Processed meat consumption and lung function: modification by antioxidants and smoking

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.

Pulmonary symptoms associated with heavy alcohol consumption among people living with HIV: an analysis of the NHANES 1999-2010

AIM

This matched case-control study aimed to provide epidemiologic evidence of increased burden of respiratory symptoms and pulmonary function decline among people living with human immunodeficiency virus (HIV) and a history of heavy alcohol consumption.

METHODS

Cases were participants with HIV (PWH; n = 75, 33%), and controls were participants without HIV (PWoH; n = 150, 67%). PWH were matched to PWoH by age and sex in the ratio of 1:2. Eligible participants responded to the respiratory health National Health and Nutrition Examination Survey questionnaire [prolonged coughs (≥3 months), bringing up of phlegm (≥3 months), and a history of wheezing or whistling in the chest (past year)]. The effects of both alcohol and HIV on participants' pulmonary function were determined using linear regression analysis.

RESULTS

History of heavy alcohol consumption was more prevalent among PWH (40%) compared to PWoH (27%). PWH who had a history of heavy alcohol consumption had a higher prevalence of coughing most days (45% vs. 4%, P = .0010), bringing up phlegm most days (31% vs. 0%, P = .0012), and wheezing or whistling in the chest (40% vs. 20%, P = .058) compared to participants who did not heavily consume alcohol. Furthermore, a history of heavy alcohol consumption was associated with decreased forced expiratory volume (ml) in 1 s/forced vital capacity among PWH (β = - 0.098 95% C.I. -0.16, -0.04, P = .03) after adjusting for having smoked at least 100 cigarettes in life.

CONCLUSION

A history of heavy alcohol use increased respiratory symptoms and suppressed pulmonary function among people living with HIV. This study provides epidemiological evidence of the respiratory symptom burden of people living with HIV who have a history of heavy alcohol consumption.

The AGE-RAGE Axis and the Pathophysiology of Multimorbidity in COPD

Chronic obstructive pulmonary disease (COPD) is a disease of the airways and lungs due to an enhanced inflammatory response, commonly caused by cigarette smoking. Patients with COPD are often multimorbid, as they commonly suffer from multiple chronic (inflammatory) conditions. This intensifies the burden of individual diseases, negatively affects quality of life, and complicates disease management. COPD and comorbidities share genetic and lifestyle-related risk factors and pathobiological mechanisms, including chronic inflammation and oxidative stress. The receptor for advanced glycation end products (RAGE) is an important driver of chronic inflammation. Advanced glycation end products (AGEs) are RAGE ligands that accumulate due to aging, inflammation, oxidative stress, and carbohydrate metabolism. AGEs cause further inflammation and oxidative stress through RAGE, but also through RAGE-independent mechanisms. This review describes the complexity of RAGE signaling and the causes of AGE accumulation, followed by a comprehensive overview of alterations reported on AGEs and RAGE in COPD and in important co-morbidities. Furthermore, it describes the mechanisms by which AGEs and RAGE contribute to the pathophysiology of individual disease conditions and how they execute crosstalk between organ systems. A section on therapeutic strategies that target AGEs and RAGE and could alleviate patients from multimorbid conditions using single therapeutics concludes this review.

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.

The Dietary Inflammatory Index and Early COPD: Results from the National Health and Nutrition Examination Survey

We examined 3962 people aged 20 to 49 years who had information on spirometry testing and underwent a 24 h dietary recall interview from the 2007-2012 National Health and Nutrition Examination Survey (NHANES) and used multivariable logistic regression to evaluate associations between Dietary Inflammatory Index (DII, a pro-inflammatory diet) and early COPD and lung function. The overall prevalence of early COPD was 5.05%. Higher DII was associated with increased odds of early COPD (quartile 4 vs. 1, the OR = 1.657, 95% CI = 1.100-2.496, p = 0.0156). In a full-adjusted model, each unit of increase in DII score was associated with a 90.3% increase in the risk of early COPD. Higher DII is significantly associated with lower FEV1 and FVC among individuals with early COPD, each unit increment in the DII was significantly associated with 0.43 L-0.58 L decrements in FEV1 (β = -0.43, 95% CI = -0.74, -0.12) and FVC (β = -0.58, 95% CI = -1.01, -0.16). These findings demonstrate that higher consumption of a pro-inflammatory diet may contribute to an increased risk of early COPD and lower lung function, and further support dietary interventions as part of a healthy lifestyle in order to preserve lung function and prevent or improve 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.

