drdna wrote:Let us not forget that an increase in saturated fat is consistently associated with increased heart disease, regardless of cholesterol numbers. Time and again, the introduction of a Westernized diet high in saturated fats has led to the emergence of heart disease in populations of indigenous and native peoples.
This brings into serious question various diets like the Atkins Diet, the Paleo Diet (?), etc that promote a high fat carnivorous diet. These diets force weight loss through ketosis, but may not provide long term health benefits. As I said, retrospective studies on numerous populations have shown a strong correlation between fat intake and heart disease regardless of cholesterol measurements. Further, human dentition strongly suggests an omnivorous diet. If observation of indigenous peoples and non-human primate populations are any indication, humans likely evolved as scavengers and foragers not as carnivores. Beyond that, the earliest recorded history from 10,000 years ago basically documents agriculture. As whimsical as the idea of the caveman with a club hunting the wild mastodon might be, it seems the truth may be a bit less toothsome.
Population data studies paint a different picture (It's large, I won't reduce its size):
http://uploader.ws/upload/200908/satfat.pngWhat's an interesting visual is the confidence interval:
http://uploader.ws/upload/200908/satfat2.pngAnd since all the espresso geeks here love data curves:
All statistics done in MATLAB. I found that if I define
SF = % saturated fat intake
CHD = # heart deaths per year per 100,000 men
then
CHD = (-4.734 +/- 2.003)*SF + (144.5 +/- 21.4)
+/- errors are standard deviations (i.e. one sigma) with an R^2 = 0.13 (terrible) between the fit data and experimental data.
The plot I provided shows the baseline along with a top and bottom curve which are the 95 % confidence interval lines (~1.96 sigmas).
Although the statistics appear fairly poor, we can make one statement of interest. A positive slope is equivalent to a positive correlation between CHD and saturated fat (i.e. saturated fat bad!) and a negative slope is a negative correlation (i.e. saturated fat good!). Evaluating that statement using confidence intervals we have a 0.9 % chance of a positive slope and a 99.1 % chance that the slope is negative.
In other words, increased saturated fat intake is 99 % likely to be correlated with decreased incidence of death from heart disease.
As it's understood now inflammation, specifically high levels of C reactive protein, is a better indicator of heart disease risk. The work of Dr. Paul Ridker (and others) can be thanked for bringing this to the forefront:
Dr. Ridker wrote:These data suggest that the C-reactive protein level is a stronger predictor of cardiovascular events than the LDL cholesterol level and that it adds prognostic information to that conveyed by the Framingham risk score.
Which isn't to say LDL shouldn't be watched, but the tiny oxidized LDL is the "bad" lipoprotein while the big fluffy LDL are just doing their job: taking cholesterol to the cells that need it. Unfortunately a simple blood panel doesn't show us which is which.
You made a point speaking of indigenous populations being introduced to a western diet and seeing rates of heart disease (and just about every other disease increase). However, a western diet, specifically our diet, isn't just high in sat fats. It's high in junk: Omega 6 fatty acids and high GI carbs in abundance. Both have been demonstrated to dramatically increase systemic inflammation. Couple that with chronic stress than many westerners have and you have a recipe for a high chronic inflammation soup...the perfect environment for heart disease. We try to reduce it to just diet when of course it's not that simple. We're also the nation of the magic bullet, so asking a person to change their diet
and reduce their stress
and get more exercise...doc, just give me a pill!
I do, however, feel most people would be served moving to a Paleo diet if only for one thing: real food. Nothing processed, nothing boxed, just shopping the outer rim of the grocery store. Real food. The romanticism is inaccurate at best; the only thing in common is the real food aspect.
One more thing about indigenous populations: they often consume high levels of saturated fats. In fact the the Masai consume massive amounts (~33% of their calories come from saturated fat) and the Tokelau consume even more (Tokelauans traditionally obtained 40-50% of their calories from saturated fat, in the form of coconut meat.) Rather than try to condense, you can read all about it here:
http://wholehealthsource.blogspot.com/2 ... round.htmlHOWEVER, this is all a detour, albeit one I quite enjoyed! My original point is that getting mired in minutia, namely worrying about a compound that can raise cholesterol levels in humans though is poorly reproduceable in studies, will only raise your stress, increase your inflammation and give you a heart attack!
by Grant on Wed Aug 12, 2009 12:20 am 
Not sure how I messed up with the quote-referencing thing. I meant to reference sbien--no offense intended! I certainly hope it didn't come across as a rant, either-I intended it as a slight point of clarification, that's all.
