You probably know that fruits are a nutritious part of a healthy diet, but you might not be aware of all the digestive benefits they offer. Packed with sweet flavor, bananas provide lots of dietary fiber and potassium, an essential mineral. Both fiber and potassium are especially beneficial to your digestive system, helping keep it functioning smoothly.
Potassium From Bananas
Your digestive tract is highly specialized to move food along smoothly, a process that depends partly on its musculature. Called involuntary or smooth muscle, it's designed to contract in a wavelike pattern, called peristalsis. The mineral potassium plays a key role in smooth muscle function, so it's important you take in adequate potassium in your diet. Adults need about 4,700 milligrams of potassium each day, and one large banana provides about 500 milligrams of this important mineral.
Bananas and Insoluble Fiber
Although dietary fiber provides no nutrition, it has other health benefits. Two types of fiber exist, called soluble and insoluble. Insoluble fiber doesn't dissolve in liquid and makes up about 70 percent of the fiber in a banana. Insoluble fiber adds bulk to your food, helping move it through your digestive tract smoothly. It helps you feel full after a meal and, according to the Harvard School of Public Health, helps prevent constipation and lowers your risk of several disorders, including an inflammatory condition called diverticular disease.
Soluble Fiber From Bananas
The other type of dietary fiber is called soluble because it becomes a gel when mixed with fluid in your stomach. Bananas are a good source of soluble fiber, with about 30 percent of their fiber in this form. Soluble fiber tends to slow absorption of carbohydrates and fats, helping keep your blood sugar in a healthy range. Research also suggests it may help promote the health of your intestines by preventing potentially harmful pathogens from attaching to their walls. For example, a paper published in the January 2013 issue of the "Journal of Nutritional Biochemistry" found that soluble fiber from plantains -- a close relative of bananas -- can block adhesion of several bacterial types, including Salmonella and Clostridium.
The Bottom Line
If you consume about 2,000 calories daily, the Dietary Guidelines for Americans 2010 recommend you take in about 2 cups of fruit daily, with the majority in the form of fresh, whole fruits. Choosing bananas for one or two servings daily can provide significant benefits for your digestive system, but add these and other high-fiber foods to your diet gradually to prevent digestive problems, such as gas or bloating. Talk to your doctor or a registered dietitian to develop a dietary plan that's right for you.
- Harvard School of Public Health: Fiber -- Start Roughing It!
- Harvard University Health System: Fiber Content of Foods in Common Portions
- University of Maryland Medical Center: Potassium
- University of Maryland Medical Center: Fiber
- USDA National Nutrient Database: Bananas, Raw
- U.S. Department of Agriculture: 2010 Dietary Guidelines for Americans
- Journal of Nutritional Biochemistry: Soluble Plantain Fibre Blocks Adhesion and M-Cell Translocation of Intestinal Pathogens