottom tertile of the OBS was not associated with the MetS (OR = 0.71, 95% CI 0.48-1.03; P = 0.07), after controlling for potential confounders. Higher OBS score was associated with a lower likelihood of abdominal obesity (OR: 0.55, 95% CI: 0.38-0.81; P = 0.003) and increased diastolic blood pressure (OR: 0.64, 95% CI: 0.41-0.99; P = 0.04). Higher OBS was not associated with other components of the MetS.

CONCLUSION

Overall, the present study showed that there was no significant relationship between OBS and MetS in Tehranian adults.

Associations of dietary and lifestyle oxidative balance scores with mortality risk among older women: the Iowa Women's Health Study

PURPOSE

Substantial basic science evidence suggests that oxidative stress may play a role in aging-related health outcomes, including cardiovascular diseases (CVD) and cancer, and oxidative stress markers were linked with all-cause and cause-specific mortality in epidemiologic studies. However, the associations of many individual dietary and lifestyle anti-/pro-oxidant exposures with mortality are inconsistent. Oxidative balance scores (OBS) that incorporated multiple dietary and lifestyle factors were previously developed and reported to reflect the collective oxidative effects of multiple exposures.

METHODS

We investigated associations of 11-component dietary and 4-component (physical activity, adiposity, alcohol, and smoking) lifestyle OBS (higher scores were considered more anti-oxidative) with all-cause and cause-specific mortality among women 55-69 years of age at baseline in the prospective Iowa Women's Health Study (1986-2012). We assessed OBS-mortality associations using multivariable Cox proportional hazards regression.

RESULTS

Of the 34,137 cancer-free women included in the analytic cohort, 18,058 died (4521 from cancer, and 6825 from CVD) during a mean/median 22.0/26.1 person-years of follow-up. Among participants in the highest relative to the lowest lifestyle OBS quintiles, the adjusted hazards ratios and their 95% confidence intervals for all-cause, all-cancer, and all-CVD mortality were 0.50 (0.48, 0.53), 0.47 (0.43, 0.52), and 0.54 (0.50, 0.58) (all P_trend < 0.001), respectively. The associations of the dietary OBS with mortality were close to null.

CONCLUSION

Our findings, combined with results from previous studies, suggest that a predominance of antioxidant over pro-oxidant lifestyle exposures may be associated with lower all-cause, all-CVD, and all-cancer mortality risk.

Oxidative balance score and risk of osteoporosis among postmenopausal Iranian women

To our knowledge, this is the first study to examine the association of oxidative balance score (OBS) and risk of osteoporosis. Findings suggest that a predominance of anti- over pro-oxidant exposures, as reflected by a higher OBS, is associated with lower risk of lumbar spine osteoporosis among postmenopausal Iranian women.

PURPOSE

The oxidative balance score (OBS) is a combined measure of pro- and anti-oxidant exposure status, with a higher OBS indicating a predominance of anti- over pro-oxidant exposures. We aimed to examine the potential association of OBS and risk of osteoporosis among postmenopausal Iranian women, hypothesizing that a higher OBS is associated with lower risk of postmenopausal osteoporosis.

METHODS

This cross-sectional study was conducted among 151 postmenopausal Iranian women aged 50-85 y. Bone mineral density (BMD) at lumbar spine and femoral neck was measured by dual-energy X-ray absorptiometry, and osteoporosis was defined using the WHO criteria as a BMD T-score of ≤ - 2.5 standard deviations. The OBS was calculated by combining information from 17 a-priori selected pro- and anti-oxidant components classified in the following four categories: non-dietary pro-oxidants (i.e., obesity and smoking); non-dietary anti-oxidants (i.e., physical activity); dietary pro-oxidants (i.e., saturated fatty acid, poly-unsaturated fatty acid, and iron); and dietary anti-oxidants (i.e., fiber, vitamin E, folate, vitamin C, alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin, lycopene, zinc, and selenium).

RESULTS

After controlling for several potential covariates in the multivariable-adjusted binary logistic regression analysis, subjects in the highest tertile of OBS had a lower risk of lumbar spine osteoporosis than those in the lowest tertile (odds ratio = 0.14; 95% confidence interval, 0.04-0.45; p = 0.001). The OBS was not associated with risk of femoral neck osteoporosis.

CONCLUSION

Findings suggest that a predominance of anti- over pro-oxidant exposures, as indicated by a higher OBS, is associated with lower risk of lumbar spine osteoporosis among postmenopausal Iranian women.