Excessive Unbalanced Meat Consumption in the First Year of Life Increases Asthma Risk in the PASTURE and LUKAS2 Birth Cohorts

A higher diversity of food items introduced in the first year of life has been inversely related to subsequent development of asthma. In the current analysis, we applied latent class analysis (LCA) to systematically assess feeding patterns and to relate them to asthma risk at school age. PASTURE (N=1133) and LUKAS2 (N=228) are prospective birth cohort studies designed to evaluate protective and risk factors for atopic diseases, including dietary patterns. Feeding practices were reported by parents in monthly diaries between the 4^th and 12^th month of life. For 17 common food items parents indicated frequency of feeding during the last 4 weeks in 4 categories. The resulting 153 ordinal variables were entered in a LCA. The intestinal microbiome was assessed at the age of 12 months by 16S rRNA sequencing. Data on feeding practice with at least one reported time point was available in 1042 of the 1133 recruited children. Best LCA model fit was achieved by the 4-class solution. One class showed an elevated risk of asthma at age 6 as compared to the other classes (adjusted odds ratio (aOR): 8.47, 95% CI 2.52–28.56, p = 0.001) and was characterized by daily meat consumption and rare consumption of milk and yoghurt. A refined LCA restricted to meat, milk, and yoghurt confirmed the asthma risk effect of a particular class in PASTURE and independently in LUKAS2, which we thus termed unbalanced meat consumption (UMC). The effect of UMC was particularly strong for non-atopic asthma and asthma irrespectively of early bronchitis (aOR: 17.0, 95% CI 5.2–56.1, p < 0.001). UMC fostered growth of iron scavenging bacteria such as Acinetobacter (aOR: 1.28, 95% CI 1.00-1.63, p = 0.048), which was also related to asthma (aOR: 1.55, 95% CI 1.18-2.03, p = 0.001). When reconstructing bacterial metabolic pathways from 16S rRNA sequencing data, biosynthesis of siderophore group nonribosomal peptides emerged as top hit (aOR: 1.58, 95% CI 1.13-2.19, p = 0.007). By a data-driven approach we found a pattern of overly meat consumption at the expense of other protein sources to confer risk of asthma. Microbiome analysis of fecal samples pointed towards overgrowth of iron-dependent bacteria and bacterial iron metabolism as a potential explanation.

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.

Processed Meat Intake and Risk of Chronic Obstructive Pulmonary Disease among Middle-aged Women

BACKGROUND

Processed meat intake may increase the risk of chronic obstructive pulmonary disease (COPD). However, the magnitude of this association may depend on smoking and unhealthy diet. Our aims were to determine whether processed meat intake increased the risk of COPD among middle-aged women, and to estimate the combined impact of high processed meat intake, smoking and unhealthy diet on the risk of COPD.

METHODS

Analyses included 87,032 registered nurses from the Nurses' Health Study II (baseline mean age 36.8 years). Over 2,296,894 person-years (1991-2017), we documented 634 incident cases of COPD. Cumulative average of processed meat intake (every 4 years) was divided into never/almost never, < 1 or ≥ 1 servings/week. A score was created to study the impact of 3-risk lifestyle factors.

FINDINGS

In multivariable-adjusted Cox proportional hazards models, after careful adjustment for smoking and unhealthy diet, we observed a positive association between processed meat intake and the risk of COPD: Hazard Ratio (HR, 95%CI) for ≥ 1 servings/week vs. never/almost never = 1.29 (1.00-1.65). In analyses stratified according to smoking or unhealthy diet, processed meat intake was associated with increased risk of COPD only among ever smokers (HR 1.37 [1.01-1.86]), and among women with unhealthy diet (HR 1.39 [1.04-1.85]). The multivariable-adjusted HR for COPD in participants with all 3 high-risk lifestyle factors compared with none was 6.32 (3.67-10.87).

