The results, which were presented this week at a digestive disease conference and have not yet been peer reviewed, showed that dried fruits containing both fiber and sorbitol — a carbohydrate that contributes to fruit’s sweetness — have a substantial positive impact on chronic constipation.
“Living with constipation can have a large impact on quality of life, but we found that a half-cup [about 3 ounces (oz)] of mixed dried fruits per day can offer a real benefit,” says study author Simon Steenson, MD, a postdoctoral research associate in the nutritional sciences department at King’s College London.
“Finding ways to get more dried fruit and some fruit juices into your diet could be a simple step towards improving your constipation,” says Dr. Steenson
Eating Dried Fruits Led to Better Bowel Movements in Just 1 Month
The trial included 150 men and women between ages 18 and 65. All participants met the clinical definition for functional constipation: having fewer than seven bowel movements per week, and at least one-quarter of these had to be small, hard stools.
Before the study, all participants reported eating less than 1 oz of fiber per day. On average, they ate about ½ oz daily.
The researchers gathered additional data from food diaries and also collected details on participants’ activity levels — but that information is still being analyzed. “This could be important, as being more active can help with constipation, so we will see soon if this might have been a factor,” says Steenson.
Subjects were evenly separated into three groups, receiving either:
- A daily serving of just over 3 ounces of dried fruits (prunes, raisin, and apricots)
- Juices from the same fruits at volumes that matched the dried fruits in terms of sorbitol and calories
- A fruit-flavored placebo syrup matched in calories
At the end of four weeks, participants who ate dried fruit saw the average weight of their stools increase by over 21 g per day — significantly more than in the placebo group, who had an average stool weight gain of just 1.6 g per day.
Dried fruit eaters also had 1.3 more complete bowel movements per week on average, and 1.3 more complete spontaneous bowel movements, compared with those taking the placebo.
“What this means is that they passed more stools where they felt they had completely emptied their bowels, and that more of these stools were passed naturally, without the need for laxatives or any digital maneuvers [using fingers],” says Steenson.
Participants in the dried fruit group also reported being more satisfied with their treatment than those on the placebo, suggesting it helped improve their quality of life.
Those in the fruit juice group experienced similar improvements in bowel movements, but average daily stool weight increase was 8 g less compared with those eating dried fruit. People in this group also reported more stomach gurgling from drinking juice.
Why Dried Fruit Is So Effective
Kyle Staller, MD, a gastroenterologist and the director of the Gastrointestinal Motility Laboratory at Mass General in Boston, says these study results reinforce the known role of fruit in potentially improving symptoms of constipation.
“This trial suggests that when it comes to the way in which dried fruit improves bowel movements, it’s likely the combination of fiber and sorbitol that drives the benefit,” says Dr. Staller, who was not involved in the study.
Fiber may help constipation by drawing water into the bowels and bulking up stools, while sorbitol draws water into the bowel and helps to make stools softer and easier to pass, according to the scientists.
Staller adds that fermentation of fiber and sorbitol in the gut could lead to changes in the gut microbiome that directly impact how well the bowels move stool through the digestive tract.
While participants who received dried fruit or juice told researchers they experienced some improvement in constipation symptoms (such as abdominal pain and time spent in the bathroom), these reports were not significantly different than those from the placebo group.
“Some measures are subjective, based on how the participants felt during the study,” says Steenson. “This is why we also measured stool weight, as this is a ‘hard end point’ that is more objective.”
Dried Fruit Is Great for Constipation — But Don’t Overdo It
Although dried fruit can certainly ease constipation issues, it’s wise not to go overboard.
“Specific compounds [in dried fruits] are known to draw water into the bowels and sometimes create more gas, bloating, and discomfort,” says Staller. “Too much of a good thing can definitely lead to unpleasant symptoms, even pushing people toward diarrhea. These potential side effects are especially magnified in people suffering from irritable bowel syndrome.”
Steenson encourages people with constipation to find ways to get more dried fruit (and some fruit juices) into their diets. He recommends the following possible ideas:
- Sprinkle dried fruit on breakfast cereal
- Take dried fruit with you as a snack when you’re on the go
- Make your own trail mix with dried fruit and seeds
- Gradually increase other fiber-providing foods in your diet, such as fresh and frozen fruits, vegetables, whole grains, and beans
“Whatever works for you — boosting your fiber intake is a great way to take care of your health,” he says.