Can an anti-inflammatory diet be effective in preventing or treating viral respiratory diseases? A systematic narrative review.

Respiratory Viruses infections (RVI) such as rhinovirus, coronavirus, influenza virus, and adenovirus affect the respiratory and the immune systems. The role of nutrition in the respiratory and immune systems has been studied in some studies, and its importance is undeniable. In addition, one of the key findings in this disease is high inflammation that affects almost all patients. This systematic narrative review aims to answer the question, "Can an anti-inflammatory diet be effective in preventing or treating viral respiratory diseases?" A systematic review search was used for the articles extraction. All studies published in English from 1999 to 2020 investigating dietary inflammatory conditions and RVI were included. Food items with anti-inflammatory properties were selected based on the definition of the dietary inflammatory index (DII). We used Google Scholar, Pub Med, Scopus, Web of Science, Springer, Science Direct, Directory of Open Access Journals, Elsevier, Taylor and Francis, ProQuest, EBSCO, MEDLINE, and SciELO databases for extracting articles. Keywords were restricted by DII. Based on DII, food items/nutrients are involved in inflammation, some of which have anti-inflammatory and some inflammatory properties. Some foods/nutrients, in addition to their anti-inflammatory properties, have antioxidant, antiviral, and immune-enhancing properties. Considering the immune system's involvement, increased inflammation, and involvement of the pulmonary system in RVI and the remarkable role of the anti-inflammatory foods for counteracting them, it is recommended to use a predominantly anti-inflammatory diet along with prevention/control and treatment protocols. An anti-inflammatory diet (based on DII) includes turmeric, ginger, garlic, onions, saffron, dietary vitamin C, vitamin D, zinc, and omega-3 are recommended to reduce infection symptoms and duration.

Vitamin D supplementation to prevent acute respiratory infections: a systematic review and meta-analysis of aggregate data from randomised controlled trials.

BACKGROUND: A 2017 meta-analysis of data from 25 randomised controlled trials (RCTs) of vitamin D supplementation for the prevention of acute respiratory infections (ARIs) revealed a protective effect of this intervention. We aimed to examine the link between vitamin D supplementation and prevention of ARIs in an updated meta-analysis. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, and the ClinicalTrials.gov registry for studies listed from database inception to May 1, 2020. Double-blind RCTs of vitamin D3, vitamin D2, or 25-hydroxyvitamin D (25[OH]D) supplementation for any duration, with a placebo or low-dose vitamin D control, were eligible if they had been approved by a research ethics committee, and if ARI incidence was collected prospectively and prespecified as an efficacy outcome. Studies reporting results of long-term follow-up of primary RCTs were excluded. Aggregated study-level data, stratified by baseline 25(OH)D concentration and age, were obtained from study authors. Using the proportion of participants in each trial who had one or more ARIs, we did a random-effects meta-analysis to obtain pooled odds ratios (ORs) and 95% CIs to estimate the effect of vitamin D supplementation on the risk of having one or more ARIs (primary outcome) compared with placebo. Subgroup analyses were done to estimate whether the effects of vitamin D supplementation on the risk of ARI varied according to baseline 25(OH)D concentration (<25 nmol/L vs 25·0-49·9 nmol/L vs 50·0-74·9 nmol/L vs >75·0 nmol/L), vitamin D dose (daily equivalent of <400 international units [IU] vs 400-1000 IU vs 1001-2000 IU vs >2000 IU), dosing frequency (daily vs weekly vs once per month to once every 3 months), trial duration (≤12 months vs >12 months), age at enrolment (<1·00 years vs 1·00-15·99 years vs 16·00-64·99 years vs ≥65·00 years), and presence versus absence of airway disease (ie, asthma only, COPD only, or unrestricted). Risk of bias was assessed with the Cochrane Collaboration Risk of Bias Tool. The study was registered with PROSPERO, CRD42020190633. FINDINGS: We identified 1528 articles, of which 46 RCTs (75 541 participants) were eligible. Data for the primary outcome were obtained for 48 488 (98·1%) of 49 419 participants (aged 0-95 years) in 43 studies. A significantly lower proportion of participants in the vitamin D supplementation group had one or more ARIs (14 332 [61·3%] of 23 364 participants) than in the placebo group (14 217 [62·3%] of 22 802 participants), with an OR of 0·92 (95% CI 0·86-0·99; 37 studies; I2=35·6%, pheterogeneity=0·018). No significant effect of vitamin D supplementation on the risk of having one or more ARIs was observed for any of the subgroups defined by baseline 25(OH)D concentration. However, protective effects of supplementation were observed in trials in which vitamin D was given in a daily dosing regimen (OR 0·78 [95% CI 0·65-0·94]; 19 studies; I2=53·5%, pheterogeneity=0·003), at daily dose equivalents of 400-1000 IU (0·70 [0·55-0·89]; ten studies; I2=31·2%, pheterogeneity=0·16), for a duration of 12 months or less (0·82 [0·72-0·93]; 29 studies; I2=38·1%, pheterogeneity=0·021), and to participants aged 1·00-15·99 years at enrolment (0·71 [0·57-0·90]; 15 studies; I2=46·0%, pheterogeneity=0·027). No significant interaction between allocation to the vitamin D supplementation group versus the placebo group and dose, dose frequency, study duration, or age was observed. In addition, no significant difference in the proportion of participants who had at least one serious adverse event in the vitamin supplementation group compared with the placebo group was observed (0·97 [0·86-1·07]; 36 studies; I2=0·0%, pheterogeneity=0·99). Risk of bias within individual studies was assessed as being low for all but three trials. INTERPRETATION: Despite evidence of significant heterogeneity across trials, vitamin D supplementation was safe and overall reduced the risk of ARI compared with placebo, although the risk reduction was small. Protection was associated with administration of daily doses of 400-1000 IU for up to 12 months, and age at enrolment of 1·00-15·99 years. The relevance of these findings to COVID-19 is not known and requires further investigation. FUNDING: None.

