Chronic Lumbosacral Radiculopathy: Impact of an Analgesic Dietary Intervention on Pain & Function

Lumbar radiculopathy is a fairly common pain syndrome which may result in chronic, severe disability. There are few successful treatment options for patients with persistent lumbosacral radicular pain (LRP) that does not respond to conventional approaches. A fundamental biologic mechanism of chronic LRP, as well as other chronic pain syndromes, may involve failure of inflammation-resolution, an active process driven by lipid mediators derived from fatty acids (resolvins, protectins, maresins). The investigators' preliminary studies indicate that dietary modifications, specifically increasing some dietary fatty acids, while reducing others, result in large, statistically significant and clinically relevant improvement in headache frequency, intensity, and other clinical outcomes in community dwelling persons with chronic headaches.

The proposed trial represents a promising approach to treatment of a disabling condition, lumbar radiculopathy. The previous headache trial by the investigators' interdisciplinary UNC/NIH team demonstrated that specific dietary manipulations can produce marked biochemical changes and have a major positive clinical impact. This project promises to enhance the generalizability of the investigators' approach by expanding from chronic headaches to another common chronic pain condition, and also by using a more cost-effective intervention. Because dietary modification is a relatively safe and low-cost health-improvement strategy, the long-term outcome of this research may be to empower individuals to take a more active role in their own health through dietary changes that reduce dependence on medical treatments, while providing significant clinical benefits.

Baseline Phase. Medical records will be obtained for the participant's history and physical examination (performed by referring physician at the Spine Center). The baseline visit will consist of review of inclusion/exclusion criteria and the components of the study prior to consenting. Those who wish to sign the consents will complete baseline assessment instruments that measure lumbosacral radiculopathy characteristics and their impact on quality-of-life. Through electronic diaries, participants will provide daily data on pain intensity, duration, function, sleep quality, and medication use over a 2-week baseline phase. Participants who are compliant with all aspects of data collection, and who experience daily radicular pain, will be eligible for study intervention participation.

Randomization. At the end of the 2-week baseline phase, participants who qualify will be randomized (computer-generated variable permuted block) to: 1) the High n-3, Low n-6 Diet (Analgesic Diet); or 2) the Control Diet. Blood will be collected for baseline biomarker assessment prior to beginning study diets.

Post Randomization. After randomization, participants will attend an initial, in-depth dietary counseling session administered by the registered dietitian. Participants will be asked to provide a dietary history and will receive detailed instruction in the specific dietary intervention per group assignment. Participants in each group will attend a total of 3 in-person follow-up sessions with the dietitian, for review of their dietary experiences, to receive encouragement, to clarify issues, and to have questions answered. At each visit, the dietitian will obtain a dietary history and assessment, provide tailored counseling, and record data for evaluation of participant variability in order to guide future sessions. Participants will have a visit with the dietitian at randomization, two weeks later, 4 weeks after that, and 6 weeks after that (at the end of the intervention). In addition, individuals will participate in brief (15-20 minute) check-in telephone calls with the dietitian every 2-3 weeks. Participants will have contact with the research assistant twice weekly to encourage diary completion and to invite adverse event reporting.