Food and functional dyspepsia: a systematic review
Duncanson K.R, Talley N.J, Walker M.M & Burrows T.L (Sept 2017)
J Hum Nutr Diet.
https://doi.org/10.1111/jhn.12506
Functional Dyspepsia (FD) is defined as early satiety, post-prandial fullness or epigastric pain/ burning related to meals that interferes with daily activities in the absence of any associated structural or metabolic disease (Rome IV criteria).
J Hum Nutr Diet.
https://doi.org/10.1111/jhn.12506
Functional Dyspepsia (FD) is defined as early satiety, post-prandial fullness or epigastric pain/ burning related to meals that interferes with daily activities in the absence of any associated structural or metabolic disease (Rome IV criteria).
FD is a debilitating functional gastrointestinal disorder believed to affect 10-20% of western populations. Very few clinical trials formally evaluate dietary interventions for the management of functional dyspepsia, however dietary fats have been reported as being associated with post-prandial fullness and may be restricted in the diets of patients with functional dyspepsia. Current dietary recommendations reported in the literature focus on eating low-fat meals, as well as more frequent, smaller meals. In contrast to irritable bowel syndrome, there is currently no standardised approach to the dietary management of functional dyspepsia. The aim of this systematic review was to identify and describe the influence of specific foods or food components on specific and/or overall symptoms of functional dyspepsia sufferers aged over 16 years.
A search of the medical literature from January 1982 to February 2016 was conducted. Studies examining the effect of nutrients, foods and food components in adults (over the age of 16 years) with functional dyspepsia were eligible for inclusion. A total of 6451 studies were identified, of which just 16 studies met the inclusion criteria and were included in the review, mean age of participants was 43 years. Dietary fat was associated with onset of symptoms after a meal challenge or reported as inducing symptoms of dyspepsia in three studies, and specifically with dyspeptic symptoms of nausea (n = 3 studies), bloating (n = 2 studies), post-prandial fullness/discomfort (n = 2 studies) and epigastric pain (n = 2 studies). Alcohol intake was found to induce dyspepsia in two studies (specifically beer and wine), but no effect was found in a further 2 studies. Coffee intake was associated with symptom induction in more than 50% of functional dyspepsia patients in four studies, although no association was found in one study that specifically analysed coffee consumption and symptoms. Other problematic foods reported by participants to be an issue in more than one study were in descending order: grain/pasta/wheat products (n = 6 studies), soft drink/carbonated drinks (n = 4) studies, tea (n = 2 studies), fruit/fruit juice (n = 3 studies), milk (n = 3 studies), red/bell pepper (n = 3 studies) and takeout/processed foods (e.g. pizza/fried food) (n = 3 studies).
The findings of this review consolidate the established reported relationship between dietary fats and functional dyspepsia. Further research into whether different types of fats induce different dyspeptic symptoms or whether specific symptoms relate to different action of fats on gastrointestinal symptoms is warranted. The role of wheat and specifically gluten in functional dyspepsia is also supported by this review. It is speculated that gluten (and other wheat related proteins) and FODMAPs are symptom triggers in irritable bowel syndrome, although this has sparked debate regarding which food component triggers which particular symptom. Wheat-containing foods were implicated in functional dyspepsia symptom induction in six studies, four of which were not specifically investigating gluten and two that were gluten-specific. Although the implementation of a gluten-free diet in both gluten-specific studies clearly demonstrated a reduction in symptoms, the elimination of dietary wheat, barley and rye would also have substantially reduced the FODMAP content of these diets, potentially influencing the results. This review indicates the need for well-designed clinical studies that involve randomising patients to a wheat-free or gluten-free diet and controlling for FODMAP content, aiming to investigate specific dyspeptic symptom associations with wheat food components.
The inconclusive results relating to the relationship between alcohol and functional dyspepsia symptoms may relate to the differing study types, as well as alcohol consumption classification and alcohol assessment. Future investigations of potential relationships between alcoholic drinks and functional dyspepsia should aim to determine whether there is a dose-dependent relationship and whether specific symptoms are triggered by specific alcoholic beverages. It is also important to determine whether alcohol itself is responsible as a gastrointestinal irritant, whether food chemicals in alcoholic drinks influence symptoms, or whether carbonation is responsible, given that three studies in this review reported carbonated drinks as inducing functional dyspepsia symptoms. Of further interest is whether carbonated drinks induce dyspeptic symptoms (particularly gas and bloating) as a result of their carbonation or acidity or salicylate content. Similarly, the relationship between coffee and symptoms of functional dyspepsia requires clarification because variable salicylate or caffeine contents of coffee may have influenced the study outcomes in the respective included studies.