Effects of Mediterranean diet in patients with recurring colds and frequent complications

Introduction: In recent years, traditional diets enriched with fresh plant-based foods have been gradually abandoned, increasing the consumption of animal foods and highly processed food. The aim of this study was to assess the effects of a nutritional intervention with a Traditional Mediterranean Diet in patients with recurring colds (RC) and frequent inflammatory complications (IC). Methods: Prospective before-after comparison study of 63 girls and 65 boys aged 1-5 years were included over a year in the nutritional programme ‘Learning to eat from the Mediterranean’. We studied clinical and therapeutic variables and various anthropometric parameters. Results: All the studied indicators (number of catarrhal episodes CB, degree of intensity, emergency and hospital admissions) showed a positive and statistically significant evolution, evidenced from the first weeks of starting treatment, until the end of the year, after which 53.9% of patients had no CB, 25% had only one, and 16.4% had two episodes, compared to the 4.64 episodes on average in the previous year. Antibiotic use decreased by 87.4%, from 3.85 ± 1.27 times/patient/year to 0.49 ± 0.79 (p<0.001). Symptomatic treatment decreased by 56.7%, from 7.03 ± 2.76 to 3.05 ± 1.69 (p<0.001). The satisfaction of the families was very high. The Kidmed index, which assesses the quality of the Mediterranean Diet, increased from 7.8 to 10.9 points. Conclusion: The adoption of a Traditional Mediterranean Diet could be a major contribution to the improvement of patients with recurring colds and frequent inflammatory complications (AU)

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Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data.

Objectives To assess the overall effect of vitamin D supplementation on risk of acute respiratory tract infection, and to identify factors modifying this effect.Design Systematic review and meta-analysis of individual participant data (IPD) from randomised controlled trials.Data sources Medline, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, ClinicalTrials.gov, and the International Standard Randomised Controlled Trials Number registry from inception to December 2015.Eligibility criteria for study selection Randomised, double blind, placebo controlled trials of supplementation with vitamin D3 or vitamin D2 of any duration were eligible for inclusion if they had been approved by a research ethics committee and if data on incidence of acute respiratory tract infection were collected prospectively and prespecified as an efficacy outcome.Results 25 eligible randomised controlled trials (total 11 321 participants, aged 0 to 95 years) were identified. IPD were obtained for 10 933 (96.6%) participants. Vitamin D supplementation reduced the risk of acute respiratory tract infection among all participants (adjusted odds ratio 0.88, 95% confidence interval 0.81 to 0.96; P for heterogeneity <0.001). In subgroup analysis, protective effects were seen in those receiving daily or weekly vitamin D without additional bolus doses (adjusted odds ratio 0.81, 0.72 to 0.91) but not in those receiving one or more bolus doses (adjusted odds ratio 0.97, 0.86 to 1.10; P for interaction=0.05). Among those receiving daily or weekly vitamin D, protective effects were stronger in those with baseline 25-hydroxyvitamin D levels <25 nmol/L (adjusted odds ratio 0.30, 0.17 to 0.53) than in those with baseline 25-hydroxyvitamin D levels ≥25 nmol/L (adjusted odds ratio 0.75, 0.60 to 0.95; P for interaction=0.006). Vitamin D did not influence the proportion of participants experiencing at least one serious adverse event (adjusted odds ratio 0.98, 0.80 to 1.20, P=0.83). The body of evidence contributing to these analyses was assessed as being of high quality.Conclusions Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall. Patients who were very vitamin D deficient and those not receiving bolus doses experienced the most benefit.Systematic review registration PROSPERO CRD42014013953.

