Hmm. Maybe fat's not so much the point as is reducing the amount of animal products? "Low Fat" is the recommendation for ApoE4, even from guys like William Davis. This sounds like an amount of fat I could easily live with; I guess you go through a lot of olive oil. (If so, there's certainly good epidemiology on that.) Anyway, if it turns out that the real killer for ApoE4 is low animal products, that is a hell of a good discovery. One question I have that someone here may know the answer to is: Do conventional lipid markers mean the same thing if you are ApoE4? That is, would the typical ApoE4 person just have terrible markers, or be more likely to have CVD or Alzheimer's than someone who was ApoE3 with the same markers?
It is pretty convincing that ApoE4 responds poorly to saturated fats compared to E3 or E2, and E4/E4 even more so than E3/E4. Likewise with cholesterol, as ApoE4 has much more efficient intestinal cholesterol absorption with much lower hepatic production. This is one of them main reasons ApoE4 subjects have greater diet-induced lipid changes, but poorer statin responses, compared to E3 or E2. Low fat may indeed be more beneficial in general, or more specifically for ApoE4, but then we'd have to figure out how low to go in order to maximize benefit. We'd also have to determine to what extent the benefit is reduced cholesterol and saturated fat, or total fat. There is evidence to suggest ApoE4 don't just have poor lipid markers, but actually do have a greater pathogenic response. IMO, If ever the lipid hypothesis were true, it would be most evident in ApoE4. I follow a lot of Michael Rae's reasoning and his wealth of posted references regarding diet and lipids. In this regard I believe *quality* olive oil is beneficial for it's ability to reduce
in vivo lipid oxidation, and there's enough epidemiology and other trials to suggest it's either positive or neutral per se. Then again, some stuff by Rudel has me thinking that excess MUFA isn't completely neutral. For example:
Arterioscler Thromb Vasc Biol.
1995 Dec;15(12):2101-10.
Compared with dietary monounsaturated and saturated fat, polyunsaturated fat protects African green monkeys from coronary artery atherosclerosis.
Rudel LL, Parks JS, Sawyer JK.
Source
Department of Comparative Medicine, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, NC 27157-1040, USA.
Abstract
Atherogenic diets enriched in saturated, n-6 polyunsaturated, and monounsaturated fatty acids were fed to African green monkeys for 5 years to define effects on plasma lipoproteins and coronary artery atherosclerosis. The monkeys fed polyunsaturated and monounsaturated fat had similar plasma concentrations of LDL cholesterol, and these values were significantly lower than for LDL in the animals fed saturated fat. Plasma HDL cholesterol concentrations were comparable in animals fed saturated and monounsaturated fat and were significantly higher than in animals fed polyunsaturated fat. Thus, the monounsaturated fat group had the lowest LDL/HDL ratio. LDL particle size was largest in the saturated and monounsaturated fat groups, significantly larger than in the polyunsaturated fat group. LDL particle enrichment with cholesteryl oleate was the greatest in the animals fed monounsaturated fat, next greatest in the saturated fat-fed animals, and was least in the polyunsaturated fat-fed animals. Coronary artery atherosclerosis as measured by intimal area was less in the polyunsaturated fat compared with the saturated fat groups, was less in the animals fed polyunsaturated fat compared with the monounsaturated fat-fed animals, but did not differ between the monounsaturated and saturated fat groups. Cholesteryl ester, particularly cholesteryl oleate, accumulation in the coronary arteries was also similar between groups fed monounsaturated and saturated fat but was minimal in the animals fed polyunsaturated fat. In sum, the monkeys fed monounsaturated fat developed equivalent amounts of coronary artery atherosclerosis as those fed saturated fat, but monkeys fed polyunsaturated fat developed less. The beneficial effects of the lower LDL and higher HDL in the animals fed monounsaturated fat apparently were offset by the atherogenic shifts in LDL particle composition. Dietary polyunsaturated fat appears to result in the least amount of coronary artery atherosclerosis because it prevents cholesteryl oleate accumulation in LDL and the coronary arteries in these primates.