INTERPRETATION

Processed meat intake was associated with elevated risk of developing COPD in middle-aged women, especially in presence of other high-risk lifestyle factors (smoking, unhealthy diet).

FUNDINGS

US CDC and NIH.

Dietary Patterns and Prevalence of Post-bronchodilator Airway Obstruction in Dairy Farmers Exposed to Organic Dusts

Exposure to organic dusts is an independent causative factor of chronic obstructive pulmonary disease (COPD). Unhealthy dietary patterns have been associated with poor lung function in smokers. This study investigated whether dietary patterns were associated with post-bronchodilator airway obstruction, a hallmark of COPD, in dairy farmers exposed to organic dusts. All subjects were identified by screening programs and patients with airflow obstruction were matched with subjects with normal spirometry. Six groups were compared, defined by their exposures (non-smoking dairy farmers, smokers ≥ 10 pack-years with no occupational exposure, and smoking dairy farmers) and the presence or absence of post-bronchodilator airflow obstruction, resulting in 321 study subjects. The Alternative Healthy Eating Index (AHEI) score was calculated based on an adapted food frequency questionnaire. Mean total AHEI scores were similar in all groups. Comparison between smokers with post-bronchodilator airway obstruction and subjects with post-bronchodilator airway obstruction related to occupational exposure found minimal differences in dietary patterns: dairy farmers had lower scores for the ratio of white to red meat and higher scores for cereal fiber consumption. As in previous studies, smokers with post-bronchodilator airway obstruction exhibited higher lipid intakes and lower carbohydrate intakes than their counterparts with normal spirometry. No evidence of any meaningful difference in dietary patterns was found between subjects with post-bronchodilator airway obstruction detected by screening and healthy controls, either in dairy farmers or in smokers with no occupational exposure.

Long-term consumption of fruits and vegetables and risk of chronic obstructive pulmonary disease: a prospective cohort study of women

Background

Fruits and vegetables, due to high antioxidant capacity, may protect the lung from oxidative damage caused by tobacco smoke and potentially prevent chronic obstructive pulmonary disease (COPD). Only one study based on baseline diet has examined fruit and vegetable consumption in relation to risk of COPD, and no previous studies have examined long-term diet.

Methods

We investigated whether long-term fruit and vegetable consumption was associated with COPD incidence among 34 739 women (age 48-83 years) in the population-based prospective Swedish Mammography Cohort. Fruit and vegetable consumption was assessed twice (1987, 1997) with a self-administered questionnaire. Cases of COPD were identified by linkage to the Swedish health register. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

During follow-up from 2002 to 2014, 1512 women were diagnosed with COPD. Long-term fruit was associated with lower risk of COPD; women in the highest vs lowest quintile of consumption (≥2.5 vs <0.8 servings/day) had a 37% lower risk of COPD (95% CI: 25-48%; P-trend < 0.0001). No association was observed with long-term vegetable intake. Current and ex-smokers with low long-term consumption of fruits (<1 serving/day) in comparison to never smokers with high consumption (≥3 servings/day) had a 38-fold (HR: 38.1; 95% CI: 20.2-71.7) and 13-fold (HR: 12.5, 95% CI: 6.5-24.1) higher risk of COPD, respectively. However, no significant interaction between smoking status and fruit intake in relation to COPD incidence was observed (P-interaction = 0.95).

Conclusions

In this prospective cohort of middle-age and older women, long-term consumption of fruits but not vegetables was inversely associated with COPD incidence.

Association between processed meat intake and asthma symptoms in the French NutriNet-Santé cohort

PURPOSE

Processed meat intake may adversely affect lung health, but data on asthma remains sparse. The magnitude of the processed meat-asthma association may also depend on other unhealthy behaviors. We investigated the association between processed meat intake and the asthma symptom score, and the combined role of unhealthy weight, smoking, low diet quality, and high processed meat intake on the asthma score.

