Processed red meat intake and risk of COPD: A systematic review and dose-response meta-analysis of prospective cohort studies

Genetic information supports a causal relationship between trace elements, inflammatory proteins, and COPD: evidence from a Mendelian randomization analysis

Objective

Dietary factors and nutritional status may be among the risk factors for Chronic Obstructive Pulmonary Disease (COPD). There exists a certain correlation between trace elements and COPD. Through Mendelian Randomization (MR) analysis, we investigated the causal relationships between trace elements, inflammatory proteins, and COPD.

Methods

We employed MR, multivariable MR (MVMR), and two-step MR (TSMR) approaches to assess the causal links between 15 trace elements and COPD, with 91 inflammatory proteins serving as mediators to further elucidate the tripartite causal relationships.

Results

Trace elements such as Folate (OR = 1.293, 95%CI 1.027-1.628; p = 0.029), Vitamin D (OR = 1.331, 95%CI 1.071-1.654; p = 0.010), Vitamin B12 (OR = 1.424, 95%CI 1.108-1.828; p = 0.006), and Iron (OR = 0.741, 95%CI 0.580-0.946; p = 0.016) demonstrated causal relationships with COPD. No causal relationship was observed in reverse MR. After adjusting for BMI, Folate (OR = 1.633, 95%CI 1.098-2.429; p = 0.015), Iron (OR = 0.507, 95%CI 0.31-0.778; p = 0.001), and Vitamin D (OR = 1.511, 95%CI 1.029-2.217; p = 0.034) were identified as independent risk factors for COPD, whereas Vitamin B12 (OR = 1.118, 95%CI 0.751-1.666; p = 0.581) was not. Mediation analysis indicated that CDCP1 (5.76%) may play a mediating role between Iron and COPD.

Conclusion

Trace elements such as Folate, Vitamin D, Vitamin B12, and Iron have causal relationships with COPD. After BMI adjustment, Folate, Vitamin D, and Iron emerge as independent risk factors. Furthermore, the inflammatory protein CDCP1 may partially mediate the causal relationship between Iron and COPD, offering a scientific basis for dietary recommendations that could benefit COPD patients. The supplementation of trace elements may be advantageous for individuals suffering from COPD.

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.

Breath of fresh air: Investigating the link between AGEs, sRAGE, and lung diseases

Advanced glycation end products (AGEs) are compounds formed via non-enzymatic reactions between reducing sugars and amino acids or proteins. AGEs can accumulate in various tissues and organs and have been implicated in the development and progression of various diseases, including lung diseases. The receptor of advanced glycation end products (RAGE) is a receptor that can bind to advanced AGEs and induce several cellular processes such as inflammation and oxidative stress. Several studies have shown that both AGEs and RAGE play a role in the pathogenesis of lung diseases, such as chronic obstructive pulmonary disease, asthma, idiopathic pulmonary fibrosis, cystic fibrosis, and acute lung injury. Moreover, the soluble form of the receptor for advanced glycation end products (sRAGE) has demonstrated its ability to function as a decoy receptor, possessing beneficial characteristics such as anti-inflammatory, antioxidant, and anti-fibrotic properties. These qualities make it an encouraging focus for therapeutic intervention in managing pulmonary disorders. This review highlights the current understanding of the roles of AGEs and (s)RAGE in pulmonary diseases and their potential as biomarkers and therapeutic targets for preventing and treating these pathologies.

Exploring the association between ultra-processed foods and COPD: a case-control study

BACKGROUND

While it is known that the overconsumption of ultra-processed foods (UPFs) is associated with a heightened risk of respiratory ailments, the specific effects of UPF intake on COPD remain unclear. This study was designed to explore the potential link between COPD and the consumption of UPFs among adult individuals in Iran.

METHODS

In this hospital-based case-control study conducted at Alzahra University Hospital in Isfahan, Iran, we enrolled 84 patients newly diagnosed with COPD, along with 252 healthy controls matched for age and sex. COPD was defined based on the results of spirometry tests, specifically when the forced expiratory volume per second (FEV1) was less than 80% or the ratio of FEV1 to forced vital capacity (FVC) was less than 70%. To evaluate the dietary intake of the participants, we utilized a validated food frequency questionnaire (FFQ) consisting of 168 items. Additionally, we gathered data on potential confounding factors using a pre-tested questionnaire.

RESULTS

The mean ages for the case and control groups were 57.07 and 55.05 years, respectively. Our study found no significant association between the intake of ultra-processed foods (UPFs) and the likelihood of COPD, with an odds ratio (OR: 0.78, 95% CI: 0.34-1.77). This lack of association persisted even after adjusting for factors such as energy intake, sex, and age (OR: 0.48; 95% CI: 0.19-1.21). Further controlling for potential confounders like body mass index (BMI), physical activity, and smoking status did not alter this finding (OR: 0.367; 95% CI: 0.123-1.1008, P = 0.074).

CONCLUSIONS

In our study, we observed no significant association between the intake of Ultra-Processed Foods (UPFs) and the odds of Chronic Obstructive Pulmonary Disease (COPD). This finding remained consistent even after adjusting for factors such as energy intake, sex, age, Body Mass Index (BMI), physical activity, and smoking status. Therefore, within the scope of our study, it appears that the consumption of UPFs does not significantly impact the likelihood of developing COPD. However, we recommend further research to deepen our understanding of the intricate relationship between dietary habits and respiratory health.

