Does lowering LDL cholesterol cause dementia? And how much dementia is actually “vascular” dementia versus Alzheimer’s disease?

In this video, I’m answering two viewer questions about dementia, vascular risk, statins, LDL cholesterol, and brain health. First, we look at the relative prevalence of vascular dementia compared with Alzheimer’s dementia — and why that distinction gets messy fast. Vascular dementia may be less common as a primary diagnosis, but vascular disease often contributes to cognitive decline even when the label is “Alzheimer’s.”

Then we spend most of the video on the bigger fear: whether lipid-lowering therapy — including statins and achieving low LDL-C — increases dementia risk. The short answer: no. Based on the evidence we have, lowering LDL does not appear to cause dementia, and in many patients, reducing cardiovascular and cerebrovascular risk may actually help protect the brain over time.

This is not about pretending statins are perfect or ignoring legitimate questions about brain health. It’s about looking carefully at the evidence instead of letting fear drive the conversation.

If you’re worried about statins, low LDL, Alzheimer’s disease, vascular dementia, or how heart health and brain health overlap, this one is for you.

If you missed the original: https://youtu.be/Rzz2g9gRL_8?si=z5Fcd-e8o2pYT19j

Chapters:
0:00 Viewer questions on dementia and lipid lowering
0:40 Is vascular dementia less common than Alzheimer’s?
2:00 Why dementia diagnoses overlap
3:17 The vascular contribution to cognitive decline
5:22 Why cardiovascular prevention matters for brain health
6:43 Can very low LDL or ApoB cause dementia?
8:16 Lipid-lowering drugs and the blood-brain barrier
10:14 What the overall evidence says
12:02 Randomized trials, meta-analyses, and dementia risk
13:30 Very low LDL in PCSK9 inhibitor trials
16:09 Could statins reduce dementia risk?
18:34 Midlife cholesterol and later dementia
20:00 The PCSK9 genetics question
22:15 Evidence strength: what we know and what we don’t

Are you more worried about heart disease risk, dementia risk, or the tradeoff between the two?

Disclaimer:
This video is for general educational purposes only and is not individual medical advice. Please talk with your own physician before making changes to medications or treatment plans.Sign up for more information on my own practice here: https://corsighthealth.com/

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___________________________
🧬 About Dr. Lily Johnston

Dr. Johnston is a double board-certified vascular and general surgeon in San Diego, specializing in metabolic and cardiovascular prevention. She’s the founder of CorSight Health and a passionate advocate for reimagining how medicine approaches chronic disease.

#MetabolicHealth #CardiovascularPrevention #HeartHealth #Longevity #InsulinResistance #DrLilyJohnston #DrLily #WomenInMedicine #Surgeon #VascularSurgeon #PreventiveMedicine #PADPrevention #HeartAttackRisks #HealthPortfolio #California #SanDiego #Arizona #Virginia #Minnesota

You asked 349 questions about my LDL video. I'm answering the ones that matter most — including who paid for the study.

Last week I broke down the LDL cholesterol trial. The comments flooded in — and several of you asked exactly the right questions. In this follow-up, I'm going through the most important ones as a vascular surgeon who's spent years treating the consequences of bad cardiovascular advice.

In this video:
🫘 Kidney function & muscle toxicity — one commenter raised a sharp mechanistic point worth spelling out: statins can cause muscle damage → muscle damage could reduce muscle mass → less muscle mass means less creatinine production → which can look like improved kidney function on labs, even if your kidneys haven't actually improved. We walk through whether this confound holds up in the data.
📊 Number Needed to Treat (NNT) — the stat based on ABSOLUTE risk reduction that keeps drug effects in perspective
🔬 Plaque measurements vs. clinical outcomes — why these are NOT the same thing
💰 Funding sources — who sponsored the trial and how to weigh that when reading the results
✅ A genuine surprise at the end — something the authors did that I didn't expect, and that actually matters for how much we can trust this data

If you're on a statin, managing ldl cholesterol, or trying to understand heart disease risk beyond what your doctor has five minutes to explain — this video is for you.

