Comparison of Effects of Palmitic and Stearic Acids in the Diet on Serum Cholesterol in Man

Should animal fats be back on the table? A critical review of the human health effects of animal fat

“…As an example from one of the hardest animal fats, approximately only 27% of tallow from pasture-fed beef is cholesterol-increasing saturated fatty acid (CISFA) (Yang et al 1999b), i.e. chain length of 12-16 carbons, and which would raise serum cholesterol, 1% is polyunsaturated,~4% is conjugated linoleic acid (CLA), and the rest is either MUFA or is the saturated fatty acid (SFA) stearic acid that causes the same effect on total serum cholesterol (TSC) as MUFA (Keys et al 1965;Grande et al 1970;Bonanome and Grundy 1988;Tholstrup et al 1994aTholstrup et al , 1994bde Roos et al 2001;Mensink et al 2003). By comparison, in butter from pasture-fed cows, 42% of the fat is CISFA (Couvreur et al 2006) and would raise serum cholesterol despite butter having a total of more than 60% SFA.…”

“…The effect of different FA on the average TSC of the sample, its sub-fractions, fasting triacylglycerides (FTG) and the number and size of low density lipoprotein cholesterol (LDL-C) particles have been determined on largely inactive people in studies in metabolic wards. The description of these average changes in TSC and FTG have been studied for more than 50 years, they are well known and are predictable using the Keys equation (Man and Gildea 1932;Havel et al 1955;Ahrens et al 1957;Havel 1957aHavel , 1957bKeys et al 1957Keys et al , 1965Albrink and Man 1959;Kuo and Carson 1959;Grande et al 1970;Acheson et al 1988; Tholstrup et al 1994aTholstrup et al , 1994bde Roos et al 2001;McDevitt et al 2001;Mensink et al 2003;Matthan et al 2004;Chapman et al 2011;Miller et al 2011). These changes can be summarised by saying, first, that substituting MUFA and stearic acid for starch causes no change in the average serum cholesterol of a population sample, although LDL-C concentration decreases while high density lipoprotein cholesterol (HDL-C) concentration increases.…”

“…The Mediterranean diet and lifestyle as originally described, is a high lipid (40% of total calories) low protein (10%) diet based on olive oil, vegetables, fruit, whole-grain cereals and legumes, wine, nuts, full fat cheese, fish, and meat, especially pork fat and offal (Keys et al 1970;Keys 1995). The fat in this specification is dominated by MUFA, with low levels of linoleic acid (2% of total calories), a ratio of n-6 to n-3 PUFA of~2, and with modest levels of SFA (8% of total calories) (Keys and Kimura 1970;Keys et al 1970Keys et al , 1980. Given the composition of olive oil and other plant oils, this suggests a substantial part of the lipid (perhaps a third) was from animal sources.…”

“…There, the East Finland cohort had the highest proportion of saturated fat in the diet and nearly twice the incidence of coronary heart disease (CHD) compared with any other cohort, the SFA derived mainly from milk fat. The overall ration also had low levels of linoleic acid as a proportion of calories and a low ratio of n-6 to n-3 FA (Keys and Kimura 1970;Keys et al 1970). First, the West Finland cohort had the same median TSC value as the East Finland cohort (Keys et al 1970;Stengard et al 1995) but had only a third the rate of age adjusted CHD compared with the East Finland cohort.…”

“…The overall ration also had low levels of linoleic acid as a proportion of calories and a low ratio of n-6 to n-3 FA (Keys and Kimura 1970;Keys et al 1970). First, the West Finland cohort had the same median TSC value as the East Finland cohort (Keys et al 1970;Stengard et al 1995) but had only a third the rate of age adjusted CHD compared with the East Finland cohort. Furthermore, West Finland had a higher average TSC than the Zutphen (Netherlands) or US Railroad cohorts, and the same or more SFA as a proportion of calories than either of those, but less CHD than either Zutphen or US Railroad.…”