Clearly, it is sound medical practice to recommend smoking cessation in all patients. Smoking cessation is often particularly recommended to patients with GERD, although whether this has any direct benefit to the management of their GERD symptoms—as opposed to their general well-being—has been debated for some time. Cigarette smoking has been linked to GERD symptoms. In 1972, Stanciu et al. [3] described reduced LES pressure in 25 chronic smokers (consuming 15–60 cigarettes daily) who complained of heartburn. All subjects also had reduced (i.e., more acidic) measured intraesophageal pH. Tobacco smoking also reduces salivary bicarbonate secretion, which is probably important for the neutralization of acidic gastric contents that have refluxed into the esophagus and are in contact with the esophageal mucosa [4, 5]. Impaired esophageal acid clearance, coughing, and deep inspiration are additional underlying mechanisms [6, 7]. Worsening GERD symptoms have been reported with longer duration of smoking. This was reported in a case–control study showing an odds ratio (OR) for reflux of 1.7 (95 % confidence interval (CI), 1.4–2.0; P < 0.001) in daily smokers with a tobacco use history of over 20 years as compared with those who smoked daily for less than one year [8]. In a study of 30 subjects [9], using 24-h intraesophageal pH monitoring, more reflux episodes were detected in subjects who smoked than in those who did not. However, that did not translate into a greater esophageal acid exposure time. Another study [10] (measuring reflux episodes and then correlating those with reflux symptoms) showed that smoking significantly increased the percentage time that the intraesophageal pH was < 4 during a 24-h period, attributed to increased reflux events and decreased acid clearance. While smoking, the patients noted a 114 % increase in daytime heartburn episodes that immediately followed an acidic reflux event identified by a fall in pH. Smit et al. [11] showed similar findings (i.e., the amount of time that intraesophageal pH was < 4) in both the upper and lower esophagus (measured by dual probe pH monitoring) in smokers during periods of active smoking compared to when they were not smoking. This suggests variation in the degree of reflux related to periods of active smoking.

Despite the known effect that smoking has on LES relaxation (and hence increased esophageal acid reflux), two reviews of earlier data did not show improvement in GERD symptoms after smoking cessation [12, 13]. However, the included studies looked at very short-term effects of smoking on GERD symptoms.

More recently, a large, prospective, population-based study (the Nord-Trøndelag Health or HUNT study) [14] was conducted from 1995–1997 to 2006–2009 in Norway and the results were reported in 2014. The study included more than 29,000 individuals. The association between smoking cessation and improvement in GERD symptoms was assessed by logistic regression. Cessation of daily tobacco smoking (along with taking anti-reflux medication at least once weekly) was associated with improvement in GERD symptoms from “severe” to “no” or “minor” complaints (adjusted OR 1.78; 95 % CI 1.07–2.97), when compared to persistent daily smoking. This association was particularly strong among individuals within the normal range of BMI (OR 5.67; 95 % CI 1.36–23.64), but not among overweight individuals.

Therefore, there is some evidence that smoking cessation may help to alleviate GERD symptoms. This may be particularly important for non-overweight individuals when given in combination with appropriate pharmacotherapy.

Obesity is a known risk factor for the development of GERD symptoms. Multiple studies in the USA, the UK, Norwegian, and Spanish populations have shown positive associations between being overweight or obese and GERD symptoms [15–19]. Furthermore, GERD symptoms tend to be worse with increasing body weight, thereby demonstrating some evidence of a “dose–response” effect. Based upon the association of obesity and GERD symptoms, it is logical to assume that GERD symptoms would improve with weight loss and consequent reduction of BMI. However, an earlier study from Sweden [20], in 20 obese GERD patients with daily symptoms despite regular daily use of anti-reflux medications found that weight reduction did not improve subjective (reflux symptoms) or objective (intraesophageal pH) manifestations of GERD. Another prospective study in GERD patients who were morbidly obese examined the effect of a liquid, low calorie diet, and vertical band gastroplasty on 24-h, ambulatory intraesophageal pH before and after surgery; it found no beneficial effect of either measure on reflux [21].

Kaltenbach et al. [13] performed a systematic review in an attempt to identify lifestyle measures that have an impact on GERD symptoms. Weight loss in the obese and elevation of head end of the bed were the only interventions resulting in improvement of intraesophageal pH profiles and symptoms.

