Effects of diets containing high or low amounts of stearic acid on plasma lipoprotein fractions and fecal fatty acid excretion of men

Abstract

Ten middle-aged males participated in a crossover study to determine the cholesterolemic effect of high amounts of stearic acid in a natural diet. They consumed a 20-d stabilization diet followed by two 40-d intervention diets containing either 1.5% of energy as stearic (18:0) acid and 7.3% of energy as palmitic (16:0) acid (low stearate: LS) or 2.4% of energy as 16:0 and 7.3% of energy as 18:0 (high stearate: HS). The experimental diets also contained approximately 10% of energy each as saturated and monounsaturated fatty acids and 7.2-8% of energy as polyunsaturated fatty acids. The primary source of 18:0 in the HS diet was sheanut oil (commercially referred to as shea butter) and palm oil and butter in the LS diet. Plasma total, low-density-lipoprotein, and high-density-lipoprotein cholesterol were significantly lower with the HS than with the LS diet. Total fecal fatty acid excretion was higher throughout the HS period. Apparent digestibility of the major dietary fatty acids showed that all of the selected fatty acids, except 18:0, were > or = 95% absorbed. These data demonstrate that feeding diets containing about two times the usual amount of stearic acid consumed in the United States, contributed to an increase in plasma lipoprotein concentrations at 40 d from an earlier decrease at 20 d. The time required to achieve stable cholesterol concentrations appears to vary depending on the kind of saturated fatty acids present in the diet.

Effects of butter oil blends with increased concentrations of stearic, oleic and linolenic acid on blood lipids in young adults

“…This is in accordance with results published earlier by others (Tholstrup et al, 1994;Yu et al, 1995;Dougherty et al, 1995;Aro et al, 1997), who also found that when stearic acid is exchanged for C12±14 saturates, a moderate decrease in HDL-C was observed.…”

Stearic acid is well absorbed from short- and long-acyl-chain triacylglycerol in an acute test meal

“…The proportion of fatty acids (free, soaps or derived from acylglycerols) of the total lipids has rarely been reported, but the fatty acid concentration in feces has been between 0.2 and 6 g/day (Bonanome and Grundy, 1988;Denke et al, 1993), typically 2-4 g/day (see e.g. Denke and Grundy, 1991;Dougherty et al, 1995;Snook et al, 1999). In the present study, crude fat excretion was at the expected level.…”

“…The absorption of stearic acid from natural fats and oil is currently estimated to lie between 86 and 98% (Denke and Grundy, 1991;Dougherty et al, 1995;Baer et al, 2003). This is in conflict with the reported 63% absorption of stearic acid from Salatrim .…”

Short-term diets enriched in stearic or palmitic acids do not alter plasma lipids, platelet aggregation or platelet activation status

“…These results are consistent with data from Bonanome and Grundy (1988), Tholstrup et al (1994) and Kelly et al (2001), who demonstrated this decrease with greater calculated total dietary stearic acid intakes of 46 g, 58 g and 19.4 g per day, respectively. Tholstrup et al (1994), Dougherty et al (1995) and Kelly et al (2001) have previously reported a significant decrease in HDL cholesterol concentrations on high stearic acid diets (58, 23.6 and 19.4 g per day, respectively) compared with baseline.…”

“…Subsequently, it was found that stearic acid was neutral in relation to plasma cholesterol changes (Hegsted et al, 1965;Keys et al, 1965). There are now a number of dietary studies which support the unique cholesterol-neutral properties of stearic acid (Kris-Etherton and Mustad, 1994;Tholstrup et al, 1994;Bonanome & Grundy, 1988), however the mechanisms behind this effect are not yet clear (Bonanome & Grundy, 1989;Kris-Etherton et al, 1993;Emken, 1994;Tholstrup et al, 1994;Dougherty et al, 1995;Rhee et al, 1997;Salter et al, 1998).…”