The effect of caffeine on exercise-induced bronchoconstriction. Influence of Mediterranean Diet on Asthma Symptoms, Lung Function, and Systemic Inflammation: A Randomized Controlled Trial Manipulating antioxidant intake in asthma: a randomized controlled trial. Randomised, double blind, placebo-controlled trial of selenium supplementation in adult asthma Dietary intake of fatty acids, antioxidants and selected food groups and asthma in adults Immediate and long term effects of weight reduction in obese people with asthma: randomised controlled study Effects of weight loss on asthma control in obese patients with severe asthma Ascorbic acid supplementation attenuates exercise-induced bronchoconstriction in patients with asthma. The impact of a medical food containing gammalinolenic and eicosapentaenoic acids on asthma management and the quality of life of adult asthma patients. A clinical pharmacological study of the potential beneficial effects of a propolis food product as an adjuvant in asthmatic patients Oral magnesium and vitamin C supplements in asthma: a parallel group randomized placebo‐controlled trial Dietary salt, airway inflammation, and diffusion capacity in exercise-induced asthma. Effect of Oral Magnesium Supplementation on Measures of Airway Resistance and Subjective Assessment of Asthma Control and Quality of Life in Men and Women with Mild to Moderate Asthma: A Randomized Placebo Controlled Trial Do dairy products induce bronchoconstriction in adults with asthma? A high-fat challenge increases airway inflammation and impairs bronchodilator recovery in asthma. Effect of vitamin D3 on asthma treatment failures in adults with symptomatic asthma and lower vitamin D levels: the VIDA randomized clinical trial. Vitamin E supplements in asthma: a parallel group randomised placebo controlled trial Are overweight asthmatics more difficult to control? Effects of dietary supplementation with n-3 fatty acids compared with n-6 fatty acids on bronchial asthma. Conjugated linoleic acid improves airway hyper‐reactivity in overweight mild asthmatics Corticosteroid sparing effects of vitamin C and magnesium in asthma: a randomised trial.
The effect of caffeine on exercise-induced bronchoconstriction was examined in ten patients with bronchial asthma .  Placebo and caffeine 3.5 mg/kg and 7 mg/kg were given two hours before exercise .  Spirometry was taken at one and two hours following caffeine and at 5 , 15 , and 30 minutes following exercise . Caffeine significantly improved baseline FEV1 and prevented exercise-induced bronchoconstriction only at a dose of 7 mg/kg . Caffeine was well tolerated by the patients . These data suggest that only high doses of caffeine significantly prevent a postexercise drop in FEV1 Objective . The rapidly increasing prevalence of asthma in developed countries suggests an environmental cause . The benefits of Mediterranean diet ( MD ) in cardiovascular disease have been tentatively attributed to its anti-inflammatory properties . Asthma is an inflammatory disease and MD is associated with reduced asthma risk in epidemiological studies , but there are no reported interventional studies of MD in asthma . Methods . In this 12-week open-label r and omized trial , 38 adults with symptomatic asthma were allocated to high-intervention ( HI ) , low-intervention ( LI ) , and control groups . The first two groups were encouraged to adopt an MD and received multiple consultation sessions with a nutritionist , written advice , and vouchers for the purchase of appropriate foods .  Food frequency question naires , asthma control question naires , asthma-related quality of life question naires ( AQLQs ) , and spirometry  were completed at the beginning and at the end of the study . Results : The MDt score increased in the HI group ( p < .001 ) , indicating successful alteration of dietary behavior . Statistically , nonsignificant improvements were seen in spirometry and several AQLQ subdomains in the two intervention groups . No changes were seen in the asthma control or in inflammatory markers . Conclusions : The trial intervention has successfully altered the dietary behavior among adults with asthma . Small but consistent improvements were seen in quality of life and spirometry among the intervention group . The use of the MD to treat asthma is feasible and warrants evaluation in a larger study , powered to examine clinical endpoints BACKGROUND Antioxidant-rich diets are associated with reduced asthma prevalence in epidemiologic studies . We previously showed that short-term manipulation of antioxidant defenses leads to changes in asthma outcomes . OBJECTIVE The