QUESTION: Is the avoid status of Coconut Oil for Type O Secretors (and other types for that matter) based on the high saturated fat content or the existence of a harmful lectin remaining in the processed (minimally for Joachim) oil. I just wanted to get this cleared up, and I don't think that it ever will until you give us a reason. Sorry, I know that sounds a bit cheeky, but all of this debate is driving me just a little batty.
ANSWER: The Traditional Argument Against Tropical Oils and Fats:
Plant oils do not contain much (if any) lauric acid. Lauryl - 12:0 - acylchains are common triglyceride (fat=oil) components of many seeds. Digestive lipases cleave the l2:0 ester to make the free fatty acid and mono- and di-glycerides.
Coconut oil contains lauryl acyl chains but the dominate acyl chain is palmitate -16:0. There are reports that 16:0 triglycerides detract from cardiovascular health.
A well-known equation by Keys is to estimate that each 1% of dietary calories in the form of palmitic acid raises serum total cholesterol by 2.7 mg/dl. Many other studies have consistently confirmed these figures. Keys' classic formula relates the effect of serum cholesterol and saturated and unsaturated fats:
d=delta (in essence, change); fchol= cholesterol in food.
d (chol)= 2.7d (sat) -1.3d (pufa) + 1.5d SQUARE ROOT(fchol)
However Keys reported that the use of certain fats, amongst them "coconut-butter", led to violation of his formula. He noticed that lauric acid c12:0, c14:0 and palmitic acid c16:0 lead to a significant increase in serum cholesterol. In 1985, Reiser found coconut oil to raise cholesterol levels at least as much as beef fat itself (about 21.6% of total calories). Of course, this is only one study but it may indicate that lauric acid under some circumstances may have a cholesterol raising effect.
So, lauryl acylchains may or may not be healthy. Palmitate is probably unhealthy. If palmitate is unhealthy (palm oil is 45% palmitate and coconut oil is about 8.5% palmitate) then relatively small concentration of lauryl acyl chains in coconut oil are likely to be of little benefit.
Although palm and coconut oil do not contain cholesterol, they are very high in saturated fat; because of this it is probable that they accelerate the cholesterol-raising properties of other foods that do contain cholesterol -a potential problem if you are type O and are using animal protein as a basis of your diet.
Saturated fat will increase serum cholesterol even if there is no cholesterol in the diet (as in a vegan diet). Most of the cholesterol in the blood is not cholesterol that has come from the diet, but rather is cholesterol which has been synthesized by the body. Evidence suggests that saturated fat has this effect because it causes a reduction in the rate that liver cells synthesize LDL receptors, which are molecules responsible for removal of cholesterol from the blood. Thus, a vegan diet that was high in coconut oil would be expected to significantly elevate serum cholesterol relative to a vegan diet without the coconut oil - a potential problem if you are type A (already with a genetic proclivity to elevated cholesterol) and are using a low fat strategy as a basis for your diet.
The Blood Type/ Lectin Argument:
Lauric acid has a reputation of possessing anti-viral activity, and had been studied against vesicular stomatitis virus, arenavirus and a few others. However virtually all studies have been in-vitro, using concentrations which if taken by mouth would certainly produce massive digestive upset. For this reason it has been used by many individuals with Chronic Fatigue Syndrome, though no studies exist that support the use of lauric acid against Epstein Barr virus or Herpes virus.
The same basis by which lauric acid gains anti-viral activity is also the mechanism by which it may promote additional sensitivity to dietary lectins. This phenomenon is called 'receptor capping.' In essence, similar charges tend to keep cell surface receptors (like the blood group antigens) uniformly spaced apart from each other. Since lauryl acyl chains act as a type of emollient/detergent on the cell wall (which is why they put it in soaps) they can disrupt the surface tension of the cell surface, thereby causing cell antigens to aggregate, potentially disrupting many cell-to-cell functions.
My advice: Keep the lauric acid in your soaps and shampoos and the coconut oil in your moisturizers.