Meat and meat products - a scoping review for Nordic Nutrition Recommendations 2023

Meat is not only a source of several nutrients but also a proposed risk factor for several non-communicable diseases. Here, we describe the totality of evidence for the role of meat intake for chronic disease outcomes, discuss potential mechanistic pathways, knowledge gaps, and limitations of the literature. Use of the scoping review is based on a de novo systematic review (SR) and meta-analysis on the association between poultry intake and cardiovascular disease (CVD) and type 2 diabetes (T2D), qualified SRs (as defined in the Nordic Nutrition Recommendations 2023 project) on meat intake and cancer by the World Cancer Research Fund (WCRF), the International Agency for Research on Cancer (IARC), and a systematic literature search of SRs and meta-analyses. The quality of the SRs was evaluated using a modified AMSTAR 2 tool, and the strength of evidence was evaluated based on a predefined criteria developed by the WCRF. The quality of the SRs was on average critically low. Our findings indicate that the evidence is too limited for conclusions for most of the chronic disease outcomes. However, findings from qualified SRs indicate strong evidence that processed meat increases the risk of colorectal cancer and probable evidence that red meat (unprocessed, processed, or both) increases the risk. The evidence suggests that both unprocessed red meat and processed meat (also including processed poultry meat) are probable risk factors for CVD mortality and stroke, and that total red meat and processed meat are risk factors for CHD. We found no sufficient evidence suggesting that unprocessed red meat, processed red meat, total red meat, or processed meat (including red and white meat) would be protective of any chronic disease. There was also no sufficient evidence to conclude on protective effect of poultry on any chronic diseases; effects on the risk of CVD, stroke, and T2D, to any direction, were regarded as unlikely.

Mendelian randomization study reveals the relationship between dietary factors and respiratory diseases

The existence of causal relationship between dietary factors and respiratory diseases is uncertain. We comprehensively investigated the association between dietary factors and respiratory diseases by using Mendelian randomization (MR). Genetic variants linked to dietary factors were selected as instrumental variables with genome-wide significance. These instrumental variables were obtained from large GWAS databases. These databases include Biobank, the FinnGen study, and other large consortia. We used multivariate MR analyses to control the effects of smoking and education. Median analysis was conducted to evaluate whether body mass index (BMI) played a role in dietary factors in respiratory diseases. Dried fruit intake was found to be associated with a decreased risk of chronic obstructive pulmonary disease (COPD) (OR: 0.211; 95% CI 0.117-0.378; P < 0.001) and asthma (OR: 0.539; 95% CI 0.357-0.815; P = 0.003). Conversely, pork intake was associated with an increased risk of international pharmaceutical federation (IPF) (OR: 1.051*102, 95% CI 4.354-2.56*103, P = 0.004). However, no significant associations were observed between the 20 dietary factors and obstructive sleep apnea (OSA). In addition, multivariate MR analyses showed that the above results were unchanged in smoking and nonsmoking populations, while the effect of dried fruit intake on asthma was significantly attenuated after corrective education. The results of the mediator variable analysis indicated that BMI could serve as a mediator of the above results. This study found that dried fruits slowed the progression of COPD and asthma, while pork promoted IPF. However, no effect of dietary factors on OSA was found. Meanwhile, we showed that the above results were unchanged in smoking and non-smoking populations. In contrast, education could influence the role of diet on asthma, and BMI could be used as a mediating variable to influence the above results.

A Kano model-based demand analysis and perceived barriers of pulmonary rehabilitation interventions for patients with chronic obstructive pulmonary disease in China

BACKGROUND

Pulmonary rehabilitation (PR) has been recognized to be an effective therapy for chronic obstructive pulmonary disease (COPD). However, in China, the application of PR interventions is still less promoted. Therefore, this cross-sectional study aimed to understand COPD patients' intention to receive PR, capture the potential personal, social and environmental barriers preventing their willingness of receiving PR, and eventually identify demanding PR services with the highest priority from patients' point of view.

METHODS

In total 237 COPD patients were recruited from 8 health care facilities in Zhejiang, China. A self-designed questionnaire was applied to investigate patients' intention to participate in PR and potentially associated factors, including personal dimension such as personal awareness, demographic factors, COPD status and health-related literacy/behaviors, as well as social policies and perceived environmental barriers. The demand questionnaire of PR interventions based on the Kano model was further adopted.

RESULTS

Among the 237 COPD patients, 75.1% of COPD patients were willing to participate in PR interventions, while only 62.9% of the investigated patients had heard of PR interventions. Over 90% of patients believed that the cost of PR services and the ratio of medical insurance reimbursement were potential obstacles hindering them from accepting PR services. The multiple linear regression analysis indicated that the PR skills of medical staff, knowledge promotion and public education levels of PR in the community, patients' transportation concerns and degree of support from family and friends were significantly associated with willingness of participation in PR interventions. By using the Kano model, the top 9 most-requisite PR services (i.e., one-dimensional qualities) were identified from patients' point of view, which are mainly diet guidance, education interventions, psychological interventions and lower limb exercise interventions. Subgroup analysis also revealed that patients' demographics, such as breathlessness level, age, education and income levels, could influence their choice of priorities for PR services, especially services related to exercise interventions, respiratory muscle training, oxygen therapy and expectoration.

CONCLUSIONS

This study suggested that PR-related knowledge education among patients and their family, as well as providing basic package of PR services with the most-requisite PR items to COPD patients, were considerable approaches to promote PR attendance in the future.