Protective effect of carnosine on hydrogen peroxide-induced oxidative stress in human kidney tubular epithelial cells

Diabetic nephropathy (DN) endangers health and is a high financial public burden worldwide. Risk of DN is positively correlated with high levels of reactive oxygen species (ROS). Carnosine, an antioxidant, actively regulates cell function and has the potential to reduce the occurrence of DN. Here, we explored whether carnosine could prevent oxidative stress in human kidney tubular epithelial (HK2) cells and, if so, the mechanisms underlying this effect. HK2 cells were cultured with the ROS hydrogen peroxide (H₂O₂) for 24 h and then treated with carnosine. In H₂O₂-damaged HK2 cells, carnosine significantly increased cell viability, assessed using a Cell Counting Kit 8, increased total superoxide dismutase (T-SOD) activity, assessed using a T-SOD activity detection kit, but decreased ROS levels, assessed using a ROS-sensitive fluorescent probe. Western blotting analyses to determine the protein expression levels of BAX, BCL-2, caspase 3, and the NADPH oxidase isoforms NOX2 and NOX4, as well as confocal laser scanning microscopy to assess changes in the mitochondrial membrane potential and the relative position of mitochondria to cytochrome c, indicated that carnosine inhibited apoptosis via the mitochondrial pathway in H₂O₂-damaged HK2 cells. Significantly decreased NOX4 expression and increased T-SOD activity in the presence of carnosine reduced the production of intracellular ROS, relieving oxidative stress to inhibit apoptosis via the mitochondrial pathway. These findings provide molecular mechanistic insights underlying the effects of carnosine, particularly as a potential therapeutic in DN.

Dietary and Lifestyle Oxidative Balance Scores and Incident Colorectal Cancer Risk among Older Women; the Iowa Women's Health Study

BACKGROUND

Basic science literature strongly supports a role of oxidative stress in colorectal cancer (CRC) etiology, but in epidemiologic studies, associations of most individual exposures with CRC have been weak or inconsistent. However, recent epidemiologic evidence suggests that the collective effects of these exposures on oxidative balance and CRC risk may be substantial.

METHODS

Using food frequency and lifestyle questionnaire data from the prospective Iowa Women's Health Study (1986-2012), we investigated associations of 11-component dietary and 4-component lifestyle oxidative balance scores (OBS) with incident CRC using multivariable Cox proportional hazards regression.

RESULTS

Of the 33,736 cancer-free women aged 55-69 years at baseline, 1,632 developed CRC during follow-up. Among participants in the highest relative to the lowest dietary and lifestyle OBS quintiles (higher anti-oxidant relative to pro-oxidant exposures), the adjusted hazard ratios (HRs) and their 95% confidence intervals (CI) were, respectively, 0.77 (0.63, 0.94) (P_trend=0.02) and 0.61 (0.52, 0.71) (P_trend<0.0001). Among those in the highest relative to the lowest joint lifestyle/dietary OBS quintile, the HR was 0.45 (95% CI 0.26, 0.77).

CONCLUSIONS

Our findings suggest that a predominance of antioxidant over pro-oxidant dietary and lifestyle exposures-separately and especially jointly-may be inversely associated with CRC risk among older women.

Association between Dietary Zinc and Selenium Intake, Oxidative Stress-Related Gene Polymorphism, and Colorectal Cancer Risk in Chinese Population - A Case-Control Study

Zinc and selenium may protect against colorectal cancer (CRC) progression through their anti-oxidative effects. This study examined the independent and combined effect of dietary zinc and selenium intake, and polymorphisms of the oxidative stress-related genes (superoxide dismutase 1, superoxide dismutase 2, glutathione peroxidase, and catalase) on CRC risk in a Chinese case-control study. A total of 493 cases and 498 sex and age-matched controls were randomly selected from an ongoing case-control study. Dietary information was assessed through face-to-face interviews using a validated food frequency questionnaire. Multiplex PCR-ligase detection reaction was used for genotyping the target SNPs. Multivariable logistic regression was used to estimate the odds ratios (ORs) and 95% confidence interval (CI). Intake of selenium was found to be inversely associated with CRC risk, while zinc was not associated with CRC risk. The ORs (95% CI) for the highest vs. the lowest quartile were 0.42 (95% CI 0.28, 0.64, P_trend < 0.001) for selenium and 0.96 (95% CI 0.63, 1.47, P_trend = 0.505) for zinc. Combined effect was observed between zinc and SOD1 rs4998557 on CRC risk (P_interaction < 0.05). This study identified a novel diet-gene interaction in the oxidative stress pathway on CRC risk in Chinese population.

Antibiotic exposure and the risk of colorectal adenoma and carcinoma: a systematic review and meta-analysis of observational studies

AIM

The Incidence of colorectal cancer (CRC) is increasing, and evidence suggests that maladaptation of the bowel microbiome may be associated with colorectal carcinogenesis. Consumption of antibiotics may cause imbalance of the bowel microbiome but research assessing an association between antibiotic exposure and CRC is inconsistent. The aim of this systematic review and meta-analysis was to appraise and synthesize the available evidence.