Comparison of the Effect of Two Kinds of Iranian Honey and Diphenhydramine on Nocturnal Cough and the Sleep Quality in Coughing Children and Their Parents.

Coughing in a child induced by upper respiratory tract infections (URTIs) can be a problem, both for the child and its parents. Current studies show a lack of proven efficacy for over-the counter (OTC) medications, but promising data support the use of honey for children. The aim of this study was to compare the effects of two kinds of Iranian honey with diphenhydramine (DPH) on nocturnal pediatric coughs and the sleep quality of children and their parents. This was a clinical trial (registered in IRCT; No.: 28.20.7932, 15 October 2013). The study consisted of 87 patients. All the parents completed a standard previously validated questionnaire. The children were randomly assigned to one of three treatment groups: Group 1, Honey type 1 (Kimia Company, Iran) (n = 42), Group 2, Honey type 2 (Shahde-Golha, Iran) (n = 25), and Group 3, DPH (n = 20). Each group received double doses of the respective treatments on two successive nights. A second survey was then administered via a telephone interview in which the parents were asked the same questions. The mean scores for all aspects of coughs were significantly decreased in each group before and after the treatment. All three treatments improved the cough and sleep scores. Honey type 1 was superior to DPH in improving all aspects of coughs, except the frequency, and Honey type 2 was more effective than DPH in improving all aspects of coughs, except the sleep quality of the child. There was no significant difference between Honey type 1 and 2 in any aspects of cough relief in the present study. The results suggest that honey may provide better cough relief than DPH in children and improve the sleep quality of children and their parents.

Effect of zinc added to a daily small-quantity lipid-based nutrient supplement on diarrhoea, malaria, fever and respiratory infections in young children in rural Burkina Faso: a cluster-randomised trial.

OBJECTIVE: Preventive zinc supplementation in the form of tablets or syrup reduces the incidence of diarrhoea and acute lower respiratory tract infections (RTI), but its effect on malaria is inconsistent. When zinc is administered with other micronutrients or foods, its effect is also uncertain. We assessed the effects of different amounts and sources of zinc on the frequency of diarrhoea, malaria, fever and RTI in young children. DESIGN, SETTING AND POPULATIONS: This community-based, double-blind, placebo-controlled, cluster-randomised trial of 2435 children 9 months of age was carried out between April 2010 and July 2012 in rural southwestern Burkina Faso. INTERVENTIONS: Participants were randomly assigned at the concession level to receive daily 1 of 4 interventions for 9 months: (1) 20 g small-quantity lipid-based nutrient supplement (SQ-LNS) without zinc and placebo tablet, (2) 20 g SQ-LNS with 5 mg zinc and placebo tablet, (3) 20 g SQ-LNS with 10 mg zinc and placebo tablet or (4) 20 g SQ-LNS without zinc and 5 mg zinc tablet. Participants were visited weekly in their homes for morbidity surveillance for 9 months, and those with uncomplicated diarrhoea and malaria received treatment from the study field workers in the community. MAIN OUTCOMES: Incidence and longitudinal prevalence of diarrhoea, malaria, fever, and lower and upper RTI by intervention group. RESULTS: The incidence of diarrhoea, malaria and fever was 1.10 (±1.03 SD), 0.61 (±0.66 SD) and 1.49 (±1.12 SD) episodes per 100 child-days at risk, respectively, and did not differ by intervention group (p=0.589, p=0.856 and p=0.830, respectively). The longitudinal prevalence of acute lower RTI (0.1%; 95% IC 0.1-0.2%) and of upper RTI (7.8%; 95% IC 7.1-8.4%) did not differ among groups (p=0.234 and p=0.501, respectively). CONCLUSIONS: Inclusion of 5 or 10 mg zinc in SQ-LNS and provision of 5 mg zinc dispersible tablet along with SQ-LNS had no impact on the incidence of diarrhoea, malaria and fever or the longitudinal prevalence of RTI compared with SQ-LNS without zinc in this population. TRIAL REGISTRATION NUMBER: NCT00944281.

