DNA Today is a weekly podcast which aims to 'educate the public on genetic and public health topics.' In this episode on dementia, host Kira Dineen spoke with biochemist Dr Dayan Goodenowe, the founder and CEO of Prodrome Sciences, a company which produces dietary supplements and blood tests for lipids known as plasmalogens, a proposed biomarker of Alzheimer's disease.
The podcast started out with what I thought was a helpful basis for the rest of the discussion, with Dr Goodenowe highlighting the distinct definitions of dementia and Alzheimer's disease. Dementia is an umbrella term for a syndrome of memory loss, and Alzheimer's disease is one of the diseases which cause dementia. This distinction is often lost to the general public, and as a researcher in a lab studying Alzheimer’s disease, I always appreciate when scientists clarify this.
Moving on to genetic factors underlying Alzheimer's disease, Dr Goodenowe explained how genetics can affect your risk of developing the disease, focusing on one of the most well-established Alzheimer's risk genes – APOE. APOE is a protein involved in the transport of lipids, such as cholesterol, between cells. There are three major types of APOE a person can have based on their variant of the gene; E2, E3, and E4. Your type of APOE affects your cell's ability to retain cholesterol. Dr Goodenowe cleverly likened the three types to Goldilocks' three bears; E2 carriers are great at getting rid of cholesterol; E3 carriers are somewhere in the middle; and E4 carriers are really bad at getting rid of cholesterol. When you're young and healthy you have other lipids, like plasmalogens, to help you get rid of cholesterol and maintain a normal balance in your brain. But as you age, your plasmalogen levels decrease and you develop a cholesterol imbalance. As Dr Goodenowe aptly put it, 'You're running a three-legged race and your partner starts to get weaker and weaker'.
Then he got to the main point – each APOE type is also associated with a different risk for Alzheimer's disease; E4 carriers have elevated levels of amyloid plaques in the brain, a hallmark of Alzheimer's disease pathology, and a higher risk of developing the disease; E3 carriers are somewhere in the middle again; and E2 carriers have a reduced risk of developing the disease. I found Dr Goodenowe's explanation of the connection between APOE and Alzheimer's disease to be well done; a listener with a basic understanding of genetics could probably get through it, although admittedly they might have to rewind once or twice to catch it all! I also appreciated Dr Goodenowe's use of colourful metaphors and similes to communicate such complex biological concepts.
Dr Goodenowe then spent the second half of the podcast discussing the focus of his own research, plasmalogens. He cited findings from his lab that E4 carriers with high plasmalogens have the same risk for Alzheimer's disease as an E3 carrier; and if you're an E3 carrier and you have high plasmalogens, you have the same risk for Alzheimer's disease as an E2 carrier. Essentially, higher levels of plasmalogens reduced the risk of Alzheimer's disease in those that normally would have a greater risk based on their genetics. I found these findings quite shocking; I had never even heard of plasmalogens before! After immediate Whatsapping with others in my lab, it transpired that no one else had either, and it inspired me to investigate. Other studies, not just by Dr Goodenowe, have found associations between plasmalogens and Alzheimer's disease, and there is definitely evidence that lipid dysfunction in general is a key component of the disease.
Yet, the rest of the podcast focused quite heavily on the potentially beneficial effects of taking plasmalogen supplements, one of the products sold by Dr Goodenowe's company. Dr Goodenowe claimed that people with Alzheimer's disease who took the supplements saw increased cognitive function. Now I don't mean to call any of these studies or results into question at all; I am not a plasmalogen or biochemistry expert (quite the opposite)! I was just wary that the podcast covered this supplement in a way that could potentially skew a listener towards purchasing it to try to improve their cognition. Thus, I'd advise listeners to take Dr Goodenowe's supplement claims with a pinch of salt, in the same way I would when listening to any researcher talk about their work! After all, a scientist's livelihood depends on their ability to promote themselves and get others to care about their research, and I include myself in that. Just keep in mind that Dr Goodenowe, unlike most other scientists, is also a CEO selling a product.
The podcast drew to a close with Dr Goodenowe's proposal that we can modify our genetic risk of Alzheimer's disease by altering our biochemistry, and while I agree that this strategy holds merit, I am hesitant to believe that taking a single supplement will treat something as complex as cognitive decline in Alzheimer's disease. His podcast is a worthwhile listen for those who want to know more about major genetic risk factors underlying Alzheimer's disease, but when the conversation veers into the endorsement of plasmalogens, I would advise listeners to approach with a healthy amount of scepticism, as we should approach all science!
The first half of this podcast was an engaging episode by a knowledgeable scientist on genetic factors underlying Alzheimer's disease, yet overall I found it ultimately focused too heavily on advocating commercial dietary supplements.
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