Ultra-processed food consumption, mediating biomarkers, and risk of chronic obstructive pulmonary disease: a prospective cohort study in the UK Biobank

Background: Ultra-processed food (UPF) is a popular supplement in the UK and other developed countries. However, whether and how UPF intake is associated with chronic obstructive pulmonary disease (COPD) remains unclear. Objective: We aimed to examine the association between UPF consumption and COPD incidence and explore the potential mediating effects of COPD-related biomarkers. Methods: This prospective cohort study included 207 002 participants without COPD at recruitment and completed 24-hour dietary recalls. UPF was defined according to the NOVA classification system. Incident COPD was ascertained using electronic hospital and mortality records. Cox regression models were used to estimate UPF consumption and the subsequent risk of COPD. Substitution analysis was performed to assess the risk of COPD by substituting UPF with an equivalent proportion of unprocessed or minimally processed food (UNPF). Mediation analyses were performed to evaluate the contribution of biomarkers related to the lipid profile, glucose metabolism, and systemic inflammation to the observed associations. Results: During a median follow-up of 13.1 (interquartile range: 12.5-13.9) years, 4670 COPD events were recorded. The adjusted hazard ratio (HR) of COPD in the highest quintile versus the lowest quintile of the UPF consumption proportion (weight percentage of the UPF) was 1.22 (95% confidence interval [CI]: 1.11-1.34). There was a 10% elevated risk of COPD incidence per SD increase in UPF intake (HR: 1.10; 95% CI: 1.08-1.13). Replacing 20% of the UNPF weight with the UPF was associated with a 13% decrease in COPD risk (95% CI: 0.84-0.91). In mediation analyses, biomarkers explained 1.0-10.1% of the association between UPF intake and COPD. Results from stratified and sensitivity analyses further support the robustness of these findings. Conclusions: Elevated UPF consumption was associated with a higher risk of COPD, and this association was primarily mediated by glucose, inflammation, and lipids, whereas substituting UNPF for UPF was associated with a decreased risk of COPD.

The Possible Role of Food and Diet in the Quality of Life in Patients with COPD-A State-of-the-Art Review

Diet has been described as a modifiable risk factor for the development and progression of chronic diseases, and emerging evidence increasingly points to its preventive and therapeutic role in chronic obstructive pulmonary disease (COPD). While the relationship between the underlying disease and diet is natural in conditions such as metabolic disorders, obesity, diabetes, etc., the direct effect is not so evident in chronic obstructive pulmonary disease. Poor diet quality and the development of nutrient deficiencies in respiratory diseases, including COPD, can be associated with disease-specific factors such as the exacerbation of respiratory symptoms. These symptoms can be improved by dietary interventions, leading to positive changes in the pathogenesis of the disease and the quality of life of patients. Therefore, our aim was to review the latest randomized controlled trials (RCTs) of dietary interventions in chronic respiratory patients and describe their effects on respiratory function, physical activity, systemic inflammatory parameters, and quality of life. We conducted a literature search on dietary interventions for COPD patients in the PubMed, ClinicalTrials.gov, and Cochrane Central Register of Controlled Trials (CENTRAL) databases, focusing on publications from 1 July 2018 to 1 July 2023. We used specific keywords and MESH terms, focusing on RCTs. A total of 26 articles and 1811 COPD patients were included in this review. On the basis of our findings, dietary interventions, in particular components of the Mediterranean diet such as protein, omega-3 polyunsaturated fatty acids, and vegetables, appear to have beneficial effects in patients with chronic respiratory diseases, and their application is beneficial. However, long-term follow-up studies are still needed to examine the effects of dietary interventions in this patient population.

The role of diet and nutrition in the management of COPD

In 2014, the European Respiratory Society published a statement on nutritional assessment and therapy in COPD. Since then, increasing research has been performed on the role of diet and nutrition in the prevention and management of COPD. Here, we provide an overview of recent scientific advances and clinical implications. Evidence for a potential role of diet and nutrition as a risk factor in the development of COPD has been accumulating and is reflected in the dietary patterns of patients with COPD. Consuming a healthy diet should, therefore, be promoted in patients with COPD. Distinct COPD phenotypes have been identified incorporating nutritional status, ranging from cachexia and frailty to obesity. The importance of body composition assessment and the need for tailored nutritional screening instruments is further highlighted. Dietary interventions and targeted single or multi-nutrient supplementation can be beneficial when optimal timing is considered. The therapeutic window of opportunity for nutritional interventions during and recovering from an acute exacerbation and hospitalisation is underexplored.

Identifying risk factors for COPD and adult-onset asthma: an umbrella review

BACKGROUND

COPD and adult-onset asthma (AOA) are the most common noncommunicable respiratory diseases. To improve early identification and prevention, an overview of risk factors is needed. We therefore aimed to systematically summarise the nongenetic (exposome) risk factors for AOA and COPD. Additionally, we aimed to compare the risk factors for COPD and AOA.

METHODS

In this umbrella review, we searched PubMed for articles from inception until 1 February 2023 and screened the references of relevant articles. We included systematic reviews and meta-analyses of observational epidemiological studies in humans that assessed a minimum of one lifestyle or environmental risk factor for AOA or COPD.

