Knife Down

Half of Alzheimer's Patients Carry APOE4 - You Don't Have to Be One of Them

If you've been told APOE4 means you're destined for Alzheimer's, the science says something very different. As a vascular surgeon who has spent years treating the end-stages of preventable disease, I want to give you a clearer picture of what APOE4 actually does, and what it doesn't. In this video, I break down: - What the APOE4 gene is and how it affects your brain - Why it raises Alzheimer's risk — but doesn't guarantee it - The surprising evolutionary reason APOE4 exists in the first place - What the science actually says about Alzheimer's prevention if you carry the allele APOE4 is the most significant genetic risk factor for late-onset Alzheimer's. But risk is not destiny. Understanding the biology gives you real options — and that's exactly what this channel is about. 🔔 Subscribe for evidence-based prevention medicine — straight from the OR to your screen. 📩 Questions? Leave them below — I read everything. I advise you to go through your clinician for testing. But if you want to do it on your own, you can order it here: https://www.ultalabtests.com/partners/lilyjohnstonmd/test/cardio-iq-apoe-genotype-test Chapters: 0:00 APOE4 is not fate 0:24 What ApoE does in the brain 1:54 ApoE2, ApoE3, and ApoE4 explained 3:22 How APOE4 became linked to Alzheimer’s 4:23 How much APOE4 raises risk 5:37 Why APOE4 does not guarantee Alzheimer’s 6:50 What APOE4 is actually doing 9:46 Amyloid, lipid trafficking, and brain fuel 11:07 Why does APOE4 still exist? 11:29 APOE4 is the original gene 14:51 APOE4 as an immune-modulator gene 17:05 Ancient immune system, modern environment 19:03 The blood-brain barrier feedback loop 20:02 Same gene, different environment 21:36 The gene is fixed, but the provocation isn’t 22:55 What we’ll cover in Part 2 23:40 Should you test for APOE4? 25:04 Knowing turns fate into a head start This content is for educational purposes only and does not constitute medical advice. Always consult your physician. 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

Can Low LDL Cause Dementia? Your Questions Answered

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/ 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

LDL Study Q&A: kidney damage, NNT, and funding sources

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 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

Is Ezetimibe the Secret to Preventing Dementia? Surgeon Reacts to Nick Norwitz MDPhD

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

Is Lower LDL Actually Better? New Research Has an Answer

Is lower LDL cholesterol actually better for your heart? In this video, I break down the brand-new results from the EZ-Pave study to answer the question that keeps my patients up at night: How low should your cholesterol really go?  As a vascular surgeon, I see the end-stage results of heart disease every day.  We’ve heard the "lower is better" mantra for decades, but new research is finally providing the hard evidence we need to settle the debate.  Study link: https://www.nejm.org/doi/full/10.1056/NEJMoa2600283  We’re looking at how LDL cholesterol levels impact actual cardiovascular events and whether adding medications like ezetimibe truly changes the outcome for your heart health. If you’ve been skeptical about statins or confused by conflicting health trends, this breakdown of the latest science is for you. My mission is to put myself out of business by giving you the truth about prevention before you ever need to see me in the operating room.  For educational purposes only. Not medical advice. Always consult your healthcare provider before changing any treatment plan.  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