Dietary antioxidants and forced expiratory volume in 1 s decline: the Health, Aging and Body Composition study

Association between dietary intake of live microbes and chronic obstructive pulmonary disease: a cross-sectional study of NHANES 2007-2012

BACKGROUND

Diet plays a crucial role in intervening in the development of chronic obstructive pulmonary disease (COPD), yet previous studies have not investigated the impact of dietary intake of live microbes on COPD. This study aims to assess the relationship between the two.

METHODS

Participants from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2012 were selected. The exposure variable was the estimated intake of live microbes in the diet, categorized into low, medium, and high groups. The outcome variable was COPD. A multivariable logistic regression model was used to assess the relationship between estimated dietary intake of live microbes and the risk of COPD.

RESULTS

In the fully adjusted multiple logistic regression model, participants with moderate and high dietary intake of live microbes showed a negative association with the prevalence of COPD compared to those with low estimated intake, with reductions of 38% (OR, 0.62; 95% CI: 0.39-0.99, P < 0.05) and 44% (OR, 0.56; 95% CI: 0.34-0.92, P < 0.05) respectively. Additionally, subgroup analysis results remained stable with no observed interactions.

CONCLUSION

Our study suggests a negative association between higher dietary live microbe intake and the risk of COPD among adults in the United States.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT00005154 First Posted date 26/05/2000(retrospectively registered).

Association between dietary niacin intake and lung function among American adults: A cross-sectional analysis from national health and nutrition examination survey, 2007-2012

Background

The pathogenesis of pulmonary senescence involves immune system dysregulation, oxidative stress, and mitochondrial dysfunction. The effects on lung function of niacin, an essential coenzyme involved in mitochondrial energy metabolism with known antioxidant properties, are poorly understood.

Methods

This cross-sectional study used data from the 2007-2012 National Health and Nutrition Examination Survey, including spirometry data and niacin intake information of 9706 adults. This study investigated various spirometry measures, such as forced expiratory volume in 1 s, forced vital capacity, pulse expiratory flow, (forced expiratory volume in 1 s)/(forced vital capacity)ratio, and predicted forced expiratory volume in 1 s and forced vital capacity percentages. Additionally, a secondary analysis was conducted using Global Initiative for Chronic Obstructive Lung Disease and chronic obstructive pulmonary disease. Foundation Spirometry Grade criteria to assess the relationship between niacin intake, airflow limitation, and obstruction. Multivariate regression models were used to adjust for relevant covariates.

Results

The study included 9706 U S. adults (4788 men and 4918 women) with a median age of 46.2 years. After adjusting for relevant factors, a positive correlation was observed between niacin intake and lung function. Compared to the lowest quintile of niacin intake (Q1, ≤14.5 mg/day), individuals in the highest quintile (Q5, >34.5 mg/day) exhibited significant increases in lung function parameters, including forced expiratory volume in 1s (69.84 mL, p = 0.003), pulse expiratory flow (254.48 mL, p < 0.001), (forced expiratory volume in 1 s)/(forced vital capacity)(0.01, p = 0.041), percent predicted forced expiratory volume in 1 s(2.05, p = 0.002), and percent predicted forced vital capacity(1.29, p = 0.042).Subset analyses of individuals with spirometry-defined airflow obstruction showed associations of high niacin intake with significantly improved forced expiratory volume, pulse expiratory flow, and percent predicted pulse expiratory flow and an interaction among race, education, and smoking status with respect to the relationship between niacin intake and lung function parameters.

Conclusions

Higher niacin intake was associated with increased measures of lung function. A diet rich in niacin-containing foods may play a role in improving lung health.

The Role of Nutrition in the Development and Management of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a prevalent lung condition associated with significant morbidity and mortality. The management of COPD classically involves pulmonary rehabilitation, bronchodilators, and corticosteroids. An aspect of COPD management that is currently lacking in the literature is nutritional management, despite the prevalence of inadequate nutritional status in patients with COPD. In addition, certain nutritional imbalances have been reported to increase the risk of COPD development. This review summarizes the current literature on the role diet and nutrients may play in the risk and management of COPD development.

Consumption of Berries and Flavonoids in Relation to Mortality in NHANES, 1999-2014

BACKGROUND

Berries are foods that are abundant in nutrients, especially flavonoids, that promote good health; however, the effects of total berries on mortality are not well characterized.

OBJECTIVES

We evaluated whether intakes of total berries and specific berry types including blueberries, strawberries, cranberries, flavonoids, and subclasses of flavonoids (anthocyanidins, flavonols, flavones, flavanones, flavan-3-ols, and isoflavones) in relation to mortality risk in United States adults.

METHODS

A nationally representative sample of the United States adult population was obtained using data from the 1994-2014 NHANES (n = 37,232). Intake of berries was estimated using 24-h food recalls (1999-2014), and flavonoids intake was calculated using the matched USDA's expanded flavonoid database. Mortality outcomes based on 8 y of follow-up were obtained using linked death certificates.

RESULTS

Compared with nonconsumers, the multivariable-adjusted hazard ratio for all-cause mortality was 0.79 [95% confidence intervals (CI): 0.7, 0.89] for any berry consumption, 0.86 (0.75, 0.99) for strawberry consumption 0.79 (0.66, 0.95) for blueberries, and 0.69 (0.51, 0.93) for cranberries. Compared with the lower median of intake, risk of all-cause mortality for greater intake was 0.85 (0.74, 0.97) for total flavonoids, 0.85 (0.76, 0.95) for anthocyanidins, 0.9 (0.82, 0.99) for flavan-3-ols, 0.89 (0.79, 0.9) for flavanols, and 0.89 (0.8, 0.99) for flavones. There was a dose-response relationship between intakes of total flavonoids, anthocyanidins, and flavones and lower all-cause mortality risks (Ptrend < 0.05). Risk for cardiometabolic mortality was 0.75 (0.58, 0.98) for berry consumers and 0.49 (0.25, 0.98) for cranberry consumers. For respiratory disease mortality, risk was 0.41 (0.2, 0.86), compared with blueberry nonconsumers.

CONCLUSION

Higher intakes of berries and flavonoids were associated with a lower overall mortality risk in adult Americans. Few adults regularly consume berries, indicating that increased intake of berries and flavonoid-rich foods may be beneficial to health.

Mediterranean Diet and Lung Function in Adults Current Smokers: A Cross-Sectional Analysis in the MEDISTAR Project

BACKGROUND

Previous studies have shown that adherence to the Mediterranean Diet (MeDi) has a positive impact on lung function in subjects with lung disease. In subjects free of respiratory diseases, but at risk, this association is not yet well established.

METHODS

Based on the reference data from the MEDISTAR clinical trial (Mediterranean Diet and Smoking in Tarragona and Reus; ISRCTN 03.362.372), an observational study was conducted with 403 middle-aged smokers without lung disease, treated at 20 centres of primary care in Tarragona (Catalonia, Spain). The degree of MeDi adherence was evaluated according to a 14-item questionnaire, and adherence was defined in three groups (low, medium, and high). Lung function were assessed by forced spirometry. Logistic regression and linear regression models were used to analyse the association between adherence to the MeDi and the presence of ventilatory defects.