RESULTS

In total, 75 reviews were included, of which 45 focused on risk factors for COPD, 28 on AOA and two examined both. For asthma, 43 different risk factors were identified while 45 were identified for COPD. For AOA, smoking, a high body mass index (BMI), wood dust exposure and residential chemical exposures, such as formaldehyde exposure or exposure to volatile organic compounds, were amongst the risk factors found. For COPD, smoking, ambient air pollution including nitrogen dioxide, a low BMI, indoor biomass burning, childhood asthma, occupational dust exposure and diet were amongst the risk factors found.

CONCLUSIONS

Many different factors for COPD and asthma have been found, highlighting the differences and similarities. The results of this systematic review can be used to target and identify people at high risk for COPD or AOA.

Healthful and Unhealthful Plant-Based Diets and Chronic Obstructive Pulmonary Disease in U.S. Adults: Prospective Study

BACKGROUND

Despite the potential protective effect of a plant-based diet against chronic obstructive pulmonary disease (COPD), it remains unknown whether intake of different types of plant foods is beneficial for COPD. Our aims were to determine whether adherence to the healthful version of a plant-based diet (healthful Plant-based Diet Index (hPDI)) is associated with a lower COPD risk, whereas adherence to the unhealthful version (unhealthful Plant-based Diet Index (uPDI)) is associated with a higher COPD risk.

METHODS

46,948 men from the Health Professionals Follow-up Study, 73,592 women from the Nurses' Health Study, and 85,515 women from the Nurses' Health Study II who completed biennial questionnaires from 1984-2018. We derived diet scores from repeated validated food frequency questionnaires. Among 5,661,994 person-years of follow-up, we documented 2605 validated COPD cases between 1984-2018.

RESULTS

After tight control for smoking and other potential confounders, COPD risk was 46% lower among participants with the highest hPDI score compared to those with the lowest score. Conversely, COPD risk was 39% higher among participants with the highest uPDI. Further adjustment for processed meat intake led to similar results.

CONCLUSIONS

These findings provide further evidence for consuming a diet that emphasizes healthful plant foods to optimize lung health.

Red/processed meat consumption and non-cancer-related outcomes in humans: umbrella review

The associations of red/processed meat consumption and cancer-related health outcomes have been well discussed. The umbrella review aimed to summarise the associations of red/processed meat consumption and various non-cancer-related outcomes in humans. We systematically searched the systematic reviews and meta-analyses of associations between red/processed meat intake and health outcomes from PubMed, Embase, Web of Science and the Cochrane Library databases. The umbrella review has been registered in PROSPERO (CRD 42021218568). A total of 40 meta-analyses were included. High consumption of red meat, particularly processed meat, was associated with a higher risk of all-cause mortality, CVD and metabolic outcomes. Dose-response analysis revealed that an additional 100 g/d red meat intake was positively associated with a 17 % increased risk of type 2 diabetes mellitus (T2DM), 15 % increased risk of CHD, 14 % of hypertension and 12 % of stroke. The highest dose-response/50 g increase in processed meat consumption at 95 % confident levels was 1·37, 95 % CI (1·22, 1·55) for T2DM, 1·27, 95 % CI (1·09, 1·49) for CHD, 1·17, 95 % CI (1·02, 1·34) for stroke, 1·15, 95 % CI (1·11, 1·19) for all-cause mortality and 1·08, 95 % CI (1·02, 1·14) for heart failure. In addition, red/processed meat intake was associated with several other health-related outcomes. Red and processed meat consumption seems to be more harmful than beneficial to human health in this umbrella review. It is necessary to take the impacts of red/processed meat consumption on non-cancer-related outcomes into consideration when developing new dietary guidelines, which will be of great public health importance. However, more additional randomised controlled trials are warranted to clarify the causality.

Efficacy of Xiyanping in the Treatment of Elderly Patients with Chronic Obstructive Pulmonary Disease and Its Effect on the Expression of GDF-15 and HIF-1α in Serum

Background

COPD is a chronic respiratory disease with a long course and recurrent characteristics. According to relevant statistics, the global incidence of COPD is more than 30%, which seriously affects the life of patients and endangers their health.

Objective

To observe the curative effect of Xiyanping in elderly patients with COPD and its influence on the expressions of growth differentiation GDF-15 and HIF-1α in serum.

Methods

From August 2019 to December 2021, 86 elderly patients with acute exacerbation of COPD were admitted to our hospital. As the research objects, they were divided into the control group (n = 43) and the observation group (n = 43) randomly. The control group received the conventional treatment, while the observation group got Xiyanping on the basis of the control group. The differences in the duration of antibiotic use, expectoration, hospital stays, adverse reactions and serum-related factors, blood routine, pulmonary function, airway hyperreactivity index, COPD assessment test (CAT) score, and Borg score were made a comparison between them.

Results

On the 3rd and 7th days after being treated, the sputum excretion in them was higher than before, but on the 3rd day of treatment, the sputum excretion in the observation group was higher than that in the control group, while on the 7th day of treatment, the sputum excretion was lower than that in the control group with statistically significant differences (P < 0.05). Before treatment, the serum-related factors and blood routine indexes between them were similar (P > 0.05). After treatment, GDF-15, HIF-1α, CXCL12, TNF-α, IL-8, TGF-β, WBC, and NEU in them were significantly lower than before, and the values in the observation group were significantly lower than those in the control group with statistically significant differences (P < 0.05). There was no difference in the related indexes of pulmonary function and airway hyperreactivity between them before treatment. After being treated, FEV1, FVC, and FEV1/FVC in them were significantly higher than those before treatment. The airway resistance and lung compliance of the two groups at exhalation and inspiration were significantly lower than before, and the values in the observation group were significantly lower than those in the control group (P < 0.05). There was no difference in CAT and Borg scores between them before treatment. After treatment, the CAT score and Borg score of these patients were significantly lower than those before treatment, and the value of the observation group was significantly lower than that of the control group (P < 0.05). The duration of antibiotic use and length of stay in the observation group were significantly shorter than those of the control group, while the incidence of adverse reactions was not statistically significantly different compared with the control group (P > 0.05).