objective was to investigate the effects of a high-antioxidant diet compared with those of a low-antioxidant diet , with or without lycopene supplementation , in asthma . DESIGN Asthmatic adults ( n = 137 ) were r and omly assigned to a high-antioxidant diet ( 5 servings of vegetables and 2 servings of fruit daily ; n = 46 ) or a low-antioxidant diet ( ≤2 servings of vegetables and 1 serving of fruit daily ; n = 91 ) for 14 d and then commenced a parallel , r and omized , controlled supplementation trial . Subjects who consumed the high-antioxidant diet received placebo . Subjects who consumed the low-antioxidant diet received placebo or tomato extract ( 45 mg lycopene/d ) . The intervention continued until week 14 or until an exacerbation occurred . RESULTS After 14 d , subjects consuming the low-antioxidant diet had a lower percentage predicted forced expiratory volume in 1 s and percentage predicted forced vital capacity than did those consuming the high-antioxidant diet . Subjects in the low-antioxidant diet group had increased plasma C-reactive protein at week 14 . At the end of the trial , time to exacerbation was greater in the high-antioxidant than in the low-antioxidant diet group , and the low-antioxidant diet group was 2.26 ( 95 % CI : 1.04 , 4.91 ; P = 0.039 ) times as likely to exacerbate . Of the subjects in the low-antioxidant diet group , no difference in airway or systemic inflammation or clinical outcomes was observed between the groups that consumed the tomato extract and those who consumed placebo . CONCLUSIONS Modifying the dietary intake of carotenoids alters clinical asthma outcomes . Improvements were evident only after increased fruit and vegetable intake , which suggests that whole-food interventions are most effective . This trial was registered at http://www.actr.org.au as ACTRN012606000286549 Background : Epidemiological evidence from observational studies has suggested that blood levels and dietary intake of selenium of adults with asthma are lower than those of controls . The only previous trial of selenium supplementation in adults with asthma found no objective evidence of benefit but involved only 24 participants . Methods : A r and omised , double blind , placebo-controlled trial of selenium supplementation was performed in adults with asthma in London , UK , the majority of whom ( 75 % ) reported inhaled steroid use at baseline . 197 participants were r and omised to receive either a high-selenium yeast preparation ( 100 µg daily , n = 99 ) or placebo ( yeast only , n = 98 ) for 24 weeks . The primary outcome was asthma-related quality of life ( QoL ) score . Secondary outcomes included lung function , asthma symptom scores , peak flow and bronchodilator usage . Linear regression was used to analyse the change in outcome between the two treatment arms by “ intention to treat ” . Results : There was a 48 % increase in plasma selenium between baseline and end of trial in the active treatment group but no change in the placebo group . While the QoL score improved more in the active treatment group than in the placebo group , the difference in change in score between the two groups was not significant ( −0.05 ( 95 % CI −0.19 to 0.09 ) ; p = 0.47 ) . Selenium supplementation was not associated with any significant improvement in secondary outcomes compared with placebo . Conclusions : Selenium supplementation had no clinical benefit in adults with asthma , the majority of whom were taking inhaled steroids Objective : Within a prospect i ve study , we explored the associations between dietary intake of fatty acids , antioxidants and relevant food sources of these nutrients on the clinical manifestation of asthma in adulthood . Method : A total of 105 newly physician-diagnosed cases of asthma from the European Prospect i ve Investigation into Cancer and Nutrition (EPIC)-Heidelberg cohort were identified during follow-up and matched with 420 controls .  Baseline dietary intake was obtained by means of vali date d food frequency question naires . The association of dietary intake variables and asthma risk was explored by unconditional logistic regression models . Results : A high intake of oleic acid ( C18:1 n-9 ) was positively associated with asthma ( P-value for trend 0.035 ) , while no significant associations were found for the other dietary fatty acids . Most prominently , a high margarine intake increased the risk of onset of asthma in adulthood ( adjusted odds ratio ( OR ) 3rd tertile : 1.73 ( 95 % confidence interval ( 95 % CI ) : 1.05–2.87 ) , P for trend=0.050 ) , the effect being stronger in men ( 2nd tertile : OR=1.66 , 3rd tertile : OR=2.51 ) than in women ( 2nd tertile : OR=0.91 ; 3rd tertile : OR=1.47 ) . The dietary intake of antioxidants and their main food sources had no effect on asthma risk . Conclusions : In summary , the present results provide evidence that even in adulthood a high margarine intake increases the risk of clinical onset of asthma . Whether oleic acid may serve as a proxy for margarine-derived trans-fatty acids ( C18:1 t9 ) remains to be clarified Abstract Objective : To investigate the influence of weight reduction on obese patients with asthma . Design : Open study , two r and omised parallel groups . Setting : Private out patients centre , Helsinki , Finl and . Participants : Two groups of 19 obese patients with asthma ( body mass index ( kg/m2 ) 30 to 42 ) recruited through newspaper advertisements . Intervention : Supervised weight reduction programme including 8 week very low energy diet . Main outcome measures : Body weight , morning peak expiratory flow ( PEF ) , forced vital capacity ( FVC ) , forced expiratory volume in one second ( FEV1 ) ; and also asthma symptoms , number of acute episodes , courses of oral steroids , health status ( quality of life ) . Results : At the end of the weight reducing programme , the participants in the treatment group had lost a mean of 14.5 % of their pretreatment weight , the controls 0.3 % . The corresponding figures after one year were 11.3 % and a weight gain of 2.2 % . After the 8 week dieting period the difference in changes in percentage of predicted FEV1 from baseline in the treatment and control groups was 7.2 % ( 95 % confidence interval 1.9 % to 12.5 % , P=0.009 ) . The corresponding difference in the changes in FVC was 8.6 % ( 4.8 % to 12.5 % , P<0.0001 ) . After one year the differences in the changes in the two groups were still significant : 7.6 % for FEV1 ( 1.5 % to 13.8 % , P=0.02 ) and 7.6 % for FVC ( 3.5 % to 11.8 % , P=0.001 ) . By the end of the weight reduction programme , reduction in dyspnoea was 13 mm ( on a visual analogue scale 0 mm to 100 mm ) in the treatment group and 1 mm in the control group ( P=0.02 ) . The reduction of rescue medication was 1.2 and 0.1 doses respectively ( P=0.03 ) . After one year the differences in the changes between the two groups were −12 for symptom scores ( range −1 to −22 , P=0.04 ) and −10 for total scores ( −18 to −1 , P=0.02 ) . The median number of exacerbations in the treatment group was 1 ( 0–4 ) and in the controls 4 ( 0–7 ) , P=0.001 . Conclusion : Weight reduction in obese patients with asthma improves lung function , symptoms , morbidity , and health status Studies on the effects of weight loss in patients with asthma are scarce . No studies have been performed in patients with severe asthma . Therefore , the aim of the present study was to assess the impact of weight loss  in patients with severe asthma associated with obesity . This was an open , prospect i ve , r and omised study of two parallel groups , in patients with severe uncontrolled asthma and moderate obesity . The primary outcome was the level of asthma control 6 months after initiation of the  weight reduction programme  , quantified using the Asthma Control Question naire ( ACQ ) . We evaluated clinical parameters , lung function , markers of airway inflammation and circulating cytokines .  22 patients were r and omised to undergo treatment for obesity and 11 to the control group .  The weight reduction programme was associated with significant improvements in asthma control ( mean±se ACQ score 3.02±0.19 to 2.25±0.28 in the treatment group versus 2.91±0.25 to 2.90±0.16 in the controls , p=0.001 ) . This improvement was not accompanied by changes in markers of airway inflammation or bronchial reactivity , but by an increase in forced vital capacity . Our results suggest  that weight reduction in obese patients with severe asthma improves asthma outcomes by mechanisms not related to airway inflammation . Weight loss improves outcomes in severely asthmatic obese patients ; poor control results from obesity-related factors BACKGROUND Previous research has shown that diet can modify the bronchoconstrictor response to exercise in asthmatic subjects . OBJECTIVE Determine the effect of ascorbic acid supplementation on pulmonary function and several urinary markers of airway inflammation in asthmatic subjects with exercise-induced bronchoconstriction ( EIB ) . METHODS Eight asthmatic subjects with documented EIB participated in a r and omized , placebo controlled double-blind crossover trial . Subjects entered the study on their usual diet and were placed on either 2 weeks of ascorbic acid supplementation ( 1500 mg/day ) or placebo , followed by a 1-week washout period , before crossing over to the alternative diet .  