RESULTS

Globally, the pulmonary alteration prevalence (impaired FEV1 and/or FVC) was 28.8%, although it was lower in participants with medium and high adherence to the MeDi, compared to those with a low score (24.2% and 27.4% vs. 38.5%, p = 0.004). Logistic regression models showed a significant and independent association between medium and high adherence to the MeDi and the presence of altered lung patterns (OR 0.467 [95%CI 0.266, 0.820] and 0.552 [95%CI 0.313, 0.973], respectively).

CONCLUSIONS

MeDi adherence is inversely associated with the risk impaired lung function. These results indicate that healthy diet behaviours can be modifiable risk factors to protect lung function and reinforce the possibility of a nutritional intervention to increase adherence to MeDi, in addition to promoting smoking cessation.

Lung Cancer Risk in Men and Compliance with the 2018 WCRF/AICR Cancer Prevention Recommendations

Lung cancer is the most common and deadly form of cancer worldwide, especially in men. The 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) updated cancer prevention recommendations, and a standard scoring system (2018 WCRF/AICR Score) was published. The purpose of this study was to develop the adapted version of the 2018 WCRF/AICR Score with respect to lung cancer prevention recommendation (Ad-LC WCRF/AICR Score) and to examine the association between lung cancer risk in men and the Ad-LC WCRF/AICR Score as well as its single components. A case-control study was conducted among 439 men aged 45-80 years (187 controls, 252 primary lung cancer cases). Lifestyle and dietary data were collected with a questionnaire including the 62-item food frequency questionnaire (FFQ-6^®). The Ad-LC WCRF/AICR Score was used as a categorized and continuous variable. Odds ratios (ORs) and 95% confidence intervals (95% CIs) for lung cancer risk were calculated with the partly and fully adjusted model. One component of the score was independently associated with a lower risk of lung cancer in men, regardless of the set of confounders used. In the fully adjusted model following the recommendation "Limit smoking" was associated with a lower risk of lung cancer-in the never smokers by 87% (OR: 0.13; 95% CI: 0.04-0.37; p = 0.0002) and in the moderate smokers by 45% (OR: 0.55; 95% CI: 0.33-0.91; p = 0.0189) compared with the heavy smokers as a reference. By adding the single components making up the Ad-LC WCRF/AICR Score, the combination of three components or more, reducing the risk of lung cancer compared to lower compliance as a reference by 45% to 78% and by 39% to 66% for intermediate compliance (except two models out of seven) and higher compliance, respectively. In the fully adjusted model, the risk of lung cancer for the total Ad-LC WCRF/AICR Score was lower by 47% (OR: 0.53; 95% CI: 0.32-0.88; p = 0.0129) in higher compliance with the score compared to those with the lower compliance. Each one-point increase in the Ad-LC WCRF/AICR Score reduced lung cancer risk by 34% (OR: 0.66; 95% CI: 0.45-0.95; p = 0.0267). The results support previous evidence that limiting smoking reduces the risk of lung cancer in men. It also provides an insight into cancer research by showing that following the combined 2018 cancer prevention recommendations related to diet, lifestyle and body fatness was associated with a lower risk of lung cancer in men.

Theophylline Extracted from Fu Brick Tea Affects the Metabolism of Preadipocytes and Body Fat in Mice as a Pancreatic Lipase Inhibitor

The dramatic increase in obesity is putting people under increasing pressure. Lipase inhibitors, as a kind of effective anti-obesity drug, have attracted more and more researchers’ attention in recent years because of their advantages of acting on the intestinal tract and having no side effects on the central nervous system. In this study, lipase inhibitor Fu Brick Theophylline (FBT) was screened based on enzyme molecular dynamics, and the inhibition mechanism of lipase inhibitors on obesity was analyzed and discussed at the cellular level and animal model level. We found that FBT had high inhibition effects of lipase with an IC₅₀ of 1.02~0.03 μg/mL. Firstly, the laboratory used 3T3-L1 proadipocytes as models, flow cytometry was used to detect the effects of FBT on the cycle, apoptosis and intracellular ROS activity of proadipocytes. To study the contents of triglyceride, total cholesterol, related metabolites and related gene and protein expression in adipocytes. The results showed that FBT could reduce ROS production and inflammatory factor mRNA expression during cell differentiation. Secondly, by establishing the animal model of high-fat feed ob nutritional obese mice, the morphological observation and gene expression analysis of body weight, fat rate, adipocyte and hepatocyte metabolism of FBT obese mice were further discussed. It was proven that FBT can effectively reduce the degree of fatty liver, prevent liver fibrosis and fat accumulation, and improve the damage of mitochondrial membrane structure. This study provides a theoretical basis for the screening and clinical treatment of lipase inhibitors.

Nutriepigenomics and chronic obstructive pulmonary disease: potential role of dietary and epigenetics factors in disease development and management

Over recent decades, a number of studies have revealed the possible role of different types of diets, as well as the nutritional elements they are made up of, in the pathogenesis of chronic obstructive pulmonary disease (COPD). To date, dietary factors have been identified to play a role in the prevention of COPD, with evidence from antioxidant nutrients, vitamins, and fiber intake. Additionally, certain dietary patterns such as the Mediterranean diet, together with other Western diets, provide evidence of the influence on COPD development, promoting lung health through nutritional approaches, and giving us an opportunity for intervention. The effect of diet on COPD is conveyed by 3 mechanisms: regulation of inflammation, oxidative stress, and carbon dioxide produced/oxygen intake. Current advances have begun to highlight the possible role of diet in modifying gene expression in certain individuals that predisposes them to COPD through epigenetic modifications. The relation between dietary intake and epigenetic factors has therefore outlined nutriepigenomics as a possible missing link in the relation between environmental exposure to smoke and the appearance of a subsequent chronic bronchial obstruction. This review summarizes the evidence regarding the influence of dietary patterns and nutrients and epigenetic regulatory mechanisms on COPD development and prevention with the aim of encouraging clinical research on the impact of dietary modifications on COPD-related clinical outcomes. This review highlights the importance of proposing and carrying out future studies focused on the modulating effects of certain nutrients on epigenetic changes in patients with specific COPD phenotypes (bronchiectasis, emphysema, asthma/COPD, chronic bronchitis), and their individual responses to cigarette smoking, environmental pollution, or other noxious particles. The objectives of these future studies must be directed to the development of novel therapeutic approaches and personalized management of COPD.

Fruit, vegetable and dietary antioxidant intake in school age, respiratory health up to young adulthood

BACKGROUND

Dietary antioxidants may protect the lung against oxidative damage and prevent chronic respiratory disease. We aimed to investigate fruit, vegetable and antioxidant intake (measured as total antioxidant capacity, TAC) at age 8 years in relation to asthma and lung function up to 24 years.

