Ron Cooper

🚨 Your cholesterol number on one random Tuesday morning means almost nothing. What actually kills you is 40 years of apoB particles parking in your artery wall. The question is no longer "what is my cholesterol." The question is "how long has it been too high." And no, this is not just about diet. It is about a system most people never learn. I am a cardiologist. I have patients who came to me at 45 with "normal" labs and a calcium score of 400. That number did not happen that year. It happened over decades. 🩺 Here is what the science actually says. Your body absorbs cholesterol from two sources. Bile contributes 75% to 85% of what gets absorbed. Diet only contributes 15% to 25%. This is why "I stopped eating eggs" rarely moves the needle the way people expect. 🔬 The mechanism. NPC1L1 pulls cholesterol into intestinal cells. ABCG5 and ABCG8 pump the excess back out. About 20% of people hyperabsorb cholesterol because this efflux system underperforms. We detect this indirectly through plasma phytosterols like sitosterol and campesterol. 🫀 This matters because LDL particles are not peripheral delivery trucks. LDL's main job is returning cholesterol to the liver. Not delivering it to your tissues. That old model is outdated. 💓 The numbers that actually define risk: ✅ LDL particles make up 90% to 95% of circulating apoB particles. ✅ LDL carries about 2500 cholesterol molecules per particle. VLDL carries about 4000. HDL carries only 45. ✅ About 40% of LDL particles are secreted directly by the liver. The other 60% come from VLDL lipolysis. These figures shift with your triglyceride levels. ❌ Your HDL-C number does not reflect how well HDL is functioning. There is no reliable correlation. ❌ Plasma LDL does not touch your brain. Your brain makes 100% of its own cholesterol, with a turnover half-life around 5 years. Lowering your LDL will not starve your brain. That fear is not supported by the biology. ❤️ Bottom line: Atherosclerosis is not triggered by a single bad lab draw. It is driven by apoB particles crossing a retention threshold in your arterial wall and sitting there for years to decades. A patient who gets apoB checked at 25 instead of 45 can start intervention 20 years earlier. That is the difference between a stent at 55 and a normal stress test at 75. Waiting until 40 to deal with high apoB may already be too late for the plaque that already formed. For hyperabsorbers specifically, ezetimibe is my preferred first move. It targets NPC1L1 directly, where their defect actually lives. The tools that change this are not mysterious. They are early testing, honest numbers, and treating apoB as a lifelong exposure, not a yearly snapshot. How long has your apoB actually been elevated. Do you even know. #Cardiology #HeartDisease #HeartHealth #CardiovascularHealth #ApoB #LDL #Cholesterol #Ezetimibe #PreventiveCardiology #LifestyleMedicine

🚨 LDL particles make up 90 to 95% of circulating apoB particles, and they are not sitting in your blood for a day. They are circulating for years, getting retained in your artery wall every single time they pass through. Your cholesterol number at age 40 is not the problem. The cumulative exposure since age 20 is. But the data says otherwise than what most people believe about a single lab draw. And no, LDL is not just a delivery truck dropping cholesterol off to your tissues. That is not its main job. I am a cardiologist. I have hundreds of patients on lipid-lowering therapy, and I walk every one of them through exactly how this system works before I prescribe anything. 🔬 Here is what the science actually says. 🫀 Your body absorbs cholesterol two ways. 75 to 85% comes from bile your liver already made. Only 15 to 25% comes from the food on your plate. 🩺 About 20% of people are hyperabsorbers. Their intestine pulls in more cholesterol than normal through a transporter called NPC1L1, and a second transporter called ABCG5/G8 cannot pump enough of it back out. 🔸 For these patients, cutting dietary cholesterol barely moves the needle. Ezetimibe, which blocks NPC1L1 directly, is the preferred drug because it targets the actual mechanism. 💓 Once absorbed, cholesterol and fat get packaged into chylomicrons, broken down by an enzyme called LPL, and cleared by the liver. 🫀 About 40% of your LDL particles are secreted directly by the liver. The other 60% come from VLDL after lipolysis. That ratio shifts with your triglyceride levels. 🔬 LDL particles are small but cholesterol-dense, carrying roughly 2500 cholesterol molecules each. HDL particles carry only about 45. That is why LDL and VLDL drive plaque risk and HDL-C levels do not reliably predict anything on their own. ❌ A normal HDL number does not mean your reverse cholesterol transport is working. There is no reliable correlation between HDL-C level and HDL function. ❌ Your brain is not affected by any of this. It makes 100% of its own cholesterol, with a half-life around 5 years, completely independent of what is happening in your bloodstream. ✅ The real driver of atherosclerosis is apoB particle concentration crossing a retention threshold in your artery wall, repeated over years to decades. "A patient who starts lowering apoB at age 25 instead of 45 can prevent decades of arterial wall retention before it ever shows up on a calcium score." "That is the difference between a clean angiogram at 60 and a stent at 50." ❤️ Bottom line: It is not your cholesterol number today. It is every year of exposure before today. This is backed by decades of outcomes trial data on apoB-lowering therapy, not a single snapshot test. Get your apoB checked, not just LDL-C. If you hyperabsorb, ask about ezetimibe specifically. Start managing this in your 20s and 30s, not after a cardiac event forces the conversation. The question is no longer whether your LDL is high. The question is how long it has been high. #Cardiology #HeartDisease #HeartHealth #CardiovascularHealth #ApoB #Cholesterol #Ezetimibe #Atherosclerosis #PreventiveCardiology #LifestyleMedicine