Another systematic review published in 2009 [22] looked at various weight-reducing modalities (including dietary/lifestyle modifications and surgical procedures such as Roux-en-Y gastric bypass and vertical band gastroplasty) on symptomatic and/or objective manifestations of GERD in obese patients. Four of seven studies reported an improvement in GERD symptoms as well as pH-metry outcomes with diet/lifestyle interventions. For Roux-en-Y gastric bypass, an improvement in GERD symptoms was found in all (mainly evaluated by questionnaires). In contrast, for vertical-banded gastroplasty, no change or even an increase of GERD manifestations (measured by pH-metry and symptoms) was noted. The results for laparoscopic adjustable gastric banding were conflicting.

The impact of a structured weight loss program on GERD symptoms in overweight and obese subjects (BMI 25–39.9 kg/m²) was assessed in a prospective cohort study [23]. BMI and waist circumference were measured at baseline and at 6 months, and all participants completed a validated reflux disease questionnaire. Mean weight loss at 6 months was 13 ± 7.7 kg. A total of 65 % had complete resolution and 15 % had partial resolution of reflux symptoms. There was a small but statistically significant correlation between percentage of body weight loss and reduction in GERD symptom scores (r = 0.17; P < 0.05).

Most recently, in a set of quality measures that are suggested for the care of GERD patients [24], eight clinical experts ranked potential measures for validity on the basis of the RAND/University of California, Los Angeles Appropriateness Methodology. They identified 24 valid GERD care quality measures (identified from literature, guidelines, and experts) related to initial diagnosis and management, monitoring, further diagnostic testing, proton pump inhibitor (PPI) refractory symptoms, symptoms of chest pain, erosive esophagitis (EE), esophageal stricture or ring, and surgical therapy of this condition. Weight loss recommendation in any obese patient with reflux symptoms was the only quality lifestyle modification with high validity.

Based on the evidence present to date, weight loss seems to improve GERD symptoms in obese and overweight individuals. This appears true whether achieved through conservative weight loss strategies or surgical management.

The recumbent position has been associated with an increase in esophageal acid exposure and a worsening of GERD symptoms. Stanciu et al. [25], measured intraesophageal pH in GERD patients when in different body positions. They reported percentage of time during which pH was below five and the number of reflux episodes. These were both significantly reduced when patients were in the head-up position than when sitting or lying. Their results suggested that elevation of the head end of the bed would improve GERD symptoms, decrease reflux episodes, and promote acid clearance. Later, another randomized crossover study by Hamilton et al. [26] compared different lying positions and their effect on esophageal pH, reflux episodes, and distal esophageal acid clearance times in 15 individuals with moderate-to-severe acid reflux symptoms. Three lying positions (flat, head elevation with 8-in. bed blocks, and head elevation by a foam wedge) were compared. The wedge caused a statistically significant decrease in the time that distal esophageal pH was less than 4 as compared to the flat position. It also decreased the longest episode experienced by the subjects. Both head elevation positions (by wedge and on blocks) showed a trend towards a decrease in acid clearance time as compared to the flat position.

In contrast to the above two studies, results of a multicenter trial [27] showed no difference in reflux scores and use of antacids after all included patients were randomly assigned to either sleeping with horizontal bedhead or having the bedhead raised by 15 cm. However, this 2-week study did not use esophageal pH monitoring and some patients were allowed use of a PPI twice a day while others were not.

More recently, a small study [28] showed that nocturnal GERD symptoms improved with elevation of the head end of the bed on a 20 cm block. Esophageal pH measurements were obtained in supine position on day 1 and then obtained on day 2 and 7 (while head end elevated). Mean supine reflux time, acid clearance time, number of reflux episodes lasting at least 5 min, and symptom score all improved. Twenty patients completed this 7-day study and there was statistically significant improvement in all measures.

Thus, there is evidence of both objective and subjective improvement in acid reflux with bedhead elevation. However, many patients and/or their spouses or sleeping partners find this impractical and unacceptable. Despite evidence to support it, a recommendation to elevate the head end of the bed is not routinely given or followed.

Nocturnal reflux symptoms have a greater impact on quality of life (QoL) compared with daytime symptoms. Both nocturnal symptoms and sleep disturbances are critical to elucidate when evaluating a patient with GERD [29]. They can improve with avoidance of late-night meals. In an older study, nocturnal intragastric pH was higher with an early dinner (6 p.m.) than with a late dinner (9 p.m.) and hence acid reflux symptoms were thought likely to improve as a result [30].

The most recent guidelines [31] for the diagnosis and management of GERD from the American College of Gastroenterology (ACG) suggested avoidance of late-night meals within 2–3 h of reclining (as well as elevation of the head end of bed) for the management of nocturnal reflux symptoms (conditional recommendation, low level of evidence).

Despite lack of substantive evidence to support it, it is common practice—and probably sensible—to advise GERD patients (particularly those with nocturnal symptoms) to avoid eating for the 2–3 h period before bedtime. This is a simple intervention that should be easily understood by patients once explained.