Conclusion

Xiyanping can improve pulmonary function of elderly patients with acute exacerbation of COPD, reduce the response of airway hyperreactivity, and promote the excretion of sputum.

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.

Epidemiological evidence relating risk factors to chronic obstructive pulmonary disease in China: A systematic review and meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD), the most common chronic respiratory disease worldwide, not only leads to the decline of pulmonary function and quality of life consecutively, but also has become a major economic burden on individuals, families, and society in China. The purpose of this meta-analysis was to explore the risk factors for developing COPD in the Chinese population that resides in China and to provide a theoretical basis for the early prevention of COPD.

METHODS

A total of 2457 cross-sectional, case-control, and cohort studies published related to risk factors for COPD in China were searched. Based on the inclusion and exclusion criteria, 20 articles were selected. Stata 11.0 was used for meta-analysis. After merging the data, the pooled effect and 95% confidence intervals (CIs) were calculated to assess the association between risk factors and COPD. Heterogeneity between studies was assessed using I2 and Cochran's Q tests. Begg's test was used to assess publication bias.

RESULTS

Exposure to particulate matter less than 2.5 μm in diameter (PM2.5) (pooled effect = 1.73; 95%CI: 1.16~2.58; P <0.01), smoking history (pooled effect = 2.58; 95%CI: 2.00~3.32; P <0.01), passive smoking history (pooled effect = 1.39; 95%CI: 1.03~1.87; P = 0.03), male sex(pooled effect = 1.70; 95%CI: 1.31~2.22; P <0.01), body mass index (BMI) <18.5 kg/m2 (pooled effect = 1.73; 95%CI: 1.32~2.25; P <0.01), exposure to biomass burning emissions (pooled effect = 1.65; 95%CI: 1.32~2.06; P <0.01), childhood respiratory infections (pooled effect = 3.44; 95%CI: 1.33~8.90; P = 0.01), residence (pooled effect = 1.24; 95%CI: 1.09~1.42; P <0.01), and a family history of respiratory diseases (pooled effect = 2.04; 95%CI: 1.53~2.71; P <0.01) were risk factors for COPD in the Chinese population.

CONCLUSION

Early prevention of COPD could be accomplished by quitting smoking, reducing exposure to air pollutants and biomass burning emissions, maintaining body mass index between 18.5 kg/m2 and 28 kg/m2, protecting children from respiratory infections, adopting active treatments to children with respiratory diseases, and conducting regular screening for those with family history of respiratory diseases.

Dietary Behaviour and Nutrition in Patients with COPD Treated with Long-Term Oxygen Therapy

BACKGROUND

It is the first study in Poland and one of the first in the world to assess the nutrition of patients with chronic obstructive pulmonary disease (COPD) treated with long-term oxygen therapy (LTOT).

METHODS

The study group consisted of 110 COPD patients treated with LTOT. Anthropometric measurements and spirometry were performed. The diet of patients was assessed using a 3-day nutrition diary.

RESULTS

When assessing the degree of airflow obstruction (FEV1% N) depending on the BMI in patients treated with LTOT, a statistically significant correlation was demonstrated between the BMI and the value of the FEV% N parameter (p = 0.0093). Patients with COPD with a BMI >30 had statistically significantly higher values of FEV1% N than patients with a BMI in the range of 20-24.9 (p = 0.0278). Intake of calcium, vitamins A, C, D, E and folates was lower than the recommended daily intake in more than 95% of COPD patients.

CONCLUSIONS

The diet of COPD patients treated with long-term oxygen therapy was improperly balanced, with deficiencies of important nutrients. Airflow obstruction in the respiratory tract was significantly smaller in obese patients, and greater in patients with diagnosed malnutrition.

Effects of Nutritional Interventions in Individuals with Chronic Obstructive Lung Disease: A Systematic Review of Randomized Controlled Trials

Background

The role of nutrition and dietary patterns has been widely investigated in cancer, cardiovascular disease, and diabetes, but there are limited data on nutritional impact on COPD. This systematic review (PROSPERO-reg. no: CRD42020172712) aimed to investigate the effect of nutritional interventions on pulmonary and physical function, inflammation, and health-related quality of life among individuals with COPD.

Methods

Systematic searches were conducted in Medline, Embase, and Cochrane, resulting in 3861 references. Studies focusing exclusively on inpatient-stays, underweight or obese patients were excluded. Double screening, extraction and bias assessment were conducted. Bias was assessed according to the Cochrane risk of bias tool for randomized controlled trials. Thirteen randomized controlled trials with 916 participants were included.

Results

These trials investigated effects of protein supplementation, beetroot juice, increased fruit and vegetable intake, black seed oil, Tualang honey, Chlorella vulgaris-extract, whey-peptide containing nutritional drink, and increased macronutrient intake. The durations of the interventions were from weeks to a few months, and only one with duration >1 year (investigating increased fruit/vegetable intake). The intervention increasing fruit/vegetables found improvement in pulmonary function tests. Some interventions observed effects on systemic inflammation, health-related quality of life and physical function, although with some mixed results. Five were classified as poor, five as fair, and three as good in terms of risk of bias and quality.

