Laryngopharyngeal reflux (LPR) is an expensive, high-prevalence disease with a high rate of medical treatment failure. In the past, it was mistakenly believed that pepsin was inactive above pH 4; however, human pepsin has been reported to be active up to pH 6.5. In addition, it has been shown by Western blot analysis that laryngeal biopsy samples from patients with symptomatic LPR have tissue-bound pepsin. The clinical impact of a low-acid diet on the therapeutic outcome in LPR has not been previously reported. To provide data on the therapeutic benefit of a strict, virtually acid-free diet on patients with recalcitrant, proton pump inhibitor (PPI)-resistant LPR, I performed a prospective study of 20 patients who had persistent LPR symptoms despite use of twice-daily PPIs and an H2-receptor antagonist at bedtime.
The reflux symptom index (RSI) score and the reflux finding score (RFS) were determined before and after implementation of the low-acid diet, in which all foods and beverages at less than pH 5 were eliminated for a minimum 2-week period. The subjects were individually counseled, and a printed list of acceptable foods and beverages was provided.
There were 12 male and 8 female study subjects with a mean age of 54.3 years (range, 24 to 72 years). The symptoms in 19 of the 20 subjects (95%) improved, and 3 subjects became completely asymptomatic. The mean pre-diet RSI score was 14.9, and the mean post-diet RSI score was 8.6 (p = 0.020). The mean pre-diet RFS was 12.0, and the mean post-diet RFS was 8.3 (p < 0.001).
A strict low-acid diet appears to have beneficial effects on the symptoms and findings of recalcitrant (PPI-resistant) LPR. Further study is needed to assess the optimal duration of dietary acid restriction and to assess the potential role of a low-acid diet as a primary treatment for LPR. This study has implications for understanding the pathogenesis, cell biology, and epidemiology of reflux disease.