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

Association between DASH diet and asthma symptoms among a large sample of adolescents: a cross-sectional study

BACKGROUND

The Dietary Approaches to Stop Hypertension (DASH) diet, which has a lot of emphasis on the consumption of fruits, vegetables, and whole grains, and on the other hand, the consumption of red meat and sodium is limited, due to its anti-inflammatory properties, which can be related to reducing the risk of asthma.

OBJECTIVES

The aim of this study was to determine the relationship between the DASH diet and asthma symptoms among children and adolescents.

METHODS

This cross-sectional study was conducted among7667 children (3414 boys and 4253 girls) aged 6-7 and 13-14 years living in central Iran. Dietary food consumption was assessed using a multiple-choice questionnaire. Logistic regression was used to obtain odds ratios for the association between the DASH-like diet with current asthma and asthma symptoms.

RESULTS

Our findings revealed that higher adherence to a DASH-like diet resulted in lower odds of asthma confirmed by a doctor among the whole population (OR = 0.53; 95%CI: 0.36-0.76) and also in females (OR = 0.47; 95%CI: 0.29-0.78). Moreover, the higher adherence to the DASH-like diet was inversely associated with the chance of wheezing in the past 12 months in all subjects (OR = 0.67; 95%CI: 0.51-0.86) and in boys (OR = 0.57; 95%CI: 0.38-0.85).

CONCLUSION

The findings of the present study showed that following the DASH diet can be associated with the improvement of asthma symptoms in children and adolescents. However, more research is needed to improve dietary recommendations for asthma prevention.

Longitudinal analysis of the Alternative Healthy Eating Index-2010 and incident non-communicable diseases over 15 years in the 1973-1978 cohort of the Australian Longitudinal Study on Women's Health

In studies that contain repeated measures of variables, longitudinal analysis accounting for time-varying covariates is one of the options. We aimed to explore longitudinal association between diet quality (DQ) and non-communicable diseases (NCDs). Participants from the 1973-1978 cohort of the Australian Longitudinal Study on Women's Health (ALSWH) were included, if they; responded to survey 3 (S3, 2003, aged 25-30 years) and at least one survey between survey 4 (S4, 2006) and survey 8 (S8, 2018), were free of NCDs at or before S3, and provided dietary data at S3 or S5. Outcomes were coronary heart disease (CHD), hypertension (HT), asthma, cancer (except skin cancer), diabetes mellitus (DM), depression and/or anxiety, and multimorbidity (MM). Longitudinal modelling using generalised estimation equation (GEE) approach with time-invariant (S4), time-varying (S4-S8) and lagged (S3-S7) covariates were performed. The mean (± standard deviation) of Alternative Healthy Eating Index-2010 (AHEI-2010) of participants (n = 8022) was 51·6 ± 11·0 (range: 19-91). Compared to women with the lowest DQ (AHEI-2010 quintile 1), those in quintile 5 had reduced odds of NCDs in time-invariant model (asthma: OR (95 % CI): 0·77 (0·62-0·96), time-varying model (HT: 0·71 (0·50-0·99); asthma: 0·62 (0·51-0·76); and MM: 0·75 (0·58-0·97) and lagged model (HT: 0·67 (0·49-0·91); and asthma: 0·70 (0·57-0·85). Temporal associations between diet and some NCDs were more prominent in lagged GEE analyses. Evidence of diet as NCD prevention in women aged 25-45 years is evolving, and more studies that consider different longitudinal analyses are needed.

Dietary Inflammatory Index and Clinical Outcome Measures in Adults With Moderate-to-Severe Asthma

BACKGROUND

Diet is increasingly recognized as a modifiable factor in lung health, predominantly due to the immunomodulatory effects of nutrients. The Dietary Inflammatory Index (DII) is a score developed to express the inflammatory potential of a diet.

OBJECTIVE

We aimed to assess the association of the DII and food groups, with clinical, functional, and inflammatory asthma outcomes in adults with asthma.

METHODS

Patients with moderate-to-severe asthma were included in this cross-sectional study between June 2019 and October 2021, and completed a 3-day food diary, to calculate the DII and intake of food groups (ie, fruits, whole grains, processed meats, and sugar-sweetened beverages). Functional outcomes included pulmonary function tests and the 6-minute walking distance, whereas clinical outcomes were assessed using questionnaires on asthma control, quality of life, and health care utilization. Inflammatory markers were exhaled nitric oxide and blood leukocytes, eosinophils, and IL-6. Multivariable regression analyses were used to examine the association of DII and food groups with asthma outcomes.