METHODS

In 2017, 35,380 participants to the NutriNet-Santé cohort answered a detailed respiratory web-questionnaire. Asthma was defined by the asthma symptom score (sum of 5 questions; continuous variable). Based on repeated 24-h dietary records collected on a dedicated website, processed meat consumption was classified as 0, < 2, 2-5, > 5 servings/week. We examined the combined role of body mass index (BMI) (< 25 vs. ≥ 25 kg/m²), smoking (never vs. ever), diet quality score (highest vs. lowest), and processed meat (≤ 5 vs. > 5 servings/week) on the asthma symptom score.

RESULTS

Participants were aged 54 on average (women: 75%, smokers: 49%, BMI ≥ 25: 32%, ≥ 1 asthma symptoms: 27%). After adjustment for confounders, processed meat intake was positively and significantly associated with asthma symptom score: odds ratios (ORs) (95% CI) for > 5 vs. 0 servings/week were 1.15 (1.04-1.27) in women; 1.23 (1.01-1.50) in men. Compared to participants with 0 unhealthy behaviors, ORs for the asthma symptom score among participants with the 4 combined unhealthy behaviors were 2.18 (1.91-2.48) in women; 2.70 (2.10-3.45) in men.

CONCLUSION

High processed meat consumption was associated with higher asthma symptoms, and combining overweight/obesity, smoking, low diet quality, with high processed meat intake was strongly associated with asthma symptoms.

Predictors of New Airway Obstruction - An 11 Year's Population-Based Follow-Up Study

In the present study we aimed to investigate the incidence and predictors of spirometry based airway obstruction in a representative population-based sample. Altogether 3,863 subjects, 1,651 males and 2,212 females aged ≥30 years had normal spirometry in year 2000. Fifty-three percent of them were never and 23% current smokers. A re-spirometry was performed 11 years later. Several characteristics, such as level of education, use of alcohol, physical activity, diet using Alternate healthy eating (AHEI) index, body mass index, circumwaist, sensitive C reactive protein (CRP) and cotinine of the laboratory values and co-morbidities including asthma, allergic rhinitis, sleep apnoea and chronic bronchitis, as potential risk factors for airway obstruction were evaluated. Using forced expiratory volume in one second/ forced vital capacity below the lower limit of normal, we observed 124 new cases of airway obstruction showing a cumulative 11-year incidence of 3.2% and corresponding to an incidence rate of 5.6/1,000 per year (PY). The incidence rate was higher in men than in women (6.3/1,000 PY vs. 5.0/1,000 PY, respectively). The strongest risk factors were current smoking (Odds ratio [OR] 2.5) and previously diagnosed asthma (OR 2.1). Sensitive CRP associated with the increased risk and high AHEI index with the decreased risk of airway obstruction. Using the similar study approach our findings on the incidence of airway obstruction are in line with the previously published figures in Europe. We were able to confirm the recent findings on the protective effect of healthy diet.

The Hertfordshire Cohort Study: an overview

The Hertfordshire Cohort Study is a nationally unique study of men and women born in the English county of Hertfordshire in the early part of the 20 ^th century. Records that detail their health in infancy and childhood have been preserved, their sociodemographic, lifestyle, medical and biological attributes have been characterised in later life, and routinely collected data on their hospital use and mortality have been acquired. This paper provides an overview of the study since its inception in the 1980s, including its methods, findings, and plans for its future.

