The DASH Diet for Adults With Uncontrolled Asthma

Inclusion Criteria:

• Ethnicity: All ethnic groups
• Body mass index (BMI) 18.5-39.9 kg/m2
• Suboptimally controlled asthma:
• Diagnosis of asthma on the current medical problem list
• Currently prescribed at least 1 medication for the treatment of asthma
• Physiological evidence of asthma with demonstrable reversibility of airway obstruction, or a specialist's confirmation of asthma diagnosis based on chart review
• Documented history of high asthma-related emergency and/or inpatient encounters or reliever medication usage
• Asthma Control Test: total score <20 or item score <3 for any of the first 4 questions regarding symptoms (3-6x/week or more), nighttime awakening (1x/week or more), interference with normal activity (at least some of the time), and rescue medication use for symptom relief (2-3x/week or more)
• Kaiser member for ≥1 year
• PCP approval of study screening
• Able and willing to enroll and provide written informed consent

Exclusion Criteria:

• Intermittent asthma, defined as either seasonal asthma or (daytime asthma symptoms <2x/week and nocturnal symptoms <2x/month and no use of long-term control medications)
• Primary diagnosis of COPD (emphysema or chronic bronchitis) on the current medical problem list or suggested by baseline spirometry and smoking history
• Previous diabetes (other than during pregnancy) or diabetes diagnosed as a result of fasting blood glucose or hemoglobin A1c levels obtained at screening
• Previous cardiovascular disease: e.g., coronary heart disease, cerebrovascular disease, peripheral vascular disease, heart failure, or aortic aneurysm
• Diagnosis of cancer (other than non-melanoma skin cancer) that is/was active or treated with radiation or chemotherapy within the past 2 years
• Inflammatory bowel disease, colostomy, malabsorption, or major gastrointestinal resection
• Diagnosis of bipolar or psychotic disorder or hospitalization for psychological or emotional problems within the last 2 years
• Diagnosis of a terminal illness and/or in hospice care
• Fasting LDL cholesterol >190 mg/dL, triglycerides >500 mg/dl, fasting blood glucose >125 mg/dl
• Significant liver enzyme abnormality as indicated by AST or ALT more than 2 times the upper limit of normal or a clinical diagnosis of hepatitis
• Renal insufficiency (GFR<60 ml/min)
• Current use of insulin or oral hypoglycemic agents
• Use of oral corticosteroids >5 days/month on average
• Current use of medications for treatment of psychosis or manic-depressive illness
• Current use of prescription or non-prescription weight-loss products or any dietary/herbal supplements and unwillingness to discontinue;
• Inability to speak, read, or understand English at the 6th-grade level or above
• Inability to perform pulmonary function tests by spirometry in a consistent manner
• DASH concordance index >60%
• Unwillingness to modify current diet
• Current or planned participation in a structured program that overtly focuses on diet and nutrition
• Planning to undergo bariatric surgery during the study period
• Actively attempting to lose weight, or weight change >15 lbs during prior 3 months
• Consumption of >21 alcoholic drinks per week, or >=6 drinks on one occasion twice or more per week, or alcoholism as determined by the Alcohol Use Disorders Identification Test
• Pregnant, lactating, or planning to become pregnant during the study period
• No longer a Kaiser patient or planning to transfer care out of Kaiser or to move out of the area during the study period
• Family/household member of another study participant or of a study staff member
• Enrolled or planning to enroll in another research study that would limit full participation in the study or confound the interpretation of the study's findings
• Investigator discretion for safety or protocol adherence reasons