Is There an Ideal Diet for Irritable Bowel Syndrome? Why a Multidimensional Approach May Be Best

Finding and sticking to a diet that helps minimize irritable bowel syndrome (IBS) symptoms can be a tedious and uncomfortable undertaking. Because there’s no known cause of IBS—nor any cure—patients are typically left to experiment on their own, trying out a range of restrictive diets in the hope that one will contain the right combination of foods. Too often, each experiment ends in disappointment, as symptoms fail to remit. Meanwhile, prescription medications are not suitable for all patients, nor do they offer a durable solution for the full range of symptoms patients may experience. As such, diet remains a primary site of potential intervention, and patients continue their search for relief.

While the medical community has yet to develop a consensus regarding the best diet for irritable bowel syndrome, there are promising options. Preliminary evidence supports at least three separate dietary interventions as being helpful for patients: curcumin-augmented diets, high-fiber diets, and gluten-free diets. For patients whose IBS symptoms remain uncontrolled by other dietary interventions and therapies, these may offer new hope for symptom relief. However, they must not necessarily be used in isolation; combining strategies like high-fiber and gluten-free diets with curcumin supplementation could provide superior support.

Curcumin-Augmented Diets

Derived from the root of the common spice called turmeric, the chemical known as curcumin is a compelling option for patients who are seeking a dietary intervention which addresses their IBS symptoms. Curcumin has a long history of human use, and because it is commonly consumed by people eating foods spiced with turmeric, is presumed to be safe. Anecdotal evidence suggests that consuming curcumin can help IBS patients control symptoms which aren’t adequately controlled by other means. While researchers aren’t yet confident about why curcumin is helpful for patients with IBS, it’s likely related to curcumin’s anti-inflammatory activity and its role in supporting the gut microbiome.

Simply consuming additional turmeric spice is unlikely to provide enough additional curcumin to help patients with IBS. However, research suggests that specialized supplements that deliver appropriate concentrations of curcumin could have a significant impact on symptoms. According to a placebo-controlled clinical trial in 2016, 19.1% of the trial’s 121 patients with minor to moderate IBS symptoms became symptom-free with the help of a curcumin supplement taken with their normal diet every day for 30 days.¹ In terms of specific IBS symptoms, a curcumin-augmented diet appears to be the most effective in reducing the mild abdominal pain associated with IBS; the severity of IBS-associated abdominal pain was reduced by as much as 50% in patients who were taking curcumin instead of a placebo. Furthermore, the benefits of pain reduction were substantial. When comparing the patients who augmented their normal diets with curcumin and those who augmented their normal diets with an inactive placebo, the curcumin patients were 13.6% less likely to report that IBS interfered with their quality of life after the trial’s conclusion. These results indicate that a curcumin-augmented diet may be a valid way forward for patients seeking a novel way of addressing their IBS symptoms.

Other scientific literature supports the idea that curcumin is a promising addition to diets intended to treat IBS. A recent meta-analysis of five trials testing curcumin’s efficacy in IBS found that patients with IBS who took curcumin exhibited a 54.4% reduction in the incidence of their IBS symptoms.² Three of the five trials also found that a curcumin supplement led to significant reductions in the severity of IBS symptoms when compared to placebo. Nonetheless, in aggregate, the authors of the meta-analysis found that despite being effective for the majority of patients, the variability of curcumin’s effectiveness was very high from trial to trial. Some trials exhibited massive reductions in symptom severity and incidence, whereas others only reported a minor reduction in incidence and no reduction in severity. This can be attributed to the fact that none of the trials used the same formulation of curcumin. The result of this variability meant that the authors of the analysis couldn’t definitively state that curcumin was confirmed to be effective for IBS.

Taking available evidence into account, curcumin is likely effective for IBS symptoms, but more research must be performed to clarify which formulations of curcumin are the most effective in the context of a diet designed to treat IBS. It is important to note, however, that none of the existing studies have found curcumin to carry adverse effects for IBS patients. As such, patients who are interested in adding curcumin to their diet today should look for curcumin supplements that have been designed for maximum bioavailability to optimize potential therapeutic benefits.

High-Fiber Diets

A growing body of evidence suggests that diets which are high in soluble fiber are likely beneficial for IBS. In a 2014 systematic review published in the American Journal of Gastroenterology, researchers examined 14 clinical trials which had treated IBS with fiber-rich diets.³ Encompassing 906 patients in total, patients enrolled in the trials who ate fiber-rich diets were 14% less likely to experience any symptoms of IBS. However, meaningful symptom reduction was only associated with soluble fiber, suggesting that foods like broccoli, figs, bananas, onions, and almonds should be included in diets intended to treat IBS.

Notably, bran cereals, a common source of insoluble fiber, were not associated with symptom reduction. Older findings go even further, suggesting that bran and perhaps other insoluble fibers may be actively harmful for IBS patients. In a 1994 study of 100 patients with IBS who included bran in their diet, 55% of the patients reported that eating bran regularly made their IBS symptoms worse, whereas only 10% said that it improved their symptoms.⁴ This indicates that simply starting a diet with “high fiber” may be counterproductive if the patient consumes food products like bran which are predominantly insoluble fiber rather than soluble fiber.

Critically, most fruits and vegetables—key sources of soluble fiber—contain a significant proportion of insoluble fiber as well. As a result, patients may have a hard time getting relief from their IBS symptoms while undergoing a high-fiber diet depending on their level of sensitivity to the insoluble fiber which will be present in their food. But while these diets may not be suitable for every patient, they may offer significant relief for those who can tolerate a certain proportion of insoluble fiber.