Effects of a dietary supplement on the incidence of acute respiratory infections in susceptible adults: a randomized controlled trial / Efectos de un suplemento nutricional en la incidencia de infecciones respiratorias agudas en adultos susceptibles: un ensayo clínico controlado

Introduction: although supplementation of specific micronutrients may improve immunologic factors, few studies about the combination of micronutrients with plant extracts on the occurrence of acute respiratory infections (ARI) have been published. Objectives: to assess the effect of a nutritional supplement with micronutrients and plant extracts on the incidence of ARI in susceptible adults between January and April, 2012. Methods: a randomized, double-blind, parallel, placebo-controlled clinical trial was performed. Participants were adults susceptible to ARI who were healthy at the time of evaluation, signed informed consent forms and were not taking medication. They completed a medical history; weight, height, vital signs and laboratory analyses were assessed. Subjects were randomly assigned for consumption of the supplement or a placebo, for a 90 days period. Subjects made daily diary entries indicating the presence ARI symptoms. Those who became ill notified researchers and the attending physician confirmed the presence of an infection. Fisher’s exact test was used to compare the proportion of ill subjects between groups. Relative risk and risk difference were also calculated (p< 0.05 significant). Results: of 59 included subjects, 45 (25 women) completed the study (21 in the supplemented group and 24 in the placebo group). There were no significant differences at baseline between groups. After the intervention, the supplemented group had a lower incidence of ARI compared with the placebo group (57.1% vs. 91.7%, p=0.013, RR=0.62, 95%CI 0.42, 0.92). Discussion: the consumption of a supplement with vitamins, minerals and plant extracts may decrease the incidence of ARI in susceptible adults (AU)

Introducción: aunque la suplementación de micronutrientes específicos puede mejorar determinados factores inmunológicos, han sido publicados pocos estudios sobre la combinación de micronutrientes con extractos herbales y la incidencia de infecciones respiratorias agudas (ARI). Objetivos: evaluar el efecto de un suplemento alimenticio con micronutrientes y extractos herbales en la incidencia de ARI en adultos susceptibles, en enero-abril de 2012. Métodos: se realizó un ensayo clínico paralelo, aleatorizado, doble ciego, controlado con placebo. Se incluyeron adultos susceptibles a ARI, sanos en el momento de la evaluación, que firmaron un consentimiento informado y que no tomaban medicamentos. Completaron una historia clínica y se evaluó: peso, talla, signos vitales y de laboratorio. Se asignaron aleatoriamente para consumir durante 90 días el suplemento o un placebo. Los sujetos registraron diariamente si presentaban o no síntomas de ARI en un diario. En caso de enfermedad, se lo notificaron a los investigadores y el médico responsable confirmó la presencia de infección. Se utilizó la prueba exacta de Fisher para comparar la proporción de enfermos entre los grupos y se calculó el riesgo relativo y la diferencia de riesgos (p < 0,05 significativa). Resultados: de 59 sujetos incluidos, 45 (25 mujeres) completaron el estudio (21 del grupo suplementado y 24 del placebo). No hubo diferencias significativas al inicio entre grupos. Al finalizar la intervención, el grupo suplementado tuvo una menor incidencia de ARI en comparación con el placebo (57,1% vs 91,7%, p=0,013, RR=0,62, IC95% 0,42, 0,92). Discusión: en conclusión, el consumo de un suplemento a base de micronutrientes y extractos herbales puede disminuir la incidencia de ARI en adultos susceptibles (AU)

Zinc supplementation in young children: A review of the literature focusing on diarrhoea prevention and treatment.

BACKGROUND & AIMS: It is estimated that zinc deficiency is responsible for 4.4% of childhood deaths in Africa, Asia, and Latin America. This review examines the impact of zinc supplementation, administered prophylactically or therapeutically, on diarrhoea. METHODS: Relevant published articles were identified through systematic searches of electronic databases. Bibliographies of retrieved articles were examined. RESULTS: A total of 38 studies were included in this review, 29 studies examined the effect of prophylactic zinc and nine studies examined the effects of therapeutic use of zinc for treatment of diarrhoea in children under five years. CONCLUSION: Prophylactic zinc has been shown to be effective in decreasing both prevalence and incidence of diarrhoea, reducing respiratory infections and improving growth in children with impaired nutritional status. There is less conclusive evidence of reduction in diarrhoea duration or diarrhoea severity. While prophylactic zinc decreases mortality due to diarrhoea and pneumonia, it has not been shown to affect overall mortality. Therapeutic use of zinc for the treatment of diarrhoea in children has been shown to reduce diarrhoea incidence, stool frequency and diarrhoea duration as well as respiratory infections in zinc deficient children. However, stool output is only reduced in children with cholera. Less conclusive evidence exists for therapeutic zinc reducing mortality due to diarrhoea and respiratory infections. Specific definitions of diarrhoea severity, respiratory infection in further studies as well as examination of prophylactic zinc effectiveness in diarrhoea duration and severity effectiveness of therapeutic zinc in reducing mortality due to diarrhoea and respiratory infections are warranted.