METHODS

In this study of 2506 participants from a Swedish birth cohort, diet was assessed using food frequency questionnaires. Information on asthma was collected by questionnaires, and lung function was measured by spirometry at ages 8, 16 and 24 years. Generalized estimating equations and mixed effect models were used to assess overall, age- and sex-specific associations.

RESULTS

After adjustment for confounders, a higher fruit intake at age 8 years was associated with a tendency to reduced odds of prevalent asthma (T3 vs. T1, OR 0.78; 95% CI 0.60-1.01, p-trend .083), with reduced odds of incident asthma and increased odds of remittent asthma (≥median, OR 0.76; 95% CI 0.58-0.99 and OR 1.60; 95% CI 1.05-2.42, respectively) up to 24 years. Comparable, but non-significant, odds ratios were observed in analyses of long-term fruit intake (mean intake at ages 8 and 16 years). In contrast, no association was observed with vegetable intake. A higher dietary TAC (T3 vs. T1) at 8 years was associated with reduced odds of prevalent asthma (OR 0.73; 95% CI 0.58-0.93, p-trend .010) and improved lung function development (FEV₁ -z +0.11; 95% CI 0.01-0.21, p-trend .036 and FVC-z +0.09; 95% CI -0.01-0.20, p-trend .072) up to 24 years. Associations were more pronounced among males, and regarding asthma, participants sensitized to aeroallergens.

CONCLUSIONS

Antioxidant intake in school age may improve asthma and lung function up to young adulthood. Although our results should be interpreted with caution, they emphasize the importance of following current dietary guidelines regarding consumption of antioxidant-rich foods as part of a balanced diet.

Nutrition as a modifiable factor in the onset and progression of pulmonary function impairment in COPD: a systematic review

CONTEXT

Chronic obstructive lung disease (COPD) is a progressive lung disease characterized by persistent airflow limitation. An increasing amount of evidence suggests an effect of dietary quality on the risk of COPD in the general population and pulmonary function decline in patients with COPD.

OBJECTIVE

The association of dietary intake and nutrient status with COPD risk and onset, as well as pulmonary function decline (change in forced expiratory volume in 1 second, forced vital capacity, or the ratio of the former to the latter) in patients with COPD was investigated in this systematic review.

DATA SOURCES

The PubMed database was searched by combining terms of pulmonary function or COPD with diet, nutrient status, or nutritional supplementation.

DATA EXTRACTION

Original studies and systematic reviews and meta-analyses were included. Articles obtained were independently screened for relevance on the bases of title and abstract by 2 researchers. Eventually, 89 articles were included in the analysis.

RESULTS

The unhealthy Western-style diet is associated with an increased risk of COPD and an accelerated decline of pulmonary function. Intake of fruit, vegetables, dietary fibers, vitamins C and E, polyphenols, and β-carotene were individually associated with lower COPD risk, whereas consumption of processed meat was associated with higher COPD risk. Data on the effect of dietary quality on pulmonary function decline in patients with COPD are limited and inconsistent. Strong evidence for beneficial effects on pulmonary function decline was found only for vitamin D supplementation.

CONCLUSION

Considering the increasing burden of COPD, more attention should be given to dietary quality as a modifiable factor in disease development and progression in patients with COPD.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021240183.

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.

Fruit and Vegetable Intake and Mortality: Results From 2 Prospective Cohort Studies of US Men and Women and a Meta-Analysis of 26 Cohort Studies

BACKGROUND

The optimal intake levels of fruit and vegetables for maintaining long-term health are uncertain.

METHODS

We followed 66 719 women from the Nurses' Health Study (1984-2014) and 42 016 men from the Health Professionals Follow-up Study (1986-2014) who were free from cardiovascular disease (CVD), cancer, and diabetes at baseline. Diet was assessed using a validated semiquantitative food frequency questionnaire at baseline and updated every 2 to 4 years. We also conducted a dose-response meta-analysis, including results from our 2 cohorts and 24 other prospective cohort studies.

RESULTS

We documented 33 898 deaths during the follow-up. After adjustment for known and suspected confounding variables and risk factors, we observed nonlinear inverse associations of fruit and vegetable intake with total mortality and cause-specific mortality attributable to cancer, CVD, and respiratory disease (all Pnonlinear<0.001). Intake of ≈5 servings per day of fruit and vegetables, or 2 servings of fruit and 3 servings of vegetables, was associated with the lowest mortality, and above that level, higher intake was not associated with additional risk reduction. In comparison with the reference level (2 servings/d), daily intake of 5 servings of fruit and vegetables was associated with hazard ratios (95% CI) of 0.87 (0.85-0.90) for total mortality, 0.88 (0.83-0.94) for CVD mortality, 0.90 (0.86-0.95) for cancer mortality, and 0.65 (0.59-0.72) for respiratory disease mortality. The dose-response meta-analysis that included 145 015 deaths accrued in 1 892 885 participants yielded similar results (summary risk ratio of mortality for 5 servings/d=0.87 [95% CI, 0.85-0.88]; Pnonlinear<0.001). Higher intakes of most subgroups of fruits and vegetables were associated with lower mortality, with the exception of starchy vegetables such as peas and corn. Intakes of fruit juices and potatoes were not associated with total and cause-specific mortality.

CONCLUSIONS

Higher intakes of fruit and vegetables were associated with lower mortality; the risk reduction plateaued at ≈5 servings of fruit and vegetables per day. These findings support current dietary recommendations to increase intake of fruits and vegetables, but not fruit juices and potatoes.

The Impact of Changes in the Intake of Fiber and Antioxidants on the Development of Chronic Obstructive Pulmonary Disease

Diet is a health-related factor that can modify lung function. This study hypothesized that the change in age-related dietary intake affects lung function. The subjects who undertook a dietary assessment and spirometry in 2012 and 2017, were retrospectively collected in a health screening center. Dietary intakes were directly evaluated using food frequency questionnaires (FFQ) administered by trained dietitians and were compared at the baseline (2012) and 5-year follow-up (2017). A forced expiratory volume in one second (FEV₁)/forced vital capacity (FVC) value below 0.70 was defined as airflow limitation. Logistic regression models were used to estimate the odds ratio (ORs) adjusted for potential confounders. A total of 1439 subjects with normal spirometry were enrolled. New airflow limitations were detected in 48 subjects (3.3%) at the 5-year follow-up, including 41 (85.4%) men and 11 (22.9%) current smokers. After adjusting for age, sex, smoking history, and baseline FEV1/FVC, the odd ratios (OR) for new airflow limitation in fiber, vitamin C, and folic acid per 10% decrease in daily recommended requirement were 2.714 (95% confidence interval (CI), 1.538–4.807; p = 0.001), 1.083 (95% CI: 1.020–1.149; p = 0.007), and 1.495 (95% CI: 1.172–1.913; p = 0.001), respectively. A decreased intake of dietary fiber, vitamin C, and folic acid is associated with a newly developed airflow limitation.