Serum phosphate levels are related to all-cause, cardiovascular and COPD mortality in men

Hyperphosphatemia has been associated with increased mortality in chronic kidney disease but the nature of such a relation in the general population is unclear. To investigate the association between phosphate (P) levels and all-cause and cause-specific mortality, we assessed two cohorts from the Rotterdam Study, with follow-up of 14.5 (RS-I) and 10.9 (RS-II) years until January 2012 with availability of fasting phosphate levels. Deaths were classified according to International Classification of Diseases into 7 groups: cardiovascular, cancer, infections, external, dementia, chronic lung diseases and other causes. Sex-stratified Weibull and competing-risks models were adjusted for age, BMI and smoking. Hazard ratios are expressed per 1 mg/dL increase in phosphate levels. The total number of participants included 3731 (RS-I, 2154 women) and 2494 (RS-II, 1361 women) subjects. The main outcome measures were all-cause and cause-specific mortality. A significant positive association was found between phosphate and all-cause mortality in men (pooled HR (95% CI): 1.46 (1.26–1.69)) but not in women (0.90 (0.77–1.05)). In men, higher phosphate increased the risk for cardiovascular mortality (1.66 (1.29–2.14)), other causes (1.67 (1.16–2.40)) and chronic lung disease mortality (1.94 (1.02–3.72)), the latter driven by mortality due to chronic obstructive pulmonary disease (COPD) (4.44 (2.08–9.49)). No relations were found for mortality due to infections, cancer, dementia or external causes. In conclusion, serum P is associated with increased all-cause, cardiovascular and COPD mortality in men but not women. The association with COPD mortality is novel and needs further research on underlying mechanisms.

Long-term unprocessed and processed red meat consumption and risk of chronic obstructive pulmonary disease: a prospective cohort study of women

Purpose

Limited studies have examined red meat consumption in relation to risk of chronic obstructive pulmonary disease (COPD), and none have examined the impact of long-term diet on COPD risk. We sought to investigate the association between long-term red meat consumption and risk of COPD.

Methods

The population-based prospective Swedish Mammography Cohort included 34,053 women, aged 48–83 years, followed for the current analyses from 2002 to 2014. Unprocessed and processed red meat consumption was assessed with a self-administered questionnaire in 1987 and 1997. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

Over a mean follow-up of 11.6 years (2002–2014; 393,831 person-years), 1488 COPD cases were ascertained via linkage to the Swedish health registers. A positive association between long-term processed red meat (average from 1987 to 1997) and risk of COPD was observed. In contrast, no association was observed with unprocessed red meat with corresponding HRs of 1.36 (95% CI 1.03–1.79) for processed and 0.87 (95% CI 0.74–1.02) for unprocessed red meat among women who consumed ≥ 50 g/day compared to < 25 g/day. The observed association with processed meat was confined to ex-smokers (P for interaction = 0.30); women consuming of ≥ 50 g/day of processed meat had a 2.3-fold (95% CI 1.24–4.12) higher risk of COPD than those consuming < 25 g/day. No similar associations were observed among current or never smokers.

Conclusion

In this prospective cohort of women with moderate red meat consumption, long-term processed red meat consumption was associated with an increased risk of COPD particularly among ex-smokers.

Electronic supplementary material

The online version of this article (10.1007/s00394-018-1658-5) contains supplementary material, which is available to authorized users.

Diet, Lung Function, and Asthma Exacerbations in Puerto Rican Children

Changes in dietary patterns may partly explain the epidemic of asthma in industrialized countries. The objective of this study was to examine the relationship between dietary patterns and lung function and asthma exacerbations in Puerto Rican children. This is a case-control study of 678 Puerto Rican children (ages 6-14 years) in San Juan (Puerto Rico). All participants completed a respiratory health questionnaire and a 75-item food frequency questionnaire. Food items were aggregated into 7 groups: fruits, vegetables, grains, protein, dairy, fats, and sweets. Logistic regression was used to evaluate consumption frequency of each group and asthma. Based on the results, a dietary score was created [range from -2 (unhealthy diet: high consumption of dairy and sweets, low consumption of vegetables and grains) to 2 (healthy diet: high consumption of vegetables and grains and low consumption of dairy and sweet)]. Multivariable linear or logistic regression was used to assess the relationship between dietary score and lung function or asthma exacerbations. After adjustment for covariates, a healthier diet (each 1-point increment in dietary score) was associated with significantly higher %predicted forced expiratory volume in the first second (FEV₁) and %predicted forced vital capacity (FVC) in control subjects. Dietary pattern alone was not associated with asthma exacerbations, but children with an unhealthy diet and vitamin D insufficiency (plasma 25(OH)D <30 ng/mL) had higher odds of ≥1 severe asthma exacerbation [odds ratio (OR) = 3.4, 95% confidence interval (CI) = 1.5-7.5] or ≥1 hospitalization due to asthma (OR = 3.9, 95% CI = 1.6-9.8, OR = 3.4, 95% CI = 1.5-7.5) than children who ate a healthy diet and were vitamin D sufficient. A healthy diet, with frequent consumption of vegetables and grains and low consumption of dairy products and sweets, was associated with higher lung function (as measured by FEV₁ and FVC). Vitamin D insufficiency, together with an unhealthy diet, may have detrimental effects on asthma exacerbations in children.