Cammarota et al. [32] showed more severe GERD symptoms in a study of 351 professional opera choristers when compared to 578 age- and sex-matched non-singers. Theoretically, at least, singers who practice and concentrate on deep inspiration might be better protected against GERD symptoms since they contract their diaphragm during inspiration to allow for chest expansion (abdominal breathing). This protective effect is based on the assumption that the diaphragmatic crura contribute to the reflux protective mechanism (along with the LES). This raises the possibility that the type of breathing could play some role in the management of GERD symptoms.

In fact, Eherer et al. [33] developed a training program to raise patients’ consciousness of their breathing as they learned to shift from thoracic movements to abdominal wall movements. They had excluded patients with anatomical abnormalities like large hiatal hernia or endoscopically diagnosed EE. Nineteen patients were included in this randomized trial (ten in the breathing exercise group and nine in the control group). QoL, pH-metry, and on-demand PPI usage were assessed at baseline and after 4 weeks of training. There was a significant decrease in time with a pH < 4.0 in the training group (9.1 ± 1.3 % vs. 4.7 ± 0.9 %; P < 0.05) but no significant change in the control group. Similarly, QoL scores improved significantly in the training group (13.4 ± 1.98 before and 10.8 ± 1.86 after training; P < 0.01) but no improvement in the control group. QoL improvement and reduced use of PPI was maintained during nine months of follow-up in 11 of 19 patients who continued breathing exercises.

Thus, based on very limited evidence, there is evidence for both subjective and objective improvement following a course of breathing exercises. However, this would be difficult to implement routinely and the results of the above study may not be generalizable to the GERD population at large. Apart from highly selected subgroups of GERD patients, as indicated above, it is doubtful that this would influence routine clinical practice.

In general, dietary modifications have not been shown to have a great impact on the alleviation of GERD symptoms. There are, however, instances when selective elimination can be recommended [31].

Some non-epidemiological studies have reported that coffee causes a relaxation of the LES, which in turn can increase reflux episodes and symptoms [34, 35]. Some studies have suggested a role of caffeine in the development of GERD symptoms. In one study, involving 17 GERD patients who ingested, in a double-blinded manner, either regular or decaffeinated coffee, decaffeination was shown to decrease the amount of time that reflux occurred [36]. Wendl et al. [37] showed that regular coffee induced significantly (P < 0.05) more reflux compared with tap water and normal tea, which were not different from each other. Decaffeination of coffee significantly diminished reflux. Interestingly, decaffeination of tea or addition of caffeine to water did not have any effect, thereby raising the possibility that some other component(s) of coffee apart from caffeine might be responsible for promoting GERD symptoms.

However, data from a randomized, crossover study [38] involving healthy subjects and GERD patients showed that coffee had no effect on postprandial acid reflux time or on the number of reflux episodes in either group. Furthermore, coffee was noted to increase percentage reflux time in the fasting state in GERD patients but not in healthy subjects. This may suggest that avoidance of coffee ingestion while in a fasting state might be beneficial in patients with GERD.

More recently, a study of over 8000 patients from Japan [39] evaluated the effect of coffee in different upper gastrointestinal (GI) disorders including reflux esophagitis (RE) and non-erosive reflux disease (NERD) . There were 994 RE patients, 1118 with NERD, and 5901 non-GERD controls. (It is unclear whether the control subjects were age and sex matched.) Coffee consumption did not show any association with RE or NERD.

In a meta-analysis published in 2014, Kim et al. [40] specifically looked at the effect that coffee intake has on GERD. Among 15 case–control studies that were included, no significant association was found (OR 1.06; 95 % CI 0.94–1.19). In a subgroup analysis, the amount of coffee intake also had no impact on GERD symptoms.

An older study has suggested that fried and spicy foods cause more GERD symptoms, although this study was uncontrolled and did not quantify the intake of dietary items [41]. Similarly, El Serag et al. conducted a cross-sectional study on 371 volunteers to elucidate the relationship between diet and GERD symptoms. They used a dietary questionnaire to estimate the amount of food intake in the previous year and then a GERD questionnaire plus upper endoscopy (performed on 164 of 371) to assess reflux severity. EE was found in 40 of 164 subjects. High fat intake was associated not only with more GERD symptoms but also with EE. This finding, however, was statistically significant only in obese individuals [42]. In another study of 58 subjects with heartburn [43], dietary cholesterol and saturated fat intake were significantly associated with increased likelihood of reflux events. Other studies have not shown an association between fat intake and reflux symptoms [44] and have concluded that it is only BMI, as opposed to dietary composition, that most influences symptoms of GERD [45].