Adherence to Prudent and Mediterranean Dietary Patterns Is Inversely Associated with Lung Cancer in Moderate But Not Heavy Male Polish Smokers: A Case-Control Study

Lung cancer is the most commonly diagnosed cancer in men worldwide. Studies regarding dietary patterns (DPs) and lung cancer are limited, with results remaining inconclusive, and the association of DPs with lung cancer in smokers is unclear. This study analyzed the associations between DPs, including the Polish-adapted Mediterranean diet (Polish-aMED) score, and lung cancer risk in Polish adult male smokers. This case-control study involved 439 men aged 45–80 years from northeastern Poland, including 187 newly diagnosed lung cancer cases. Dietary data was collected with a 62-item food frequency questionnaire (FFQ-6). Two approaches were applied to identify dietary patterns. The Polish-aMED score was calculated (hypothesis-driven approach) and a principal component analysis (PCA) was used to identify PCA-driven DPs (data-driven approach). A logistic regression analysis was performed to estimate the odds ratio (OR) and 95% confidence interval (95% CI) of the lung cancer risk associated with the adherence to DPs overall as well as for moderate (2.5–11 pack-years) and heavy (>11 pack-years) smokers. Among moderate smokers, the risk of lung cancer was lower by 41% (OR: 0.59; 95% CI: 0.39–0.90; p < 0.05; adjusted model) in the higher adherence to the prudent DP when compared to the lower adherence, and by 66% (OR: 0.34; 95% CI: 0.15–0.76; p < 0.05; adjusted model) in the high adherence (7–9 points) to the Polish-aMED score when compared to the low adherence (0–3 points). No significant association between the westernized traditional DP or the sweet dairy DP and lung cancer was revealed. In conclusion, the current study suggests that pro-healthy dietary patterns, including the Mediterranean pattern, may favour lower risk of lung cancer in moderate smokers, although it was not confirmed in heavy smokers.

Higher Blood Uric Acid in Female Humans and Mice as a Protective Factor against Pathophysiological Decline of Lung Function

The oxidant/antioxidant imbalance plays a pivotal role in the lung. Uric acid (UA), an endogenous antioxidant, is highly present in lung tissue, however, its impact on lung function under pathophysiological conditions remains unknown. In this work, pharmacological and genetic inhibition of UA metabolism in experimental mouse models of acute and chronic obstructive pulmonary disease (COPD) revealed that increased plasma UA levels improved emphysematous phenotype and lung dysfunction in accordance with reduced oxidative stress specifically in female but not in male mice, despite no impact of plasma UA induction on the pulmonary phenotypes in nondiseased mice. In vitro experiments determined that UA significantly suppressed hydrogen peroxide (H₂O₂)-induced oxidative stress in female donor-derived primary human bronchial epithelial (NHBE) cells in the absence of estrogen, implying that the benefit of UA is limited to the female airway in postmenopausal conditions. Consistently, our clinical observational analyses confirmed that higher blood UA levels, as well as the SLC2A9/GLUT9 rs11722228 T/T genotype, were associated with higher lung function in elderly human females. Together, our findings provide the first unique evidence that higher blood UA is a protective factor against the pathological decline of lung function in female mice, and possibly against aging-associated physiological decline in human females.

Are Dietary Factors Associated with Lung Function in Canadian Adults?

Purpose: The purpose of this study was to explore the impact of dietary factors and biomarkers on lung function among Canadian adults (18-79 years). Methods: Our data source was the Canadian Health Measures Survey Cycle-3, which included 3397 adults. The household and clinic questionnaires and physical measures were used to assess individual dietary factors, modified Mediterranean Diet Scores, and biomarkers. Results: The overall mean percent predicted values for FVC and FEV₁ were 97% and 95%, respectively. While somewhat inconsistent between outcomes, higher lung function was associated with bean, grain, milk, fruit, and vegetable consumption, whereas lower lung function was associated with egg and potato consumption. Among the biomarkers, vitamin D, chloride, total serum protein, and red blood cell folate were associated with higher lung function, whereas C-reactive protein and vitamin B₁₂ was associated with lower lung function. Conclusion: Our study provides support for an association between some dietary factors and lung function, though not entirely consistent between a specific dietary factor and the outcomes studied (FVC, FEV₁, FVC/FEV₁, and FEF_25%-75%). The associations between a specific biomarker and lung function were more consistent (i.e., observed with a larger number of lung function outcomes) than were the dietary factors.

Dietary antioxidant intake in school age and lung function development up to adolescence

Dietary antioxidant intake has been hypothesised to influence lung function. The association between total antioxidant capacity (TAC) of the diet at age 8 years and lung function development up to 16 years in 2307 participants from the Swedish population-based birth cohort BAMSE (Children, Allergy, Milieu, Stockholm, Epidemiology) was investigated.

Information on TAC was obtained from a food frequency questionnaire at 8 years. Lung function was measured by spirometry at 8 and 16 years, impulse oscillometry (IOS) and exhaled nitric oxide fraction (F_eNO) at 16 years. Low lung function was defined as forced expiratory volume in 1 s (FEV₁) z-score below the 25th percentile. Longitudinal associations between TAC and lung function were analysed by mixed effect models adjusted for potential confounders. Stratification by asthma at 8 years was performed to examine effect modification.

The median TAC intake was 10 067 μmol Trolox equivalents (TE)·g⁻¹, with males having a lower mean compared to females (9963 versus 10 819 μmol TE·g⁻¹). In analyses of lung function change between 8 and 16 years, there were no statistically significant associations between TAC in tertiles and spirometry results for the total study population. Among children with asthma at 8 years (prevalence 7%), higher TAC was associated with higher mean FEV₁ (0.46 sd, 95% CI 0.11–0.80) and decreased odds of low lung function at 16 years (OR 0.28, 95% CI 0.12–0.65). There were no associations between TAC and forced vital capacity or IOS/F_eNO results.

High dietary antioxidant intake in school age may be associated with improved lung function development from school age to adolescence among children with asthma.

Dietary antioxidant intake at school age may influence lung function development as measured by FEV₁ up to adolescence among children with asthma. In contrast, no association was observed among children without asthma.http://bit.ly/2CzEZ8W

A clinical trial to evaluate the effect of the Mediterranean diet on smokers lung function

Data on the association between lung function and some dietary patterns have been published. However, it is not yet well known if whether the Mediterranean Diet (MD) pattern can preserve or improve lung function. Our purpose is to evaluate the effect of increased MD adherence on lung function in smokers. A multicenter, parallel, cluster-randomized, controlled clinical trial is proposed. A total of 566 active smokers (>10 packs-year), aged 25–75 years will be included, without previous respiratory disease and who sign an informed consent to participate. Twenty Primary Care Centres in Tarragona (Spain) will be randomly assigned to a control or an intervention group (1:1). All participants will receive advice to quit smoking, and the intervention group, a nutritional intervention (2 years) designed to increase MD adherence by: (1) annual visit to deliver personalized nutritional education, (2) annual telephone contact to reinforce the intervention, and (3) access to an online dietary blog. We will evaluate (annually for 2 years): pulmonary function by forced spirometry and MD adherence by a 14-item questionnaire and medical tests (oxidation, inflammation and consumption biomarkers). In a statistical analysis by intention-to-treat basis, with the individual smoker as unit of analysis, pulmonary function and MD adherence in both groups will be compared; logistic regression models will be applied to analyze their associations. We hope to observe an increased MD adherence that may prevent the deterioration of lung function in smokers without previous respiratory disease. This population may benefit from a dietary intervention, together with the recommendation of smoking cessation.