Pre- and post-exercise pulmonary function , asthma symptom scores , fraction of exhaled nitric oxide ( FENO ) , and urinary leukotriene ( LT ) C4-E4 and 9alpha , 11beta-prostagladin ( PG ) F2 ] were assessed at the beginning of the trial ( usual diet ) and at the end of each treatment period . RESULTS The ascorbic acid diet significantly reduced ( p < 0.05 ) the maximum fall in post-exercise FEV1 ( -6.4 + /- 2.4 % ) compared to usual ( -14.3 + /- 1.6 % ) and placebo diet ( -12.9 + /- 2.4 % ) . Asthma symptoms scores significantly improved ( p<0.05 ) on the ascorbic acid diet compared to the placebo and usual diet . Post-exercise FENO , LTC4-E4 and 9alpha , 11beta-PGF2 concentration was significantly lower ( p<0.05 ) on the ascorbic acid diet compared to the placebo and usual diet . CONCLUSION Ascorbic acid supplementation provides a protective effect against exercise-induced airway narrowing in asthmatic subjects BACKGROUND Leukotriene synthesis inhibitors and receptor antagonists are efficacious for the treatment of asthma . Diets containing the fatty acids gammalinolenic acid ( GLA ) and eicosapentaenoic acid ( EPA ) decrease leukotriene synthesis ; however , their impact on asthma management and quality of life ( QOL ) has not been evaluated in asthmatic subjects . OBJECTIVE To evaluate asthma management and the QOL of asthmatic adult subjects consuming a medical food emulsion containing GLA and EPA .  RESEARCH DESIGN AND METHODS Trial 1 was a r and omized , prospect i ve , double-blind , placebo-controlled , parallel group trial in atopic subjects with mild-to-moderate asthma ( n = 35 evaluable ) consuming a low dose ( 0.75 g GLA + 0.5 g EPA ) , high dose ( 1.13 g GLA + 0.75 g EPA ) or placebo emulsion daily . Subjects were question ed about their asthma management using a non-vali date d question naire after 2 and 4 weeks . Blood leukotrienes were measured at baseline and after 4 weeks . Trial 2 was an open-label study ( n = 65 evaluable ) where subjects consumed the low-dose medical food emulsion , EFF1009 , daily . QOL and asthma management were measured using the vali date d Mini Asthma Quality of Life ( MiniAQLQ ) and the Asthma Control ( ACQ ) question naires , respectively , administered at baseline and after 4 weeks . RESULTS In Trial 1 , leukotriene bio synthesis decreased ( p < 0.05 ) . Self-reported asthma status and bronchodilator use improved in subjects consuming low- and high-dose emulsion between week 2 and week 4 ( p < 0.01 ) , but not compared to placebo ( p > 0.1 ) . In Trial 2 , mean + /- st and ard error total MiniAQLQ and ACQ scores improved by 1.5 + /- 0.2 and 1.0 + /- 0.1 , respectively ( p < 0.001 ) . Subdomain scores from MiniAQLQ improved and rescue bronchodilator use decreased ( p < 0.001 ) . CONCLUSION The inclusion of the medical food EFF1009 in asthma management regimens can improve patient quality of life and decrease reliance on rescue medication The aqueous extract of propolis has been formulated as a nutritional food product and administered , as an adjuvant to therapy , to patients with mild to moderate asthma daily for 2 months in the framework of a comparative clinical study in parallel with a placebo preparation . The diagnosis of asthma was made according to the criteria of patient classification of the National Institutes of Health and Global Initiative for Asthma Management . At inclusion , the pulmonary forced expiratory volume in the first second ( FEV1 ) as a percentage of the forced vital capacity ( FVC ) was more than 80 % in mild persistent cases , and between 60 and 80 % in moderate persistent cases , showing an increase in the degree of reversibility of > 15 % in FEV1 . All patients were on oral theophylline as controller therapy , none was receiving oral or inhaled corticosteroids , none had other comorbidities necessitating medical treatment , and all were from a middle‐class community and had suffered from asthma for the last 2–5 years . Twenty‐four patients received the placebo , with one drop‐out during the study , while 22 received the propolis extract  , with no drop‐outs . The age range of the patients was 19–52 years ; 36 were male and 10 female .  