Low-carbohydrate and ketogenic diets: a scoping review of neurological and inflammatory outcomes in human studies and their relevance to chronic pain.

Dietary restriction of carbohydrate has been demonstrated to be beneficial for nervous system dysfunction in animal models and may be beneficial for human chronic pain. The purpose of this review is to assess the impact of a low-carbohydrate/ketogenic diet on the adult nervous system function and inflammatory biomarkers to inform nutritional research for chronic pain. An electronic database search was carried out in May 2021. Publications were screened for prospective research with dietary carbohydrate intake <130 g per day and duration of ≥2 weeks. Studies were categorised into those reporting adult neurological outcomes to be extracted for analysis and those reporting other adult research outcomes. Both groups were screened again for reported inflammatory biomarkers. From 1548 studies, there were 847 studies included. Sixty-four reported neurological outcomes with 83% showing improvement. Five hundred and twenty-three studies had a different research focus (metabolic n = 394, sport/performance n = 51, cancer n = 33, general n = 30, neurological with non-neuro outcomes n = 12, or gastrointestinal n = 4). The second screen identified sixty-three studies reporting on inflammatory biomarkers, with 71% reporting a reduction in inflammation. The overall results suggest a favourable outcome on the nervous system and inflammatory biomarkers from a reduction in dietary carbohydrates. Both nervous system sensitisation and inflammation occur in chronic pain, and the results from this review indicate it may be improved by low-carbohydrate nutritional therapy. More clinical trials within this population are required to build on the few human trials that have been done.

Ketogenic diets and the nervous system: a scoping review of neurological outcomes from nutritional ketosis in animal studies.

OBJECTIVES: Ketogenic diets have reported efficacy for neurological dysfunctions; however, there are limited published human clinical trials elucidating the mechanisms by which nutritional ketosis produces therapeutic effects. The purpose of this present study was to investigate animal models that report variations in nervous system function by changing from a standard animal diet to a ketogenic diet, synthesise these into broad themes, and compare these with mechanisms reported as targets in pain neuroscience to inform human chronic pain trials. METHODS: An electronic search of seven databases was conducted in July 2020. Two independent reviewers screened studies for eligibility, and descriptive outcomes relating to nervous system function were extracted for a thematic analysis, then synthesised into broad themes. RESULTS: In total, 170 studies from eighteen different disease models were identified and grouped into fourteen broad themes: alterations in cellular energetics and metabolism, biochemical, cortical excitability, epigenetic regulation, mitochondrial function, neuroinflammation, neuroplasticity, neuroprotection, neurotransmitter function, nociception, redox balance, signalling pathways, synaptic transmission and vascular supply. DISCUSSION: The mechanisms presented centred around the reduction of inflammation and oxidative stress as well as a reduction in nervous system excitability. Given the multiple potential mechanisms presented, it is likely that many of these are involved synergistically and undergo adaptive processes within the human body, and controlled animal models that limit the investigation to a particular pathway in isolation may reach differing conclusions. Attention is required when translating this information to human chronic pain populations owing to the limitations outlined from the animal research.

Experience of participants with chronic pain in a pilot randomized clinical trial using a ketogenic diet.

Aim: To report the experience of chronic pain participants after a well-formulated ketogenic diet (WFKD) or whole-food diet (WFD). The quantitative outcomes for this trial have been published separately (clinical trial registration number ACTRN12620000946910). Patients & methods: The experience of 24 participants was evaluated after 12 and 24 weeks of dietary intervention using survey responses and open questions. Results & conclusion: Retention rates for the WFKD and WFD groups were 93 and 89%, respectively. Average adherence to the WFKD was 82% and to the WFD was 87%. The WFKD enjoyment was rated at 66 and 81% for the WFD group. The ease of adhering to the diet varied more widely for the WFKD group. Barriers included knowledge integration, time management, navigating social food environments and emotional attachment to eliminated foods. Facilitators included structured support and coaching, and comprehensive learning materials. The WFKD was shown to be a feasible and effective treatment option for chronic pain.

This paper reports the experiences of 24 individuals with chronic pain when undertaking either a whole-food diet or a whole-food ketogenic diet as an intervention for their chronic pain. The diet ran for 12 weeks, and participants were surveyed at the end of the diet and again after another 12 weeks. There was a low dropout rate for both the groups, and participants reported adhering to the diet they were allocated to. Participants in the ketogenic group reported less enjoyment and were more varied in their adherence to the diet; however, the diet was shown to be feasible in this patient population. There were barriers to engaging with the diet including: implementing the rules of the diet, finding the extra time required, eating out and missing high carbohydrate foods. Having good information to follow and someone to coach them assisted participants to successfully implement the diet.

Hope Tree: An Interactive Art Installation to Facilitate the Expression of Hope in a Hospice Setting.

BACKGROUND: Individuals confronting a terminal illness can experience intense psychological distress. Previous research has shown that hope can enhance one's ability to acknowledge, accept, and fight a terminal illness. Patients can continue to have hope or be hopeful, even in the face of a terminal illness. Can participation in a creative writing practice improve the expression of hope in a hospice setting? METHODS: In this program evaluation, each expressed hope placed on the "Hope Tree" was independently coded by all research team members utilizing inductive content analysis. Overall themes were derived using a constant comparative approach and arranged into overarching themes based on consensus. RESULTS: Eight major themes emerged from the data: "Peace," "Dreams," "Total well-being," "Acknowledgment of loss," "Relationships," "Hospice care," "Spirituality," and "Dichotomies." CONCLUSION: The Hope Tree is a creative art project that can be used within a hospice environment to promote hope among family members and the health-care professionals who care for patients.