Conclusion

Increasing intake of fruits and vegetables over prolonged periods might have positive effects on lung function in individuals with COPD. Some nutritional interventions also observed effects on systemic inflammation, health-related quality of life, and physical function, although with some mixed results. Many of the trials were underpowered, had high dropout rates, or had a high risk of bias. Further research should investigate effect of prolonged dietary interventions.

Association Between Diet-Related Inflammation and COPD: Findings From NHANES III

Background and Aims: Little is known about diet-related inflammation in chronic obstructive pulmonary disease (COPD). In this study, we aimed to explore the association between COPD and dietary inflammatory index (DII) scores in adults over 40 years old.

Methods: Data were obtained from the 2013 to 2018 National Health and Nutrition Examination Survey (NHANES). In the present study, 9,929 participants were included and analyzed. The DII score was calculated and divided into tertiles. Logistic regression analysis was performed to determine the odds ratios of DII tertiles.

Results: Participants were categorized into COPD (565, 5.69%) and non-COPD groups (9,364, 94.31%) according to interview information. COPD individuals had higher DII scores than non-COPD individuals (0.429 ± 1.809 vs. −0.191 ± 1.791, p < 0.001). The highest DII score tertile included 46.55% of COPD individuals was associated with lower family incomes and education and a higher smoking rate (p < 0.01). The odds ratios (95% CIs) of COPD according to logistic regression were 0.709 (0.512–0.982) for T1 and 0.645 (0.475–0.877) for T2 of the DII score (p = 0.011).

Conclusion: Higher DII scores were positively correlated with COPD in participants over 40 years old. These results further support that diet can be used as an intervention strategy for COPD management.

Effectiveness of a Motivational Nutritional Intervention through Social Networks 2.0 to Increase Adherence to the Mediterranean Diet and Improve Lung Function in Active Smokers: The DIET Study, a Randomized, Controlled and Parallel Clinical Trial in Primary Care

BACKGROUND

Diet can help preserve lung function in smokers, as well as aid individuals who avoid smoking. This study aimed to evaluate the effectiveness of a nutritional intervention, using the Social Networks 2.0 tool, to increase adherence to the Mediterranean diet (MD) and improve lung function in smokers without prior respiratory disease.

METHODS

A randomized controlled parallel design was used. The participants were assigned to either the intervention or control group. Data from representative smokers without respiratory disease (n = 77) aged 18-70 years were analyzed. The participants completed a validated semi-quantitative food-frequency questionnaire, and their adherence to the diet was evaluated by using the questionnaire called the Mediterranean Diet Adherence Score (MEDAS, with 14 items), which considers ≥9 points to indicate high adherence. The lung function was assessed by spirometry. Associations among variables were determined by logistic regression.

RESULTS

A comparison of the variables at the end of the study between the control and intervention groups showed that the intervention significantly increased adherence to the MD based on the MEDAS questionnaire (0.69 (2.1) vs. 2.05 (2.03); p = 0.009). Specifically, the consumption of fruits was increased after two years in both groups; however, a more significant increase was detected in the intervention group (121 (178) vs. 12.7 (167) in the control group; p-value = 0.008). In the unadjusted analysis, the intervention only showed a statistical significant increase in the score of adherence to the MD (β: 1.36; 95% CI 0.35; 2.3; p = 0.009), and this increase was maintained after adjusting for age and sex (β: 1.15; 95% CI 0.05; 2.2; p = 0.040) and after adjusting for various sociodemographic, lifestyle and anthropometric variables (β: 1.17; 95% CI 0.02; 2.31; p = 0.046). The pulmonary function parameters improved more in the intervention group; however, no significant differences were observed between the two groups.

CONCLUSIONS

A nutritional intervention based on a dietetic-nutritional education program resulted in a significant increase in adherence to the MD. However, some evidence suggests that an MD dietary intervention can improve lung function, but in our study, we were not able to demonstrate this. Further research is needed to obtain more robust data and confirm a possible benefit of the program before it can be extended to general practice.

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.

Adherence to Low Carbohydrate Diet in Relation to Chronic Obstructive Pulmonary Disease

Purpose: Data on the link between adherence to low-carbohydrate diet (LCD) and odds of chronic obstructive pulmonary disease (COPD) are scarce. The current study aimed to investigate the relation between adherence to LCD and COPD in Iranian adults.

Methods: In this hospital-based case-control study, we enrolled 84 newly-diagnosed COPD patients and 252 age and sex matched healthy controls in Alzahra University Hospital, Isfahan, Iran. COPD was defined based on findings of spirometry test (forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) < 70% or FEV1 < 80%). Dietary intakes of study participants were assessed using the validated Block-format 168-item FFQ. Data on potential confounders were also collected through the use of a pre-tested questionnaire.

Results: Mean age of cases and controls were 57.7 and 55.07 years, respectively. Adherence to LCD was inversely associated with odds of COPD (0.35; 95% CI: 0.16-0.75). This inverse association did not alter after controlling for age, sex, and energy intake (0.42; 95% CI: 0.19-0.93). Adjustments for other potential confounders, including dietary intakes, smoking, and educational status, did not affect these findings; such that those in the highest quintile of LCD score were 64% less likely to have COPD than those in the lowest quintile (OR: 0.36; 95% CI: 0.13-0.99).

