Brigham Emily P, Matsui Elizabeth C, Appel Lawrence J, Bull Deborah A, Curtin-Brosnan Jean, Zhai Shuyan, White Karen, Charleston Jeanne B, Hansel Nadia N, Diette Gregory B, McCormack Meredith C
The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
The Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America.
PLoS One. 2017 Jul 13;12(7):e0180068. doi: 10.1371/journal.pone.0180068. eCollection 2017.
Evidence from observational studies and to a lesser extent clinical trials suggest that a healthy diet may improve symptoms and lung function in patients with asthma. We conducted a pilot study to determine the feasibility of conducting a larger scale dietary trial and to provide preliminary evidence on the impact of a healthy diet on asthma outcomes.
In a randomized, two period cross-over trial, participants with asthma received a 4-week dietary intervention followed by a usual diet (or vice versa), separated by a 4-week washout. The dietary intervention was a healthy diet rich in unsaturated fat. During the dietary intervention, participants ate three meals per week on site at the Johns Hopkins ProHealth Research Center. All remaining meals and snacks were provided for participants to consume off-site. During the control diet, participants were instructed to continue their usual dietary intake. Relevant biomarkers and asthma clinical outcomes were assessed at 0, 2, and 4 weeks after starting each arm of the study.
Eleven participants were randomized, and seven completed the full study protocol. Among these seven participants, average age was 42 years, six were female, and six were African American. Participant self-report of dietary intake revealed significant increases in fruit, vegetable, and omega-3 fatty acid intake with the dietary intervention compared to usual diet. Serum carotenoids (eg. lutein and beta-cryptoxanthin) increased in the intervention versus control. Total cholesterol decreased in the intervention versus control diet. There was no consistent effect on asthma outcomes.
The findings suggest that a feeding trial in participants with asthma is feasible. Larger trials are needed to definitively assess the potential benefits of dietary interventions on pulmonary symptoms and function in patients with asthma.
观察性研究以及在较小程度上临床试验的证据表明，健康饮食可能改善哮喘患者的症状和肺功能。我们开展了一项初步研究，以确定进行更大规模饮食试验的可行性，并提供关于健康饮食对哮喘结局影响的初步证据。
在一项随机、两阶段交叉试验中，哮喘患者接受为期4周的饮食干预，随后是常规饮食（或反之亦然），中间间隔4周的洗脱期。饮食干预是富含不饱和脂肪的健康饮食。在饮食干预期间，参与者每周在约翰霍普金斯ProHealth研究中心现场吃三餐。所有其余餐食和零食提供给参与者在非现场食用。在对照饮食期间，指示参与者继续其常规饮食摄入。在研究各阶段开始后的0、2和4周评估相关生物标志物和哮喘临床结局。
11名参与者被随机分组，7名完成了完整的研究方案。在这7名参与者中，平均年龄为42岁，6名是女性，6名是非洲裔美国人。参与者饮食摄入的自我报告显示，与常规饮食相比，饮食干预使水果、蔬菜和ω-3脂肪酸的摄入量显著增加。与对照组相比，干预组血清类胡萝卜素（如叶黄素和β-隐黄质）增加。与对照饮食相比，干预组总胆固醇降低。对哮喘结局没有一致的影响。
研究结果表明，对哮喘患者进行喂养试验是可行的。需要更大规模的试验来明确评估饮食干预对哮喘患者肺部症状和功能的潜在益处。