METHOD

The MEDLINE, EMBASE and CINAHL databases were searched for published observational studies. We included eight studies of 3 408 312 patients. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) for the odds of CRC following antibiotic exposure were estimated. Sensitivity analyses were performed according to exposure definition, study design and risk of bias.

RESULTS

A weak association between antibiotic exposure and CRC was demonstrated when exposure was assessed cumulatively by the number of prescriptions (OR 1.204, 95% CI 1.097-1.322, P < 0.001) or duration of antibiotic exposure (OR 1.168, 95% CI 1.087-1.256, P < 0.001). Antibiotic exposure assessed as a binary variable demonstrated no association with CRC.

CONCLUSION

The findings suggest a weak association between cumulative antibiotic consumption and risk of CRC but no causal conclusions can be made. Limitations include the heterogeneity and quality of the available research, particularly with regard to measurement of antibiotic exposure.

A Review of A Priori Defined Oxidative Balance Scores Relative to Their Components and Impact on Health Outcomes

Oxidative Balance Scores (OBSs) are tools that have emerged to evaluate the global balance of individuals’ oxidation—reduction status. The aim was to compare OBSs available in the literature regarding their characteristics and associations with chronic diseases in epidemiological studies. Studies that developed OBSs were searched in PubMed until August 2018. A total of 21 OBSs were identified. These OBSs presented different scoring schemes and different types of anti- and pro-oxidant components, including dietary factors (dietary intake and/or nutrient biomarkers), lifestyle factors, and medications. Most OBSs were based on over 10 components, and some included only dietary factors. Few considered weighted components in the score. Only three OBSs were validated as potential surrogates of oxidative balance through inflammation and OS-related biomarkers. Notably, all the OBSs were associated—to a varying degree—with a reduced risk of cardiovascular diseases, chronic kidney disease, colorectal adenomas, and different cancer types (colorectal and breast cancer), as well as with all-cause and cancer-related mortality. For other outcomes, e.g., prostate cancer, contradictory results were reported. In summary, there is a great heterogeneity in the definition of OBSs. Most studies are concordant in supporting that excessive OS reflected by a lower OBS has deleterious effects on health. Unified criteria for defining the proper OBSs, valuable to gauge OS-related aspects of the diet and lifestyle that may lead to adverse health outcomes, are needed.

Dietary Oxidative Balance Scores and Biomarkers of Inflammation among Individuals with and without Chronic Kidney Disease

BACKGROUND

Oxidative stress and inflammation are proposed mechanisms of nonspecific kidney injury and progressive kidney failure. Higher dietary oxidative balance scores (OBS) are associated with lower prevalence of chronic kidney disease (CKD).

METHODS

We investigated the association between OBS and biomarkers of inflammation using data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. Nutrient estimates from the Block Food Frequency Questionnaires were used to define tertiles of 11 pro- and antioxidant factors. Points for each OBS component were summed, with a higher score indicating predominance of antioxidant exposures. Multivariable linear regression models were used to estimate the association between OBS and biomarkers of inflammation (interleukin-6 [IL-6], interleukin-8 [IL-8], interleukin-10 [IL-10], fibrinogen, C-reactive protein [CRP], white blood cell count, and cystatin C). An interaction term was included to determine if associations between OBS and inflammatory markers differed between individuals with and without CKD.

RESULTS

Of 682 participants, 22.4% had CKD. In adjusted models, OBS was associated with CRP and IL-6. For every 5-unit increase in OBS, the CRP concentration was -15.3% lower (95% CI: -25.6, -3.6). The association of OBS with IL-6 differed by CKD status; for every 5-unit increase in OBS, IL-6 was -10.7% lower (95% CI: -16.3, -4.7) among those without CKD, but there was no association among those with CKD (p = 0.03).

CONCLUSION

This study suggests that a higher OBS is associated with more favorable levels of IL-6 and CRP, and that the association of OBS and IL-6 may be modified by CKD status.