PMID: 7489230
Curr Atheroscler Rep.
2010 Nov;12(6):391-6.
Dietary monounsaturated fatty acids appear not to provide cardioprotection.
Degirolamo C, Rudel LL.
Source
Department of Translational Pharmacology, Consorzio Mario Negri Sud, via Nazionale 8/A, 66030, S. Maria Imbaro, CH, Italy. degirolamo@negrisud.it
Abstract
Dietary interventions have been consistently proposed as a part of a comprehensive strategy to lower the incidence and severity of coronary heart disease (CHD), in the process providing long-term cardioprotection. Replacement of dietary saturated fatty acids (SFA) with higher intakes of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) has been reported to be inversely associated with risk of CHD. The observed lower incidence of CHD among populations consuming a Mediterranean-type diet, mainly enriched in MUFA from olive oil, has long supported the belief that MUFA are an optimal substitution for SFA. However, both epidemiologic and interventional studies suggest that although substituting MUFA-rich foods for SFA-rich foods in the diet can potentially lower total plasma cholesterol concentrations, this substitution does not lower the extent of coronary artery atherosclerosis. In addition, although recent evidence suggests that the source of MUFA (animal fat vs vegetable oils) may differentially influence the correlation between MUFA intake and CHD mortality, animal studies suggest that neither source is cardioprotective.
PMID: 20725810
I figure that I need to get enough fat to buffer my postprandial glucose, to enhance nutrient absorption, enhance palatability, and primarily (for me) to reduce overall meal volume. I eat 30g almonds, 30g walnuts, and 10g chia with breakfast, and then have olive oil with lunch and dinner. Any more nuts and my digestion is impaired and I become concerned with fatty acid profiles. Given the evidence, I believe olive oil is a better choice for me than coconut, palm, soy, canola, and other oils. There's also this and similar studies (keep in mind that there are always studies to show the converse):
Arteriosclerosis.
1987 Mar-Apr;7(2):125-34.
Regression of experimental atherosclerotic lesions in rhesus monkeys consuming a high saturated fat diet.
Eggen DA, Strong JP, Newman WP, Malcom GT, Restrepo C.
Abstract
Atherosclerotic lesions were induced in rhesus monkeys by feeding them a high-fat, high-cholesterol diet for 2 years. Arteries were examined after autopsy of a subgroup of animals (group P) and cholesterol was removed from the diet of the remaining animals. Lesions were examined in other subgroups after 30 weeks (group R1) and after 52 weeks (group R2). A control group (group C) was fed the diet without cholesterol throughout the study. The mean total serum cholesterol concentration before, during, and after lesion induction was 151, 390, and 157 mg/dl, respectively. The mean percent of surface area with fatty streak or fibrous plaque and the free and esterified cholesterol content of the artery increased in all six arterial segments examined in group P. The means for percent of surface with fatty streak and for arterial cholesterol content or concentration (but not for extent of surface with fibrous plaque) were consistently less in groups R1 and R2 than in group P, although they remained greater in groups R1 and R2 than in group C. The mean intimal thickness for coronary arteries was 10-fold greater in group P than in group C and 60 percent less in groups R1 and R2 than in group P; there was, however, much variability among animals and these differences among groups were not statistically significant. By using several measures in several arterial systems, we have shown that there was regression of diet-induced atherosclerotic lesions in rhesus monkeys while they were fed a diet high in saturated fat but without cholesterol for 30 or 52 weeks.
PMID: 3579722
It's really difficult to figure out what's what with so many conflicting, overlapping, poorly designed, and misinterpreted studies. I try to read as much as I can, but in the end I need to follow a diet that I can maintain long-term, and I think the diet I outlined above meets those criteria, at least at this stage in my life, physically and mentally. Another reason I kept my fat intake high is to make a more appropriate comparison with my prior diets, so it was more beneficial to change only dietary lipid intake, rather than to change both the type and amount. I was expecting improvement, but not to this degree, so I plan on continuing with a full-vegan diet to the best of my ability and retest in a few months.