A daily dose of dried plums is more effective for constipation relief than
the soluble fiber psyllium, say results from a randomized clinical trial
that support claims from grandmothers the world over.
Fifty grams of prunes, providing a daily fiber dose of 6 grams, outperformed
an equal fiber dose from psyllium for constipation relief over three weeks,
with the fruit’s laxative effects linked to its sorbitol, fiber, and
polyphenol contents, according to findings of a study supported by the
California Dried Plum Board.
“Given their palatability, tolerability and availability, dried plums should
be considered in the initial approach to the management of mild to moderate
constipation in the general population,” write the authors, led by Satish
Rao, MD, PhD., from the University of Iowa Carver College of Medicine in
Alimentary Pharmacology & Therapeutics.
The stats
According to the National Institute of Diabetes and Digestive and Kidney
Disease (NIDDK), over four million Americans suffer from constipation every
year. As a result, approximately $725 million is spent on laxatives in the
US.
Constipation, considered a symptom and not a disease, is defined as fewer
than three bowel movements per week.
Dietary approaches to alleviate constipation are well known, with prunes
ranking high on the list of foods to help maintain regularity. However,
while traditional use is well known, the University of Iowa researchers
state that efficacy of this approach is not currently known.
Indeed, the European Food Safety Authority's (EFSA) Panel on Dietetic
Products, Nutrition and Allergies (NDA) rejected an article 13.1 health
claim in October 2010 of the long-standing association between prunes and
bowel function due to insufficient evidence. The new study appears to fill
some of the scientific gaps.
Study details
Dr Rao and his co-workers recruited 40 people with constipation to
participate in their randomized control crossover trial. The average age of
the participants was 38. Volunteers were randomly assigned to consume 50
grams per day of prunes, or 11 grams per day of psyllium (Metamucil, Proctor
and Gamble Pharmaceuticals) for three weeks. One week of ‘washout’ separated
the interventions.
Results showed that daily prune consumption significantly improved
spontaneous bowel movements per week, compared with psyllium. The prune
intervention increased spontaneous bowel movements per week from an average
of 1.8 at the start of the study to 3.5, while psyllium was associated with
an increase from an initial average of 1.6 to 2.8.
In addition, stool consistency measures also improved more in the prune
group, compared with psyllium. In terms of tolerability and palatability,
there were no reported differences between prunes and psyllium, said the
researchers.
“These findings confirm the general notion that dried plums that are widely
consumed can be useful for the treatment of constipation,” wrote the
authors.
Active ingredients
Commenting on the potential benefits of prunes, the authors note that prunes
contain about 15 grams of sorbitol per 100 grams, and this is known to act
as an “osmotic laxative and holds on to water”, while there is also 184
milligrams of polyphenols per 100 grams, and six grams of fiber per 100
grams.
“Since we tested an equivalent dose of dietary fiber, it is likely that the
clinical improvement observed with dried plums is most likely due to the
other beneficial components of plums over and above its fiber content and ?
or the blend of soluble and insoluble fiber in this compound,” they added.
Source: Alimentary Pharmacology & Therapeutics
Volume 33, Issue 7, April 2011, Pages: 822–828, DOI:
10.1111/j.1365-2036.2011.04594.x
“Randomised clinical trial: dried plums (prunes) vs. psyllium for
constipation”
Authors: A. Attaluri, R. Donahoe, J. Valestin, K. Brown and S. S. C. Rao