A little something I found lurking in my documents. From Dr. Steven Joyal:
"So what about saturated fats ? How does myristic, palmitic, or stearic acid affect lipid metabolism ? Are all saturated fats bad for us or increase total cholesterol and/or LDL levels?
Well, there’s evidence to suggest that stearic acid is neutral compared to both myristic and palmitic acid in terms of elevating cholesterol; e.g., serum total, esterified and LDL cholesterol were all significantly lower depending on which of these fatty acids are ingested. There are a number of interesting studies in the literature that support this data. One such study supplemented subjects’ diets with synthetic forms of different saturated fatty acids to determine the effects on serum cholesterol (Snook JT; Park S; Williams G; Tsai Y-H; Lee N. Effect of synthetic triglycerides of myristic, palmitic, and stearic acid on serum lipoprotein metabolism. Eur J Clin Nutr 1999 Aug;53(8):597-605)
In fact, stearic acid is poorly incorporated into VLDL as compared to palmitic or myristic acid(s), and is even poorly incorporated as compared to oleic acid ! (Pai T; Yeh YY.
Stearic acid modifies very low density lipoprotein lipid composition and particle size differently from shorter-chain saturated fatty acids in cultured rat hepatocytes. Lipids 1997 Feb;32(2))
The bottom line : the major cholesterol-raising saturated fatty acid in the diet is palmitic acid, and, in fact, there is evidence to suggest that stearic acid is quickly converted into a mono-unsaturated fatty acid in vivo, and thus, the real culprit in terms of saturated fatty acids and their respective negative effects on cholesterol are due to
palmitic acid, and not stearic acid.(Grundy SM, Denke MA. Dietary influences on serum lipids and lipoproteins. J Lipid Res 1990 Jul;31(7):1149-72)
[Editors Note: Guess which fat the body produces from excess carbohydrates? If you guessed palmitate, you go to the head of the class! The reason why the high carb low fat studies above found negative blood lipid changes from higher carb intakes as opposed to lower carb moderate fat intakes?]
In addition, the media has blitzed the public at large about the “evils” of saturated fats in the diet . However, there is epidemiological evidence to support that if saturated fats were significantly reduced from the diet (8-10% saturated fat diet), this change would only increase life expectancy by several months! (Grover SA, et al. Life expectancy following dietary modification or smoking cessation. Estimating the benefits of a prudent lifestyle. Arch Intern Med. 1994 Aug 8;154(15):1697-704). Considering how vilified the
media and other groups have made saturated fats over the past few decades, this is not very impressive to say the least.
So, what does it all mean ?
Don’t fall for the hype from the mega-carb gurus who view all fats as an evil enemy sure to ruin your health. It is simply not true and is far more complex than the high carb low fat gurus want us to believe."