FROM CLINICAL GASTROENTEROLOGY AND HEPATOLOGY
High intake of myristic acid approximately tripled the odds of relapse in patients with ulcerative colitis (UC), compared with low intake, according to the results of a 12-month multicenter, prospective, observational study reported in the September 2017 issue of Clinical Gastroenterology and Hepatology ( doi: 10.1016/j.cgh.2016.12.036 ).
Relapsers consumed an average of 2.2 g of this saturated fatty acid daily from sources such as palm and coconut oils, as well as dairy fats, reported Edward L. Barnes, MD, MPH, and his associates at Brigham and Women’s Hospital, Boston, on behalf of the DREAM (Diet’s Role in Exacerbations of Mesalamine Maintenance) investigators. Nonrelapsers averaged 1.4 g/day. “Our broader goal is to determine how alterations in diet can improve the care of people with IBD [inflammatory bowel disease],” the researchers wrote. “These findings can help design interventional dietary studies to determine if supplementation or avoidance of certain compounds might reduce the risk of a flare for patients with ulcerative colitis in remission.”
Dietary factors are thought to underlie relapse in ulcerative colitis, but specific culprits are poorly defined, the investigators said. Therefore, the DREAM study prospectively tracked dietary intake and flares among a homogeneous group of 412 patients with UC from 25 academic and community gastroenterology practices in the United States. Between 2007 and 2014, patients were interviewed by telephone every 3 months for 1 year or until they reported a flare, defined as a Simple Clinical Colitis Activity Index score of at least 5 or a change in disease activity that entailed a change in medication.
A total of 34 patients were lost to follow-up, and 45 (11% of those remaining) flared within a year of study enrollment. “When analyzed in tertiles, increasing intake of multiple fatty acids was associated with increasing odds of relapse,” the researchers wrote. Predictors of flare in the univariate analysis included high intake of myristic acid, oleic acid, eicosenoic acid, palmitelaidic acid, total translinoleic acid, saturated fat, monounsaturated fat, and omega-3 fatty acids. These predictors also included moderate or high intake of alpha-linolenic acid. Only high intake of myristic acid maintained a significant dose-response relationship in the multivariable analysis (odds ratio, 3.0; 95% confidence interval, 1.2-7.7; P = .02 for high vs. low intake). Moderate intake of alpha-linolenic acid predicted flare (OR, 5.5; CI, 95%, 1.6-19.3; P = .001) in the multivariable analysis, but high intake did not (OR, 1.3; CI, 95%, 0.3-7.0; P = .4). “Other foods previously implicated in flares of UC, such as processed meat, alcohol, and foods high in sulfur, were not associated with an increased risk of flare,” the researchers wrote.
Study participants were generally in their mid- to late 40s, white, and not current smokers. More than half were male. Most had proctitis or left-sided colitis, not pancolitis. Relapsers averaged 2.4 flares in the 18 months before enrollment (standard deviation, 1.9), compared with 1.8 flares for nonrelapsers (SD, 2.4; P = .003).
This observational study not only was subject to unmeasured confounding, but also excluded many types of patients. Among those excluded were anyone with a history of allergy to salicylates, aminosalicylates, or mesalamine tablets. Also excluded were those who had recent exposure to NSAIDs, oral or parenteral antibiotics, antidiarrheals, antispasmodics, immunosuppressives, biologics, or corticosteroids (except budesonide). Requiring monotherapy with an aminosalicylate might limit the generalizability of the findings, the investigators noted. Patients also were on variable doses of aminosalicylates, and higher doses might have helped inhibit flares.
Actavis and the National Institutes of Health provided funding. The investigators reported having no relevant financial conflicts.