Registered dietitian Joy Bauer gives juicing an A+ for its ability to deliver concentrated amounts of nutrients from fruits and vegetables to your body, but she says consuming too much juice and forsaking a well-rounded diet can result in glaring nutritional gaps. A glass of fresh juice as part of a balanced diet isn't likely to cause trouble for your digestive system; however, the American Cancer Society warns that drinking too much juice can lead to severe diarrhea.
A Change in Your Diet
Any time you change your diet, your digestive system has to adjust. Making a major change to your diet, such as cutting out solid foods to go on a juice "cleanse" or adding large amounts of juice to your diet, can wreak havoc on your tummy, causing any number of symptoms including nausea, vomiting, abdominal cramping, bloating, gas, heartburn, bad breath, stronger odor to bowel movement and urine, mucus in the stool, constipation and diarrhea, according to nutritionist Claire Georgiou.
Certain fruits can cause a type of diarrhea called osmotic diarrhea. Substances in these fruits are not absorbed through the colon wall and stay in the intestine, where they cause large amounts of water to collect in the stool, leading to diarrhea. The Family Practice Notebook website identifies excessive intake of high-sugar juices such as apple and pear as being most likely to cause osmotic diarrhea. How much of the substance is ingested is linked to the severity of the diarrhea.
Fruits like pears, apples and peaches are particularly high in fructose, or fruit sugar. People with fructose malabsorption are not able to process this sugar. Undigested fructose travels to the colon and is fermented by bacteria, producing gas and swelling in the intestine. It may also cause diarrhea. You may be able to tolerate a small amount of fructose without a problem, but when you start juicing, it may become too much for your system to handle.
Even a little bit of fresh juice can cause diarrhea if a fruit or vegetable used to make it is contaminated with bacteria. This can happen if you buy fresh, unpasteurized juice at a store, or if you make the juice at home with contaminated fruit. The U.S. Food and Drug Administration notes that most people's immune systems are strong enough to fight off pathogens, but children, the elderly and people with compromised immune systems are especially at risk of serious health effects from drinking contaminated juices.
Steps to Take
Following a juice fast for more than a few days can pose health risks, Dr. Pamela Peeks told CNN. Adding a fresh juice to your diet is a good way to fit in more fruits and vegetables, but don't go overboard, especially if you start to experience diarrhea. In that event, reduce your intake of juice.
If you know you have fructose malabsorption syndrome, choose low-fructose fruits and vegetables or those that have a good balance of fructose and glucose, such as grapefruit, cranberry and carrot, because glucose helps in absorbing fructose. The FDA warns against buying untreated juices and advises consumers to wash fruits and vegetables thoroughly under running water before cutting.