RESULTS

A total of 109 patients participated (35% male, mean ± standard deviation age 51.8 ± 14.2 years, body mass index 27.4 ± 5.3 kg/m2). Overall, 62% had a DII score >0, indicating a proinflammatory diet, which was not related to asthma severity. A more proinflammatory diet was consistently associated with lower forced vital capacity (%pred), but inconsistent results were observed with respect to airway obstruction. Neither the DII nor food groups were associated with clinical outcomes. Except for higher levels of exhaled nitric oxide in relation to an anti-inflammatory diet, we found no associations between inflammatory markers and the DII.

CONCLUSION

Results from this cross-sectional study among patients with moderate-to-severe asthma do not support the hypothesis that a proinflammatory diet is associated with worse asthma outcomes, although limitations in study design and dietary intake estimation should be considered. Future well-designed experimental studies are needed to assess whether targeting the inflammatory potential of diet could lead to better outcomes in adults with asthma.

Diet quality, food intake and incident adult-onset asthma: a Lifelines Cohort Study

PURPOSE

Dietary factors have been suggested as drivers of the rising prevalence of adult-onset asthma, but evidence is inconclusive, possibly due to the complex interrelation with obesity. We aim to explore the relation of diet quality and food intake with incident adult-onset asthma in normal weight and overweight adults of the prospective population-based Lifelines Cohort Study.

METHODS

Incident adult-onset asthma was defined as self-reported asthma at ± 4-year follow-up, in adults free of airway disease at baseline. Diet quality scores and food group intake were assessed at baseline. Log-binomial regression analyses were used to estimate adjusted relative risks (RR) between dietary intake (per portion) and incident adult-onset asthma, in categories of BMI (cutoff: 25 kg/m²).

RESULTS

477 incident asthma cases (75% female, 62% overweight) and 34,698 controls (60% female, 53% overweight) were identified. Diet quality-assessed by the Lifelines Diet Score and Mediterranean Diet Score-was not associated with incident adult-onset asthma in the two BMI groups. Although the dietary intake of several food groups differed between cases and controls, after adjustment for confounders only few remained associated with adult-onset asthma, including red and processed meat (RR: 0.93 per 15 g intake; 95% CI 0.86-0.99) in the normal weight group and intake of cheese (RR 1.09 per 20 g intake; 95% CI 1.00-1.17) and vegetables (RR 1.10 per 50 g intake; 95% CI 1.00-1.21) in the overweight group.

CONCLUSION

The results of this study question the role of food as a 'simple' predictor of adult-onset asthma and call for an integrative approach, including a range of modifiable lifestyle factors and further asthma phenotyping.

Alternative Healthy Eating Index-2010 and Incident Non-Communicable Diseases: Findings from a 15-Year follow up of Women from the 1973–78 Cohort of the Australian Longitudinal Study on Women’s Health

Non-communicable diseases (NCDs) and multimorbidity (≥two chronic conditions), are increasing globally. Diet is a risk factor for some NCDs. We aimed to investigate the association between diet quality (DQ) and incident NCDs. Participants were from the Australian Longitudinal Study on Women’s Health 1973–78 cohort with no NCD and completed dietary data at survey 3 (2003, aged 25–30 years) who responded to at least one survey between survey 4 (2006) and survey 8 (2018). DQ was measured by the Alternative Healthy Eating Index-2010 (AHEI-2010). Outcomes included coronary heart disease (CHD), hypertension (HT), asthma, cancer (excluding skin cancer), diabetes mellitus (DM), depression and/or anxiety, multimorbidity, and all-cause mortality. Repeated cross-sectional multivariate logistic regressions were performed to investigate the association between baseline DQ and NCDs over 15 years. The AHEI-2010 mean (±sd) for participants (n = 8017) was 51.6 ± 11.0 (range: 19–91). There was an inverse association between AHEI-2010 and incident asthma at survey 4 (OR_Q5–Q1: 0.75, 95% CI: 0.57, 0.99). Baseline DQ did not predict the occurrence of any NCDs or multimorbidity between the ages of 25–45 years. Further well-planned, large prospective studies conducted in young women are needed to explore dietary risk factors before the establishment of NCDs.

Association of the gut microbiome and metabolome with wheeze frequency in childhood asthma

BACKGROUND

While the microbiome has an established role in asthma development, less is known about its contribution to morbidity in children with asthma.

OBJECTIVE

In this ancillary study of the Vitamin D Antenatal Asthma Reduction Trial (VDAART), we analyzed the gut microbiome and metabolome of wheeze frequency in children with asthma.

METHODS

Bacterial 16S ribosomal RNA microbiome and untargeted metabolomic profiling were performed on fecal samples collected from 3-year-old children with parent-reported physician-diagnosed asthma. We analyzed wheeze frequency by calculating the proportion of quarterly questionnaires administered between ages 3 and 5 years in which parents reported the child had wheezed (wheeze proportion). Taxa and metabolites associated with wheeze were analyzed by identifying log fold changes with respect to wheeze frequency and correlation/linear regression analyses, respectively. Microbe-metabolite and microbe-microbe correlation networks were compared between subjects with high and low wheeze proportion.

