Five lifestyle factors tracked with half the reflux risk in 42,955 women

Clinicians have recommended diet and lifestyle changes for reflux for decades, and until recently there were no prospective data behind the advice at all. A Nurses' Health Study II analysis published in January 2021 supplied some: women meeting all five of an antireflux lifestyle score had roughly half the risk of developing reflux symptoms compared with women meeting none, with a multivariable hazard ratio of 0.50 (95% CI 0.42 to 0.59) [s1].

The authors state plainly that no prospective data were available to inform these recommendations before their analysis [s1].

What was measured

The Nurses' Health Study II is an ongoing nationwide prospective cohort established in 1989 with 116,671 female participants returning biennial health questionnaires, with follow-up exceeding 90% [s1]. Participants were asked about acid reflux or heartburn in 2005, 2009, 2013 and 2017 [s1].

For this analysis, women were excluded at baseline if they already reported weekly or more frequent reflux symptoms, had cancer, regularly used proton pump inhibitors or histamine receptor antagonists, had missing dietary data, or were lost to follow-up [s1]. That left 42,955 women aged 42 to 62, with a mean age of 52.0 years [s1]. Over 392,215 person-years of follow-up between June 2007 and June 2017, 9,291 incident cases of reflux symptoms were identified [s1].

The antireflux lifestyle score ran from 0 to 5 and consisted of five dichotomised factors: normal weight (body mass index of at least 18.5 and under 25.0); never smoking; at least 30 minutes of moderate-to-vigorous physical activity daily; no more than two cups of coffee, tea or soda daily; and a prudent diet, defined as the top 40% of a dietary pattern score [s1].

Models were adjusted for age, calendar period, total caloric intake, alcohol intake, use of menopausal hormones, use of proton pump inhibitors or histamine receptor antagonists, use of medications that may reduce lower oesophageal sphincter pressure — calcium channel blockers, benzodiazepines and antidepressants — and history of diabetes [s1].

What the numbers say about which factor matters

The proportion of reflux cases the authors calculated as potentially preventable by all five factors together was 37% (95% CI 28% to 46%) [s1].

Split by factor, and with each mutually adjusted for the other four, the contributions were very unequal. Body mass index in the 18.5 to 24.9 range carried a hazard ratio of 0.69 (95% CI 0.66 to 0.72) and a population-attributable risk of 19% (95% CI 15% to 23%) [s1]. Physical activity of at least 30 minutes came next at 8% (95% CI 6% to 11%), then a prudent diet at 7% (95% CI 6% to 8%), then limiting coffee, soda and tea to two cups a day at 4% (95% CI 1% to 7%) [s1].

Never smoking came last, with a hazard ratio of 0.94 (95% CI 0.90 to 0.99) and a population-attributable risk of 3% (95% CI 0% to 6%) [s1].

That ordering is the practically useful result. The advice most commonly given for reflux — cutting coffee, cutting particular foods — sits at the small end of the effect distribution, while body weight sits at the large end, at 19% against a combined 37% for all five [s1].

Each of the five factors was independently associated with reflux symptoms, so none of them is inert [s1]. But the population-attributable risks run from 19% for body mass index down to 3% for never smoking [s1].

What a cohort study cannot establish

This is observational. Women who maintain a normal body mass index, exercise daily, never smoke and eat a prudent diet differ from women who do none of those things in ways no adjustment fully captures. The population-attributable risk figure is a modelled estimate of what would happen if everyone adopted all five factors, not an observed result of anyone doing so.

The outcome is also self-reported symptoms — acid reflux or heartburn at least weekly — rather than endoscopic or pH-measured disease [s1]. And the cohort is entirely female and entirely nurses, which limits how far the estimates transfer.

Where the guideline sits

The American College of Gastroenterology's guideline on gastro-oesophageal reflux disease, published in November 2021, describes GERD as remaining among the most common conditions seen by gastroenterologists, surgeons and primary care physicians [s2]. It provides updated recommendations covering pharmacological, lifestyle, surgical and endoscopic management, graded with the GRADE system, and includes key concepts and suggestions that at the time of writing did not have sufficient evidence to grade [s2].

The guideline also records the state of the debate around drug treatment: scrutiny of proton pump inhibitors has increased considerably, and although they remain the medical treatment of choice for GERD, multiple publications have raised questions about adverse events, doubts about the safety of long-term use, and concern about overprescribing [s2].

The honest summary

The lifestyle advice has prospective evidence behind it for the first time, and the evidence points somewhere slightly different from where the advice usually points. Weight is the dominant modifiable factor in this dataset; coffee and smoking are the smallest [s1]. Meeting all five factors was associated with half the risk, and around a third of cases were estimated to be attributable to not meeting them [s1].

None of that makes reflux a lifestyle failure. It is a common condition with anatomical and physiological contributors this study did not measure, and the guideline's treatment ladder exists because lifestyle change is often not sufficient [s2].

This article is informational and is not medical advice. Persistent reflux, difficulty swallowing, unintended weight loss or symptoms that do not respond to treatment need clinical assessment, and decisions about acid-suppressing medication belong with a reader and their clinician.

Sources

• Association of Diet and Lifestyle With the Risk of Gastroesophageal Reflux Disease Symptoms in US Women — JAMA Internal Medicine, 2021-01-04
• ACG Clinical Guideline for the Diagnosis and Management of Gastroesophageal Reflux Disease — American Journal of Gastroenterology, 2021-11-22