Associations between antioxidants and all-cause mortality among US adults with obstructive lung function

Antioxidant diet/lifestyle could mitigate the adverse impacts of urinary polycyclic aromatic hydrocarbons on lung function

BACKGROUND

Extant research has demonstrated a correlation between exposure to polycyclic aromatic hydrocarbons (PAHs) and impaired lung function. The maintenance of an antioxidant-rich diet/lifestyle positively benefits pulmonary health. However, the potential ameliorative impact of an antioxidant-based diet/lifestyle on PAH-induced detrimental effects remains unclear.

METHODS

The study drew upon cross-sectional data encompassing 1615 participants derived from the National Health and Nutrition Examination Survey 2007 to 2012. To gauge the maintenance of an antioxidant-rich diet/lifestyle, we employed Oxidative Balance Score (OBS) that incorporates sixteen nutrients and four lifestyle factors. Lung function was evaluated using percent-predicted Forced Vital Capacity (FVC), Forced Expiratory Volume 1st Second (FEV1), FEV1/FVC, and fractional exhaled nitric oxide (FENO). Our analytical approach entailed the utilization of weighted linear models.

RESULTS

Our analysis unveiled interaction effects between urinary monohydroxy polycyclic aromatic hydrocarbons (OH-PAHs) and OBS concerning lung function. A one-unit increase in ∑OH-PAH (sum of eight OH-PAHs) was linked to a -0.75% reduction (95% CI: -1.28, -0.22) in FEV1/FVC. Individuals exhibiting low OBS displayed a marked decrease in FEV1/FVC (mean difference = -1.10%; 95% CI: -1.82, -0.39) for each unit increase in ∑OH-PAH, whereas no significant associations were discerned for those with medium or high OBS. Further stratification by gender yielded consistent results. The correlation between ∑OH-PAH and FENO proved statistically significant among participants with low OBS (P = 0.002) and medium OBS (P = 0.001), but non-significant for those with high OBS. Parallel findings emerged when examining percent-predicted FEV1 and FVC.

CONCLUSIONS

In conclusion, our study underscores the existence of statistically significant interactions between OH-PAHs and the maintenance of an antioxidant-rich diet and lifestyle concerning lung function. These findings underscore the pivotal role of maintaining an antioxidant-based diet and lifestyle in mitigating the adverse impacts of PAH exposure on lung function.

Associations of different isomeric forms of serum lycopene with cardiovascular disease and all-cause mortality

Background: The effect of serum lycopene on the progression of cardiovascular diseases (CVDs) and their longevity remains a controversial topic. The purpose of this study was to evaluate the associations of different isomeric forms of serum lycopene with CVD and all-cause mortality in the American population. Methods: The National Health and Nutrition Examination Survey (NHANES) is a large population survey to investigate public health in the US. We analyzed data from 2003-2006 linked with mortality data obtained in 2015. Cox proportional hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated to assess the risk of CVD and all-cause mortality caused by serum lycopene. Results: Among 7452 participants (aged 20-85 years, 46.7% male), 298 died from CVDs among the total 1213 deaths during a median follow-up of 10.7 years. Serum lycopene is a protective factor for all-cause and CVD mortality. In multivariable-adjusted models, the hazard ratio (with 95% confidence intervals) associated with Q4 compared to Q1 of serum total-lycopene, trans-lycopene and cis-lycopene was 0.49 (0.38,0.63), 0.49 (0.39,0.63) and 0.55 (0.43,0.70) for all-cause mortality (Ptrend<0.05), and was 0.53 (0.32,0.96), 0.48 (0.32,0.72) and 0.63 (0.41,0.97) for CVD mortality (Ptrend<0.05). The subgroup analyses showed that different isomeric forms of lycopene showed varied associations with CVD and all-cause mortality based on age, drinking status, history of hypertension and diabetes. Conclusions: Serum lycopene concentration was significantly associated with the risk of CVD and all-cause mortality. Cis-lycopene had a U-shaped relationship with mortality, while trans-lycopene had an inverse relationship with it.

Associations of serum carotenoids with asthma and mortality in the US adults

Objective

This study was to investigate the association between serum carotenoid levels and the prevalence of asthma, as well as the relationship between serum carotenoid levels and the risk of mortality among individuals with asthma.

