Knife Down
"Knife Down" is what a surgeon says in the OR when she puts her scalpel down so no one gets hurt — and it’s the mission here: put the knife down, long before anyone needs to use it.
Knife Down is a podcast about how to actually invest in your health so you can live longer, stronger, and with less time in doctors’ offices. The core focus is the world’s leading cause of death—cardiovascular disease—and what to do about it before it shows up as a catastrophe.
Hosted by a vascular surgeon on a mission to put herself out of business, the show translates cutting-edge science on prevention, metabolic health, and longevity into real-world strategies you can use in clinic or at your kitchen table. Expect evidence, nuance, and zero wellness hype—plus the occasional dark joke about the state of modern medicine.
Knife Down
1 in 5 People Have This — And Most Never Get Tested
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Lp(a) Explained: The Genetic Cholesterol Most Doctors Don’t Check (And Why It Matters)
You can be fit, lift heavy, eat “clean,” and still have a hidden cardiovascular risk most standard cholesterol tests miss.
In this video, I break down lipoprotein(a), or Lp(a) — a genetically determined cholesterol particle that quietly raises the risk of heart attack, stroke, peripheral artery disease, and calcific aortic valve stenosis, even in people who look metabolically healthy.
You’ll learn:
• What Lp(a) actually is (and why it’s different from LDL)
• Why 1 in 5 people have elevated Lp(a) and don’t know it
• How to read your own Lp(a) lab result (mg/dL vs nmol/L)
• The green / yellow / red risk zones most guidelines now agree on
• How much Lp(a) really increases cardiovascular risk (with real numbers)
• Who should absolutely get tested — and why this is usually a once-in-a-lifetime lab
• Why Lp(a) is linked to early plaque and aortic stenosis
We start with the story of Bob Harper (The Biggest Loser trainer) — lean, athletic, doing everything “right” — who suffered a sudden cardiac arrest caused in part by undiagnosed high Lp(a). His story highlights why this particle matters even when everything else looks fine.
This is Part 1 of a series.
In Part 2 (dropping next week) we’ll cover:
• How metabolic health and fat distribution change Lp(a) risk
• Why statins can still be lifesaving even if Lp(a) nudges up
• How hormone therapy affects Lp(a) in post-menopausal women
• The new Lp(a)-lowering drugs in trials that reduce levels by 80–95%
⚠️ Important disclaimer:
This video is for education only and is not personal medical advice. Always review results and decisions with your own medical team.
👇 Your homework after this video:
• Check whether you’ve ever had Lp(a) measured
• If you have, see which risk zone you’re in. If you're high, talk to your family and get them screened too!
• If you haven’t — and you have family history, plaque, or unexplained risk — ask about it
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Want to get your labs checked without going through your doctor's office? Check out the options below where you can order your own tests, including everything we discussed in the video above! Just order your labs, checkout online, then go to a collection center (Ulta uses Quest, Own Your Labs uses LabCorp). If you have limited time or transportation, several companies including Ulta offer MOBILE phlebotomy where the lab comes to you in your home or office!
https://www.ultalabtests.com/partners/lilyjohnstonmd
https://ownyourlabs.com/
Sign up for more information on my own practice here: https://corsighthealth.com/
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Sleep Mask: https://amzn.to/48fSJV5
Air Purifier: https://amzn.to/4puzTQZ
Buy me a coffee: https://buymeacoffee.com/lilyjohnstonmd
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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 #InsulinResista