The number of nocturnal attacks was recorded on a weekly basis , while pulmonary function tests were performed on all patients at the beginning of the trial , 1 month later and at the termination of the trial . Immunological parameters , including various cytokines and eicosanoids known to play a role in asthma , were measured in all patients at the beginning of the trial and 2 months later . Analysis of the results at the end of the clinical study revealed that patients receiving propolis showed a marked reduction in the incidence and severity of nocturnal attacks and improvement of ventilatory functions . The number of nocturnal attacks dropped from an average of 2.5 attacks per week to only 1 . The improvement in pulmonary functions was manifested as a nearly 19 % increase in FVC , a 29.5 % increase in FEV1 , a 30 % increase in peak expiratory flow rate ( PEFR ) , and a 41 % increase in the forced expiratory flow rate between 25 and 75 % of the vital capacity ( FEF25‐75 ) . The clinical improvement was associated with decreases by 52 , 65 , 44 and 30 % , respectively , of initial values for the pro‐inflammatory cytokines tumor necrosis factor (TNF)‐α , ICAM‐1 , interleukin (IL)‐6 and IL‐8 , and a 3‐fold increase in the ‘ protective ’ cytokine IL‐10 . The levels of prostagl and ins E2 and F2α and leukotriene D4 were decreased significantly to 36 , 39 , and 28 % , respectively , of initial values . Patients on the placebo preparation showed no significant improvement in ventilatory functions or in the levels of mediators . The findings suggest that the aqueous propolis extract tested is potentially effective as an adjuvant to therapy in asthmatic patients . The benefits may be related to the presence in the extract of caffeic acid derivatives and other active constituents Background Epidemiological studies suggest that higher intakes of dietary vitamin C and magnesium may be associated with a reduced risk of asthma PURPOSE Recent studies have supported a role for dietary salt as a modifier of the severity of  exercise-induced asthma .  The main aim of this study was to demarcate a possible mechanism by which dietary salt modification may alter exercise-induced airway narrowing in asthmatic patients . METHODS Twenty-four patients participated in a r and omized , double-blind crossover study . Subjects entered the study on their normal salt diet ( NSD ) and were then placed on either a low-salt diet ( LSD ) or high-salt diet ( HSD ) for 2 wk with a 1-wk washout period occurring between diets . Pre- and postexercise spirometry , pulmonary diffusion capacity ( DLCO ) and its subdivisions , and induced sputum were obtained on the NSD and at the end of each 2-wk treatment period ( LSD and HSD ) . RESULTS FEV1 decreased by 7.9 + /- 2.8 % on LSD , 18.3 + /- 4.0 % on NSD , and 27.4 + /- 3.2 % on HSD at 20 min postexercise . The NSD and HSD induced significant reductions ( P < 0.05 ) in DLCO and its subdivisions . However , postexercise pulmonary capillary blood volume significantly increased ( P < 0.05 ) by 6.3 and 9.6 mL on NSD and HSD , respectively , compared with baseline values , with no significant change ( P > 0.05 ) being observed on LSD . Postexercise-induced sputum neutrophil and eosinophil differential cell counts and induced sputum supernatant concentration of eosinophil cationic protein , interleukin (IL)-1beta , IL-8 , leukotriene ( LT ) C(4)-E(4 ) , LTB(4 ) , and prostagl and in D(2 ) were significantly elevated ( P < 0.05 ) on NSD and HSD compared with LSD . CONCLUSION Our findings indicate that dietary salt loading enhances airway inflammation following exercise in asthmatic subjects , and that small salt-dependent changes in vascular volume and microvascular pressure might have substantial effects on airway function following exercise in the face of mediator-induced increased vascular permeability Background : Epidemiological data shows low dietary magnesium(Mg ) may be related to incidence and progression of asthma . Objective To determine if long term(6.5 month ) treatment with oral Mg would improve asthma control and increase serum measures of Mg status in men and women with mild-to-moderate asthma . Subjects : 55 males and females aged 21 to 55 years with mild to moderate asthma according to the 2002 National Heart , Lung , and Blood Institute(NHLBI ) and Asthma Education and Prevention Program(NAEPP ) guidelines and who used only beta-agonists or inhaled corticosteroids(ICS ) as asthma medications were enrolled . Design : Subjects were r and omly assigned to consume 340 mg(170 mg twice a day ) of Mg or a placebo for 6.5 months . Measurements : Multiple measures of Mg status including serum , erythrocyte , urine , dietary , ionized and IV Mg were measured . Objective : markers of asthma control were : methacholine challenge test(MCCT ) and pulmonary function test(PFT ) results . Subjective vali date d question naires on asthma quality of life(AQLQ ) and control(ACQ ) were completed by participants . Markers of inflammation , including