Methods

Data on five serum carotenoids (α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin, and lycopene) were obtained from the National Health and Nutrition Examination Survey (NHANES) 2001-2006. Mortality data was extracted from the pertinent mortality records within the NHANES database, up to December 31, 2019. Logistic regression analysis was employed to investigate the association between serum carotenoid concentrations and asthma prevalence. Cox proportional hazards models were used to investigate the connection between serum carotenoids and mortality rates in asthma individuals.

Results

Among the study population, 1569 (12.63 %) individuals were diagnosed with asthma, while 25.01 % of asthma patients died within a median follow-up duration of 15.5 (13.8-17.3) years. After controlling for all other variables, greater serum levels of certain carotenoids, such asα-carotene, β-carotene, β-cryptoxanthin, and lutein/zeaxanthin, were found to be substantially linked with a decreased prevalence of asthma. Furthermore, persons with asthma who had greater levels of serum carotenoids in the fourth quartile had a significantly lower risk of all-cause death compared to those in the first quartile. Specifically, the presence of α-carotene, β-cryptoxanthin, and lutein/zeaxanthin was associated with reductions in all-cause mortality by 45 % (HR = 0.55 [0.36-0.84], Ptrend = 0.002), 38 % (HR = 0.62 [0.42-0.92], Ptrend = 0.004), and 45 % (HR = 0.55 [0.41-0.73], Ptrend<0.001), respectively. The above relationships are mostly linear and remain robust in sensitivity analyses.

Conclusions

Our findings indicate that higher serum carotenoids are related with a reduced likelihood of mortality in asthmatic individuals.

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.

Untapping the protective role of carotenoids against respiratory diseases

BACKGROUND

Recent studies revealed a substantial role of carotenoids to treat respiratory diseases. This review aimed to give an updated overview of the investigational evidence on the preventive properties of carotenoids against respiratory diseases both in vitro and in vivo along with their pathophysiology and mechanisms of action.

HYPOTHESIS

Carotenoids as a potential therapeutic class of bioactive compounds to treat respiratory diseases.

RESULTS

Carotenoids such as β-carotene, lycopene, crocin, bixin, lutein, and astaxanthin show beneficial effects against chronic lung diseases (e.g., asthma, emphysema, fibrosis, COPD, acute lung injury, and lung cancer). Moreover, in vitro and in vivo studies also supported the preventive role of carotenoids. These carotenoids showed a beneficial role by activation of the NRF2/HO-1 pathway and inhibition of the NF-кB, MAPK, JAK/STAT-3, and PI3K/AKT pathways. Additionally, epidemiological studies also showed that dietary intake of carotenoids lowers the risk of lung diseases.

CONCLUSION

Carotenoids may be used as drugs or can be given in combination with other drugs to prevent and treat respiratory diseases. Although in vitro and in vivo results are encouraging, further well-conducted randomized clinical trials are required to approve carotenoids as drug candidates.

Serum antioxidant vitamins and respiratory morbidity and mortality: a pooled analysis

BACKGROUND

Oxidative stress plays a key role in the pathogenesis of respiratory diseases; however, studies on antioxidant vitamins and respiratory outcomes have been conflicting. We evaluated whether lower serum levels of vitamins A, C, D, and E are associated with respiratory morbidity and mortality in the U.S. adult population.

METHODS

We conducted a pooled analysis of data from the 1988-1994 and 1999-2006 National Health and Nutrition Examination Survey (participants aged ≥ 20 years). We estimated covariate-adjusted odds ratios (aOR) per interquartile decrease in each serum vitamin level to quantify associations with respiratory morbidity, and covariate-adjusted hazard ratios (aHR) to quantify associations with respiratory mortality assessed prospectively through 2015. Vitamin supplementation and smoking were evaluated as potential effect modifiers.

