Actually, you should eat as much fruit as possible, because apples, pears and cherries are healthy. But they also contain a lot of fructose, which can spoil some people’s enjoyment. Why is that – and what helps if you get stomach ache or even diarrhea from fruit?
At the start of the cherry season, many grandmothers’ warning voice echoes through their heads: “Don’t drink water with the stone fruit, otherwise you’ll get a stomach ache!” In addition to cherries, other fruits can also cause stomach aches. Why is that exactly? And is there anything we can do about it?
First to the cherries: According to the Federal Center for Nutrition (BZfE), there are several explanations for the stomach ache after the snack. Yeast fungi, which often sit on the skin of cherries, can be to blame. If you eat large amounts of cherries, it can happen that the yeast fungi ferment the sugar into alcohol. Carbon dioxide is then produced as a breakdown product, which causes flatulence. According to the BZfE, the water can increase the effect because it dilutes the stomach acid – and it can no longer kill the yeast fungi so successfully.
The second explanation is that the cherries get into the intestines faster through the water. The result: fermentation processes in the colon cause abdominal pain. But: “It is much more likely that the warning is due to the poor drinking water quality in earlier times,” says Harald Seitz from the BZfE. Germs in the water can – even without cherries – cause flatulence and diarrhea.
A problem that should no longer occur in view of the good drinking water quality nowadays. The advice of the BZfE is therefore: Wash the cherries well and don’t snack on too many at once.
Contaminated water aside, why does fruit give some people stomach pains and other digestive problems – even in small amounts? According to Astrid Donalies from the German Society for Nutrition (DGE), this is due to the so-called fructose malabsorption. That means some people just can’t tolerate fructose. This intolerance is particularly common in children, and it also causes annoying symptoms in some adults after eating fruit.
“In fructose malabsorption, the fructose is not or not fully absorbed in the small intestine,” says Donalies. The fructose can therefore reach the large intestine in large quantities, where it is broken down by intestinal bacteria. This creates short-chain fatty acids and gases – and with them a feeling of fullness up to stomachache and diarrhea.
Astrid Donalies advises anyone who gets a stomach ache just looking at an apple to keep a log of all meals together with a certified nutritionist. First of all, it must be clarified which foods are causing the symptoms. If fructose malabsorption is suspected, the so-called “hydrogen breath test” can also bring certainty. The doctor examines the air you breathe for hydrogen, which is produced as a breakdown product of fructose.
However, the nutrition expert advises against self-diagnosis and treatment on your own. Reason: If you do without fruit completely, you can get a vitamin C deficiency. If an intolerance has been diagnosed, it is best to remove the respective fruit from the menu, depending on the severity – and also finished products. Because they are often sweetened with fructose-glucose syrup.
According to the DGE, you should look closely at dried fruit, honey, soft drinks such as lemonade, ice cream and muesli bars. A complete list can be found on the DGE website. But Astrid Donalies has good news for those suffering from stomach ache: because an intolerance can often be controlled or even eliminated with the help of a diet. However, this only applies if you do not have a hereditary fructose intolerance. Those affected absorb sugar, but cannot break it down due to an enzyme defect.
In order to get an intolerance under control, you should initially avoid fructose altogether. According to the DGE, those affected should pay attention to names such as sugar substitute, starch syrup, apple/pearwort, artificial honey and sorbitol (E 420), mannitol (E 421), isomalt (E 953), maltitol (E 965), lactitol (E 966) and Xylitol (E 967).
By the way: The promising formulation “sugar-free” only means that the product contains no household sugar – i.e. sucrose – warns the DGE. It can still contain fructose.
Donalies also advises avoiding sucrose to begin with. Only those who initially avoid both fructose and table sugar and sweeteners can get the intolerance under control in this way. According to the DGE recommendation, after a few weeks those affected can return to their normal diet. Assuming the complaints have subsided.
According to Donalies, if you tend to have an intolerance, it is best to use more digestible fruits that contain comparatively little fructose. These include avocado, banana, pineapple, strawberry and peach.
And the nutrition expert has another tip: If you eat fruit together with fats and protein, the meal can be more digestible because the fructose is absorbed with a delay. Means: A fruit quark causes less stomach ache than an apple on an empty stomach. Basically, the nutritional recommendation of the DGE is: Eat three servings of vegetables and two servings of fruit per day.