In conclusion, wheat and specifically gluten, and also FODMAP ingestion, high fat ingestion and naturally occurring food chemicals, may play key roles in the generation of functional dyspepsia symptoms. Randomised trials are warranted and further investigation of the responsible mechanisms is now required. Despite the well documented link between food consumption and functional dyspepsia, relatively few studies were found and included in this review, limiting the conclusions that can be drawn between dietary intakes and symptoms. The lack of a standardised approach to dietary assessment methods with respect to those included studies in which primary outcome measures related to food measurement also limited comparison between studies.
Link to original paper
A search of the medical literature from January 1982 to February 2016 was conducted. Studies examining the effect of nutrients, foods and food components in adults (over the age of 16 years) with functional dyspepsia were eligible for inclusion. A total of 6451 studies were identified, of which just 16 studies met the inclusion criteria and were included in the review, mean age of participants was 43 years. Dietary fat was associated with onset of symptoms after a meal challenge or reported as inducing symptoms of dyspepsia in three studies, and specifically with dyspeptic symptoms of nausea (n = 3 studies), bloating (n = 2 studies), post-prandial fullness/discomfort (n = 2 studies) and epigastric pain (n = 2 studies). Alcohol intake was found to induce dyspepsia in two studies (specifically beer and wine), but no effect was found in a further 2 studies. Coffee intake was associated with symptom induction in more than 50% of functional dyspepsia patients in four studies, although no association was found in one study that specifically analysed coffee consumption and symptoms. Other problematic foods reported by participants to be an issue in more than one study were in descending order: grain/pasta/wheat products (n = 6 studies), soft drink/carbonated drinks (n = 4) studies, tea (n = 2 studies), fruit/fruit juice (n = 3 studies), milk (n = 3 studies), red/bell pepper (n = 3 studies) and takeout/processed foods (e.g. pizza/fried food) (n = 3 studies).
The findings of this review consolidate the established reported relationship between dietary fats and functional dyspepsia. Further research into whether different types of fats induce different dyspeptic symptoms or whether specific symptoms relate to different action of fats on gastrointestinal symptoms is warranted. The role of wheat and specifically gluten in functional dyspepsia is also supported by this review. It is speculated that gluten (and other wheat related proteins) and FODMAPs are symptom triggers in irritable bowel syndrome, although this has sparked debate regarding which food component triggers which particular symptom. Wheat-containing foods were implicated in functional dyspepsia symptom induction in six studies, four of which were not specifically investigating gluten and two that were gluten-specific. Although the implementation of a gluten-free diet in both gluten-specific studies clearly demonstrated a reduction in symptoms, the elimination of dietary wheat, barley and rye would also have substantially reduced the FODMAP content of these diets, potentially influencing the results. This review indicates the need for well-designed clinical studies that involve randomising patients to a wheat-free or gluten-free diet and controlling for FODMAP content, aiming to investigate specific dyspeptic symptom associations with wheat food components.
The inconclusive results relating to the relationship between alcohol and functional dyspepsia symptoms may relate to the differing study types, as well as alcohol consumption classification and alcohol assessment. Future investigations of potential relationships between alcoholic drinks and functional dyspepsia should aim to determine whether there is a dose-dependent relationship and whether specific symptoms are triggered by specific alcoholic beverages. It is also important to determine whether alcohol itself is responsible as a gastrointestinal irritant, whether food chemicals in alcoholic drinks influence symptoms, or whether carbonation is responsible, given that three studies in this review reported carbonated drinks as inducing functional dyspepsia symptoms. Of further interest is whether carbonated drinks induce dyspeptic symptoms (particularly gas and bloating) as a result of their carbonation or acidity or salicylate content. Similarly, the relationship between coffee and symptoms of functional dyspepsia requires clarification because variable salicylate or caffeine contents of coffee may have influenced the study outcomes in the respective included studies.
In conclusion, wheat and specifically gluten, and also FODMAP ingestion, high fat ingestion and naturally occurring food chemicals, may play key roles in the generation of functional dyspepsia symptoms. Randomised trials are warranted and further investigation of the responsible mechanisms is now required. Despite the well documented link between food consumption and functional dyspepsia, relatively few studies were found and included in this review, limiting the conclusions that can be drawn between dietary intakes and symptoms. The lack of a standardised approach to dietary assessment methods with respect to those included studies in which primary outcome measures related to food measurement also limited comparison between studies.
Link to original paper
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