I'm suppose to be reading up on Sex-Hormone Binding Globulin today (exciting! ) but I'm going to take a nice break to write the definitive guide saturated fat.
It keeps coming up over and over again on the forum so I thought I'd put this thread here so we can refer back to it to stop re-inventing the wheel.
These group of fats are referred to as 'saturated' as every carbon molecule in the 'chain' of fatty acids has an attached hydrogen molecule. This makes for the most 'stable' chemical structure as in the least likely to react with any other chemicals.
This non-reactivity is a good thing as most of the threats that our body uses its resources fighting is created by oxidisation, as in oxygen reacting to another substance. This is why anti-oxidants have such a good reputation. Though it must be said some oxidation is appropriate and contributes to a healthy metabolism, as it promotes an adaptive response such as after exercise. But generally speaking we want to keep oxidisation intermittent and brief.
But, doesn't saturated fat raise LDL or cholesterol, the 'bad' cholesterol? Well that's not actually established, most of the trials are short-term (<12 weeks), low-quality and the results are all over the place, some show slight reductions from reducing saturated fat but they are usually poorly controlled, as in they don't take into account what they are replacing the saturated fat with and how that effected cholesterol level. In the longer term trials the association pretty much disappears when other factors are controlled for (like smoking and obesity.).
Saturated fat does consistently and reliably raise HDL cholesterol however, and unless you're crazily out of range, indicative of a serious infection, the higher the better.
Risk of Heart Disease
But even if saturated fat doesn't adversely affect cholesterol, it's still really associated with getting a heart attack though right? I mean arterycloggingsaturatedfat is almost one word it's been drilled into us so often.
Well, again the science just doesn't back this up. If you look at observational studies you'll find some studies showing that people who go heavy on the butter and bacon tend to die of more heart attacks. But the problem with these kinds of studies is that you cannot infer a causal relationship from an retrospective observational study because the 'experiment' has been tainted.
An example: Lets pretend 20 years ago we decide that people that wear more yellow clothes have less heart disease. All the health-conscious people listen to their doctors and start wearing yellow shirts, along with doing thousands of other things that health-conscious people tend to do either unconsciously or consciously (exercise, no smoking, less fast food) that can't be fully accounted for by mathematically controlling the statistics. Lo and behold a few decades later it's as clear as day that people who wear yellow clothes have less heart attacks!
If you think the above example is completely silly then think how silly it is that even the observational evidence from the last few decades is not consistent the theory. The totality of the studies of this nature don't even support an association with an increase in heart disease even though we've been told to lay off the cream and butter for decades now.
The best version of an observational study is a prospective cohort study, this is where rather than asking people to remember what they were eating ten years ago, you ask them what they eat now and at regular intervals and follow their progress for a number of years. Although still far from perfect, these kind of studies minimise 'recall' bias or the bias we all have in remembering what we eat.
There have been 25 prospective studies done examining the relationship between heart-disease and saturated fat and only four of them managed to find any relationship whatsoever. If there was a real danger from eating saturated fat, we would see a far more consistent relationship, especially considering how healthy people in general tend to avoid it based on public health recommendations.
This recent meta-analysis by Krauss et al. is the most comprehensive review of it's nature:
Background: A reduction in dietary saturated fat has generally been thought to improve cardiovascular health.
Objective: The objective of this meta-analysis was to summarize the evidence related to the association of dietary saturated fat with risk of coronary heart disease (CHD), stroke, and cardiovascular disease (CVD; CHD inclusive of stroke) in prospective epidemiologic studies.
Design: Twenty-one studies identified by searching MEDLINE and EMBASE databases and secondary referencing qualified for inclusion in this study. A random-effects model was used to derive composite relative risk estimates for CHD, stroke, and CVD.
Results: During 5–23 y of follow-up of 347,747 subjects, 11,006 developed CHD or stroke. Intake of saturated fat was not associated with an increased risk of CHD, stroke, or CVD. The pooled relative risk estimates that compared extreme quantiles of saturated fat intake were 1.07 (95% CI: 0.96, 1.19; P = 0.22) for CHD, 0.81 (95% CI: 0.62, 1.05; P = 0.11) for stroke, and 1.00 (95% CI: 0.89, 1.11; P = 0.95) for CVD. Consideration of age, sex, and study quality did not change the results.
Conclusions: A meta-analysis of prospective epidemiologic studies showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD. More data are needed to elucidate whether CVD risks are likely to be influenced by the specific nutrients used to replace saturated fat.
-Increases testosterone in men
-Reduces Lp(a) (this stuff correlates with heart disease and stroke like no other biomarker out there, it's the most potent risk factor by a mile.)
-Aids the clearance of excess fat from the liver (this is why a lot of people find their cholesterol jumps up on a weight loss diet, that's your body ridding itself of visceral liver fat and it is only temporary)
-Sat fat will also protect your liver from the damage inflicted by alcohol and certain medications.
The tide is turning, albeit at the speed of a fatigued snail. I don't believe most doctors today have taken their own honest appraisal of the literature. If they have and still believe that the same substance that your body will use to store energy is somehow out to get us, then they've seen evidence I don't have access to.
Oh and by the by, I got a cholesterol test done recently for the laugh (I'm a 28 year old woman so barring something genetic my risk of a heart attack is next to zero anyway):
Total: 4.0 (Healthy range 3.0 - 4.0)
LDL: 1.4 (Healthy < 3.0)
HDL: 1.8 (Health > 1.0) My doctor was shocked with how high my HDL was and asked me what my secret was, she almost fell off her chair when I said 'butter'.
Triglycerides: 0.6 (Healthy < 1.0)
I'm not even saying that all of the above is even relevant to my heart disease risk but it goes to show even by conventional measurements a high saturated fat diet has proved beneficial for me.
If I've left anything out please do let me know, I wouldn't want to be accused of cherry-picking anything. There are soooo many crap studies in this area that if I were to name them all I'd be writing a small thesis, and I've already got one of those going on at the moment. But chances are I have come across any study you care to mention in this arena, so don't hold back, come at me bro! I'd love this thread to become a large repository for addressing any concerns in this area.