Study: Prunes act as a laxative

reference

Attaluri A, Donahoe R, Valestin J, Brown K, Rao SS. Randomized clinical trial: dried prunes (prunes) vs. psyllium for constipation.Aliment Pharmacol Ther.2011;33(7):822-828.

design

An 8-week, single-blind, randomized, cross-over study.

Participant

Forty constipated subjects, three male and the rest female, with an average age of 38 years

Study medications

Subjects were given either prunes or psyllium to provide 6 grams of fiber daily for 3 weeks. After a one-week washout period, the therapy was changed.

Target parameters

Subjects kept a daily symptom and stool diary in which they recorded the number of complete spontaneous bowel movements per week, overall relief from constipation, stool consistency, straining, tolerance, and taste.

Key findings

The number of complete spontaneous bowel movements per week (primary outcome measure) and stool consistency scores improved significantly (P<0.05) for dried plums compared to psyllium.

Effects on practice

Plums work. That said, plums seem to do exactly what everyone always expected them to do; they act as a mild laxative. Although some would think this effect is obvious, this study by Attaluri et al. are among the first clinical studies on humans published in the scientific literature that demonstrate the effectiveness of plums.

The results of a 2002 clinical trial comparing the effects of prunes with dried apples on factors affecting bone density "suggest that dried prunes may have beneficial effects on bone in postmenopausal women."¹Although the results were positive, they could not confirm whether prunes work as a laxative.²

Two 2010 studies suggested that prunes may act as a stool softener. Both studies compared eating prunes as a snack with cookies. A June 2010 article that appeared in the magazineappetiteinformed us that prunes are more effective at suppressing hunger and creating a feeling of satiety than sugar cookies.³An article from September 2010 in theJournal of the American Dietary Associationreported that snacking on prunes lowered triglyceride levels more than sugar cookies, and mentioned that prunes tend to soften stools.⁴

Few experienced practitioners or consumers will consider this data as new. Instead, most will be surprised that this study even needed to be done.

There is another article about plums that is worth mentioning. Appears in theJournal of the American College of NutritionIn 2007, a review article compared the effect of consuming plums with consuming berries or other fruits on serum antioxidant capacity (AOC). While data from a number of clinical trials “showed that consumption of certain berries and fruits such as blueberries, mixed grapes and kiwis “increased plasma AOC levels,” eating prunes or drinking prune juice did not alter measured levels of antioxidant capacity.⁵

With the publication of the current study by Attaluri et al. The use of prunes as a laxative has taken the first step from a product of old wives' tales (OWT) to the field of evidence-based medicine (EBM). Supporters of EBM can now prescribe prunes to patients with constipation without fear of criticism. It should be noted that this current study has weaknesses: it was single and not double-blind, participants were predominantly female, little is known about the etiology of participants' constipation, and obviously a study is far from conclusive.

There is actually something absurd about this new advance in medicine. Few experienced practitioners or consumers will consider this data as new. Instead, most will be surprised that this study even needed to be done; The effect of prunes on the human digestive tract is obvious.

The attraction that many of us have to EBM and our resulting desire to find support for therapies in published studies, meta-analyses or – the Holy Grail of all workCochrane Reviewsappears both reasonable and commendable on the surface, but can be a barrier to achieving the best patient outcomes.

So far the evidence suggests that we use psyllium fiber because it is more effective than sodium docusate.⁶However, practitioners relying on anecdotes, common sense, and data obtained through OWT have historically used prunes to soften stool and increase stool frequency.

This plum story is reminiscent of how my colleague Steve Austin, ND, when writing about breast cancer years ago, pointed out the difference between Type 1 and Type 2 errors in statistics, and how various medical professions place greater emphasis on avoiding one form of error over the other. For a medical oncologist who prescribes chemotherapy, the requirement is to be sure that the drugs have benefit against the cancer. You have to be sure that the medication is beneficial because the side effects are so great.⁷For naturopathic physicians who use non-toxic therapies, in this case prunes, the requirements should be reversed. If there is a chance that therapy will help, then we should be interested in trying it: the classic "it won't hurt and it might help" view of practice.

However, when it comes to prunes, we can now safely prescribe them; They have officially moved up from unproven OWT to trusted EBM.