The relationship between fiber and constipation has been with us for about 50 years. However, scientific studies do not have enough evidence in this regard.
Fiber and constipation, that strange but at the same time globally accepted couple. Yes, I know what I'm saying: weird couple. For many years (specifically since 1971, when the surgeon Denis Parsons Burkitt mentioned it in his walks in the colonies), popular belief and many health professionals associate fiber with a high potential to prevent both constipation and other related ailments and diseases. with the colon (such as colorectal cancer, diverticula, or even hemorrhoids). The theory is that "the more fiber, the less constipation."
The surprise comes when we are told that not only have, we been wrong for decades, but that some (many) scientific papers, including large and prestigious meta-analyzes or sets of studies have come to the conclusion that fiber not only does not prevent or prevent constipation, but may even make it worse. Let's see today why the relationship between fiber and constipation is a fallacy that we should forget.
Fiber and constipation, a myth debunked by science
Probably on more than one occasion, some other friends and even health professionals have recommended us to eat more fiber in order to combat constipation (I used to do it myself, until I informed myself as I should): eat more fruit kiwis, vegetables, legumes, whole grains and anything that precisely associates the word " whole ".
All these foods, which are based on plants, contain two types of fiber: soluble or insoluble, thus classified according to whether or not they can be fermented by intestinal microorganisms. Be that as it may, any type of fiber is accepted as a panacea to combat constipation, since it supposedly facilitates intestinal transit and alleviates all the symptoms of this disease.
However, it seems that science disagrees. Already in 1997, the first systemic review on this topic was published in the Journal of General Internal Medicine, concluding that both fiber and laxatives improved constipation, but in a very modest way. Later, in 2011 and 2012, two other reviews published in Alimentary Pharmacology & Therapeutics and in the World Journal of Gastroenterology, with modest conclusions to support the use of fiber against constipation.
Subsequently, a couple of clinical trials were carried out in this regard, that is, explicitly checking in a group of individuals whether taking more or less fiber improved constipation. One of these trials was published in 2012 also in the World Journal of Gastroenterology, where 63 people with chronic constipation were initially put on a fiber-free diet for two weeks, and subsequently divided into groups (increasing fiber in the diet, continuing on low levels, or diets with no fiber at all). Interestingly, when 6 months passed, those individuals who did not eat any fiber at all were the ones who felt better; For their part, those who increased their fiber consumption were the ones who were worse off.
Yes, that's right: eliminating fiber from the diet can improve constipation symptoms more than increasing its amount.
On the other hand, some more recent studies carried out in elderly patients and in hospitalized critical patients have reached completely contrary conclusions. On the one hand, a study published last year in 2017 in the Canadian Journal of Dietetic Practice & Research suggests that, although more studies are needed in this regard, adding fiber to the diet of individuals who need long-term hospital admissions can increase the frequency of your bowel movements and decrease your use of laxatives. For its part, another work published at the end of last year 2017 in the Spanish journal of Intensive Nursing This time in critically ill hospitalized patients, he concluded that adding fiber to the diet can improve and prevent constipation; Likewise, they also advise monitoring the use of medications that can increase the risk of constipation (such as those derived from morphine, or iron and calcium supplements for example).
As we can see, the studies are controversial and contradict each other. Although I must add that these last two works, although newer, are so-called “observational” studies and not trials as such. In other words, whether giving more or less fiber improves the situation has not been compared between groups, and there may be many other contributing factors, such as the use of laxatives.
How can you fight constipation?
Currently, the hypothesis being considered is that fiber does increase the frequency of bowel movements, but it does not solve constipation, nor does it improve the consistency of the stool, nor does it reduce the use of laxatives as such, nor does it improve the pain associated with defecation in constipation.
In fact, as we have seen in some study, many patients who suffer from constipation take the same amount of fiber or more than those who do not suffer from it.
The most widespread myth about chronic constipation without apparent cause is that constipation causes stool not to move throughout the intestine. However, the problem is that what occurs is a difficulty to evacuate them once they have been compacted in the final area of the colon, the rectum.
European Doctor of Medicine and Surgery, author of several books and one of the ICNS professors explains, what happens with fiber is similar to a car jam: the more cars are involved, the longer it will take. in clearing the traffic jam; if more cars are introduced, the worse the situation will be. In the case of fiber, if we already have an excessive amount of stool that we are unable to expel and we also take fiber, we will increase the amount of stool, worsening the problem.
First of all, we must know why constipation occurs (lack of exercise and poor hydration are some of its causes), taking into account drugs or dietary supplements, some of which can lead to constipation in a secondary way. If this is not the case, and it is concluded that it is an "idiopathic chronic constipation", that is, with no known cause, currently, and until more clinical trials are carried out, which studies suggest is that the use of lax