In this episode of The Metabolic Classroom, Dr. Ben Bikman challenges the traditional view that saturated fats are the primary cause of atherosclerotic plaques and heart disease. He asserts that while plaques, or atheromas, in coronary arteries are composed partly of fats and foam cells, the exact process of plaque formation remains speculative. Dr. Bikman emphasizes that anyone claiming to know the definitive cause of plaque formation is likely overstating their knowledge. Foam cells, which are fat-laden macrophages, play a critical role in plaque development and are consistently present at the sites of these plaques.
Dr. Bikman explains that inflammation is a significant factor in atherosclerosis, and C-reactive protein (CRP), a marker of inflammation, is a better predictor of heart disease than LDL cholesterol. He describes how macrophages engulf oxidized LDL cholesterol, turning into foam cells and secreting pro-inflammatory proteins like CRP. This process is driven by the presence of oxidized lipids, particularly those derived from omega-6 polyunsaturated fats such as linoleic acid, which are prevalent in modern diets due to the widespread use of vegetable oils.
Ben highlights several studies to support his argument. A notable study from 1979 by Brown and Goldstein showed that macrophages only consume LDL cholesterol when it is oxidized, not in its native form. Another study from 1998 found that oxidized LDL containing specific bioactive lipids, nine and 13 HODE, is particularly problematic. These oxidized lipids are derived from linoleic acid, not from saturated or monounsaturated fats. Moreover, historical dietary studies, such as the Minnesota Coronary Experiment and the Sydney Diet Heart Study, revealed that participants consuming more polyunsaturated fats had higher mortality rates than those consuming saturated fats.
To conclude, Dr. Bikman argues that the traditional belief that saturated fat causes heart disease is flawed. He points out that recent studies, including a correlational study published in the British Medical Journal, show that refined grains, not saturated fats, are more strongly linked to heart disease and overall mortality. He suggests that the real dietary culprit is the overconsumption of omega-6 polyunsaturated fats, particularly linoleic acid, found in processed foods. This shift in perspective underscores the importance of reevaluating dietary guidelines and focusing on the types of fats consumed.
00:18 - Challenging Traditional Views on Saturated Fats
01:26 - Uncertainty About Plaque Formation
02:22 - Inflammation and Heart Disease Predictors
03:23 - Foam Cells and Macrophages
04:37 - Brown and Goldstein's 1979 Study
06:51 - Role of Oxidized Lipids in Atherosclerosis
08:51 - 1998 Study on Hydroxy Fatty Acids
11:19 - Ramsden’s 2012 Study
13:23 - Reanalysis of Old Dietary Studies
15:27 - Correlation Studies and Refined Grains
16:25 - Rethinking Dietary Fats
#HeartHealth #SaturatedFat #Atherosclerosis #Inflammation #InsulinResistance #LDLCholesterol #OxidizedLDL #FoamCells #Macrophages #BenBikman #MetabolicHealth #CholesterolMyths #LinoleicAcid #PolyunsaturatedFats #DietaryFats #CardiovascularResearch
Studies referenced:
Binding Site on Macrophages that Mediates Uptake in Degradation by Brown and Goldstein (1979): academic.oup.com/clinchem/art...
Oxidized LDL Regulates Macrophage Gene Expression (1998): You can find more details on this study in resources like ScienceDirect and Cell Journal (you may need specific access or subscriptions to retrieve full texts).
Strong Increase in Hydroxy Fatty Acids Derived from Linoleic Acid in Human Low-Density Lipoproteins of Atherosclerotic Patients (1998): www.sciencegate.app/document/...
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19 май 2024