c-reactive protein(CRP ) and exhaled nitric oxide(eNO ) were determined . Results : The concentration of methacholine required to cause a 20 % drop in forced expiratory volume in in minute(FEV1 ) increased significantly from baseline to month 6 within the Mg group . Peak expiratory flow rate(PEFR ) showed a 5.8 % predicted improvement over time(P = 0.03 ) in those consuming the Mg . There was significant improvement in AQLQ mean score units(P < 0.01 ) and in overall ACQ score only in the Mg group(P = 0.05 ) after 6.5 months of supplementation . Despite these improvements , there were no significant changes in any of the markers of Mg status . Conclusion : Adults who received oral Mg supplements showed improvement in objective measures of bronchial reactivity to methacholine and PEFR and in subjective measures of asthma control and quality of life BACKGROUND Dairy products have often been implicated as a cause of exacerbation of asthma , but there is little scientific evidence to support this hypothesis . OBJECTIVE We sought to determine whether dairy products induce bronchoconstriction in a group of adults with asthma . METHODS Twenty subjects with asthma ( 13 women and 7 men ) were recruited from respondents who had previously completed a food and asthma question naire . Ten subjects perceived that their asthma became worse with ingestion of dairy products ( positive perceivers ) , whereas ten were negative perceivers . None of the subjects had positive skin prick test results with cow 's milk . The study was a r and omized , cross-over , double-blind , placebo-controlled trial . Subjects complied with a dairy-free diet throughout the study . The active challenge was a single-dose drink equivalent to 300 ml of cow 's milk . A positive reaction was defined as a 15 % reduction in both FEV1 and peak expiratory flow ( PEF ) on the active challenge day compared with results obtained at the same time on the placebo day . RESULTS For both FEV1 and PEF there were no statistically significantly differences in group means between active challenge and placebo challenge , between sequence of administration , or between perceptions . Nine subjects showed FEV1 or PEF changes that were greater than 15 % of baseline values : four patients showed changes after both active and placebo treatment ; two after treatment with placebo only ; and three after active treatment alone . Of the latter group , two subjects showed changes only in PEF , and when one of these subjects underwent a further detailed study , no asthmatic reaction could be demonstrated . CONCLUSION It is unlikely that dairy products have a specific bronchoconstrictor effect in most patients with asthma , regardless of their perception BACKGROUND Dietary fat activates systemic innate immune responses , but the effect on airway responses is unknown . OBJECTIVE To examine effects of a high-fat versus low-fat meal on systemic and airway inflammation in asthma . METHODS Nonobese subjects with asthma were r and omized to consume a high-fat ( n = 19 ; 48 % [ 49 g ] fat ) or low-fat ( n = 18 ; 15 % [ 3 g ] fat ) meal .  Fourteen obese patients with asthma and 21 healthy controls also consumed a high-fat meal . Another group of patients with asthma consumed a high-trans ( n = 5 ; 5.2 g trans fat ) or nontrans ( n = 5 , < 0.3 g trans fat ) fatty acid meal .  Lung function was measured at baseline ( prebronchodilator ) and 2 , 3 , and 4 hours after bronchodilator . Airway inflammation was assessed by using induced sputum cell counts and Toll-like receptor 4 mRNA expression by real-time PCR . Systemic inflammation was measured by ELISA quantification of plasma TNF-α , high-sensitivity C-reactive protein , and IL-6 concentrations . RESULTS In patients with asthma , at 4 hours postmeal , increases in sputum % neutrophils and Toll-like receptor 4 mRNA expression were higher and increases in FEV(1)/forced vital capacity ( FVC ) were lower in the high-fat versus low-fat groups . Changes in plasma fatty acids correlated with changes in sputum % neutrophils and were negatively associated with changes in % FEV(1 ) , % FVC , and FEV(1)/FVC . After the high-trans fatty acid meal , sputum % neutrophils were significantly higher than after the nontrans meal . CONCLUSION A high-fat meal  augments neutrophilic airway inflammation , with the effect dependent on the type of fat consumed . A high-fat meal also suppresses bronchodilator recovery in asthma . Modifying dietary fat intake may be useful in asthma IMPORTANCE In asthma and other diseases , vitamin D insufficiency is associated with adverse outcomes . It is not known if supplementing inhaled corticosteroids