Is dementia caused by genetics? | Prof. Claire Steves

Summary

The transcript discusses genetic and environmental factors contributing to dementia, emphasizing early onset in people aged 50-60. The APOE4 gene increases dementia risk, though lifestyle factors can still build cognitive resilience. Brain development is influenced by maternal nutrition, education, and psychological factors starting from fetal life. Physical activity and social engagement are key in boosting brain reserve, while inflammation and other health issues can accelerate cognitive decline. Exciting new drugs slow disease progression but carry risks, such as brain swelling, limiting their widespread use.

Takeaways

• 🧬 Genetic factors play a significant role in early-onset dementia, with genes like APOE4 increasing the risk.
• 🧬 Having two APOE4 alleles increases the risk of dementia eightfold, but it's not a guarantee.
• 👶 Early life experiences, including in utero, significantly affect cognitive reserve and future dementia risk.
• 🍽 Nutrition and stimulation from an early age are crucial for brain development and resilience against dementia.
• 🏃‍♂️ Physical fitness and social activity contribute to a healthy brain reserve, which can delay the onset of dementia symptoms.
• 🧠 High cognitive functioning gives individuals a greater reserve, allowing dementia symptoms to appear later in life.
• 🚭 Lifestyle factors like smoking and alcohol consumption can negatively impact brain development and increase dementia risk.
• 👨‍⚕️ New antibody-based medications can remove proteins associated with Alzheimer's disease, slowing its progression.
• 💊 While these new drugs show promise, they only modestly improve cognition and come with risks like brain swelling.
• 🏥 Regular brain scans are required for patients on these new medications, highlighting logistical and resource challenges.

Q & A

What is the role of genetic factors in the development of dementia?

Genetic factors are important in the development of dementia, especially in early-onset dementias, which typically occur in people in their 50s or 60s. Specific genes, such as the APOE gene, play a significant role in increasing the risk of dementia.

What is the APOE gene, and how does it influence the risk of dementia?

The APOE gene comes in different forms, including APOE4, which is associated with an increased risk of dementia. People who carry two copies of the APOE4 gene have about an eight times greater risk of developing dementia, though it is not guaranteed they will get the disease.

What percentage of the population has two copies of the APOE4 gene?

About 2-3% of the population has two copies of the APOE4 gene, while around 25% of people have one copy of the gene.

Can environmental factors also influence the risk of dementia?

Yes, there is an interaction between genes and the environment that can be important in influencing dementia risk. Environmental factors such as diet, medications, and lifestyle choices can affect the brain's resilience, even in people with genetic predispositions.

How does early-life development, including fetal conditions, affect the risk of dementia later in life?

Factors affecting brain development in utero, such as maternal nutrition and environmental exposure, can influence cognitive reserve and the risk of dementia later in life. Higher cognitive reserve helps delay the onset of dementia symptoms.

What is cognitive reserve, and why is it important in dementia?

Cognitive reserve refers to the brain's ability to cope with damage and maintain function. Individuals with higher cognitive reserve can better withstand brain damage caused by dementia and delay the onset of symptoms that interfere with daily life.

What are the lifestyle factors that contribute to building cognitive reserve in children?

Key factors include intellectual stimulation, social engagement, psychological stability, and good nutrition. Physical activity and reducing sedentary behavior are also important in building cognitive and brain reserve.

How does physical fitness benefit brain health?

Physical fitness is beneficial for both vascular and brain health. Regular physical activity, even outside of structured exercise, improves brain function, reduces sedentary time, and helps slow brain aging.

What are some early signs of dementia that people should watch for?

Early signs of dementia include changes in cognitive function, such as short-term memory loss (in Alzheimer's disease) or personality changes. Some forms of dementia may also manifest through physical symptoms like balance problems, blood pressure regulation issues, or sleep disturbances.

What is the current status of treatment options for dementia?

There are new antibody-based medications that target the proteins associated with Alzheimer's disease, removing them from the brain and slowing the progression of the disease. However, these drugs provide modest improvements and come with risks, such as brain swelling and microhemorrhages, which require regular monitoring through brain scans.