Potential Micronutrients and Phytochemicals against the Pathogenesis of Chronic Obstructive Pulmonary Disease and Lung Cancer

Lung cancer and chronic obstructive pulmonary disease have shared etiology, including key etiological changes (e.g., DNA damage and epigenetics change) and lung function impairment. Focusing on those shared targets may help in the prevention of both. Certain micronutrients (vitamins and minerals) and phytochemicals (carotenoids and phenols) have potent antioxidant or methyl-donating properties and thus have received considerable interest. We reviewed recent papers probing into the potential of nutrients with respect to lung function preservation and prevention of lung cancer risk, and suggest several hypothetical intervention patterns. Intakes of vitamins (i.e., A, C, D, E, B₁₂), carotenoids, flavonoids, curcumins, resveratrol, magnesium, and omega-3 fatty acids all show protective effects against lung function loss, some mainly by improving average lung function and others through reducing decline rate. Dietary interventions early in life may help lung function reserve over the lifespan. Protective nutrient interventions among smokers are likely to mitigate the effects of cigarettes on lung health. We also discuss their underlying mechanisms and some possible causes for the inconsistent results in observational studies and supplementation trials. The role of the lung microbiome on lung health and its potential utility in identifying protective nutrients are discussed as well. More prospective cohorts and well-designed clinical trials are needed to promote the transition of individualized nutrient interventions into health policy.

Favorable association of polyphenol-rich diets with lung function: Cross-sectional findings from the Moli-sani study

BACKGROUND

The association of the polyphenol content of human diet with pulmonary function is not yet fully understood. This study aims at evaluating the association of polyphenol consumption with lung function in a novel holistic approach.

METHODS

A cross-sectional analysis of 4551 women and 5108 men (age ≥35 years) from the Moli-sani study was performed. Participants were randomly recruited from the general population. The EPIC-FFQ was used for the dietary assessment. Polyphenol intakes were calculated using Eurofir-eBASIS, and a polyphenol antioxidant content (PAC) score was constructed to assess the total content of the diet in these nutrients. Pulmonary function maneuvers were performed, and the forced vital capacity (FVC) and forced expiratory volume in the first second (FEV₁) were measured; FVC% predicted and FEV₁% predicted were computed using the European Community of Coal and Steel prediction equations that included height and age.

RESULTS

In both genders, in age, height, and energy intake adjusted models, the majority of classes of polyphenols (mg/day) showed a positive association with FEV₁, FVC, FEV₁% predicted, and FVC% predicted (β-coef >0, P < .05). Associations remained significant after adjustment for confounding factors in most cases (β-coef >0, P < .05). The PAC score was associated in both genders with an increase in pulmonary function parameters (β-coef >0, P < .05). The inclusion of white blood cell (WBC) counts in the multivariate model reduced the association in men but not in women. .

CONCLUSIONS

A higher overall polyphenol content of human diet was associated with better pulmonary function in a general population. The association might be partially mediated by WBC in men.

Consuming Green Tea at Least Twice Each Day Is Associated with Reduced Odds of Chronic Obstructive Lung Disease in Middle-Aged and Older Korean Adults

Background

The frequent consumption of green tea has been shown to have antioxidant and anti-inflammatory effects and to reduce the risk of lung cancer and type 2 diabetes. However, few studies have investigated the relation between green tea consumption and the risk of chronic obstructive lung disease (COPD).

Objective

This study aimed to examine the association between green tea intake and COPD with the use of a nationwide representative database.

Methods

This study was designed as a cross-sectional survey with the use of data from the Korean National Health and Nutritional Examination Survey collected between 2008 and 2015. Of these participants, 13,570 participants aged ≥40 y were included in the study population. COPD was defined as forced expiratory volume in 1 s (FEV1) divided by forced vital capacity (FVC) <0.70. Multiple linear and logistic regression models were used to examine the association between the frequency of green tea intake and risk of COPD after adjusting for age, sex, body mass index, smoking status, alcohol consumption, physical activity, and socioeconomic status.

Results

The incidence of COPD decreased from 14.1% to 5.9% with increased frequency of green tea intake from never to ≥2 times/d (P < 0.001). In the fully adjusted multiple linear regression model, the frequency of green tea intake showed a linear dose-response relation with FEV1/FVC (P-trend = 0.031). In the multiple logistic regression model, the OR for COPD among people who consumed green tea ≥2 times/d was 0.62 (95% CI: 0.40, 0.97), compared with those who never drank green tea, after adjusting for all covariates.

Conclusion

This study suggests that the consumption of green tea ≥2 times/d is associated with a reduced risk of COPD in Korean populations.

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.

Dietary nutrients associated with preservation of lung function in Hispanic and non-Hispanic white smokers from New Mexico

Background

COPD is the third leading cause of death in the United States. Cigarette smoking accelerates the age-related forced expiratory volume in 1 s (FEV₁) decline, an important determinant for the genesis of COPD. Hispanic smokers have lower COPD prevalence and FEV₁ decline than non-Hispanic whites (NHWs).

Patients and methods

A nutritional epidemiological study was conducted in the Lovelace Smokers cohort (LSC; n=1,829) and the Veterans Smokers cohort (n=508) to identify dietary nutrients (n=139) associated with average FEV₁ and its decline and to assess whether nutrient intakes could explain ethnic disparity in FEV₁ decline between Hispanics and NHW smokers.

Results

Nutrients discovered and replicated to be significantly associated with better average FEV₁ included magnesium, folate, niacin, vitamins A and D, eicosenoic fatty acid (20:1n9), eicosapentaenoic acid (20:5n3), docosapentaenoic acid (DPA; 22:5n3), docosahexaenoic acid (22:6n3), and fiber. In addition, greater intakes of eicosenoic fatty acid and DPA were associated with slower FEV₁ decline in the LSC. Among omega 3 polyunsaturated fatty acids, DPA is the most potent nutrient associated with better average FEV₁ and slower FEV₁ decline. Adverse effect of continuous current smoking on FEV₁ decline was completely negated in LSC members with high DPA intake (>20 mg/day). Slower FEV₁ decline in Hispanics compared to NHWs may be due to the greater protection of eicosenoic fatty acid and DPA for FEV₁ decline rather than greater intake of protective nutrients in this ethnic group.