Conclusion: We found an inverse association between adherence to LCD and odds of COPD. The association remained statistically significant even after taking other potential confounders, including socioeconomic characteristic and dietary intakes into account.

Daily Vegetables Intake and Response to COPD Rehabilitation. The Role of Oxidative Stress, Inflammation and DNA Damage

Chronic obstructive pulmonary disease (COPD) is a respiratory disease associated with airways inflammation and lung parenchyma fibrosis. The primary goals of COPD treatment are to reduce symptoms and risk of exacerbations, therefore pulmonary rehabilitation is considered the key component of managing COPD patients. Oxidative airway damage, inflammation and reduction of endogenous antioxidant enzymes are known to play a crucial role in the pathogenesis of COPD. Recently, also natural antioxidants have been considered as they play an important role in metabolism, DNA repair and fighting the effects of oxidative stress. In this paper we evaluated the response of 105 elderly COPD patients to pulmonary rehabilitation (PR), based on high or low vegetable consumption, by analyzing clinical parameters and biological measurements at baseline and after completion of the three weeks PR. We found that daily vegetable intake in normal diet, without any specific intervention, can increase the probability to successfully respond to rehabilitation (65.4% of responders ate vegetables daily vs. 40.0% of non-responders, p = 0.033). The association was especially evident in subjects ≥ 80 year of age (OR = 17.0; p < 0.019). Three weeks of pulmonary rehabilitation are probably too short to reveal a reduction of the oxidative stress and DNA damage, but are enough to show an improvement in the patient’s inflammatory state.

A Case-Control Study on Dietary Acid Load in Relation to Glioma

Limited data are available linking dietary factors to glioma. The current study was conducted to investigate the association between Dietary Acid Load (DAL) and odds of glioma in Iranian adults. This case-control study was done on 128 newly diagnosed patients with glioma and 256 healthy controls in Tehran, Iran. A validated detailed food frequency questionnaire (FFQ) was used to assess dietary intakes of participants. DAL was estimated using the protein to potassium ratio (Pro: K). Glioma was diagnosed based on pathological tests. A detailed questionnaire including several non-dietary confounders was also completed. Participants in the highest tertile of DAL score had a non-significant higher odds of glioma as compared to those in the lowest tertile (OR: 1.50; 95% CI: 0.88-2.57), which remained after controlling for some potential confounders (OR: 1.66; 0.70-3.91). After further adjustment for dietary intakes of meats and processed meats, legumes and nuts, fruits, salt tea, and coffee, those in the top tertile of DAL score were significantly more likely to have glioma than those in the bottom tertile (OR: 3.09; 95% CI: 1.06, 8.99; P = 0.03). This association was also reached following further adjustment for BMI (OR: 3.05; 95% CI: 1.04, 8.91; P = 0.03). We found a significant positive association between dietary acid load, as estimated by Prot:K ratio, and odds of glioma among adults. Further studies, in particular prospective cohorts with long-term follow up, are required to confirm these findings.

Impact of Mediterranean Diet on Chronic Non-Communicable Diseases and Longevity

The average life expectancy of the world population has increased remarkably in the past 150 years and it is still increasing. A long life is a dream of humans since the beginning of time but also a dream is to live it in good physical and mental condition. Nutrition research has focused on recent decades more on food combination patterns than on individual foods/nutrients due to the possible synergistic/antagonistic effects of the components in a dietary model. Various dietary patterns have been associated with health benefits, but the largest body of evidence in the literature is attributable to the traditional dietary habits and lifestyle followed by populations from the Mediterranean region. After the Seven Countries Study, many prospective observational studies and trials in diverse populations reinforced the beneficial effects associated with a higher adherence to the Mediterranean diet in reference to the prevention/management of age-associated non-communicable diseases, such as cardiovascular and metabolic diseases, neurodegenerative diseases, cancer, depression, respiratory diseases, and fragility fractures. In addition, the Mediterranean diet is ecologically sustainable. Therefore, this immaterial world heritage constitutes a healthy way of eating and living respecting the environment.

Impact of Mediterranean Diet on Chronic Non-Communicable Diseases and Longevity

The average life expectancy of the world population has increased remarkably in the past 150 years and it is still increasing. A long life is a dream of humans since the beginning of time but also a dream is to live it in good physical and mental condition. Nutrition research has focused on recent decades more on food combination patterns than on individual foods/nutrients due to the possible synergistic/antagonistic effects of the components in a dietary model. Various dietary patterns have been associated with health benefits, but the largest body of evidence in the literature is attributable to the traditional dietary habits and lifestyle followed by populations from the Mediterranean region. After the Seven Countries Study, many prospective observational studies and trials in diverse populations reinforced the beneficial effects associated with a higher adherence to the Mediterranean diet in reference to the prevention/management of age-associated non-communicable diseases, such as cardiovascular and metabolic diseases, neurodegenerative diseases, cancer, depression, respiratory diseases, and fragility fractures. In addition, the Mediterranean diet is ecologically sustainable. Therefore, this immaterial world heritage constitutes a healthy way of eating and living respecting the environment.

