New Dietary Guidelines for Chronic Constipation

Recently, new guidelines for managing chronic constipation have garnered attention in the media. A particular focus has been on the recommendation to consume kiwifruit on a daily basis. However, some other important advice has gone largely unnoticed, especially the shift away from high-fiber diets.

What Did the Guidelines Examine?

Researchers reviewed 75 clinical trials to formulate their recommendations related to food, drink, and supplements for adults dealing with chronic constipation. The quality of these trials varied, leading to a consensus on their data quality. Notably, they used a broad definition for constipation, comprised of personal perceptions as well as clinical trial definitions. Typically, chronic constipation is defined as infrequent, hard stools lasting for at least three months.

In total, the researchers came up with 59 recommendations, though most were based on limited evidence.

Why Kiwifruit? How Many a Day?

The guidelines suggest eating two to three kiwifruits daily for at least four weeks to alleviate constipation. Whether you choose green or gold kiwifruit, research indicates they can be beneficial.

So, what’s behind this recommendation? Well, kiwifruit’s fiber swells significantly when mixed with water, more so than apple fiber, helping to bulk up stools and ease their passage through the digestive tract.

While eating the whole fruit, skin and all, provides additional fiber, it’s perfectly fine to eat just the flesh. Green kiwifruit also contains an enzyme called actinidin, which can aid in digesting proteins, potentially easing constipation by softening food proteins.

Additionally, kiwifruits have a type of crystalline structure known as raphides, believed to enhance mucus production in the gut, which helps facilitate stool passage. There’s even some evidence suggesting that kiwifruit consumption may reduce certain methane-producing bacteria linked to constipation.

Mineral Water and Magnesium

Drinking mineral water might also offer benefits, with researchers recommending 0.5–1.5 liters a day for a duration of two to six weeks. This is largely due to magnesium content, which acts as a laxative, and magnesium oxide is commonly used as a dietary supplement for chronic constipation.

The guidelines assert that magnesium oxide can help soften stools and increase frequency. They recommend a daily intake of 0.5–1.5 grams for at least four weeks, though caution is needed for individuals with kidney conditions or those on certain medications.

Rye Bread

Interestingly, studies have shown that rye bread can relieve constipation more effectively than both white bread and typical laxatives. The recommendation here is to consume six to eight slices daily for at least three weeks, although this might be impractical for many. Plus, those with coeliac disease should avoid rye due to its gluten content.

A High-Fiber Diet May Not Be Necessary After All

Perhaps the most surprising takeaway from these guidelines is the lack of strong evidence supporting high-fiber diets for constipation. They identified only one randomized controlled trial comparing high-fiber diets (25–30g/day) with low-fiber diets (15–20g/day), which found no benefits from the high-fiber approach. People on the low-fiber diet experienced less gas and bloating.

This doesn’t negate the benefits of fiber entirely. There’s strong evidence supporting fiber supplements for constipation relief. Instead of a high-fiber diet, the guidelines suggest a minimum intake of 10 grams a day from a supplement like psyllium.

Traditionally, high-fiber diets have been a staple recommendation in dietary guidelines. For instance, the Dietary Guidelines for Americans suggest 28 grams of fiber daily for some adults, noting various health benefits. But it seems this isn’t essential for relieving chronic constipation.

Key Takeaways from the Guidelines

These new guidelines offer more tailored and evidence-based dietary advice than what has been provided in the past. Kiwifruits stand out as a safe and effective approach to treat chronic constipation, alongside mineral water, magnesium supplements, and rye bread. However, it’s advisable to consult a healthcare professional regarding magnesium, especially if kidney issues or other medications are a concern.