Alzheimer’s disease discussed in reddit ‘AMA’

Albert Hofman, chair of the Department of Epidemiology, answered questions about Alzheimer’s disease research during a reddit “Ask Me Anything” (AMA) on Thursday, March 16, 2017. According to the 2015 World Alzheimer Report, 46 million people worldwide are living with dementia—a number that is expected to triple by 2050. Hofman studies the epidemiology of common neurologic and vascular diseases, in particular dementia and stroke, and has initiated and served as the principal investigator for two population-based, prospective cohort studies examining neurological, cardiovascular, and endocrine diseases. These studies harnessed new epidemiological tools, including the genome-wide assessment and large-scale imaging of whole cohorts, enabling researchers to study the interrelations of those diseases and their development.

Here are some highlights from the AMA, and you can read the full discussion here.

What can I do at 31 to sustain my brain?  

Dementia and Alzheimer disease is unfortunately very frequent in the elderly. It is seen in about 1% of people aged 65, and at least 35% in those aged 95. The best way to try prevent dementia is to take measures to prevent heart disease and stroke, i.e., do not smoke, have regular physical activity, have low blood pressure and cholesterol. These preventive measures cannot start too early, so at 31 please continue with these preventive measures.

Why do you expect the population with dementia to triple?

This is because we are living longer. Every four years we add one year to life expectancy (in most countries). So we get more really old people who have a high risk of dementia. We are, in other words, the victims of our own success in increasing life expectancy. The increase in dementia is not because the incidence rate (new cases) of the disease increase: On the contrary there is quite some evidence that the dementia incidence has declined in the past decade (evidence first from European studies, and more recently also for U.S. studies). I think the latter is because of better prevention and treatment of cardiovascular diseases.

From what I’ve learned, prions are suspected to be the cause of Alzheimer’s, how do the cardiovascular risk factors contribute to the development of the disease?

Indeed, prions have been proposed as a possible cause of dementia (like in the human form of mad cow disease, Creutfeldt-Jakob disease). There is actually no evidence that prions lead to Alzheimer’s disease itself. Cardiovascular risk factors indeed contribute to the development of dementia and Alzheimer disease. It can be through chronic lack of blood (due to atheriosclerosis, particularly of the small blood vessels in the brain), so called chronic hypo-perfusion, or through the effect on amyloid, leading to deposits in the brain. This cardiovascular link is important in that it is currently the only known way to help prevent the disease.

What are emerging technologies’ roles in learning about and fighting against Alzheimer’s?

New imaging technologies (MRI, PET) are tremendously important in studying Alzheimer’s because it allows us to see changes in the brain over time and study its possible causes. Genomic technologies have helped us find a relatively large number of genes implicated in the disease, and hopefully these may also yield future clues to prevention and treatment.