Ketone bodies mediate alterations in brain energy metabolism and biomarkers of Alzheimer’s disease

Alzheimer’s disease (AD) is the most common form of dementia. AD is a progressive neurodegenerative disorder characterized by cognitive dysfunction, including learning and memory deficits, and behavioral changes. Neuropathology hallmarks of AD such as amyloid beta (Aβ) plaques and neurofibrillary tangles containing the neuron-specific protein tau is associated with changes in fluid biomarkers including Aβ, phosphorylated tau (p-tau)-181, p-tau 231, p-tau 217, glial fibrillary acidic protein (GFAP), and neurofilament light (NFL). Another pathological feature of AD is neural damage and hyperactivation of astrocytes, that can cause increased pro-inflammatory mediators and oxidative stress. In addition, reduced brain glucose metabolism and mitochondrial dysfunction appears up to 15 years before the onset of clinical AD symptoms. As glucose utilization is compromised in the brain of patients with AD, ketone bodies (KBs) may serve as an alternative source of energy. KBs are generated from the β-oxidation of fatty acids, which are enhanced following consumption of ketogenic diets with high fat, moderate protein, and low carbohydrate. KBs have been shown to cross the blood brain barrier to improve brain energy metabolism. This review comprehensively summarizes the current literature on how increasing KBs support brain energy metabolism. In addition, for the first time, this review discusses the effects of ketogenic diet on the putative AD biomarkers such as Aβ, tau (mainly p-tau 181), GFAP, and NFL, and discusses the role of KBs on neuroinflammation, oxidative stress, and mitochondrial metabolism

Stress and Coping in Older Australians During COVID-19:Health, Service Utilization, Grandparenting, and Technology Use

Objectives: This study examined the impacts of COVID-19 lockdown on health and lifestyle factors for older adults in Sydney, Australia. The study examined demographic differences, social engagement, loneliness, physical activity, emotion regulation, technology use, and grandparenting experiences and their contribution to emotional health and quality of life during lockdown. Methods: Participants were 201 community-dwelling older adults (60–87 years, M = 70.55, SD = 6.50; 67.8% female) who completed self-report scales measuring physical and emotional health outcomes, quality of life, health service utilization, changes in diet and physical activity, impacts on grandparenting roles, and uptake of new technology. Results: One-third of older adults experienced depression, and 1 in 5 experienced elevated anxiety and/or psychological distress during lockdown. Specific emotion regulation strategies, better social and family engagement, and new technology use were associated with better emotional health and quality of life; 63% of older adults used new technologies to connect with others. Conclusions: Older adults were adaptable and resilient during lockdown, demonstrating high uptake of new technologies to remain connected to others, while negative emotional health outcomes were linked to loneliness and unhelpful emotion regulation. Clinical implications: Further diversifying use of video technologies may facilitate improved physical and emotional health outcomes

Long‐term relapse rates after cognitive behaviour therapy for anxiety and depressive disorders among older adults: A follow‐up study during COVID‐19

Objective: This study assessed the long-term symptom relapse rates among older adults previously treated with cognitive behaviour therapy (CBT) for anxiety and/or depression during COVID-19. Methods: Participants were 37 older adults (M = 75 years, SD = 5; 65% female) previously treated with CBT for anxiety and/or unipolar depression who were re-assessed an average of 5.6 years later, during the first Australian COVID-19 lockdown. Results: On average, there was no significant group-level change in anxiety, depression or quality of life. When assessing change in symptoms based on clinical cut-off points on self-report measures, results suggest only 17%-22% showed a relapse of symptoms by the COVID-19 pandemic. Conclusions: Findings suggest that CBT may be protective in coping with life stressors many years after treatment ends. However, results warrant replication to attribute continued symptom improvement to CBT given the lack of control group