Gluten-Free Diets

Currently, one of the most popular dietary strategies amongst patients with gastrointestinal conditions is gluten-free diets. These diets contain only foods that have no wheat gluten or related chemicals, meaning that many common foods like bread are off-limits. In recent years, gluten-free diets have become somewhat of a fad and have been promoted as alleviating a broad range of health conditions, though robust evidence supporting most of these claims remains forthcoming. While gluten-free diets are highly restrictive, they may provide relief for certain patients with IBS.

Although there is some evidence that gluten-free diets might be beneficial for patients with IBS, there is no medical consensus despite a considerable volume of research on the topic. This research is still ongoing, however. A systematic review published in 2018, for example, examined two clinical trials which measured whether gluten-free diets were beneficial for patients with IBS.⁵ In these trials, strict adherence to a gluten-free diet reduced the risk of developing IBS symptoms by an aggregate 58%, indicating that gluten elimination could produce significant benefits. Nonetheless, the researchers conducting the review found that patients who ate a gluten-free diet in the two trials did not necessarily exhibit IBS symptoms when they were later exposed to gluten, casting doubt on the validity of the results.

Despite the lack of empirical evidence supporting a gluten-free diet for patients with IBS, there are still compelling reasons for these patients to avoid consuming excessive amounts of gluten. The connection between worsening IBS symptoms and increasing gluten consumption is firmly established, with a 2015 analysis of seven studies finding that gluten exposure significantly aggravated IBS symptoms of the vast majority of patients in all seven trials.⁶ Indeed, researchers found that anywhere from 30% to 90% of the patients exhibited worsening symptoms when exposed to gluten in a meal. As the research currently stands, patients with IBS should probably try to avoid consuming foods with high levels of gluten, but there is no guarantee that doing so will prevent all symptoms because gluten is not the only factor which can aggravate IBS.

The Possibility of a Synthesis Diet for Inflammatory Bowel Syndrome

In light of the inconclusive evidence regarding the ideal diet for inflammatory bowel syndrome, patients must look to new horizons to more fully control symptoms. Using several diets in conjunction might be the best approach, as they may target IBS symptoms via multiple mechanisms. For some patients, refraining from consuming excessive quantities of gluten, consuming more soluble fiber comprises, and taking a high-quality curcumin supplement may provide the multidimensional support necessary to minimize symptoms. While there is no research which has opted to investigate this synthesis of dietary strategies as of yet, an abundance of evidence suggests that it could help patients by eliminating ingredients known to aggravate symptoms while supplying the body with the nutrients necessary to alleviate inflammation and support gut health. Most importantly, the synthesis of a high-fiber and gluten-free diet supported by curcumin supplementation is safe and does not prohibit the consumption of any nutrient, vitamin, mineral, protein, or calorie source. This means that many patients may be able to retain their preferred diet and merely make a few modifications ensure compliance with the necessary restrictions.

However, choosing the correct format of curcumin is critical for this synthesis diet or any curcumin augmentation diet. Chemically, curcumin is the representative member of a group of molecules called curcuminoids. Certain curcuminoids, such as tetrahydrocurcumin, have greater bioavailability and are easier for the body to use, potentially leading to better results. As such, choosing a supplement with tetrahydrocurcumin could help patients experience greater efficacy and optimal therapeutic benefits.

Regardless of the treatment strategy a patient chooses, they can take solace in the fact that all potential dietary avenues of treating IBS are under intense scrutiny by researchers. Though a comprehensive diet which patients with IBS can use to stay symptom-free has yet to be developed, research is ongoing and advances are being made. In the meantime, patients should work with their doctors to create multidimensional treatment plans geared toward their individual needs and preferences.

Works Cited

1. Portincasa P, Bonfrate L, Scribano ML, Kohn A, Caporaso N, et al. 2016. Curcumin and fennel essential oil improve symptoms and quality of life in patients with irritable bowel syndrome. Journal of Gastrointestinal and Liver Disease. 25(2):151-157. https://www.ncbi.nlm.nih.gov/pubmed/27308645
2. Ng QX, Soh AYS, Loke W, Venkatanarayanan N, Lim DY, et al. 2018. A meta-analysis of the clinical use of curcumin for irritable bowel syndrome (IBS). Journal of Clinical Medicine. 7(10):298. https://www.mdpi.com/2077-0383/7/10/298
3. Moayyedi P, Quigley EM, Lacy BE, Lembo AJ, Saito YA, et al. 2014. The effect of fiber supplementation on irritable bowel syndrome: a systematic review and meta-analysis. American Journal of Gastroenterology. 109(9):1367-1374. https://www.ncbi.nlm.nih.gov/pubmed/25070054
4. Francis CY and Whorwhell PJ. 1994. Bran and irritable bowel syndrome: time for reappraisal. Lancet. 344(8914):39-40. https://www.ncbi.nlm.nih.gov/pubmed/7912305
5. Dionne J, Ford AC, Yuan Y, Chey WD, Lacy BE, et al. 2018. A systematic review and meta-analysis evaluating the efficacy of a gluten-free diet and a low FODMAPs diet in treating symptoms of irritable bowel syndrome. American Journal of Gastroenterology. 113(9):1290-1300. https://www.ncbi.nlm.nih.gov/pubmed/30046155
6. De Giorgio R, Volta U, Gibson PR. 2015. Sensitivity to wheat, gluten and FODMAPs in IBS: facts or fiction? Gut. 65:169-178. https://gut.bmj.com/content/gutjnl/65/1/169.full.pdf