Association Between Improved Serum Fatty Acid Profiles and Cognitive Function During a Dietary Intervention Trial in Relapsing-Remitting Multiple Sclerosis

Solange M Saxby; Carlyn Haas; Farnoosh Shemirani; Tyler J Titcomb; Patrick Ten Eyck; Linda M Rubenstein; Karin F Hoth; Linda G Snetselaar; Terry L Wahls

doi:10.7224/1537-2073.2023-037

Association Between Improved Serum Fatty Acid Profiles and Cognitive Function During a Dietary Intervention Trial in Relapsing-Remitting Multiple Sclerosis

Int J MS Care. 2024 Mar-Apr;26(2):61-68. doi: 10.7224/1537-2073.2023-037. Epub 2024 Mar 11.

Authors

Affiliations

¹ Department of Internal Medicine (SMS, CH, FS, TJT, TLW).
² Institute for Clinical and Translational Science (PTE).
³ Department of Epidemiology (LMR, LGS).
⁴ Department of Psychiatry (KFH).
⁵ The Iowa Neuroscience Institute (KFH), University of Iowa, Iowa City, IA, USA.

^# Contributed equally.

Abstract

Background: Cognitive impairment is a common multiple sclerosis (MS)-related symptom that impacts quality of life (QOL). Diet interventions are shown to be beneficial in managing QOL, and the intake of essential fatty acids is linked with improved cognitive function. However, the effect of diets on serum fatty acid profiles and cognitive function is unknown.

Methods: A previous randomized, parallel-arm trial recruited participants with relapsing-remitting MS (N = 77). Study visits included 4 time points: run-in, baseline, 12 weeks, and 24 weeks. During the run-in phase, participants followed their usual diet and were then randomly assigned to either a modified paleolithic (Wahls) or a low saturated fat (Swank) diet at baseline. Assessments at study visits included cognitive function assessed by Symbol Digit Modalities Test-Oral (SDMT-O) and Perceived Deficits Questionnaire (PDQ), and serum fatty acids, including eicosapentaenoic (EPA), docosahexaenoic (DHA), and arachidonic (ARA) acids.

Results: Both groups had significant improvements in all serum fatty acids (P < .01), except for ARA, as well as SDMT-O at 24-weeks (P < .05), total PDQ at 12 and 24 weeks (P < .01) compared with baseline values. The 12-week changes in ω-3 (EPA + DHA) index and EPA serum fatty acids were associated with SDMT-O changes (P ≤ .05); however, the changes in fatty acid levels did not mediate the effect of the diets on SDMT-O or PDQ (P > .05).

Conclusions: Both diets led to improvements in serum fatty acid profiles and cognitive function, with associations between the 12-week ω-3 (EPA + DHA) index and EPA changes with SDMT-O.

Keywords: cognitive function; diet; multiple sclerosis; omega-3 fatty acids.

Grants and funding

FUNDING/SUPPORT: This study was supported in part by the National Multiple Sclerosis Society grant RG-1506-04312 (TLW), the Institute for Clinical and Translational Science (ICTS) at the University of Iowa, and University of Iowa institutional funds. The ICTS is supported by the National Institutes of Health Clinical and Translational Science Award program (grant UL1TR002537). Dr Saxby is a research trainee of the University of Iowa Fraternal Order of Eagles Diabetes Research Center (T32DK112751-06). Dr Saxby, Dr Titcomb, and Dr Shemirani are supported by the Carter Chapman Shreve Family Foundation and the Carter Chapman Shreve Fellowship Fund for diet and lifestyle research conducted by the Wahls Research team at the University of Iowa. In-kind support was provided by the University of Iowa College of Public Health Preventive Intervention Center.