Yes, fruits have fiber, and yes, they are good for digestion. But when you eat too many grapes, you could give yourself diarrhea (per WebMD). This is because grapes, like most fruits, have fructose (natural sugar) in them. In fact, they’re considered a high-fructose fruit. They also contain tannins. Both of these natural compounds can lead to gas, an upset stomach, and diarrhea, per the Australian Institute of Food Safety.
In some instances, like when you have food intolerances or irritable bowel syndrome (IBS), consuming grapes might cause digestive issues like bloating, constipation, or diarrhea. There is also such a thing as a grape allergy, where even eating a small amount of grapes can cause an upset stomach, vomiting, stomach cramps, and other physiological symptoms.
Poop color, food intolerances, and allergies aside, grapes — known for their antioxidant, anti-inflammatory, and lipid-reducing properties — are a great fruit to add to your diet. Their rich concentration of fiber and potassium supports cardiovascular health, relieves constipation, and regulates blood pressure levels (per Medical News Today). Regular consumption of grapes is also linked with better eye and brain health. The vitamin K in grapes could ward off osteoporosis, according to Healthline. Ultimately, it’s about understanding the fruit’s benefits and side effects and also knowing how much is too much.