Associations of mitochondrial polymorphisms with sporadic colorectal adenoma

Somatic mutations in mitochondrial DNA have been reported in colorectal adenomatous polyps (adenomas), the precursors to most colorectal cancers. However, there are no reports of associations of germline variation in mitochondrial DNA with adenoma risk. We investigated associations of germline polymorphisms in the displacement loop (D-loop) and non-D-loop region of the mitochondrial genome with incident, sporadic colorectal adenoma in three pooled colonoscopy-based case-control studies (n = 327 adenoma cases, 420 controls) that used identical methods for case and risk factor ascertainment. We sequenced a 1124 bp fragment to identify all genetic variation in the mitochondrial D-loop region, and used the Sequenom platform to genotype 64 tagSNPs in the non-D-loop region. We used multivariable unconditional logistic regression to estimate associations of the polymorphisms with adenoma. The odds ratios (OR) for associations of four polymorphisms in the HV1 region (mt16294, mt16296, mt16278, mt16069) with adenoma were 2.30, 2.63, 3.34, and 0.56, respectively; all 95% confidence intervals (CI) excluded 1.0, however, after correction for multiple comparisons, none of the findings remained statistically significant. Similar results were found for six polymorphisms in the non-D-loop region. In the HV1 region poly C tract, relative to those with 5 repeats, the ORs for those with fewer or more repeats were, respectively, 2.29 (95%CI 1.07-4.89) and 0.63 (95%CI 0.36-1.08), but repeat numbers in the HV2 region were not associated with adenoma. These findings suggest that mitochondrial D-loop HV1 region polymorphisms may be associated with colorectal adenoma risk and support further investigation.

A Mini-Review of Reactive Oxygen Species in Urological Cancer: Correlation with NADPH Oxidases, Angiogenesis, and Apoptosis

Oxidative stress refers to elevated reactive oxygen species (ROS) levels, and NADPH oxidases (NOXs), which are one of the most important sources of ROS. Oxidative stress plays important roles in the etiologies, pathological mechanisms, and treatment strategies of vascular diseases. Additionally, oxidative stress affects mechanisms of carcinogenesis, tumor growth, and prognosis in malignancies. Nearly all solid tumors show stimulation of neo-vascularity, termed angiogenesis, which is closely associated with malignant aggressiveness. Thus, cancers can be seen as a type of vascular disease. Oxidative stress-induced functions are regulated by complex endogenous mechanisms and exogenous factors, such as medication and diet. Although understanding these regulatory mechanisms is important for improving the prognosis of urothelial cancer, it is not sufficient, because there are controversial and conflicting opinions. Therefore, we believe that this knowledge is essential to discuss observations and treatment strategies in urothelial cancer. In this review, we describe the relationships between members of the NOX family and tumorigenesis, tumor growth, and pathological mechanisms in urological cancers including prostate cancer, renal cell carcinoma, and urothelial cancer. In addition, we introduce natural compounds and chemical agents that are associated with ROS-induced angiogenesis or apoptosis.

Index-Based Dietary Patterns and the Risk of Prostate Cancer

Prostate cancer is the second leading cause for cancer incidence in male. Although this high incidence is due to prostate specific antigen screening, other risk-factors, such as diet, might also be involved. The results of previous studies on the association between prostate cancer risk and individual dietary components have been conflicting. Thus, evaluation by dietary pattern analysis rather than individual dietary factors is suggested. The purpose of this study was to review the association of prostate cancer with a priori dietary indices, which are less studied and reviewed to date compared to a posteriori indices. Studies reviewed in this research were published from January 1997 to March 2017. Seventeen studies with nine indices were selected. In Mediterranean Diet Score (MDS), all four studies were non-significant. In Dietary Inflammatory Index (DII), 3 out of 4 studies significantly increased risk by 1.33-2.39 times, suggesting that a higher pro-inflammatory diet may be a possible prostate cancer risk factor. In Oxidative Balance Score (OBS), 2 out of 5 studies had decreased risk by 0.28 and 0.34 times, whereas 1 study had increased risk by 1.17 times. Among other indices, Healthy Eating Index (HEI) and prostate cancer dietary index were associated with decreased risk, while the results from 2 studies of Low Carbohydrate, High Protein Diet (LCHP) score were conflicting. In conclusion, we observed that it is insufficient to support the association between a priori indices and prostate cancer risk, except for MDS and DII, which had relatively constant results among studies. Therefore, further studies are required to identify consistent criteria for each a priori index, and should be conducted actively in various populations.

DNA Damage Is a Potential Marker for TP53 Mutation in Colorectal Carcinogenesis

PURPOSE

The ability to measure oxidative DNA damage in a tissue allows establishment of the relationship between DNA damage and mutations in normal and neoplastic cells. It is well known that TP53 is a key inhibitor of tumor development and preserves the genome integrity in each cell. The aim of the present study was to investigate the relationship between DNA damage and TP53 mutation in colorectal adenoma and adenocarcinoma, and the value of DNA damage as potential marker of TP53 mutation in non-tumor tissues adjacent to colon malignant lesions.

METHODS

Tissue samples were obtained by colonoscopy from patients with adenoma and/or adenocarcinoma and from healthy volunteers. Diagnosis was defined by histopathology. Immunohistochemistry with computer-assisted image analysis was performed to quantify TP53 mutation. Oxidative DNA damage was determined by comet assay. Statistical analyses were performed with 5 % of significance level.

