In a series of studies in the early 00s The Quebec Heart Health Study examined the small-dense and the large bouyant fraction of LDL cholesterol, and determined in their patients that the entire risk of LDL occurred in the segment of patients with small-dense LDL predominent. https://pubmed.ncbi.nlm.nih.gov/15618542/ You won't hear this today from the cardio-medical-statin complex, but it was taken very seriously at the time. Prior to this, the upper limit of normal for Triglycerides was 200. In light of this research, they lowered the normal level to 150, where it remains today. (I was treating patients with insulin resistance with ketogenic diet at the time and remember this change). The reason for the change: Triglycerides and LDL fraction are related, and it is when TG rise above 150 (the new normal) the liver begins to produce large amounts of sdLDL. On this basis they lowered normal TG to 150. Insulin is the elephant in the room as under conditions of hyperinsulinemia the liver begins to produce larger amounts of triglycerides and lower levels of HDL cholesterol. So the increase in sdLDL is a factor of hyperinsulinemia. SO ... if you see LDL elevated on a ketogenic diet, it is possible that it is not the dangerous type of LDL. This could be measured with certain lab tests. Another issue is that often LDL is not measured directly, but is calculated form the other lipids with this formula: Friedewald equation: LDL = Total cholesterol - HDL cholesterol - Triglycerides/5 So if you correct hyperinsulinemia, lower triglycerides (often a dramatic lowering on keto diet) then the calculated figure will make LDL go up. This is so common it is a normal result with correction of hyperinsulinemia and hypertriglyceridemia. Direct measurement of LDL is also available depending on the requesting physician.
Relevant to what Mike and I talked about in the pod:
"Increased low-density lipoprotein cholesterol on a low-carbohydrate diet in adults with normal but not high body weight: A meta-analysis"
https://www.sciencedirect.com/science/article/pii/S0002916524000091
Thanks for following up with this, Dr. Sharpe! Super relevant to many people in the general population who might want to try going keto.
In a series of studies in the early 00s The Quebec Heart Health Study examined the small-dense and the large bouyant fraction of LDL cholesterol, and determined in their patients that the entire risk of LDL occurred in the segment of patients with small-dense LDL predominent. https://pubmed.ncbi.nlm.nih.gov/15618542/ You won't hear this today from the cardio-medical-statin complex, but it was taken very seriously at the time. Prior to this, the upper limit of normal for Triglycerides was 200. In light of this research, they lowered the normal level to 150, where it remains today. (I was treating patients with insulin resistance with ketogenic diet at the time and remember this change). The reason for the change: Triglycerides and LDL fraction are related, and it is when TG rise above 150 (the new normal) the liver begins to produce large amounts of sdLDL. On this basis they lowered normal TG to 150. Insulin is the elephant in the room as under conditions of hyperinsulinemia the liver begins to produce larger amounts of triglycerides and lower levels of HDL cholesterol. So the increase in sdLDL is a factor of hyperinsulinemia. SO ... if you see LDL elevated on a ketogenic diet, it is possible that it is not the dangerous type of LDL. This could be measured with certain lab tests. Another issue is that often LDL is not measured directly, but is calculated form the other lipids with this formula: Friedewald equation: LDL = Total cholesterol - HDL cholesterol - Triglycerides/5 So if you correct hyperinsulinemia, lower triglycerides (often a dramatic lowering on keto diet) then the calculated figure will make LDL go up. This is so common it is a normal result with correction of hyperinsulinemia and hypertriglyceridemia. Direct measurement of LDL is also available depending on the requesting physician.