Cheese fondue is a meal served on festive occasions or when family and friends get together in Switzerland. It is also among the most popular dishes ordered by tourists in Switzerland; no skiing trip is complete without a fondue dinner! In terms of nutrient composition, Swiss cheese fondue is not much different from any other fondue; however, Swiss people will, of course, claim that it is the original and by far the best! Those familiar with local customs, perhaps having read the classic reference Asterix in Switzerland
will know that there can be punishments for fondue eaters who lose their bread in the cheese, ranging from an extra shot of schnapps to being thrown into a freezing lake. This kind of psychosocial stress is likely to affect gastric function and could trigger dyspeptic symptoms.12
In this study, the participants consumed fondue from individual “rechauds” so avoiding potential embarrassment to those less skilful with a fork. Moreover, in compliance with the stringent requirements of the local ethics committee, no punishments were threatened, or indeed meted out!
The debate about what to drink with a cheese fondue is one about which everyone at the Swiss dinner table has an opinion. Although the importance of this question to the “rest of the world” should not, perhaps, be overstated, the findings of this study can be generalised to address the wider issue of alcohol’s effects on digestion and digestive comfort after any large, rich meal of the kind enjoyed by all over the festive season. This randomised controlled trial is an important contribution to this debate as it is the first to apply well validated and concurrent assessments of gastric emptying, alcohol concentrations, and postprandial symptoms. The results show that drinking white wine with a high fat, high energy meal such as Swiss cheese fondue decreases the rate of gastric emptying compared with black tea. Taking a shot of spirits after the meal has additional gastrointestinal effects. At the highest doses studied, alcohol seemed to suppress appetite after the meal; however, irrespective of beverage, dyspeptic symptoms were reported only occasionally by the healthy participants.
We observed an important decrease in gastric emptying rate when a moderate amount of white wine (300 ml; 14% alcohol) was consumed with a Swiss cheese fondue compared with the same volume of black tea. The decrease was both rapid and prolonged, with the recovery of 13
C reduced from the first breath sample and never attaining the level observed in the control arm (fig 1). This finding is consistent with reports that ethanol and a variety of alcoholic beverages slow gastric emptying when taken before a meal4
; although, this effect was not always observed if the total energy content of food and drink consumed during the meal was controlled.2
We chose not to control energy intake because this would have required 12 teaspoons of sugar. Tea sweetened to this extent is not palatable and the osmolality of sugar in solution is greater than that of alcohol. This would also slow gastric emptying and indeed might explain the divergent results of previous reports.13
Comparison of our results with those of a dietary intervention study that controlled both energy and osmolality,15
indicates that the approximate 25% increase in total energy intake is not sufficient to explain the approximate 50% decrease in gastric emptying rate that we observed when alcohol was consumed with fondue.
A shot of cherry schnapps (20 ml; 40%) taken after the Swiss cheese fondue also reduced the rate of gastric emptying. One previous paper did not show similar effects with brandy5
; however, the assessment of gastric emptying by antral ultrasound applied in that study was confounded by any redistribution of the meal within the stomach or increase in gastric secretion that occurs with alcohol.16
Again, the effect was rapid, with an immediate decrease in 13
C recovery observed after intake (fig 1). It is inconceivable that a small volume of spirits could “bypass” the solid meal in the distal stomach quickly enough to exert such rapid effects through feedback from nutrient receptors in the small bowel. Although a trend relating alcohol intake and gastric emptying rate was evident (fig 2), we found no correlation between the concentration of alcohol in the breath and the effects on gastric emptying. Together these observations support the hypothesis that alcohol has direct, rather than indirect or systemic effects, on stomach function. Direct relaxation of gastric wall musculature would suppress antral contraction waves that break down the meal and also inhibit the tonic “pressure pump” mechanism that drives gastric emptying.15
The effects of alcohol on appetite and abdominal symptoms are complex, depending on the timing, quantity, and other characteristics (for example, caloric load, palatability) of the drink and the meal.7
In this study alcohol suppressed appetite, but this effect was apparent only at the highest concentration (48 g alcohol consumed as wine and schnapps). Although the energy density of alcohol is second only to that of fat, its effect on satiation seems to be less than that of other macronutrients.7
When alcohol is consumed with food a dynamic balance exists between short term stimulation of appetite,19
mid-term reduction in appetite due to slow gastric emptying with prolonged distension of the stomach,21
and long term compensation to maintain energy balance.
Notwithstanding the concerns of traditionalists,1
we found no association between beverage consumed during the meal and dyspepsia after the meal in healthy volunteers. Impaired gastric relaxation (accommodation) has been associated with early satiety and discomfort after meals in patients with functional dyspepsia; whereas slow gastric emptying has been associated with prolonged fullness, nausea, and vomiting.22
Alcohol promotes gastric relaxation but delays gastric emptying. As a consequence, drinking white wine and schnapps with a Swiss cheese fondue may provide short term relief of postprandial dyspepsia; this may, however, come at the cost of more prolonged fullness (the feared “cheese baby” syndrome) and reflux.
Limitations of the study
In common with other real life dietary interventions the limitations of this study are the inability to fully blind or control for both energy load and osmolality. White wine was consumed cold and tea warm and this may have had some effect on stomach function.23
Some connoisseurs will point out that wine or schnapps is often added to cheese fondue during preparation; this would not, however, confound the results because, as noted by James Peterson, a cookbook writer who studied chemistry at the University of California at Berkeley, as alcohol boils at 78°C it will be evaporated in sauces simmered for more than 20-30 seconds.25
Finally, although alcohol slows gastric emptying, a prokinetic effect of black tea may also be present. Animal experiments have shown that a hot water extract of black tea (Camellia sinensis) promotes gastric emptying in rats, possibly as a result of inhibition of nitric oxide mediated relaxation of the stomach by thearubignins and theaflavins.26
This study shows that gastric emptying is noticeably slower if white wine rather than black tea is consumed with a Swiss cheese fondue. Healthy readers should be reassured that they can continue to enjoy this traditional meal with the beverage of their choice without undue concern about postprandial digestive comfort.
What is already known on this topic
- The effects of alcohol on gastric function, appetite, and abdominal symptoms are complex, depending on the characteristics of the drink and meal
- Claims about the benefits or otherwise of alcohol intake with high energy, high fat meals are conflicting
- Previous studies rarely assessed the effects of alcohol on gastric function and symptoms after a meal and none with a high energy, high fat meal
What this study adds
- Gastric emptying is noticeably slower if alcohol rather than black tea is consumed with Swiss cheese fondue
- A trend relating alcohol intake to a progressive decrease in gastric emptying was evident
- Higher concentrations of alcohol consumed with or after a high energy meal may suppress appetite, but with no effect on digestive comfort