Watch the original video first: https://www.youtube.com/watch?v=Q2lvd9ND7rA

Sign up for more information on my own practice here: https://corsighthealth.com/

High Quality 3rd-party tested supplements at Fullscript (10% discount): https://us.fullscript.com/welcome/ljohnstonmd/store-start

Other tools for optimal health (note these are affiliate links):
Home BP Cuff: https://amzn.to/49Cq7rh
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Sleep Mask: https://amzn.to/48fSJV5
Air Purifier: https://amzn.to/4puzTQZ

___________________________
🧬 About Dr. Lily Johnston

Dr. Johnston is a double board-certified vascular and general surgeon in San Diego, specializing in metabolic and cardiovascular prevention. She’s the founder of CorSight Health and a passionate advocate for reimagining how medicine approaches chronic disease.

#MetabolicHealth #CardiovascularPrevention #HeartHealth #Longevity #InsulinResistance #DrLilyJohnston #DrLily #WomenInMedicine #Surgeon #VascularSurgeon #PreventiveMedicine #PADPrevention #HeartAttackRisks #HealthPortfolio #California #SanDiego #Arizona #Virginia #Minnesota

A common cholesterol drug might protect your brain from Alzheimer's — but I read the actual study, and there's a red flag nobody is talking about.

Nick Norwitz covered this story. I went further — I pulled the original paper published in Aging Biology and read every line. Here's what I found.Researchers ran a hypothesis-free screen of FDA-approved drugs to find compounds that could disrupt the 14-3-3/hexokinase protein interaction — a mechanism implicated in the protein aggregation that drives Alzheimer's disease and other dementias.

Six drugs emerged from the screen. Ezetimibe was one of them, and it stood out for one reason: it can cross the blood-brain barrier. That's where the excitement starts. But it's also where you need to slow down. Because buried in the study design, I found something that changes everything.

As a vascular surgeon who has spent years watching patients lose their brains — and their lives — to preventable disease, this is the kind of detail I can't ignore. It's exactly why I won't be prescribing this for dementia prevention in my practice.This video is for anyone who heard the ezetimibe-for-dementia claim and wanted the full picture — not the highlight reel.

Sign up for more information on my own practice here: https://corsighthealth.com/

High Quality 3rd-party tested supplements at Fullscript (10% discount): https://us.fullscript.com/welcome/ljohnstonmd/store-start

Other tools for optimal health (note these are affiliate links):
Home BP Cuff: https://amzn.to/49Cq7rh
Sonicare Toothbrush: https://amzn.to/3KllfMS
WaterPik: https://amzn.to/4894Xi8
Apple Watch with sleep & HR monitoring: https://amzn.to/3XaUn5d
Oura Ring with sleep, cycle, and recovery monitoring: https://amzn.to/4riyhLS
Intake Breathing Nasal Support: https://amzn.to/48dfQQ1
Personal Blender: https://amzn.to/4pyNGGl
True Nutrition Protein: https://oken.do/q2xzqeqw
Glass Meal Prep Containers: https://amzn.to/4ocEPJ2
Sleep Mask: https://amzn.to/48fSJV5
Air Purifier: https://amzn.to/4puzTQZ

___________________________
🧬 About Dr. Lily Johnston

Dr. Johnston is a double board-certified vascular and general surgeon in San Diego, specializing in metabolic and cardiovascular prevention. She’s the founder of CorSight Health and a passionate advocate for reimagining how medicine approaches chronic disease.

#MetabolicHealth #CardiovascularPrevention #HeartHealth #Longevity #InsulinResistance #DrLilyJohnston #DrLily #WomenInMedicine #Surgeon #VascularSurgeon #PreventiveMedicine #PADPrevention #HeartAttackRisks #HealthPortfolio #California #SanDiego #Arizona #Virginia #Minnesota