RESULTS

Lower serum vitamin C increased the odds of wheeze among all participants (overall aOR: 1.08, 95% CI: 1.01-1.16). Among smokers, lower serum α-tocopherol vitamin E increased the odds of wheeze (aOR: 1.11, 95% CI: 1.04-1.19) and chronic bronchitis/emphysema (aOR: 1.13, 95% CI: 1.03-1.24). Conversely, lower serum γ-tocopherol vitamin E was associated with lower odds of wheeze and chronic bronchitis/emphysema (overall aORs: 0.85, 95% CI: 0.79-0.92 and 0.85, 95% CI: 0.76-0.95, respectively). Lower serum vitamin C was associated with increased chronic lower respiratory disease (CLRD) mortality in all participants (overall aHR: 1.27, 95% CI: 1.07-1.51), whereas lower serum 25-hydroxyvitamin D (25-OHD) tended to increase mortality from CLRD and influenza/pneumonia among smokers (aHR range: 1.33-1.75). Mortality from influenza/ pneumonia increased with decreasing serum vitamin A levels in all participants (overall aHR: 1.21, 95% CI: 0.99-1.48). In pooled analysis, vitamin C deficiency and 25-OHD insufficiency were associated with mortality from influenza/pneumonia, increasing mortality risk up to twofold.

CONCLUSIONS

Our analysis of nationally representative data on over 34,000 participants showed that lower serum levels of vitamins A, C, D, and α-tocopherol vitamin E are associated with increased respiratory morbidity and/or mortality in U.S. adults. The results underscore the importance of antioxidant vitamins in respiratory health.

Antioxidants in smokers

Cigarette smoke (CS) is likely the most common preventable cause of human morbidity and mortality worldwide. Consequently, inexpensive interventional strategies for preventing CS-related diseases would positively impact health systems. Inhaled CS is a powerful inflammatory stimulus and produces a shift in the normal balance between antioxidants and oxidants, inducing oxidative stress in both the respiratory system and throughout the body. This enduring and systemic pro-oxidative state within the body is reflected by increased levels of oxidative stress and inflammation biomarkers seen in smokers. Smokers might benefit from consuming antioxidant supplements, or a diet rich in fruit and vegetables, which can reduce the CS-related oxidative stress. This review provides an overview of the plasma profile of antioxidants observable in smokers and examines the heterogeneous literature to elucidate and discuss the effectiveness of interventional strategies based on antioxidant supplements or an antioxidant-rich diet to improve the health of smokers. An antioxidant-rich diet can provide an easy-to-implement and cost-effective preventative strategy to reduce the risk of CS-related diseases, thus being one of the simplest ways for smokers to stay in good health for as long as possible. The health benefits attributable to the intake of antioxidants have been observed predominantly when these have been consumed within their natural food matrices in an optimal antioxidant-rich diet, while these preventive effects are rarely achieved with the intake of individual antioxidants, even at high doses.

Total Antioxidant Status in Stable Chronic Obstructive Pulmonary Disease

Objective

This study evaluates the total antioxidant status (TAS) in plasma of stable chronic obstructive pulmonary disease (COPD) patients. Earlier studies of their relationship showed inconsistent findings.

Patients and Methods

We compared TAS between 90 COPD patients and 30 age- and sex-matched controls (mean age 67 ± 7.9, 87 males and 33 females) according to airway obstruction severity, gender, smoking status (current/ former/ non-smoker), smoking-dose, the number of exacerbations in the previous year, nutritional status and hypercapnia.

Results

There were no differences in pack-years between COPD and controls, neither in COPD groups. The median time from the last exacerbation was 5 months (interquartile range 3-8.3). TAS was significant higher in COPD than controls (1.68 [1.55-1.80] versus 1.59 [1.54-1.68], respectively; P = 0.03). TAS was significantly higher in COPD men than women (1.7 [1.6-1.8] versus 1.57 [1.5-1.7], respectively; P = 0.001). In COPD groups, there were no significant differences between the severity of airway obstruction and TAS. We found significant positive correlation between pack-years and TAS in all participants (Rho = 0.429, P = 0.004) and COPD patients (Rho = 0.359, P = 0.02), but not in controls. TAS was a significant predictor of COPD (β = 3.26; P = 0.04; OR = 26.01; 95% CI: 1.20 to 570.8). We failed to find significant differences between TAS and smoking status, frequency of exacerbations in the previous year, nutritional status and hypercapnia.

