Gluten, Inflammation, and Neurodegeneration

Effects of different dietary interventions in multiple sclerosis: a systematic review of evidence from 2018 to 2022

BACKGROUND

Nutrition is an important risk factor for both Multiple sclerosis (MS) development and post-diagnosis disease prognosis. However, it is important to evaluate the diet as a whole instead of considering the effects of nutrients individually.

AIMS

In this systematic review, it was aimed to evaluate the effect of different dietary interventions in MS patients and to determine the most appropriate dietary model for this group.

METHODS

The search was carried out between February 2022 and March 2022 in three different databases, 'PubMed', 'Web of Science' and 'The Cochrane Library' over the university access network. After the search for the determined keywords, a total of 269 studies conducted between 2018 and 2022 were identified, but only 17 of them were found to be suitable for inclusion criteria.

RESULTS AND CONCLUSION

Although there are studies reporting positive health outcomes for energy-restricted/intermittent fasting diets, ketogenic diet, and modified paleolithic diet, these diets may not be applicable diets in the long-term as they may cause deficiencies of various nutrients. No current study was found for low-fat diets, gluten-free diet and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet applied to individuals with MS. The Mediterranean diet, on the other hand, is more recommendable than other diet models due to the positive health results reported in long-term studies and the absence of any side effects. However, more studies are needed to reach a definite conclusion.

Risk of Parkinson's Disease in Celiac Disease: A Swedish Population-Based Study

Using a population-based matched cohort design, we assessed the association of celiac disease (CeD) with risk of PD by comparing patients with biopsy-confirmed CeD in Sweden to a biopsy-free population and their unaffected siblings, separately. No overall association was observed but CeD diagnosed before age 60 associated positively with incident diagnosis of PD (hazard ratio [HR] = 1.29; 95% confidence interval [CI]: 1.02-1.62), which was mainly attributed to the significantly elevated risk detected after 10-15 years since biopsy (HR = 1.68; 95% CI: 1.05-2.68). Our findings imply an increased vulnerability to long-term PD development among patients with CeD diagnosed before 60s. ANN NEUROL 2023;94:911-916.

Healthy lifestyles and wellbeing reduce neuroinflammation and prevent neurodegenerative and psychiatric disorders

Since the mid-20th century, Western societies have considered productivity and economic outcomes are more important than focusing on people's health and wellbeing. This focus has created lifestyles with high stress levels, associated with overconsumption of unhealthy foods and little exercise, which negatively affect people's lives, and subsequently lead to the development of pathologies, including neurodegenerative and psychiatric disorders. Prioritizing a healthy lifestyle to maintain wellbeing may slow the onset or reduce the severity of pathologies. It is a win-win for everyone; for societies and for individuals. A balanced lifestyle is increasingly being adopted globally, with many doctors encouraging meditation and prescribing non-pharmaceutical interventions to treat depression. In psychiatric and neurodegenerative disorders, the inflammatory response system of the brain (neuroinflammation) is activated. Many risks factors are now known to be linked to neuroinflammation such as stress, pollution, and a high saturated and trans fat diet. On the other hand, many studies have linked healthy habits and anti-inflammatory products with lower levels of neuroinflammation and a reduced risk of neurodegenerative and psychiatric disorders. Sharing risk and protective factors is critical so that individuals can make informed choices that promote positive aging throughout their lifespan. Most strategies to manage neurodegenerative diseases are palliative because neurodegeneration has been progressing silently for decades before symptoms appear. Here, we focus on preventing neurodegenerative diseases by adopting an integrated "healthy" lifestyle approach. This review summarizes the role of neuroinflammation on risk and protective factors of neurodegenerative and psychiatric disorders.

Celiac Disease and Neurological Manifestations: From Gluten to Neuroinflammation

Celiac disease (CD) is a complex multi-organ disease with a high prevalence of extra-intestinal involvement, including neurological and psychiatric manifestations, such as cerebellar ataxia, peripheral neuropathy, epilepsy, headache, cognitive impairment, and depression. However, the mechanisms behind the neurological involvement in CD remain controversial. Recent evidence shows these can be related to gluten-mediated pathogenesis, including antibody cross-reaction, deposition of immune-complex, direct neurotoxicity, and in severe cases, vitamins or nutrients deficiency. Here, we have summarized new evidence related to gut microbiota and the so-called "gut-liver-brain axis" involved in CD-related neurological manifestations. Additionally, there has yet to be an agreement on whether serological or neurophysiological findings can effectively early diagnose and properly monitor CD-associated neurological involvement; notably, most of them can revert to normal with a rigorous gluten-free diet. Moving from a molecular level to a symptom-based approach, clinical, serological, and neurophysiology data might help to disentangle the many-faceted interactions between the gut and brain in CD. Eventually, the identification of multimodal biomarkers might help diagnose, monitor, and improve the quality of life of patients with "neuroCD".