with oral vitamin D3 improves outcomes in patients with asthma and vitamin D insufficiency . OBJECTIVE To evaluate if vitamin D supplementation would improve the clinical efficacy of inhaled corticosteroids in patients with symptomatic asthma and lower vitamin D levels . DESIGN , SETTING , AND PARTICIPANTS The VIDA ( Vitamin D Add-on Therapy Enhances Corticosteroid Responsiveness in Asthma ) r and omized , double-blind , parallel , placebo-controlled trial study ing adult patients with symptomatic asthma and a serum 25-hydroxyvitamin D level of less than 30 ng/mL was conducted across 9 academic US medical centers in the National Heart , Lung , and Blood Institute 's AsthmaNet network , with enrollment starting in April 2011 and follow-up complete by January 2014 . After a run-in period that included treatment with an inhaled corticosteroid , 408 patients were r and omized . INTERVENTIONS Oral vitamin D3 ( 100,000 IU once , then 4000 IU/d for 28 weeks ; n = 201 ) or placebo ( n = 207 ) was added to inhaled ciclesonide ( 320 µg/d ) . If asthma control was achieved after 12 weeks , ciclesonide was tapered to 160 µg/d for 8 weeks , then to 80 µg/d for 8 weeks if asthma control was maintained . MAIN OUTCOMES AND MEASURES The primary outcome was time to first asthma treatment failure ( a composite outcome of decline in lung function and increases in use of β-agonists , systemic corticosteroids , and health care ) . RESULTS Treatment with vitamin D3 did not alter the rate of first treatment failure during 28 weeks ( 28 % [ 95 % CI , 21%-34 % ] with vitamin D3 vs 29 % [ 95 % CI , 23%-35 % ] with placebo ; adjusted hazard ratio , 0.9 [ 95 % CI , 0.6 - 1.3 ] ) . Of 14 prespecified secondary outcomes , 9 were analyzed , including asthma exacerbation ; of those 9 , the only statistically significant outcome was a small difference in the overall dose of ciclesonide required to maintain asthma control ( 111.3 µg/d [ 95 % CI , 102.2 - 120.4 µg/d ] in the vitamin D3 group vs 126.2 µg/d [ 95 % CI , 117.2 - 135.3 µg/d ] in the placebo group ; difference of 14.9 µg/d [ 95 % CI , 2.1 - 27.7 µg/d ] ) . CONCLUSIONS AND RELEVANCE Vitamin D3 did not reduce the rate of first treatment failure or exacerbation in adults with persistent asthma and vitamin D insufficiency . These findings do not support a strategy of therapeutic vitamin D3 supplementation in patients with symptomatic asthma . TRIAL REGISTRATION clinical trials.gov Identifier : NCT01248065 Background : Increased dietary vitamin E intake is associated with a reduced incidence of asthma , and combinations of antioxidant supplements including vitamin E are effective in reducing ozone induced bronchoconstriction . A study was undertaken to investigate the effect of supplementation with vitamin E for 6 weeks on bronchial hyperresponsiveness in atopic adults with asthma . Methods : 72 participants from a clinical trial register of adults with asthma were r and omised to receive 500 mg natural vitamin E or matched placebo for 6 weeks in a placebo controlled , double blind parallel group clinical trial . Inclusion criteria included age 18–60 years , maintenance treatment of at least one dose of inhaled corticosteroid per day , a positive skin prick test to one of three common allergens , and bronchial hyperresponsiveness to methacholine ( defined as a dose provoking a 20 % fall in forced expiratory volume in 1 second ( FEV1 ) ( PD20 ) of 12.25 μmol ) . Secondary outcomes were FEV1 , forced vital capacity , mean morning and evening peak flow , symptom scores , bronchodilator use , and serum immunoglobulin E levels . Results : In the primary intention to treat analysis the change in PD20 was similar in the vitamin E and placebo groups with a mean difference of + 0.25 doubling doses of methacholine ( 95 % confidence interval −0.67 to + 1.16 greater with vitamin E ) . There was no effect of vitamin E supplementation on any other measure of asthma control , either in the intention to treat or per protocol analysis . There was also no effect of vitamin E supplementation on serum immunoglobulin levels . Conclusion : Dietary supplementation with vitamin E adds no benefit to current st and ard treatment in adults with mild to moderate asthma The relationship between asthma and obesity appears to be quite complex . The aim of this study was to assess the effect of excess weight on asthma control evolution in a cohort of asthmatics . A prospect i ve data base was set up , which enrolled adult asthmatics with persistent ( mild , moderate or severe ) asthma . The control of asthma was defined as a binary variable , acceptable or unacceptable . In order to