Conclusion

TAS was a significant predictor of COPD. TAS was a significantly higher in stable COPD than controls, higher in COPD men than women, but there was no significant correlation between TAS and the airway obstruction severity. Our results suggest that it could be appropriate to include the time from the last exacerbation in the oxidant-antioxidant balance analysis of COPD patients.

Plasma vitamin C concentrations and risk of incident respiratory diseases and mortality in the European Prospective Investigation into Cancer-Norfolk population-based cohort study

BACKGROUND/OBJECTIVES

Cancerous and non-cancerous respiratory diseases are common and contribute significantly to global disease burden. We aim to quantify the association between plasma vitamin C concentrations as an indicator of high fruit and vegetable consumption and the risk of incident respiratory diseases and associated mortality in a general population.

SUBJECTS/METHODS

Nineteen thousand three hundred and fifty-seven men and women aged 40-79 years without prevalent respiratory diseases at the baseline (1993-1997) and participating in the European Prospective Investigation into Cancer (EPIC)-Norfolk study in the United Kingdom were followed through March 2015 for both incidence and mortality from respiratory diseases.

RESULTS

There were a total of 3914 incident events and 407 deaths due to any respiratory diseases (excluding lung cancers), 367 incident lung cancers and 280 lung cancer deaths during the follow-up (total person-years >300,000 years). Cox's proportional hazards models showed that persons in the top quartiles of baseline plasma vitamin C concentrations had a 43% lower risk of lung cancer (hazard ratio (HR) 0.57; 95% confidence interval (CI): 0.41-0.81) than did those in the bottom quartile, independently of potential confounders. The results are similar for any non-cancerous respiratory diseases (HR 0.85; 0.77-0.95), including chronic respiratory diseases (HR 0.81; 0.69-0.96) and pneumonia (HR 0.70; 0.59-0.83). The corresponding values for mortality were 0.54 (0.35-0.81), 0.81 (0.59-1.12), 0.85 (0.44-1.66) and 0.61 (0.37-1.01), respectively. Confining analyses to non-smokers showed 42% and 53% risk reduction of non-smoking-related lung cancer incidence and death.

CONCLUSIONS

Higher levels of vitamin C concentrations as a marker of high fruit and vegetable consumption reduces the risk of cancerous and non-cancerous respiratory illnesses including non-smoking-related cancer incidence and deaths.

Effects of dietary antioxidant vitamins on lung functions according to gender and smoking status in Korea: a population-based cross-sectional study

OBJECTIVE

Cigarette smoke-induced oxidative stress plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Dietary antioxidants are thought to prevent smoke-induced oxidative damage. The aim of this study was to investigate associations between lung function and the consumption of antioxidant vitamins in Korean adults.

METHODS

In total, 21 148 participants from the Korean National Health and Nutrition Examination Survey (2007-2014) were divided into four groups based on smoking history and gender. Multivariate regression models were used to evaluate associations between lung function and intake of dietary antioxidants.

RESULTS

Subjects in the highest intake quintile (Q5) of vitamin A, carotene and vitamin C intake had mean forced expiratory volume in 1 s (FEV₁) measurements that were 30 mL, 32 mL and 36 mL higher than those of individuals in the lowest intake quintile (Q1), respectively (p for trend; p=0.008, p=0.010 and p<0.001, respectively). The risks of COPD for male smokers in Q1 increased 7.60-fold (95% CI 5.92 to 9.76), 7.16-fold (95% CI 5.58 to 9.19) and 7.79-fold (95% CI 6.12 to 9.92), for vitamin A, carotene and vitamin C, respectively, compared with those of female non-smokers in Q5. Among patients with COPD, men who smoked >20 pack-years had mean FEV₁ measurements that were 192 mL, 149 mL and 177 mL higher than those of patients in Q1 (p for trend; p=0.018, p=0.024 and p=0.043, for vitamin A, carotene and vitamin C, respectively).

CONCLUSIONS

These findings indicate that the influence of antioxidant vitamins on lung function depends on gender and smoking status in the Korean COPD population.