RESULTS

Specific taxa, including the genus Veillonella and histidine pathway metabolites, were enriched in subjects with high wheeze proportion. Among wheeze-associated taxa, Veillonella and Oscillospiraceae UCG-005, which was inversely associated with wheeze, were correlated with the greatest number of fecal metabolites. Microbial networks were similar between subjects with low versus high wheeze frequency.

CONCLUSION

Gut microbiome features are associated with wheeze frequency in children with asthma, suggesting an impact of the gut microbiome on morbidity in childhood asthma.

The Role of Nutritional Factors in Asthma: Challenges and Opportunities for Epidemiological Research

The prevalence of asthma has nearly doubled over the last decades. Twentieth century changes in environmental and lifestyle factors, including changes in dietary habits, physical activity and the obesity epidemic, have been suggested to play a role in the increase of asthma prevalence and uncontrolled asthma worldwide. A large body of evidence has suggested that obesity is a likely risk factor for asthma, but mechanisms are still unclear. Regarding diet and physical activity, the literature remains inconclusive. Although the investigation of nutritional factors as a whole (i.e., the “diet, physical activity and body composition” triad) is highly relevant in terms of understanding underlying mechanisms, as well as designing effective public health interventions, their combined effects across the life course has not received a lot of attention. In this review, we discuss the state of the art regarding the role of nutritional factors in asthma, for each window of exposure. We focus on the methodological and conceptual challenges encountered in the investigation of the complex time-dependent interrelations between nutritional factors and asthma and its control, and their interaction with other determinants of asthma. Lastly, we provide guidance on how to address these challenges, as well as suggestions for future research.

[Diet and asthma: Better eating for better breathing?]

Inhaled therapies are the cornerstone of asthma treatment. However, according to national and international guidelines, non-pharmacological interventions should not be neglected in asthma. It has been demonstrated that a healthy diet is beneficial to general health. Recently, the effect of diet on asthma has been highlighted in many studies. Two diets have been particularly studied: the Mediterranean diet (high in fruits and vegetables and low in fat) and the Western diet (high in saturated fat and low in fruits and vegetables). A beneficial effect of the Mediterranean diet and deleterious effect of the Western diet on the development or control of asthma has been shown in some studies even after adjustment for overweight. Study findings have not been unanimous, probably related to the complexity of conducting studies on a diet that may change from day to day for any individual subject. In addition, the effect of physical exercise, which is known to be beneficial in asthma, is rarely taken into account in these studies. However, studies on diet are becoming more complex with the use of specific dietary indices, which should bring interesting data in the future.

Consumption of Lamb Meat or Basa Fish Shapes the Gut Microbiota and Aggravates Pulmonary Inflammation in Asthmatic Mice

Objective

In China, lamb and fish are well-known triggers for an asthma attack. Our investigation aims at assessing whether the long-term intake of lamb meat or Basa fish would aggravate pulmonary inflammation as well as exploring changes in the intestinal microbiota and immune cells in asthmatic mice.

Materials and Methods

The murine asthmatic model was established by intraperitoneal injection of ovalbumin (OVA) plus aluminum on day 0 and 14 and nebulization of OVA from day 21 to 27. Lamb meat or fish was administered to asthmatic mice by oral gavage from day 0 to 27.

Results

Our results showed that long-term consumption of lamb meat or Basa fish in asthmatic mice increased the number of inflammatory cells in bronchoalveolar lavage fluid (BALF), enhanced levels of IL-5, IL-13 in BALF and total IgE in serum, aggravated pulmonary inflammatory cell infiltration and mucus secretion. Long-term oral lamb enhanced the proportion of type 2 innate lymphoid cells (ILC2) from small intestine while it inhibited that of Treg from lung in asthmatic mice. Oral fish showed no remarkable effect on that of ILC2 from lung and small intestine but inhibited that of intestinal Treg in asthmatic mice. What’s more, the chao-1 and observed species richness as well as PD whole tree diversity increased in asthmatic mice while these increments were inhibited after lamb treatment. PCA analysis indicated that there were significant differences in the bacterial community composition after lamb or fish treatment in asthmatic mice. Both lamb and fish treatment enhanced the abundance of colonic Alistipes in asthmatic mice.

Conclusion

Collectively, long-term intake of lamb or fish shapes colonic bacterial communities and aggravates pulmonary inflammation in asthmatic mice, which provides reasonable food guidance for asthmatic patients.