A pro-inflammatory diet in people with multiple sclerosis is associated with an increased rate of relapse and increased FLAIR lesion volume on MRI in early multiple sclerosis: A prospective cohort study

A systematic review and meta-analysis of Dietary Inflammatory Index and the likelihood of multiple sclerosis/ demyelinating autoimmune disease

Diet and inflammation may contribute to the development of multiple sclerosis (MS). The aim of this systematic review and meta-analysis was to assess the association between proinflammatory diet, as estimated by the Dietary Inflammatory Index (DII®), and the likelihood of developing MS or other demyelinating autoimmune diseases. A systematic search was performed of search engines and databases (PubMed, ISI Web of Sciences, Scopus, and Embase) to identify relevant studies before 10th June 2023. The search identified 182 potential studies, from which 39 full-text articles were screened for relevance. Five articles with case-control design (n = 4,322, intervention group: 1714; control group: 2608) met the study inclusion criteria. The exposure variable was DII, with studies using two distinct models: quartile-based comparisons of DII and assessment of continuous DII. The meta-analysis of high versus low quartiles of DII with four effect sizes showed a significant association with MS/demyelinating autoimmune disease likelihood, with an odds ratio (OR) of 3.26 (95% confidence interval (CI) 1.16, 9.10). The meta-analysis of four studies with DII fit as a continuous variable showed a 31% increased likelihood of MS per unit increment; which was not statistically significant at the nominal alpha equals 0.05 (OR 1.31; 95% CI 0.95, 1.81). In conclusion, this systematic review and meta-analysis provides evidence of a positive association between higher DII scores with the likelihood of developing MS, highlighting that diet-induced inflammation could play a role in MS or other demyelinating autoimmune diseases risk.

Associations between diet and disease progression and symptomatology in multiple sclerosis: A systematic review of observational studies

BACKGROUND

Although many people with MS (pwMS) modify their diet after diagnosis, there is still no consensus on dietary recommendations for pwMS. A number of observational studies have explored associations of diet and MS progression, but no studies have systematically reviewed the evidence. This systematic review aimed to provide an objective synthesis of the evidence for associations between diet and MS progression, including symptoms and clinical outcomes from observational studies.

METHODS

We performed a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic database searches were performed for studies completed up to 26 July 2023 using PubMed (Medline), Web of Science, CINAHL, Embase (Ovid), and Scopus, followed by citation and reference list checking. We included studies using diet quality scores or dietary indices. Studies assessing individual foods, nutrients, or dietary supplements were excluded. We used the Newcastle-Ottawa Scale to assess the risk of bias of included studies.

RESULTS

Thirty-two studies met the inclusion criteria. Of these, 20 were cross-sectional and 12 prospective. The most frequent outcomes assessed were disability (n = 19), quality of life (n = 12), fatigue (n = 12), depression (n = 9), relapse (n = 8), anxiety (n = 3), and magnetic resonance imaging (MRI) outcomes (n = 4). Based on prospective studies, this review suggests that diet might be associated with quality of life and disability. There were also potential effects of higher diet quality scores on improved fatigue, disability, depression, anxiety, and MRI outcomes but more evidence is needed from prospective studies.

CONCLUSIONS

Observational studies show some evidence for an association between diet and MS symptoms, particularly quality of life and disability. However, the impact of diet on other MS outcomes remains inconclusive. Ultimately, our findings suggest more evidence is needed from prospective studies and well-designed tailored intervention studies to confirm associations.

Association Between the Risk of Multiple Sclerosis and Dietary Proinflammatory/Anti-Inflammatory Food Intake and Dietary Diversity: A Case-Control Study

A diet rich in proinflammatory components and inflammation are suggested to be significant risk factors for multiple sclerosis (MS). This study aimed to investigate the association between the risk of MS and the inflammatory potential of an individual's diet and dietary diversity through pro-inflammatory/anti-inflammatory food intake score (PAIFIS) and dietary diversity score (DDS). In a hospital-based case-control study, 397 participants, including 197 patients with MS and 200 healthy participants aged over 18 years, were evaluated. The history of smoking, dietary intake, and anthropometric characteristics, including body mass index, waist circumference, total body fat, and fat-free mass were assessed. A validated 160-item semiquantitative food frequency questionnaire was used to calculate the PAIFIS and DDS scores. The mean age of the participants was 32.45 ± 8.66 years, and most were females (274, 79.4%). The PAIFIS score was significantly higher among MS patients than healthy participants (p = 0.001). Between PAIFIS and DDS, only PAFIS was significantly related to MS risk (odds ratio, 1.002; 95% confidence interval, 1.001-1.004; p = 0.001). PAIFIS, as an index of dietary inflammation, can predict MS. Further studies are needed to document these findings.

Higher dietary quality is prospectively associated with lower MRI FLAIR lesion volume, but not with hazard of relapse, change in disability or black hole volume in people with Multiple Sclerosis

BACKGROUND

The influence of diet quality on multiple sclerosis (MS) progression or inflammatory activity is not well understood.

METHODS

Study participants with MS from the AusLong cohort, were followed annually (10 years, n = 223 post-onset). At baseline, 5 and 10-year reviews, indices of dietary quality - the Australian Recommended Food Score (ARFS) and Diet Quality Tracker (DQT) - were calculated from self-reported dietary intake data of the preceding 12 months (Food Frequency Questionnaire, Dietary Questionnaire for Epidemiological Studies v2). Associations were examined between measures of dietary quality with measures of MS progression and inflammatory activity hazard of relapse, annualised disability progression (Expanded Disability Status Scale, EDSS) and Magnetic Resonance Imaging (MRI) outcomes. MRI outcomes included fluid-attenuated inversion recovery (FLAIR, T2 MRI) lesion volume and black hole volume (T1 MRI) in the juxtacortical, periventricular, and infratentorial regions of the brain, as well as total calculated from the sum of the three regions.

RESULTS

A higher diet quality (at least with the ARFS) was associated with lower FLAIR lesion volume in the periventricular region only (highest vs lowest quartile: β=-1.89,95%CI=-3.64, -0.13, p = 0.04, periventricular FLAIR region median (IQR) for 5-year review: 4.41 (6.06) and 10-year review: 4.68 (7.27)). Associations with black hole lesion volume, hazard of relapse, and annualised EDSS progression, lacked in significance and/or dose-dependency.

CONCLUSION

We found evidence that diet quality may have a role in modulating one aspect of MS inflammatory activity (periventricular MRI FLAIR lesion volume), but not other MRI and clinical outcome measures.