evaluate the effect of body mass index ( BMI ; < 25 or ≥25 ) , data were analysed using a continuous time homogeneous Markov model in which the forces ruling the transition between the two health states were estimated . The following confounding covariates were also evaluated in the model : severity of asthma , current treatment with oral corticosteroids ( OCS  ) and history of OCS over the year preceding inclusion . About 406 asthmatics were included who made a total of 1639 consultations ; the median length of follow up was 182 days . Using a univariate model , overweight patients had a lower risk of transiting from the unacceptable to the acceptable health state ( RR = 0.45 ; P < 0.01 ) . The effect of weight remained significant ( RR = 0.53 ; P < 0.01 ) in the multivariate model including the other covariates . Moreover , transition probabilities stabilized more rapidly for patients with BMI < 25 ( 200 vs 300 days ) . In this study , we thus demonstrated that there is an association between excess weight and transition from unacceptable to acceptable control . Because control of asthma clearly drives asthma management , this finding has consequences for defining original new strategies for managing asthma in overweight patients OBJECTIVE The effects of perilla seed oil ( n-3 fatty acids ) on bronchial asthma were compared with the effects of corn oil ( n-6 fatty acids ) in relation to the pulmonary function and the generation of leukotriene B4 ( LTB4 ) and C4 ( LTC4 ) by leucocytes . METHODS AND SUBJECTS 14 asthmatic subjects were divided r and omly into two groups : one group ( 7 subjects ) consumed perilla seed oil-rich supplementation and the other group ( 7 subjects ) consumed corn oil-rich supplementation for 4 weeks .  Generation of LTs by leucocytes and respiratory function were compared between the two groups . RESULTS The generation of LTB4 and LTC4 by leucocytes tended to increase in subjects ( N=7 ) with corn oil-rich supplementation , and decrease in subjects ( N=7 ) with perilla seed oil-rich supplementation . Significant differences between the two groups were observed in the generation of LTB4 at 2 weeks ( p<0.05 ) and LTC4 at 2 weeks ( p<0.05 ) after dietary supplementation . Significant increases in the value of PEF ( p<0.05 ) , FVC ( p<0.01 ) , FEV(1.0 ) ( p<0.05 ) and V(25 ) ( p<0.05 ) were found in subjects who received perilla seed oil supplementation for 4 weeks . And significant differences in the value of FVC ( p<0.05 ) and FEV(1.0 ) ( p<0.05 ) were observed between the two groups after 4 weeks of dietary supplementation . CONCLUSION These results suggest that perilla seed oil-rich supplementation is useful for the treatment of asthma in terms of suppression of LTB4 and LTC4 generation by leucocytes , and improvement of pulmonary function Background Conjugated linoleic acids ( CLA ) are naturally occurring fatty acids that have multiple biological properties including the regulation of metabolic , proliferative and immune processes AIM The study aims to assess the a priori hypothesis that regular supplementation with vitamin C or magnesium will permit a reduction in the corticosteroid dose required to maintain asthma control in adults . METHODS We invited all participants recruited from primary care centres who completed a parallel-group , r and omised , placebo-controlled  , 16-week supplementation trial of 1g/day vitamin C or 450 mg/day magnesium to continue and participate in a structured corticosteroid reduction protocol over 10 weeks . RESULTS A total of 92 participants ( 29 vitamin C , 31 magnesium and 32 placebo ) entered the study . Assuming no reduction in corticosteroid dose in the 10 who subsequently withdrew , the geometric mean reductions in inhaled corticosteroid dose achieved with vitamin C , magnesium and placebo were 49 , 13 and 11 microg , respectively . Relative to placebo , the unadjusted effect of vitamin C was significant , and remained at borderline significance after adjustment for baseline corticosteroid dose ( relative reduction ratio=4.03 , 95 % CI 0.95 to 17.1 , P=0.06 ) . CONCLUSIONS We conclude that while vitamin C supplements may have modest corticosteroid sparing effects and hence the potential to reduce exposure to their side effects , magnesium supplements have no effect on the inhaled corticosteroid dose required to maintain asthma control
ABSTRACT Introduction : Obesity in asthmatic patients has important relationships with asthma control , pulmonary function , and quality of life .
The objective of this study was to conduct a systematic review of the literature on the effect of diet on asthma management in adults .