RESULTS

The TP53 level was higher in non-tumor tissues from tumor patients than in normal tissues from healthy volunteers (p = 0.01). Likewise, higher TP53 levels were observed in tumor tissues compared with the non-tumor tissues (p = 0.00). Oxidative DNA damage levels were higher in tumor tissues than in non-tumor tissues (p = 0.00). The amount of TP53 (p = 0.00) and oxidative DNA damage (p = 0.00) in normal and tumor tissue was related. The relationship between oxidative DNA damage and TP53 mutation was demonstrated in all samples (p = 0.00).

CONCLUSION

Oxidative DNA damage is an intervening variable for TP53 mutation in colorectal adenoma-carcinoma. Our data suggests that oxidative DNA damage is a potential marker of TP53 mutation in colorectal carcinogenesis.

DNA base excision repair genetic risk scores, oxidative balance, and incident, sporadic colorectal adenoma

Associations of individual base excision repair (BER) genotypes with colorectal adenoma risk are unclear, but likely modest. However, genetic risk scores (GRS) that aggregate information from multiple genetic variants might be useful for assessing genetic predisposition to colorectal adenoma. We analyzed data pooled from three colonoscopy-based case-control studies of incident, sporadic colorectal adenoma (n = 488 cases, 604 controls) that collected blood for genotyping and extensive dietary and other data. We randomly split our population sample into training samples (half of the participants) and validation samples (the remaining participants) 10 times. Associations of 65 individual single nucleotide polymorphisms (SNPs) in 15 BER genes were assessed in the training samples and used to combine information from multiple risk variants into a BER GRS among the validation samples using unweighted and weighted methods. We also combined 15 extrinsic exposures with known pro- or antioxidant properties into an oxidative balance score (OBS). Associations of the BER GRS with colorectal adenoma, overall and jointly with the OBS, were assessed using multivariable logistic regression. The odds ratio for those in the highest relative to the lowest tertile of the weighted BER GRS was 2.07 (95% confidence interval, 1.26-3.40; p_trend  = 0.01). Relative to those with both a low GRS and a high (more antioxidant) OBS, the estimated direct association for those with both a high BER GRS and a low OBS was stronger than for those in other GRS/OBS categories. Our findings suggest that BER genotypes collectively may be associated with incident sporadic colorectal adenomas.

Potential biomarkers associated with oxidative stress for risk assessment of colorectal cancer

Cells are continuously threatened by the damage caused by reactive oxygen/nitrogen species (ROS/RNS), which are produced during physiological oxygen metabolism. In our review, we will summarize the latest reports on the role of oxidative stress and oxidative stress-induced signaling pathways in the etiology of colorectal cancer. The differences in ROS generation may influence the levels of oxidized proteins, lipids, and DNA damage, thus contributing to the higher susceptibility of colon. Reactive species (RS) of various types are formed and are powerful oxidizing agents, capable of damaging DNA and other biomolecules. Increased formation of RS can promote the development of malignancy, and the "normal" rates of RS generation may account for the increased risk of cancer development in the aged. In this review, we focus on the role of oxidative stress in the etiology of colorec-tal cancer and discuss free radicals and free radical-stimulated pathways in colorectal carcinogenesis.

Nitrate in drinking water and risk of colorectal cancer in Yogyakarta, Indonesia

Nitrate concentration in well water in Yogyakarta, Indonesia, and its surroundings tended to increase rapidly from time to time, and it may be associated with an elevated risk for several types of cancer. The purpose of this study was to examine the association between nitrate in drinking water and colorectal cancer (CRC) risk occurrence. A case-control study was conducted in Yogyakarta Special Province. Pathologically confirmed 75 CRC patients and 75 controls were consulted and their individual well water was sampled and examined for nitrate concentrations. Logistic regression analysis was conducted to establish the association between nitrate and CRC risk development. There was a significant correlation between nitrate in drinking water and CRC occurrence, and this value was relatively stable after being adjusted for protein intake, smoking history, age, and family history of cancer. These findings demonstrated that the risk of CRC development was fourfold among those with >10 years of nitrate exposure from well water compared with those with ≤10 years of nitrate exposure. Consequently, a significant association between nitrate in drinking water and occurrence of CRC in Yogyakarta was established.

