Brain Health Q&A: ApoB, APOE2, pTau217 & More

Got APOE4? A Vascular Surgeon’s EXACT Plan to Protect Your Brain

Got APOE4? Here’s the exact prevention strategy I would use to protect my own brain if I carried this gene. In this video, I walk through the major modifiable dementia risk factors identified by the Lancet Commission — and how I would actually approach them in real life as a vascular surgeon specializing in cardiometabolic prevention. We cover: * ApoB, vascular disease, and why “brain health” starts in the arteries * What you can do NOW without any clinical support * Blood pressure, insulin resistance, exercise, sleep, and inflammation * Hearing loss, social isolation, alcohol, smoking, and other overlooked dementia risks * Which interventions matter most * How I prioritize prevention clinically * What people with APOE4 often misunderstand about risk ⏰ Chapters: 0:00 Almost Half of Dementia Cases May Be Preventable 0:24 APOE4 Is Not Fate 0:53 Why a Vascular Surgeon Cares About Dementia 2:05 Meet “Carol”: APOE4, Family History, and Fear 3:11 The Lancet Commission’s 14 Modifiable Risk Factors 5:29 Why APOE4 Carriers Still Have Real Hope 6:48 What You Can Start Doing Without a Prescription 7:08 Exercise: The Biggest Lever for Brain Health 8:49 The 4 Exercise Buckets I Recommend 11:56 How to Eat for an APOE4 Brain 16:49 Why I’d Keep Alcohol Near Zero 19:16 Loneliness, Social Connection, and Dementia Risk 21:29 When to Bring Your Doctor Into the Plan 22:11 Make Your Lipids Boring 24:47 Obicetrapib, pTau217, and New Alzheimer’s Biomarkers 29:58 Blood Pressure and APOE4 Risk 32:06 Sleep, Sleep Apnea, and the Brain’s Cleaning System 33:54 Insulin Resistance Is a Brain Problem 36:54 Hearing Loss and Cognitive Decline 38:39 The Shingles Vaccine Dementia Data 41:23 Bonus: Hormones, Homocysteine, and Dental Health 45:37 Why Supplements Are Part 3 APOE4 is NOT destiny. But it is a signal to get serious earlier, and there's so much you can do TODAY to head in the right direction. Missed Part 1? Check it out here:  https://youtu.be/y8vkJE_Zy7A 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. Disclaimer: This video is for educational purposes only and does not constitute medical advice or establish a doctor-patient relationship.

Brain Health Q&A: ApoB, APOE2, pTau217 & More

What's the optimal ApoB level to reduce Alzheimer’s risk? Is lifestyle or genetics more important? And what does a pTau217 result actually mean for your brain health? In this Brain Health Q&A, I answer your questions about ApoB, APOE2, dementia prevention, blood-based biomarkers, and what the science actually says right now. Missed the first video? Check it out here: https://youtu.be/y8vkJE_Zy7A Topics include: • How low I think ApoB should ideally be for brain health (and what matters more!) • How to think about lifestyle vs genetic risk like APOE4 • What current guidelines recommend for pTau217 and its limitations • What I’d personally focus on for long-term brain protection (and teasers for our upcoming videos in the series) As a vascular surgeon specializing in cardiometabolic prevention, I spent years treating the downstream consequences of vascular disease after the damage was already done. Brain health is no different. Prevention matters most before symptoms start. The brain is not magically separate from the rest of the body. Blood vessels, inflammation, metabolic health, sleep, exercise, and genetics all interact over decades. So let’s talk about how to think about that risk honestly — and practically. 👇 Drop your questions in the comments for the next Q&A. 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

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