Cured meat intake is associated with worsening asthma symptoms

BACKGROUND

Cured meat intake-a recent carcinogenic factor-may increase the risk of COPD, but its association with asthma remains unknown. Though body mass index (BMI) is a likely risk factor for asthma, its role in the diet-asthma association as a mediator has never been studied. We investigated the association between cured meat intake and worsening asthma symptoms in adults, and the role of BMI as a potential mediator.

METHODS

Using data from the French prospective EGEA study (baseline: 2003-2007; follow-up: 2011-2013), we applied a mediation analysis in the counterfactual framework, a marginal structural model (MSM), to estimate the direct effect of baseline cured meat intake (<1, 1-3.9, ≥4 servings/week) on change in asthma symptom score (worsening or not), and the indirect effect mediated by BMI.

RESULTS

Among the 971 participants (mean age 43 years; 49% men; 42% with asthma), 20% reported worsening asthma symptoms during the mean follow-up time of 7 years. Using the MSM, we reported a positive direct effect of cured meat intake on worsening asthma symptoms (multivariable OR=1.76, 95% CI 1.01 to 3.06 for ≥4 vs <1 serving/week). We also reported an indirect effect mediated by BMI (OR=1.07; 95% CI 1.01 to 1.14), accounting for 14% of the total effect.

CONCLUSIONS

Higher cured meat intake was associated with worsening asthma symptoms over time, through a direct effect and to a lesser extent an effect mediated by BMI. This research extends the effect of diet on asthma in adults.

Consumption of Unprocessed and Processed Red Meat and the Risk of Chronic Obstructive Pulmonary Disease: A Prospective Cohort Study of Men

Consumption of both processed and unprocessed red meat has been associated with a higher risk of major chronic diseases. However, only processed meat consumption has been studied in relation to chronic obstructive pulmonary disease (COPD). Therefore, we endeavored to determine the association between the risk of COPD and consumption of processed and unprocessed red meat while taking into account smoking status. The population-based prospective Cohort of Swedish Men included 43,848 men who were 45-79 years of age and had no history of COPD or cancer at baseline. Meat consumption was assessed using a self-administered questionnaire in 1997. During 13.2 years of follow-up, 1,909 COPD cases were ascertained. Consumption of processed meat was associated with risk of COPD: Compared with men who consumed less than 25 g/day of processed meat, men who consumed 75 g/day or more had a multivariable-adjusted hazard ratio of 1.21 (95% confidence interval: 1.02, 1.44; P for trend = 0.03). The positive association was confined to current smokers (P for interaction = 0.003); among smokers who consumed 75 g/day or more of processed red meat, the hazard ratio was 1.26 (95% confidence interval: 1.00, 1.60) when compared with persons who consumed less than 25 g/day. Consumption of unprocessed red meat was not associated with COPD incidence. Findings from this prospective study indicate that high consumption of processed red meat is associated with an increased COPD risk among smokers.

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.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0326-x) contains supplementary material, which is available to authorized users.