Diet and lifestyle factors associated with miRNA expression in colorectal tissue

MicroRNAs (miRNAs) are small non-protein-coding RNA molecules that regulate gene expression. Diet and lifestyle factors have been hypothesized to be involved in the regulation of miRNA expression. In this study it was hypothesized that diet and lifestyle factors are associated with miRNA expression. Data from 1,447 cases of colorectal cancer to evaluate 34 diet and lifestyle variables using miRNA expression in normal colorectal mucosa as well as for differential expression between paired carcinoma and normal tissue were used. miRNA data were obtained using an Agilent platform. Multiple comparisons were adjusted for using the false discovery rate q-value. There were 250 miRNAs differentially expressed between carcinoma and normal colonic tissue by level of carbohydrate intake and 198 miRNAs differentially expressed by the level of sucrose intake. Of these miRNAs, 166 miRNAs were differentially expressed for both carbohydrate intake and sucrose intake. Ninety-nine miRNAs were differentially expressed by the level of whole grain intake in normal colonic mucosa. Level of oxidative balance score was associated with 137 differentially expressed miRNAs between carcinoma and paired normal rectal mucosa. Additionally, 135 miRNAs were differentially expressed in colon tissue based on recent NSAID use. Other dietary factors, body mass index, waist and hip circumference, and long-term physical activity levels did not alter miRNA expression after adjustment for multiple comparisons. These results suggest that diet and lifestyle factors regulate miRNA level. They provide additional support for the influence of carbohydrate, sucrose, whole grains, NSAIDs, and oxidative balance score on colorectal cancer risk.

Effects of exercise on markers of oxidative stress: an Ancillary analysis of the Alberta Physical Activity and Breast Cancer Prevention Trial

BACKGROUND

Oxidative stress may contribute to cancer aetiology through several mechanisms involving damage to DNA, proteins and lipids leading to genetic mutations and genomic instability. The objective of this study was to determine the effects of aerobic exercise on markers of oxidative damage and antioxidant enzymes in postmenopausal women.

METHODS

The Alberta Physical Activity and Breast Cancer Prevention Trial (ALPHA) was a two-centre, two-armed randomised trial of 320 inactive, healthy, postmenopausal women aged 50-74 years. Participants were randomly assigned to a year-long exercise intervention (225 min/week) or a control group while being asked to maintain a normal diet. Fasting blood samples were obtained and plasma concentrations of two oxidative damage markers (8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-isoprostaglandin F2α (8-Iso-PGF2α)) and two antioxidant enzymes (superoxide dismutase and catalase) were measured at baseline, 6 months and 12 months. Intention-to-treat (ITT) and per-protocol analyses were performed using linear mixed models adjusted for baseline biomarker concentrations. A further exercise adherence analysis, based on mean minutes of exercise per week, was also performed.

RESULTS

In the ITT and per-protocol analyses, the exercise intervention did not have any statistically significant effect on either oxidative damage biomarkers or antioxidant enzyme activity.

CONCLUSIONS

A year-long aerobic exercise intervention did not have a significant impact on oxidative stress in healthy, postmenopausal women.

TRIAL REGISTRATION NUMBER

NCT00522262.

Dietary patterns and risk of colorectal adenoma: a systematic review and meta-analysis of observational studies

BACKGROUND

Current evidence suggests that dietary patterns may play an important role in colorectal cancer risk. The present study aimed to perform a systematic review and meta-analysis of observational studies exploring the association between dietary patterns and colorectal adenomas (a precancerous condition).

METHODS

Pubmed and EMBASE electronic databases were systematically searched to retrieve eligible studies. Only studies exploring the risk or association with colorectal adenomas for the highest versus lowest category of exposure to a posteriori dietary patterns were included in the quantitative analysis. Random-effects models were applied to calculate relative risks (RRs) of colorectal adenomas for high adherence to healthy or unhealthy dietary patterns. Statistical heterogeneity and publication bias were explored.

RESULTS

Twelve studies were reviewed. Three studies explored a priori dietary patterns using scores identifying adherence to the Mediterranean, Paleolithic and Dietary Approaches to Stop Hypertension (DASH) diet and reported an association with decreased colorectal adenoma risk. Two studies tested the association with colorectal adenomas between a posteriori dietary patterns showing lower odds of disease related to plant-based compared to meat-based dietary patterns. Seven studies identified 23 a posteriori dietary patterns and the analysis revealed that higher adherence to healthy and unhealthy dietary patterns was significantly associated risk of colorectal adenomas (RR = 0.81, 95% confidence interval = 0.71, 0.94 and RR = 1.24, 95% confidence interval = 1.13, 1.35, respectively) with no evidence of heterogeneity or publication bias.

CONCLUSIONS

The results of this systematic review and meta-analysis indicate that dietary patterns may be associated with the risk of colorectal adenomas.

Circulating Biomarkers of Gut Barrier Function: Correlates and Nonresponse to Calcium Supplementation among Colon Adenoma Patients

BACKGROUND

Gut barrier dysfunction contributes to several gastrointestinal disorders, including colorectal cancer, but factors associated with intestinal hyperpermeability have been minimally studied in humans.