Conclusion

The protective nutrients for the preservation of FEV₁ in ever smokers could lay foundation for designing individualized nutritional intervention targeting “optimal physiological levels” in human to improve lung function in ever smokers. Ethnic disparity in FEV₁ decline may be explained by difference in magnitude of protection of dietary intakes of eicosenoic fatty acid and DPA between Hispanics and NHWs.

Dietary patterns are associated with lung function among Spanish smokers without respiratory disease

BACKGROUND

Diet can help preserve lung function in smokers, in addition to avoidance of smoking. The study aimed to evaluate associations between dietary patterns and lung function in smokers without respiratory disease.

METHODS

This cross-sectional study analysed baseline data from randomised representative smokers without respiratory disease (n = 207, aged 35-70 years), selected from 20 primary health-care centres. Participants completed a validated semi-quantitative food-frequency questionnaire. Dietary patterns were identified by Principal Component Analysis (PCA). Impaired lung function was defined as FVC <80% and/or FEV1 < 80% of predicted value and/or FEV1/FVC <0.7. Associations were determined by logistic regression.

RESULTS

Three major dietary patterns were identified. In multivariate-adjusted model, impaired lung function was associated with the Alcohol-consumption pattern (OR 4.56, 95% CI 1.58-13.18), especially in women (OR 11.47, 95% CI 2.25-58.47), and with the Westernised pattern in women (OR 5.62, 95% CI 1.17-27.02), whereas it not was associated with the Mediterranean-like pattern (OR 0.71, 95% CI 0.28-1.79).

CONCLUSION

In smokers without respiratory disease, the Alcohol-consumption pattern and the Westernised pattern are associated with impaired lung function, especially in women. The Mediterranean-like pattern appears to be associated with preserved lung function because no statistical association is observed with impaired lung function. In addition to smoking cessation, modifying dietary patterns has possible clinical application to preserve lung function.

Dietary anthocyanin intake and age-related decline in lung function: longitudinal findings from the VA Normative Aging Study

BACKGROUND

It is unknown whether habitual intake of dietary flavonoids, known for their antioxidative and anti-inflammatory properties, affects longitudinal change in lung function.

OBJECTIVE

We investigated whether different flavonoid subclasses present in the habitual diet were associated with beneficial changes in lung function over time in the elderly.

DESIGN

This longitudinal analysis included 839 participants from the VA (Veterans Affairs) Normative Aging Study whose lung function [forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC)] was measured at 2 and up to 5 visits between 1992 and 2008 (n = 2623 measurements). Yearly average intake of major flavonoid subclasses (anthocyanins, flavanones, flavan-3-ols, flavonols, flavones, and polymers) was calculated from food-frequency questionnaires at each visit. We estimated adjusted differences in annual change in lung function associated with each flavonoid subclass, categorized into quartiles, in linear mixed-effects regression models after adjustment for lifestyle and dietary confounders.

RESULTS

Strong inverse associations were found between anthocyanin intake and age-related decline in lung function. Independent of dietary and nondietary risk factors, slower rates of FEV1 and FVC decline by 23.6 (95% CI: 16.6, 30.7) and 37.3 (95% CI: 27.8, 46.8) mL/y, respectively, were observed in participants in the fourth quartile of intake compared with participants in the first quartile (P-trend < 0.0001). The protective associations observed for anthocyanin intake were present in both current/former and never smokers. Compared with no or very low intakes, an intake of ≥2 servings of anthocyanin-rich blueberries/wk was associated with slower decline in FEV1 and FVC by 22.5 (95% CI: 10.8, 34.2) and 37.9 (95% CI: 22.1, 53.7) mL/y, respectively. To a lesser extent, higher flavan-3-ol intake was also associated with slower lung function decline.

CONCLUSIONS

An attenuation of age-related lung function decline was associated with higher dietary anthocyanin intake in this longitudinal sample of predominantly elderly men. Further prospective studies are needed to confirm these novel associations.

Modification of additive effect between vitamins and ETS on childhood asthma risk according to GSTP1 polymorphism: a cross -sectional study

Background

Asthma is characterized by airway inflammation, and bronchial airways are particularly susceptible to oxidant-induced tissue damage.

Objective

To investigate the effect of dietary antioxidant intake and environmental tobacco smoke (ETS) on the risk of childhood asthma according to genotypes susceptible to airway diseases.

Methods

This cross-sectional study included 1124 elementary school children aged 7–12 years old. Asthma symptoms and smoking history were measured using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Intake of vitamin A (including retinol and β-carotene), C, and E was measured by a semi-quantitative food frequency questionnaire (FFQ). GSTP1 polymorphisms were genotyped from peripheral blood samples.

Results

ETS was significantly associated with presence of asthma symptoms (adjusted odds ratio [aOR], 2.48; 95 % confidence interval [CI], 1.29–4.76) and diagnosis (aOR, 1.91; 95 % CI, 1.19–3.06). Dietary antioxidant intake was not associated with asthma symptoms, although ETS plus low vitamin A intake showed a significant positive association with asthma diagnosis (aOR, 2.23; 95 % CI, 1.10–4.54). Children with AA at nucleotide 1695 in GSTP1 who had been exposed to ETS and a low vitamin A intake have an increased risk of asthma diagnosis (aOR, 4.44; 95 % CI,1.58–12.52) compared with children who had not been exposed to the two risk factors. However, ETS exposure and low vitamin A intake did not significantly increase odds of asthma diagnosis in children with AG or GG genotypes.

Conclusion

Low vitamin A intake and ETS exposure may increase oxidative stress and thereby risk for childhood asthma. These relationships may be modified by gene susceptibility alleles of GSTP1.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-015-0093-0) contains supplementary material, which is available to authorized users.

Investigating the effects of arctic dietary intake on lung health

BACKGROUND/OBJECTIVE

Preservation of lung health requires understanding the modifiable risk factors of airflow limitation. This study investigates the association between diet and lung function in a population of Greenland Inuit residing in the Arctic (Greenland) or Western Europe (Denmark).

SUBJECTS/METHODS

Two unselected Inuit populations were recruited, one living in Greenland (Urban (Nuuk) n=358; Rural (Uummannaq) n=207) and the other in Denmark (n=539). Lung function was measured using spirometry and diet by a food frequency questionnaire. Factors associated with airflow limitation were assessed using multiple linear regression models.

RESULTS

The dietary composition differed significantly in the two regions, with higher whale, seal and wild meat intake and lower fruit and vegetable intake in the Arctic regions compared with Denmark. Consumption of vegetables (P=0.004) and whale and/or seal (P<0.0001) was significantly and positively associated with FEV1, as well as with FVC (vegetables: P=0.001, whale and/or seal: P=0.002). Regular fruit intake was included in the statistical models; however, it did not reach statistical significance (FEV1: P=0.053; FVC: P=0.055).

CONCLUSIONS

High dietary intake of vegetables as well as intake of arctic marine mammals had independent positive associations with lung function in this cohort of Greenlandic Inuit. These findings suggest an additive role of dietary intake of antioxidants and unsaturated fatty acids in lung health, which warrants prospective evaluation.