Follow-up formula consumption in 3- to 4-year-olds and respiratory infections: an RCT.

OBJECTIVE: Children are vulnerable to diet inadequacies, which may affect immune function. Our objective was to determine if a follow-up formula (FUF) containing DHA, the prebiotics PDX and GOS, and yeast ß-glucan affects incidence of respiratory infections and diarrheal disease in healthy children. METHODS: In a double-blind, randomized, controlled, prospective trial, 3-4 year old children were fed 3 servings per day of either a FUF with 25 mg DHA, 1.2 g PDX/GOS, and 8.7 mg yeast ß-glucan per serving or an unfortified, cow's milk-based beverage (control) for 28 weeks. Fecal and blood samples were collected to assess immune markers and iron/zinc status. Incidence of acute respiratory infections (ARI), diarrheal disease, and antibiotic treatment were obtained from medical records. RESULTS: The FUF group had fewer episodes and shorter duration of ARI (mean days [SE]; control = 4.3 [0.2]; FUF = 3.5 [0.2]; P = .007), less antibiotic use (n [%]; control = 21 [14%]; FUF = 8 [5%]; P = .01), and fewer missed days of day care due to illness. No diarrheal disease was diagnosed in either group. The FUF group had higher interleukin-10 and white blood cell count at the end of the study. There were no differences in hemoglobin, serum ferritin and zinc, or fecal secretory immunoglobulin A. CONCLUSIONS: Daily consumption of a FUF was associated with fewer episodes and shorter duration of ARI, as well as less antibiotic use. The children who consumed the FUF had increased interleukin-10 and white blood cells, suggesting an antiinflammatory mechanism and/or an increase of effector immune cells.

The effect of vitamin C on upper respiratory infections in adolescent swimmers: a randomized trial.

The risk of upper respiratory infections (URIs) is increased in people who are under heavy physical stress, including recreational and competitive swimmers. Additional treatment options are needed, especially in the younger age group. The aim of this study was to determine whether 1 g/day vitamin C supplementation affects the rate, length, or severity of URIs in adolescent swimmers. We carried out a randomized, double-blind, placebo-controlled trial during three winter months, among 39 competitive young swimmers (mean age 13.8 ± 1.6 years) in Jerusalem, Israel. Vitamin C had no effect on the incidence of URIs (rate ratio = 1.01; 95% confidence interval (CI) = 0.70-1.46). The duration of respiratory infections was 22% shorter in vitamin C group, but the difference was not statistically significant. However, we found a significant interaction between vitamin C effect and sex, so that vitamin C shortened the duration of infections in male swimmers by 47% (95% CI: -80% to -14%), but had no effect on female swimmers (difference in duration: +17%; 95% CI: -38% to +71%). The effect of vitamin C on the severity of URIs was also different between male and female swimmers, so that vitamin C was beneficial for males, but not for females. Our study indicates that vitamin C does not affect the rate of respiratory infections in competitive swimmers. Nevertheless, we found that vitamin C decreased the duration and severity of respiratory infections in male swimmers, but not in females. This finding warrants further research.

Treatments for damaged skin.

This is the fifth of a series of articles looking at the available evidence for complementary medicine relating to the theme topic in Australian Family Physician. Any ointment or device when applied to damaged skin whether it be burned or cut, has a legion of tasks to perform: maintaining the integrity of the skin affected, repelling infective agents, and promotion of the healing process.

Essential fatty acids: the effects of dietary supplementation among children with recurrent respiratory infections.

The impact of dietary supplementation with essential fatty acids (EFA) on recurrent respiratory infections (RRI) in children was evaluated by means of a randomized cross-over double-blind study. Linoleic acid (596 mg/day) and alpha-linolenic acid [855 mg/day] as a commercial preparation or placebo (olive oil) were administered for two consecutive winter seasons (November to February, T0-T120) to 20 children affected by RRI, aged between 36 and 49 months. Plasma levels of n-3 and n-6 metabolites increased after the administration of EFA. The number of infective episodes, days' fever and days' absence from school were reduced significantly during the observation period (extended from T120 to T180) in children receiving EFA supplementation. Our results suggest that n-3 and n-6 polyunsaturated fatty acids may play a favourable role in the defence mechanism of these subjects.