METHODS

We tested the effects of two doses of calcium (1.0 or 2.0 g/d) on circulating biomarkers of gut permeability [anti-flagellin and anti-lipopolysaccharide (LPS) Ig, measured via ELISA] over a 4-month treatment period among colorectal adenoma patients in a randomized, double-blinded, placebo-controlled clinical trial (n = 193), and evaluated the factors associated with baseline levels of these biomarkers.

RESULTS

Baseline concentrations of anti-flagellin IgA and anti-LPS IgA were, respectively, statistically significantly proportionately higher by 11.8% and 14.1% among men, 31.3% and 39.8% among those with a body mass index ≥ 35 kg/m(2), and 19.9% and 22.0% among those in the upper relative to the lowest sex-specific tertile of waist circumference. A combined permeability score (the summed optical densities of all four biomarkers) was 24.3% higher among women in the upper tertile of plasma C-reactive protein (Ptrend < 0.01). We found no appreciable effects of supplemental calcium on anti-flagellin or anti-LPS Igs.

CONCLUSIONS

Our results suggest that (i) men and those with higher adiposity may have greater gut permeability, (ii) gut permeability and systemic inflammation may be directly associated with one another, and (iii) supplemental calcium may not modify circulating levels of gut permeability biomarkers within 4 months.

IMPACT

Our findings may improve the understanding of the factors that influence gut permeability to inform development of treatable biomarkers of risk for colorectal cancer and other health outcomes.

Oxidative Balance Score and Chronic Kidney Disease

BACKGROUND

The oxidative balance score (OBS) is a composite estimate of the overall pro- and antioxidant exposure status in an individual. The aim of this study was to determine the association between OBS and renal disease.

METHODS

Using the Reasons for Geographic and Racial Differences in Stroke cohort study, OBS was calculated by combining 13 a priori-defined pro- and antioxidant factors by using baseline dietary and lifestyle assessment. OBS was divided into quartiles (Q1-Q4) with the lowest quartile, Q1 (predominance of pro-oxidants), as the reference. Multivariable logistic regression and Cox proportional hazards models were used to estimate adjusted ORs for albuminuria defined as urine albumin/creatinine ratio (ACR)>30 mg/g, macroalbuminuria defined as ACR>300 mg/g and chronic kidney disease (CKD) defined as estimated glomerular filtration rate<60 ml/min/1.73 m2 according to the Chronic Kidney Disease Epidemiology Collaboration and hazards ratios for end-stage renal disease (ESRD), respectively.

RESULTS

Of the 19,461 participants analyzed, 12.9% had albuminuria and 10.1% had CKD at baseline; over a median follow-up of 3.5 years (range 2.14-4.32 years), 0.46% developed ESRD. Higher OBS quartiles were associated with lower prevalence of CKD (OR vs. Q1: Q2=0.93 [95% CI 0.80-1.08]; Q3=0.90 [95% CI 0.77-1.04] and Q4=0.79 [95% CI 0.67-0.92], p for trend<.01). The associations between OBS and albuminuria (p for trend 0.31) and incident ESRD (p for trend 0.56) were not significant in the fully adjusted models.

CONCLUSIONS

These findings suggest that higher OBS is associated with lower prevalence of CKD. Lack of association with ESRD incidence in the multivariable analyses indicates that temporal relation between OBS and renal damage remains unclear.

Oxidative stress, inflammation, and markers of cardiovascular health

OBJECTIVE

To investigate associations of a oxidative balance score (OBS) with blood levels of total cholesterol, low-density lipoprotein- (LDL)-cholesterol, high-density lipoprotein- (HDL) cholesterol and triglycerides, and biomarkers of inflammation (serum C-reactive protein [CRP], albumin and venous total white blood cell [WBC] counts) among 19,825 participants in a nationwide study.

METHODS

Using cross-sectional data 14 dietary and lifestyle components were incorporated into the OBS and the resulting score (range 3-26) was then divided into five equal intervals. Multivariable-adjusted odds ratios (ORs) for abnormal biomarker levels and 95% confidence intervals (CIs) were calculated using logistic regression models.

RESULTS

The ORs (95% CIs) comparing those in the highest relative to those in the lowest OBS equal interval categories were 0.50 (0.38-0.66) for CRP, 0.50 (0.36-0.71) for the total WBC count, and 0.75 (0.58-0.98) for LDL-cholesterol; all three p-values for trend were <0.001. The OBS-HDL-cholesterol association was statistically significantly inverse among females, but not among males. The OBS was not associated with serum albumin or triglycerides.

CONCLUSION

Our findings suggest that an OBS may be associated with some, but not all, circulating lipids/lipoproteins and biomarkers of inflammation.

