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Kraken
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One big problem is this attempt to connect PUFAs to heart disease, the actual outcome evidence does not support it; in fact, it like strongly supports the opposite.
Replacement of SFAs with PUFAs has a consistent protective effect on CVD.
https://pubmed.ncbi.nlm.nih.gov/30019767/
This is likely due to a few different mechanisms, the first being that SFAs reliably increase blood LDL cholesterol levels and by default Apolipoprotein B (ApoB) which is thought to be a major factor contributing to atherosclerosis and CVD (more discussion on this later). Replacement of SFAs with PUFAs (particularly omega-3 PUFAs) has been shown to have a protective effect on CVD, likely by lowering LDL, ApoB, reducing inflammation, and various other proposed mechanisms.
This even holds true in a meta-analysis of CVD risk and linoleic acid intake.
https://pubmed.ncbi.nlm.nih.gov/32020162/
Omega 3 PUFAs do appear to reduce risk in RCTs.
While randomized controlled trials are the gold standard in research, we cannot neglect their limitations, especially when it comes to subject number and time duration. Compare this with the cohort studies on the effects of replacing SFA with PUFA that demonstrate quite a powerful protective effect of replacing SFA with PUFA that appears to be dose dependent.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6451787/
Further, even when specifically looking at omega 6 PUFAs there is a protective effect when replacing SFA with them.
In this cohort study, those with higher blood levels of omega 6 PUFAs had a 50% lower risk of a CVD incident during a 35 year follow up.
TLDR: All of this to bring it back to the topic that saturated fat supposedly is good for you while PUFAs are bad. There is no hard evidence to back this up. People attempt to draw a mechanistic link between PUFA oxidation and CVD while ignoring the fact that saturated fat has a much STRONGER mechanistic link to CVD, which is backed up by actual outcome data in humans. Meanwhile, we not only have mechanistic data showing saturated fat can damage the arterial wall, but we also have outcome data and MR data across multiple lines of evidence showing saturated fat and LDL are most likely causal for CVD. There is no evidence that I am aware of demonstrating that PUFAs are casual for CVD, and if anything, they likely have a protective effect.
@ChristianChad @RabidRosaries @Moggable @russiancel
Replacement of SFAs with PUFAs has a consistent protective effect on CVD.
https://pubmed.ncbi.nlm.nih.gov/30019767/
A systematic review of the effect of dietary saturated and polyunsaturated fat on heart disease - PubMed
Reducing saturated fat and replacing it with carbohydrate will not lower CHD events or CVD mortality although it will reduce total mortality. Replacing saturated fat with PUFA, MUFA or high-quality carbohydrate will lower CHD events.
pubmed.ncbi.nlm.nih.gov
This is likely due to a few different mechanisms, the first being that SFAs reliably increase blood LDL cholesterol levels and by default Apolipoprotein B (ApoB) which is thought to be a major factor contributing to atherosclerosis and CVD (more discussion on this later). Replacement of SFAs with PUFAs (particularly omega-3 PUFAs) has been shown to have a protective effect on CVD, likely by lowering LDL, ApoB, reducing inflammation, and various other proposed mechanisms.
This even holds true in a meta-analysis of CVD risk and linoleic acid intake.
https://pubmed.ncbi.nlm.nih.gov/32020162/
Dietary linoleic acid and risk of coronary heart disease: a systematic review and meta-analysis of prospective cohort studies - PubMed
In prospective observational studies, dietary LA intake is inversely associated with CHD risk in a dose-response manner. These data provide support for current recommendations to replace saturated fat with polyunsaturated fat for primary prevention of CHD.
pubmed.ncbi.nlm.nih.gov
Omega 3 PUFAs do appear to reduce risk in RCTs.
The effect of replacing saturated fat with mostly n-6 polyunsaturated fat on coronary heart disease: a meta-analysis of randomised controlled trials - PubMed
Available evidence from adequately controlled randomised controlled trials suggest replacing SFA with mostly n-6 PUFA is unlikely to reduce CHD events, CHD mortality or total mortality. The suggestion of benefits reported in earlier meta-analyses is due to the inclusion of inadequately...
pubmed.ncbi.nlm.nih.gov
The effect of replacing saturated fat with mostly n-6 polyunsaturated fat on coronary heart disease: a meta-analysis of randomised controlled trials - PubMed
Available evidence from adequately controlled randomised controlled trials suggest replacing SFA with mostly n-6 PUFA is unlikely to reduce CHD events, CHD mortality or total mortality. The suggestion of benefits reported in earlier meta-analyses is due to the inclusion of inadequately...
pubmed.ncbi.nlm.nih.gov
N-3 polyunsaturated fatty acids in coronary heart disease: a meta-analysis of randomized controlled trials - PubMed
This meta-analysis suggests that dietary and non-dietary intake of n-3 polyunsaturated fatty acids reduces overall mortality, mortality due to myocardial infarction, and sudden death in patients with coronary heart disease.
pubmed.ncbi.nlm.nih.gov
While randomized controlled trials are the gold standard in research, we cannot neglect their limitations, especially when it comes to subject number and time duration. Compare this with the cohort studies on the effects of replacing SFA with PUFA that demonstrate quite a powerful protective effect of replacing SFA with PUFA that appears to be dose dependent.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6451787/
Further, even when specifically looking at omega 6 PUFAs there is a protective effect when replacing SFA with them.
Association between Plasma N-6 Polyunsaturated Fatty Acids Levels and the Risk of Cardiovascular Disease in a Community-based Cohort Study - Scientific Reports
Most studies support that saturated fatty acid replacement with polyunsaturated fatty acids (PUFAs) may reduce the risk of cardiovascular diseases (CVDs) and put emphasis on the effects of N-3 PUFAs. The reported relationships between N-6 PUFAs and CVD risks vary. We aimed to examine the...
www.nature.com
TLDR: All of this to bring it back to the topic that saturated fat supposedly is good for you while PUFAs are bad. There is no hard evidence to back this up. People attempt to draw a mechanistic link between PUFA oxidation and CVD while ignoring the fact that saturated fat has a much STRONGER mechanistic link to CVD, which is backed up by actual outcome data in humans. Meanwhile, we not only have mechanistic data showing saturated fat can damage the arterial wall, but we also have outcome data and MR data across multiple lines of evidence showing saturated fat and LDL are most likely causal for CVD. There is no evidence that I am aware of demonstrating that PUFAs are casual for CVD, and if anything, they likely have a protective effect.
@ChristianChad @RabidRosaries @Moggable @russiancel
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