Alternate Healthy Eating Index 2010 and risk of chronic obstructive pulmonary disease among US women and men: prospective study

OBJECTIVE

To investigate the association between the Alternate Healthy Eating Index 2010 (AHEI-2010)--a measure of diet quality--and the risk of chronic obstructive pulmonary disease (COPD).

DESIGN

Prospective cohort study.

SETTING

Participants in the Nurses' Health Study and the Health Professionals Follow-up Study, United States.

PARTICIPANTS

73,228 female nurses from 1984 to 2000 and 47,026 men from 1986 to 1998, who completed biennial questionnaires.

MAIN OUTCOME MEASURES

The primary outcome was the self report of newly diagnosed COPD. Multivariable Cox proportional hazards models were adjusted for age, physical activity, body mass index, total energy intake, smoking, second hand tobacco exposure (only in the Nurses' Health Study), race/ethnicity, physician visits, US region, spouse's highest educational attainment (only in the Nurses' Health Study), and menopausal status (only in the Nurses' Health Study).

RESULTS

Over the study period, 723 cases of newly diagnosed COPD occurred in women and 167 in men. In the pooled analysis, a significant negative association was seen between the risk of newly diagnosed COPD and fifths of the AHEI-2010: hazard ratios were 0.81 (95% confidence interval 0.51 to 1.29) for the second fifth, 0.98 (0.80 to 1.18) for the third fifth, 0.74 (0.59 to 0.92) for the fourth fifth, and 0.67 (0.53 to 0.85) for participants who ate the healthiest diet according to the AHEI-2010 (that is, were in the highest fifth), compared with those who ate the less healthy diet (participants in the lowest fifth). Similar findings were observed among ex-smokers and current smokers.

CONCLUSIONS

A higher AHEI-2010 diet score (reflecting high intakes of whole grains, polyunsaturated fatty acids, nuts, and long chain omega-3 fats and low intakes of red/processed meats, refined grains, and sugar sweetened drinks) was associated with a lower risk of COPD in both women and men. These findings support the importance of a healthy diet in multi-interventional programs to prevent COPD.

Oxidative stress and lung function profiles of male smokers free from COPD compared to those with COPD: a case-control study

BACKGROUND

The mechanisms of smoking tobacco leading to chronic obstructive pulmonary disease (COPD) are beginning to be understood. However, conclusions about the role of blood or lung oxidative stress markers were disparate.

AIMS

To investigate the oxidative stress in blood or lung associated with tobacco smoke and to evaluate its effect on pulmonary function data and its relation with physical activity.

METHODS

It is a case-control study. Fifty-four male-smokers of more than five pack-years (PY) and aged 40-60 years were included (29 Non-COPD, 16 COPD). Physical activity score was determined. Blood sample levels of malondialdehyde (MDA), protein-cys-SH (PSH), and Glutathione (GSH) were measured. Fractional exhaled nitric oxide (FeNO) and plethysmographic measurements were performed. Correlation coefficients (r) evaluated the association between oxidative stress markers and independent variables (plethysmographic data and physical activity score).

RESULTS

Non-COPD (48 ± 6 years) and COPD (49 ± 5 years) groups had similar tobacco consumption patterns, that is, 27 ± 14 PY versus 30 ± 19 PY, respectively. Compared to the Non-COPD group, the COPD group had significantly lower levels of GSH and PSH, that is, mean ± SE were 40 ± 6 versus 25 ± 5 µg/mL and 54 ± 10 versus 26 ± 5 µg/g of hemoglobin, respectively. However, MDA level and FeNO values were similar. In the COPD group, none of the oxidative stress markers was significantly correlated with plethysmographic data or physical activity score. In the Non-COPD group, GSH was significantly correlated with physical activity score (r = 0.47) and PSH was significantly correlated with total lung capacity (TLC) (r = -0.50), residual volume (r = 0.41), and physical activity score (r = 0.62). FeNO was significantly correlated with TLC of the COPD group (r = -0.48).

CONCLUSION

Compared to the Non-COPD group, the COPD group had a marked decrease in blood antioxidant markers (GSH and PSH) but similar blood oxidant (MDA) or lung (FeNO) burden.