Effects of calcium supplementation on biomarkers of inflammation and oxidative stress in colorectal adenoma patients: a randomized controlled trial

Inflammation and oxidative stress play important roles in colorectal carcinogenesis. There is strong evidence that calcium reduces risk for colorectal neoplasms, possibly through its ability to bind bile acids and prevent their colonic toxicity (which occurs via an oxidative mechanism and results in an inflammatory response). In a previously reported pilot, randomized, controlled trial among sporadic colorectal adenoma patients we found that those on 2.0 g/day of calcium, relative to those on placebo, had an estimated drop in a combined cytokine z-score of 48% (P = 0.18) over 6 months. To follow-up these promising preliminary findings, we tested the efficacy of two doses of supplemental calcium (1.0 or 2.0 g/day) relative to placebo on modulating circulating biomarkers of inflammation [C-reactive protein (CRP) and 10 cytokines] and oxidative stress (F2-isoprostanes) over a 4-month treatment period among 193 patients with previous sporadic, colorectal adenoma in a randomized, double-blinded, placebo-controlled clinical trial. The inflammation markers were measured in plasma using electrochemiluminescence detection-based immunoassays, and F2-isoprostanes were measured in plasma using gas chromatography-mass spectrometry. Over a 4-month treatment period, we found no appreciable effects of calcium on CRP, cytokines, or F2-isoprostanes (P > 0.4), overall or within strata of several major risk factors for colorectal carcinogenesis, such as body mass index and regular use of nonsteroidal anti-inflammatory drugs. Overall, our results provide no evidence that calcium supplementation favorably modulates concentrations of circulating biomarkers of inflammation or oxidative stress over 4 months among patients with a previous colorectal adenoma.

Differential Gene Expression in Colon Tissue Associated With Diet, Lifestyle, and Related Oxidative Stress

Several diet and lifestyle factors may impact health by influencing oxidative stress levels. We hypothesize that level of cigarette smoking, alcohol, anti-inflammatory drugs, and diet alter gene expression. We analyzed RNA-seq data from 144 colon cancer patients who had information on recent cigarette smoking, recent alcohol consumption, diet, and recent aspirin/non-steroidal anti-inflammatory use. Using a false discovery rate of 0.1, we evaluated gene differential expression between high and low levels of exposure using DESeq2. Ingenuity Pathway Analysis (IPA) was used to determine networks associated with de-regulated genes in our data. We identified 46 deregulated genes associated with recent cigarette use; these genes enriched causal networks regulated by TEK and MAP2K3. Different differentially expressed genes were associated with type of alcohol intake; five genes were associated with total alcohol, six were associated with beer intake, six were associated with wine intake, and four were associated with liquor consumption. Recent use of aspirin and/or ibuprofen was associated with differential expression of TMC06, ST8SIA4, and STEAP3 while a summary oxidative balance score (OBS) was associated with SYCP3, HDX, and NRG4 (all up-regulated with greater oxidative balance). Of the dietary antioxidants and carotenoids evaluated only intake of beta carotene (1 gene), Lutein/Zeaxanthine (5 genes), and Vitamin E (4 genes) were associated with differential gene expression. There were similarities in biological function of de-regulated genes associated with various dietary and lifestyle factors. Our data support the hypothesis that diet and lifestyle factors associated with oxidative stress can alter gene expression. However genes altered were unique to type of alcohol and type of antioxidant. Because of potential differences in associations observed between platforms these findings need replication in other populations.

Oxidative balance scores and risk of incident colorectal cancer in a US prospective cohort study

Although oxidative stress is implicated in colorectal carcinogenesis, human studies on associations of individual prooxidants and antioxidants with colorectal cancer (CRC) have been inconclusive. We incorporated individual environmental factors known to affect oxidative stress into 4 oxidative balance scores (OBS) and investigated their associations with CRC in the Cancer Prevention Study II Nutrition Cohort. During 1999-2009, a total of 1,109 incident CRC cases were identified among 80,063 participants in the Nutrition Cohort who had completed detailed questionnaires. Four OBS with different weighting methods (equal weights, literature review-based, a posteriori data-based, and weights based on Bayesian analysis) were created by combining 16 dietary and nondietary lifestyle factors. Higher values for all 4 OBS, representing more antioxidant exposures than prooxidant exposures, were associated with 41%-53% lower risks of CRC; for example, the relative risk for the highest OBS quartile versus the lowest in the Bayesian analysis was 0.50 (95% confidence interval: 0.41, 0.61). The associations were more modest when OBS was restricted to either dietary or nondietary components. These results, obtained using comprehensive summary measures of oxidative balance-especially considering the similarity of the findings derived using the different weighting methods-support the hypothesis that a predominance of antioxidant lifestyle exposures (both dietary and nondietary) over prooxidant lifestyle exposures reduces risk of CRC.