Dietary antioxidants and 10-year lung function decline in adults from the ECRHS survey

The relationship between lung function decline and dietary antioxidants over 10 years in adults from three European countries was investigated.In 2002, adults from three participating countries of the European Community Respiratory Health Survey (ECRHS) answered a questionnaire and underwent spirometry (forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC)), which were repeated 10 years later. Dietary intake was estimated at baseline with food frequency questionnaires (FFQ). Associations between annual lung function decline (mL) and diet (tertiles) were examined with multivariable analyses. Simes' procedure was applied to control for multiple testing.A total of 680 individuals (baseline mean age 43.8±6.6 years) were included. A per-tertile increase in apple and banana intake was associated with a 3.59 mL·year-1 (95% CI 0.40, 7.68) and 3.69 mL·year-1 (95% CI 0.25, 7.14) slower decline in FEV1 and FVC, respectively. Tomato intake was also associated with a slower decline in FVC (4.5 mL·year-1; 95% CI 1.28, 8.02). Only the association with tomato intake remained statistically significant after the Simes' procedure was performed. Subgroup analyses showed that apple, banana and tomato intake were all associated with a slower decline in FVC in ex-smokers.Intake of fruits and tomatoes might delay lung function decline in adults, particularly in ex-smokers.

Higher levels of serum lycopene are associated with reduced mortality in individuals with metabolic syndrome

Metabolic syndrome increases the risk of mortality. Increased oxidative stress and inflammation may play an important role in the high mortality of individuals with metabolic syndrome. Previous studies have suggested that lycopene intake might be related to the reduced oxidative stress and decreased inflammation. Using data from the National Health and Nutrition Examination Survey, we examined the hypothesis that lycopene is associated with mortality among individuals with metabolic syndrome. A total of 2499 participants 20 years and older with metabolic syndrome were divided into 3 groups based on their serum concentration of lycopene using the tertile rank method. The National Health and Nutrition Examination Survey from years 2001 to 2006 was linked to the mortality file for mortality follow-up data through December 31, 2011, to determine the mortality rate and hazard ratios (HR) for the 3 serum lycopene concentration groups. The mean survival time was significantly higher in the group with the highest serum lycopene concentration (120.6 months; 95% confidence interval [CI], 118.8-122.3) and the medium group (116.3 months; 95% CI, 115.2-117.4), compared with the group with lowest serum lycopene concentration (107.4 months; 95% CI, 106.5-108.3). After adjusting for possible confounding factors, participants in the highest (HR, 0.61; P = .0113) and in the second highest (HR, 0.67; P = .0497) serum lycopene concentration groups showed significantly lower HRs of mortality when compared with participants in the lower serum lycopene concentration. The data suggest that higher serum lycopene concentration has a significant association with the reduced risk of mortality among individuals with metabolic syndrome.

Antioxidant nutrients in plasma of Japanese patients with chronic obstructive pulmonary disease, asthma-COPD overlap syndrome and bronchial asthma

BACKGROUND

Few studies to date have investigated the antioxidant nutrients such as vitamin C (ascorbic acid), vitamin E (α-tocopherol), retinol and carotenoids in plasma from patients with pulmonary disease in Japan. To clarify the role of antioxidant nutrients such as vitamin C, vitamin E, retinol and various carotenoids in plasma of Japanese patients with chronic obstructive lung diseases (COPD), asthma-COPD overlap syndrome (ACOS) and/or bronchial asthma (BA), we compared to healthy elderly controls.

METHODS

Ascorbic acid (AA), carotenoids (lutein, zeaxanthin, β-cryptoxanthin, α-carotene, β-carotene and lycopene), retinol and α-tocopherol levels in plasma were determined by using a high performance liquid chromatography. Reduced glutathione (GSH), oxidised glutathione (GSSG) in whole blood and urinary 8-OHdG were also determined.

RESULTS

Plasma AA level of COPD subjects was significantly lower than that of healthy elderly people. Conversely, ACOS and BA subjects showed no significant difference from healthy elderly people. Moreover, plasma lycopene and total carotenoid levels and GSH content in blood were significantly lower in COPD subjects than these in healthy elderly people. However, other redox markers such as GSSG, GSH/GSSG ratio and urinary 8-OHdG found no significant differences between COPD, ACOS and BA compared to healthy elderly people.

CONCLUSIONS

These results suggested that COPD of Japanese patients may develop partly because of oxidative stress derived from a shortage of antioxidant nutrients, especially of AA and lycopene, as well as GSH while this may not be the case in both ACOS and BA.