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The Lancet Commission on Dementia Prevention, Intervention, and Care is a collaboration between the journal The Lancet, and international experts from several academic and charitable institutions to create evidence-based recommendations for dementia care. The commission’s goal is to help prevent dementia, reduce symptoms, and improve the lives of people with dementia and their families. Sadly, despite the increasing prevalence of this devastating disease, and the intense efforts of the international research community (see my podcast episode with Dr. Rima Kaddura), no treatments have been developed that could reduce its development, or to effectively treat the symptoms in affected patients.

The commission’s recently published 2024 report on dementia offers an in-depth examination of dementia prevention, intervention, and care, incorporating recent research and reflecting on the lessons learned since the previous report released in 2020. This report is significant because dementia remains one of the leading causes of disability and dependency among older adults worldwide. With the global population aging, the number of people affected by dementia is projected to increase dramatically, making it a critical public health issue.

Rising Dementia Prevalence Despite Decreased Age-Specific Incidence

The report starts by acknowledging that the age-specific incidence of dementia is decreasing in some high-income countries. A study published in 2022 analyzed data from the Health and Retirement Study and found that the prevalence of dementia among adults aged 65 and older declined from 12.2% in 2000 to 8.5% in 2016. This trend has been observed in several other studies as well, indicating a decrease in the risk of dementia at specific ages. This positive trend has been explained by the better management of cardiovascular risk factors, such as high blood pressure, increased education levels and several public health measures such as smoking cessation, healthy diets, and physical activity.

In contrast, the absolute number of dementia cases continues to rise globally and this rise is primarily driven by the growing number of older adults, especially in low- and middle-income countries where the population is aging rapidly. As a result, dementia is becoming a more significant global health challenge, requiring concerted efforts in both prevention and care.

Multifactorial Pathophysiology

Like all diseases that make up the current chronic non-communicable disease epidemic, including but not limited to Parkinson’s disease, colon cancer and cardiovascular disease, current evidence suggests that there is not a single risk factor like a microbial infection, or a single dietary factor that is underlying the overall rise in dementia, but it is the interactions of several modifiable risk factors with a individual genetic predisposition.

Expansion of Modifiable Risk Factors

Building on previous reports, the 2024 Lancet Commission adds to the list of modifiable risk factors associated with dementia. The original 12 risk factors identified include low educational attainment, midlife hypertension, hearing loss, smoking, midlife obesity, depression, physical inactivity, diabetes, social isolation, excessive alcohol consumption, head injuries, and exposure to air pollution. The new report introduces untreated vision loss and high LDL cholesterol as additional risk factors. Like high blood pressure, smoking and diabetes, high LDL cholesterol is linked to vascular health, and vascular damage is a well-known contributor to cognitive impairment and dementia. It is not surprising that the multiple risk factors that the Lancet Commission has identified for dementia, are also risk factors for the other diseases of the chronic disease epidemic, which are related to systemic low grade immune system activation and metabolic dysregulation.

“…nearly half of all dementia cases could be prevented by addressing the 14 modifiable risk factors.”

It is obvious, that the promotion of supplements are not the simple answer to the increasing prevalence of dementia, even though a handful of compounds which have been shown to reduce systemic immune activation (i.e. turmeric) or improve endothelial function (i.e. flavanols). Depending on an individual patient’s risk factors and environmental exposures, dietary factors alone are not a solution either, even though such interventions (together with regular physical exercise) to prevent the development of metabolic dysregulation, obesity and associated systemic immune activation, play an important role.

“…the report advocates for a life-course approach to dementia prevention…”

The Lancet Commission report advocates for a life-course approach to dementia prevention, suggesting that nearly half of all dementia cases could be prevented by addressing the 14 modifiable risk factors. This approach involves targeting risk factors at different stages of life to maintain cognitive health. For example, promoting education in childhood, adhering to a healthy diet, managing hypertension and cholesterol in midlife, and preventing hearing loss and depression in later life can all contribute to reducing the overall risk of dementia.

The Importance of Early Intervention

Early intervention is critical for reducing dementia risk. The report highlights the importance of detecting and managing risk factors such as hypertension, diabetes, and high cholesterol as early as possible, starting even in childhood. These conditions, if left unchecked, can lead to significant vascular damage, which is a major contributor to cognitive decline. The report also underscores the importance of addressing lifestyle factors, such as smoking, physical inactivity, and poor diet, which are modifiable and have a substantial impact on brain health.

Cognitive and Physical Activity

Maintaining cognitive and physical activity throughout life is emphasized as a key strategy for dementia prevention. Engaging in mentally stimulating activities, such as reading, learning new skills, and participating in social activities, can help build cognitive reserve, which may delay the onset of dementia symptoms. Similarly, regular physical exercise has been shown to improve brain health by enhancing blood flow, reducing inflammation, and promoting the growth of new neurons.

“Hearing loss is another significant risk factor for dementia, particularly in midlife…”

Hearing loss is another significant risk factor for dementia, particularly in midlife. The report advocates for the early use of hearing aids to mitigate the impact of hearing loss on cognitive decline. Untreated hearing loss can lead to social isolation, depression, and cognitive strain, all of which increase the risk of dementia. By using hearing aids, individuals can maintain their ability to communicate and engage socially, which are crucial for cognitive health.

Air Pollution and Traumatic Brain Injuries (TBIs)

The report also highlights the growing evidence linking air pollution to dementia. Fine particulate matter and other pollutants have been shown to increase the risk of cognitive decline and dementia. This finding has significant implications for public health policies, as reducing air pollution could have a substantial impact on lowering dementia risk. Additionally, the report emphasizes the need to prevent traumatic brain injuries (TBIs), particularly in younger individuals, as TBIs are associated with an increased risk of dementia later in life.

“…medications can help improve cognitive function and delay the progression of symptoms, although their effects are modest.”

Pharmacological treatments, such as cholinesterase inhibitors, are recommended for managing symptoms of Alzheimer’s disease, the most common form of dementia. These medications can help improve cognitive function and delay the progression of symptoms, although their effects are modest. The report also discusses new anti-amyloid treatments, which target the amyloid plaques that are characteristic of Alzheimer’s disease. While these treatments represent a significant advancement in dementia research, their benefits are limited, and they come with considerable challenges, including high costs and potential side effects.

“The report emphasizes the need for a life-course approach to prevention, early intervention, and personalized care for individuals with dementia.”

In conclusion, the 2024 Lancet Commission report on dementia provides a comprehensive overview of the current state of dementia prevention, intervention, and care. It offers hopeful evidence that dementia risk can be significantly reduced through targeted interventions and policy changes. The report emphasizes the need for a life-course approach to prevention, early intervention, and personalized care for individuals with dementia. It serves as a critical resource for policymakers, healthcare providers, and researchers working to combat the global dementia crisis.