The prevalence of acid reflux experienced at least once a week has increased by almost 50% over the past decade, NTNU researchers report in a long term study of almost 80,000 people published online in Gut.
Women seem to be more vulnerable to developing the condition than men, the figures show.
Acid reflux is associated with an increased risk of gullet (oesophageal) cancer, which is difficult to treat successfully and rates of which have been rising rapidly in developed countries.
30,000 people, 11 years
The researchers studied the digestive health of just under 80,000 people and tracked almost 30,000 people for an average of 11 years between 1995-7 and 2006-9.
All the participants were part of the Norwegian Nord-Trøndelag Health Study, which draws on regular health surveys of a representative sample of the population.
Between 1995-7 and 2006-9 the prevalence of any acid reflux (gastro-oesophageal reflux) symptoms rose 30%, while that of severe symptoms rose by 24%. And the prevalence of acid reflux symptoms experienced at least weekly rose by 47%.
The increases were seen in both men and women and across all age groups, although the rise in the most severe symptoms occurred mainly in the middle aged.
Medicine for severe symptoms
Almost all (98%) of those with severe acid reflux experienced symptoms and/or used medication to treat them at least once a week, compared with around one in three (31%) of those with mild symptoms.
The average annual incidence of any and severe acid reflux symptoms was just over 3% and 0.23%, respectively.
Women under 40 were the least likely to have acid reflux, but were more likely to develop symptoms the older they got. And those aged 60 to 69 were the most likely to have severe symptoms.
Acid reflux symptoms can spontaneously disappear without the aid of medication, but during the study period this happened to just over 2% of those with symptoms each year.
Younger women and resolution of symptoms
Women under 40 were the most likely to find that their symptoms resolved of their own accord. And while this possibility diminished with age in both sexes, it was most evident among women.
The use of anti-reflux medication, or pregnancy, when acid reflux often occurs, could not explain these patterns.
The rise in prevalence of acid reflux may be partly explained by increasing rates of overweight and obesity, which are known risk factors for the condition, while the patterns seen in women might be down to the use of hormone replacement therapy, suggest the authors.
But they warn: "The increasing prevalence of [acid reflux] is alarming, because it will most likely contribute to the increasing incidence of adenocarcinoma of the oesophagus in the western population."
More information: Changes in prevalence, incidence and spontaneous loss of gastro-oesophageal reflux symptoms: a prospective population based cohort study, the HUNT study, Online First, doi:10.1136/gutjnl-2011-300715