Ventilatory function in young adults and dietary antioxidant intake

Dietary antioxidants may protect against poor ventilatory function. We assessed the relation between ventilatory function and antioxidant components of diet in young Chileans. Forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), and the ratio FEV₁/FVC were measured in 1232 adults aged 22–28 years, using a Vitalograph device. Dietary intake was ascertained with a food frequency questionnaire (FFQ) designed for this study, from which nutrient and flavonoid intakes were estimated. Dietary patterns were derived with Principal Component Analysis (PCA). After controlling for potential confounders, dietary intake of total catechins was positively associated with FVC (Regression coefficient (RC) of highest vs. lowest quintile of intake 0.07; 95% CI 0.01 to 0.15; p per trend 0.006). Total fruit intake was related to FVC (RC of highest vs. lowest quintile 0.08; 95% CI 0.003 to 0.15; p per trend 0.02). Intake of omega 3 fatty acids was associated with a higher FEV₁ (RC for highest vs. lowest quintile 0.08; 95% CI 0.01 to 0.15 L; p per trend 0.02) and with FVC 0.08 (RC in highest vs. lowest quintile of intake 0.08, 95% CI 0.001 to 0.16; p per trend 0.04). Our results show that fresh fruits, flavonoids, and omega 3 fatty acids may contribute to maintain ventilatory function.

Effects of mediterranean diet on lung function in smokers: a randomised, parallel and controlled protocol

BACKGROUND

There is evidence of an association between pulmonary function and various nutrients, although no association has been observed in our setting between the Mediterranean Diet (MD) eating pattern and improved lung function. The objective of this study is to evaluate the effect of an intervention designed to increase MD adherence on lung function in smokers with no previous respiratory disease.

METHODS/DESIGN

Randomized, controlled, parallel clinical trial.

SETTING

primary health care centers in Catalonia (Spain).

PARTICIPANTS

Current smokers (cumulative > 10 pack-years) aged 35-70 years, with Internet access, who provide signed informed consent to participate.

INTERVENTION

A nutritionist will conduct a 2-year multicomponent intervention to increase MD adherence, based on: 1) a personalized dietary-nutritional education intervention, 2) a Web 2.0 approach, the DIET Blog of nutritional information, and 3) group sessions to increase motivation to increase MD adherence and motivation to make changes in eating habits. Annually, an office visit and one group session will reinforce the nutritional intervention. The control group will follow their usual diet, with general nutritional counselling. In both groups, a 14-item questionnaire will evaluate individual MD dietary patterns and forced spirometry will assess lung function.

ANALYSIS

Intention to treat. The unit of analysis will be the individual smoker. Primary outcome is lung function indicated by spirometry, FVC, FEV1 and FEV1/FVC %. Lung function parameters in both groups will be compared by adherence to the MD pattern.

DISCUSSION

The DIET study could contribute data on a protective action of the MD pattern on lung function in smokers. If so, this population may benefit from a nutritional intervention, along with the fundamental recommendation to stop smoking.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02151669 . Registered 26 May 2014.

Dietary and supplemental antioxidant and anti-inflammatory nutrient intakes and pulmonary function

OBJECTIVE

A limited but growing body of evidence supports a significant role of antioxidant and anti-inflammatory micronutrients in pulmonary health. We investigated the associations of dietary and supplemental intakes of vitamins A, C, E and D, Se and n-3 PUFA with pulmonary function in a population-based study.

DESIGN

Population-based, cross-sectional study and data analysis of fruits and vegetables, dairy products and fish, vitamins A, C, E and D, Se and n-3 PUFA supplemental intakes, pulmonary risk factors and spirometry.

SUBJECTS

Chinese older adults (n 2478) aged 55 years and above in the Singapore Longitudinal Ageing Studies.

RESULTS

In multiple regression models that controlled simultaneously for gender, age, height, smoking, occupational exposure and history of asthma/chronic obstructive pulmonary disease, BMI, physical activity, and in the presence of other nutrient variables, daily supplementary vitamins A/C/E (b = 0·044, SE = 0·022, P = 0·04), dietary fish intake at least thrice weekly (b = 0·058, SE = 0·016, P < 0·0001) and daily supplementary n-3 PUFA (b = 0·068, SE = 0·032, P = 0·034) were individually associated with forced expiratory volume in the first second. Supplemental n-3 PUFA was also positively associated with forced vital capacity (b = 0·091, SE = 0·045, P = 0·045). No significant association with daily dairy product intake, vitamin D or Se supplements was observed.

CONCLUSIONS

The findings support the roles of antioxidant vitamins and n-3 PUFA in the pulmonary health of older persons.

Social integration and pulmonary function in the elderly

OBJECTIVE

This study sought to determine whether social integration, defined as number of social roles, is associated with better pulmonary function in the elderly and which roles are associated with greatest benefit. It also examined pathways that connect social integration to better lung health.

METHODS

High functioning men (n = 518) and women (n = 629) ages 70-79 were recruited as part of the MacArthur Study of Successful Aging, and data were collected on social roles as well as pulmonary function as assessed by peak expiratory flow rate (PEFR). Multiple regressions predicting PEFR from the number of social roles controlled for age, sex, race, education, weight, and height. Physiological, behavioral, social, and psychological factors were tested as mediators of the association between the number of social roles and PEFR.

RESULTS

More social roles were associated with better PEFR. Analysis of specific roles indicated that marriage was the strongest positive correlate of PEFR. However, greater numbers of roles were also associated with better PEFR independent of marriage. Being a relative or friend were each also individually associated with better PEFR. Even so, greater numbers of social roles were associated with better PEFR independent of relative and friend. The data were consistent with greater happiness, not smoking, and more physical activity acting as pathways linking the number of roles to PEFR.

CONCLUSIONS

Number of social roles is an important correlate of healthy lung function in the elderly. This association may be driven by healthier behaviors and greater feelings of well-being.

Influence of diet and obesity on COPD development and outcomes

The global increase in the prevalence and incidence of obesity has called serious attention to this issue as a major public health concern. Obesity is associated with many chronic diseases, including cardiovascular disease and diabetes, and recently the role of overweight and obesity in lung disease has received new interest. Independently of obesity, diet also plays a role as a risk factor for many chronic diseases, and evidence is accumulating to support a role for diet in the prevention and management of several lung diseases. Chronic obstructive lung disease is the third-leading cause of death globally, and both obesity and diet appear to play roles in its pathophysiology. Obesity has been associated with decreased lung-function measures in population-based studies, with increased prevalence of several lung diseases and with compromised pulmonary function. In contrast, obesity has a protective effect against mortality in severe chronic obstructive pulmonary disease (COPD). Nutrient intake and dietary patterns have also been associated with lung-function measures and the development and progression of COPD. Taken together, this suggests that a focus on obesity and diet should be part of public health campaigns to reduce the burden of lung disease, and could have important implications for clinicians in the management of their patients. Future research should also focus on elucidating these relationships in diverse populations and age-groups, and on understanding the complex interaction between behavior, environment, and genetics in the development and progression of COPD. The goal of this article is to review current evidence regarding the role that obesity and diet play in the development of COPD, and in COPD-related outcomes.