Mediterranean-Type Dietary Pattern and Physical Activity: The Winning Combination to Counteract the Rising Burden of Non-Communicable Diseases (NCDs)

Non-communicable diseases (NCDs) (mainly cardiovascular diseases, cancers, chronic respiratory diseases and type 2 diabetes) are the main causes of death worldwide. Their burden is expected to rise in the future, especially in less developed economies and among the poor spread across middle- and high-income countries. Indeed, the treatment and prevention of these pathologies constitute a crucial challenge for public health. The major non-communicable diseases share four modifiable behavioral risk factors: unhealthy diet, physical inactivity, tobacco usage and excess of alcohol consumption. Therefore, the adoption of healthy lifestyles, which include not excessive alcohol intake, no smoking, a healthy diet and regular physical activity, represents a crucial and economical strategy to counteract the global NCDs burden. This review summarizes the latest evidence demonstrating that Mediterranean-type dietary pattern and physical activity are, alone and in combination, key interventions to both prevent and control the rise of NCDs.

Dietary phenotype and advanced glycation end-products predict WTC-obstructive airways disease: a longitudinal observational study

BACKGROUND

Diet is a modifier of metabolic syndrome which in turn is associated with World Trade Center obstructive airways disease (WTC-OAD). We have designed this study to (1) assess the dietary phenotype (food types, physical activity, and dietary habits) of the Fire Department of New York (FDNY) WTC-Health Program (WTC-HP) cohort and (2) quantify the association of dietary quality and its advanced glycation end product (AGE) content with the development of WTC-OAD.

METHODS

WTC-OAD, defined as developing WTC-Lung Injury (WTC-LI; FEV1 < LLN) and/or airway hyperreactivity (AHR; positive methacholine and/or positive bronchodilator response). Rapid Eating and Activity Assessment for Participants-Short Version (REAP-S) deployed on 3/1/2018 in the WTC-HP annual monitoring assessment. Clinical and REAP-S data of consented subjects was extracted (7/17/2019). Diet quality [low-(15-19), moderate-(20-29), and high-(30-39)] and AGE content per REAP-S questionnaire were assessed for association with WTC-OAD. Regression models adjusted for smoking, hyperglycemia, hypertension, age on 9/11, WTC-exposure, BMI, and job description.

RESULTS

N = 9508 completed the annual questionnaire, while N = 4015 completed REAP-S and had spirometry. WTC-OAD developed in N = 921, while N = 3094 never developed WTC-OAD. Low- and moderate-dietary quality, eating more (processed meats, fried foods, sugary drinks), fewer (vegetables, whole-grains),and having a diet abundant in AGEs were significantly associated with WTC-OAD. Smoking was not a significant risk factor of WTC-OAD.

CONCLUSIONS

REAP-S was successfully implemented in the FDNY WTC-HP monitoring questionnaire and produced valuable dietary phenotyping. Our observational study has identified low dietary quality and AGE abundant dietary habits as risk factors for pulmonary disease in the context of WTC-exposure. Dietary phenotyping, not only focuses our metabolomic/biomarker profiling but also further informs future dietary interventions that may positively impact particulate matter associated lung disease.

Adherence to a Mediterranean-like Diet as a Protective Factor Against COPD: A Nested Case-Control Study

A diet rich in nutrients has been suggested to have protective effects against the development of chronic obstructive pulmonary disease (COPD). Since the traditional Mediterranean diet is high in nutrients, including antioxidants, vitamins, and minerals, it is of interest to study as a protective factor against COPD. Our aim was therefore to study its associations with development of COPD using population-based prospective data from the Västerbotten Intervention Programme (VIP) cohort. Data on diet from 370 individuals, who later visited the Department of Medicine at the University Hospital, Umeå, Sweden, with a diagnosis of COPD, were compared to 1432 controls. Adherence to a Mediterranean diet was assessed by a modified version of the Mediterranean diet score (MDS). Cases were diagnosed with COPD 11.1 years (mean) (standard deviation [SD] 4.5 years) after first stating their dietary habits in the VIP at a mean age of 55.5 years (SD 6.6 years). Higher MDS was associated with a higher level of education and not living alone. After adjustment for co-habiting and education level, individuals with an intermediate MDS and those with the highest MDS had a lower odds of developing COPD (odds ratio [OR] 0.73, 95% confidence interval [CI] 0.56-0.95; OR 0.56, 95% CI 0.37-0.86, respectively). These results remained also after adjustment for smoking intensity, i.e., numbers of cigarettes smoked per day (OR 0.73, 95% CI 0.53-0.99; OR 0.59, 95% CI 0.35-0.97), respectively). To conclude, adherence to a Mediterranean-like diet seems to be inversely associated with the development of COPD.

Role of Diet in Chronic Obstructive Pulmonary Disease Prevention and Treatment

Chronic obstructive pulmonary disease is one of the leading causes of morbidity and mortality worldwide and a growing healthcare problem. Identification of modifiable risk factors for prevention and treatment of COPD is urgent, and the scientific community has begun to pay close attention to diet as an integral part of COPD management, from prevention to treatment. This review summarizes the evidence from observational and clinical studies regarding the impact of nutrients and dietary patterns on lung function and COPD development, progression, and outcomes, with highlights on potential mechanisms of action. Several dietary options can be considered in terms of COPD prevention and/or progression. Although definitive data are lacking, the available scientific evidence indicates that some foods and nutrients, especially those nutraceuticals endowed with antioxidant and anti-inflammatory properties and when consumed in combinations in the form of balanced dietary patterns, are associated with better pulmonary function, less lung function decline, and reduced risk of COPD. Knowledge of dietary influences on COPD may provide health professionals with an evidence-based lifestyle approach to better counsel patients toward improved pulmonary health.