Ketogenic Diet Shows Promise for Alzheimer's Disease

The search for effective interventions for Alzheimer's disease continues to challenge researchers worldwide. As the most common form of cognitive impairment affecting nearly a quarter of those over 80 years old, Alzheimer's places an enormous burden on individuals, families and healthcare systems. With global prevalence expected to increase dramatically in coming decades, particularly in low and middle-income countries, identifying accessible treatment approaches is critical.

A systematic review and meta-analysis published in The Journal of Nutrition, Health and Aging offers compelling evidence that ketogenic diets may provide significant benefits for cognitive function in those with Alzheimer's disease.

Understanding the Metabolic Connection

The human brain is an energy-hungry organ, consuming approximately 120-130g of glucose daily and accounting for about 16% of the body's total oxygen consumption. In Alzheimer's disease, abnormal glucose metabolism appears to be a key factor in disease progression, disrupting insulin signalling, β-amyloid metabolism, and Tau protein phosphorylation.

When glucose availability decreases, whether through fasting or dietary modification, the body can utilise ketone bodies (acetoacetate and β-hydroxybutyric acid) as alternative energy sources. Research indicates that in people with mild cognitive impairment and Alzheimer's disease, the brain actually absorbs ketones more readily than glucose, creating a potential therapeutic opportunity.

What the Research Shows

Rong et al. (2004) published a meta-analysis included 10 randomised controlled trials involving 691 people with Alzheimer's disease. These studies evaluated various forms of ketogenic interventions, primarily medium-chain triglyceride (MCT) supplementation, over periods ranging from 3 to 15 months.

The results were promising, showing statistically significant improvements across multiple cognitive assessments:

• Mental state (as measured by the Nishimura Geriatric Rating Scale)
• Mini-Mental State Examination (MMSE) scores
• Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog)

Findings suggest that ketogenic interventions can meaningfully enhance cognitive function and mental state in those with Alzheimer's disease.

How Ketogenic Diets May Help

The therapeutic effects of ketogenic diets in Alzheimer's work through several mechanisms:

1. Improved energy metabolism: Ketones provide an alternative energy source for brain cells when glucose metabolism is compromised.
2. Enhanced neural plasticity: Ketones promote the secretion of brain-derived neurotrophic factor (BDNF) and support mitochondrial biogenesis, potentially improving synaptic maintenance.
3. Reduced neuroinflammation: Research indicates ketogenic diets decrease levels of inflammatory cytokines.
4. Altered neurotransmitter metabolism: Ketone bodies participate in the metabolism of excitatory neurotransmitter glutamate and may inhibit AMPAR receptor-mediated glutamate neurotoxicity.

Ketogenic Diet Approaches

The reviewed studies utilised several different ketogenic approaches:

• Standard ketogenic diet: Typically containing approximately 58% fat, 29% protein, 7% fibre, and 6% net carbohydrates by weight
• Medium-chain triglyceride (MCT) supplements: The most common intervention, containing varying ratios of C8:0 and C10:0 fatty acids
• Modified Atkins diet: Limiting carbohydrates while allowing greater protein consumption than traditional ketogenic diets

Implications for Clinical Practice

For clinicians and families considering ketogenic approaches for Alzheimer's, these findings suggest potential benefits that may outweigh risks for many individuals. The research supports that:

1. Ketogenic interventions can significantly improve cognitive measures in people living with Alzheimer's disease
2. Medium-chain triglyceride supplements offer a practical implementation option
3. Effects can be measured within 3-6 months of intervention
4. Monitoring of lipid profiles is advisable during treatment

Conclusion

Metabolic interventions can provide meaningful benefits for people living with Alzheimer's. As a relatively accessible, non-pharmaceutical approach, ketogenic diets represent a promising adjunctive therapy for improving cognitive function and quality of life in those affected by this devastating condition.

For families and practitioners considering this approach, consulting a healthcare provider familiar with both Alzheimer's disease and metabolic interventions is recommended to develop an individualised plan that maximises benefits while managing any associated risks.

Let Metabolic Psychology help you transition into ketosis to improve brain health and improve cognitive function. Click the link in bio to book an appointment.

Wishing you health & happiness, 

Perri

Citation: Rong, L., Peng, Y., Shen, Q., Chen, K., Fang, B., & Li, W. (2024). Effects of ketogenic diet on cognitive function of patients with Alzheimer's disease: a systematic review and meta-analysis. The Journal of Nutrition, Health and Aging, 28, 100306. https://doi.org/10.1016/j.jnha.2024.100306