Promotion of lung health: NHLBI Workshop on the Primary Prevention of Chronic Lung Diseases

Lung-related research primarily focuses on the etiology and management of diseases. In recent years, interest in primary prevention has grown. However, primary prevention also includes "health promotion" (actions in a population that keep an individual healthy). We encourage more research on population-based (public health) strategies that could not only maximize lung health but also mitigate "normal" age-related declines-not only for spirometry but across multiple measures of lung health. In developing a successful strategy, a "life course" approach is important. Unfortunately, we are unable to achieve the full benefit of this approach until we have better measures of lung health and an improved understanding of the normal trajectory, both over an individual's life span and possibly across generations. We discuss key questions in lung health promotion, with an emphasis on the upper (healthier) end of the distribution of lung functioning and resiliency and briefly summarize the few interventions that have been studied to date. We conclude with suggestions regarding the most promising future research for this important, but largely neglected, area of lung research.

Healthy Eating Index 2005 and selected macronutrients are correlated with improved lung function in humans

A number of dietary components have been associated with lung function. However, a comprehensive measure of a healthy diet has not been compared with lung function. Herein, we test the hypothesis that a healthy overall diet, as assessed by the Healthy Eating Index 2005 (HEI-2005), will be associated with increased lung function. This is an investigation using the Atherosclerosis Risk in Communities Research Materials obtained from the National Heart Lung Blood Institute. The study surveyed dietary habits of 15 567 American subjects from 4 communities in 1987 to 1990. Spirometric measures of lung function were also taken at entry to the study and a second time 3 years later. Based on food and nutritional data collected by food frequency questionnaire, an HEI-2005 score was calculated for each subject. This total score, together with its 12 components scores and associated macronutrient, was compared with lung function results by linear regression. Models were controlled for smoking behavior, demographics, and other important covariates. The HEI-2005 total scores were positively associated with forced expiratory volume in 1 second per forced vital capacity (FEV(1)/FVC) at visit 1 (β = .101 per increase in 1 quintile of HEI-2005) and visit 2 (β = .140), and FEV(1) as percentage of the predicted FEV(1) at visit 2 (β = .215) (P < .05). In addition, HEI-2005 component scores that represented high intakes of whole grains (β = .127 and .096); saturated fats (β = -.091); and solid fats, alcohol, and added sugar (β = -.109 and -.131) were significantly associated with FEV(1)/FVC at either visit 1 or visit 2. Intakes of total calories (β =-.082 at visit 1) and saturated fatty acids (β = -.085 at visit 2) were negatively associated with FEV(1)/FVC. Dietary polyunsaturated fatty acids (β = .085 and .116) and long-chain omega-3 fatty acids (β = .109 and .103), animal protein (β = .132 and .093), and dietary fiber (β = .129) were positively associated with lung health. An overall healthy diet is associated with higher lung function.

Nutrition as a metabolic modulator in COPD

COPD is an important global health problem. In addition to pulmonary impairment, systemic inflammation, musculoskeletal abnormalities, and cardiovascular comorbidity influence disease burden and mortality risk. Body weight and body composition are important discriminants in classifying disease heterogeneity. The rationale for and efficacy of caloric supplementation in preventing and treating involuntary weight loss is currently well established. For maintenance of muscle and bone tissue, appropriately timed, high-quality protein intake and addressing vitamin D deficiency must be considered. Specific nutrients (eg, n-3 polyunsaturated fatty acids and polyphenolic compounds) may have the pharmacologic potential to boost decreased muscle mitochondrial metabolism and enhance impaired physical performance, particularly when the metabolic stimulus of physical activity alone is limited. At this stage, evidence is insufficient to support an intake of high doses of single nutritional supplements to modulate respiratory pathology, but some small studies have identified micronutrient modulation via the diet as a promising intervention.

Diet and vitamin D as risk factors for lung impairment and COPD

Epidemiologic and observational studies have shown an association between increased intakes of certain micronutrients and higher levels of lung function and health. The National Health and Nutrition Examination Surveys of the U.S. population have demonstrated repeatedly that increased intakes or serum levels of some micronutrients, including the vitamins E, D, C, and A, and carotenes are associated positively with forced expiratory volume in 1 second (FEV1). These findings are complemented by other observational studies, including the MORGEN study as well as the Seven Countries Study, both of which found micronutrient status had positive correlations with pulmonary function. In addition, epidemiologic studies have demonstrated that dietary intake patterns with increased intakes of fruit, vegetables, fish, vitamin E, and whole grains have been associated with a decreased development of chronic obstructive pulmonary disease (COPD) in smokers and nonsmokers, higher levels of FEV1, and decreased long-term COPD mortality. Diets high in refined food have been associated with accelerated longitudinal decline in FEV1 over 5 years. Taken together, these results suggest that micronutrient status may impact lung function, and that nutrition interventions could be a useful tool in a public health campaign aimed at the prevention of lung disease. Future research should focus on the effect of nutrition interventions on the natural history of lung disease.

Genetic variation in antioxidant enzymes, cigarette smoking, and longitudinal change in lung function

Antioxidant enzymes play an important role in the defense against oxidative stress in the lung and in the pathogenesis of chronic obstructive pulmonary disease (COPD). Sequence variation in genes encoding antioxidant enzymes may alter susceptibility to COPD by affecting longitudinal change in lung function in adults. We genotyped 384 sequence variants in 56 candidate genes in 1281 African American and 1794 European American elderly adults in the Health, Aging, and Body Composition study. Single-marker associations and gene-by-smoking interactions with rate of change in FEV₁ and FEV₁/FVC were evaluated using linear mixed-effects models, stratified by race/ethnicity. In European Americans, rs17883901 in GCLC was statistically significantly associated with rate of change in FEV₁/FVC; the recessive genotype (TT) was associated with a 0.9% per year steeper decline (P = 4.50 × 10(-5)). Statistically significant gene-by-smoking interactions were observed for variants in two genes in European Americans: the minor allele of rs2297765 in mGST3 attenuated the accelerated decline in FEV₁/FVC in smokers by 0.45% per year (P = 1.13 × 10(-4)); for participants with greater baseline smoking pack-years, the minor allele of rs2073192 in IDH3B was associated with an accelerated decline in FEV₁/FVC (P = 2.10 × 10(-4)). For both genes, nominally significant interactions (P < 0.01) were observed at the gene level in African Americans (P = 0.007 and 4.60 × 10(-4), respectively). Nominally significant evidence of association was observed for variants in SOD3 and GLRX2 in multiple analyses. This study identifies two novel genes associated with longitudinal lung function phenotypes in both African and European Americans and confirms a prior finding for GCLC. These findings suggest novel mechanisms and molecular targets for future research and advance the understanding of genetic determinants of lung function and COPD risk.