Hydrogenation alternatives: Effects of trans fatty acids and stearic acid versus linoleic acid on serum lipids and lipoproteins in humans

The objective of this study was to compare the effects of linoleic acid (cis,cis-C18:2(n-6)) and its hydrogenation products elaidic (trans-C18:1(n-9)) and stearic acid (C18:0) on serum lipoprotein levels in humans.Twenty-six men and 30 women, all no

Dietary fatty acids and risk factors for coronary heart disease : controlled studies in healthy volunteers

High levels of LDL cholesterol, blood pressure and Lp(a), and low levels of HDL cholesterol increase the risk for coronary heart disease (CHD). This thesis describes the effects of dietary fatty acids on these risk factors. In each of three trials we fed diets with tailored fatty acid composition to about 60 healthy men and women. Each diet within a trial was supplied to every volunteer for 3 weeks.In the first study we compared the effects of monounsaturated trans fatty acids with those of linoleic acid, the fatty acid from which trans fatty acids are formed upon partial hydrogenation, and with those of stearic acid, a product of complete hydrogenation of linoleic acid. Relative to linoleic acid, both trans fatty acids and stearic acid raised LDL and lowered HDL cholesterol. Thus, partial as well as complete hydrogenation of linoleic acid produces fatty acids that unfavorably affect serum lipids relative to linoleic acid itself. Trans fatty acids and stearic acid did not influence blood pressure, but trans fatty acids modestly raised Lp(a).The second study addressed the relative cholesterol-raising potentials of two specific saturates, myristic and palmitic acid. Relative to oleic acid, myristic acid was about 1.5 times as cholesterol-raising a's palmitic acid, due to increases in both LDL and HDL cholesterol. The differences between myristic and palmitic acid were statistically significant. However, both saturates caused high LDL cholesterol levels and raise the LDL to HDL cholesterol ratio.In the third study we examined the effect of the positional distribution of fatty acids within dietary triglycerides. Two diets had identical total fatty acid composition, but a major contrast in fatty acid configuration. Total, LDL, and HDL cholesterol levels were the same on both diets. The position of the dietary fatty acids was partly reflected in fasting plasma lipids, but the fatty acid configuration had no important effect on lipoprotein levels.In conclusion, monounsaturated trans fatty acids and the saturates myristic and palmitic acid have adverse effects on the serum lipoprotein risk profile for CHID. People at high risk for CHD should replace the hard fats in their diets by carbohydrates or unsaturated oils

Effect of Dietary cis and trans fatty acids on serum lipoprotein[a] levels in humans

Serum lipoprotein[a] (Lp[a]) is a strong risk factor for coronary heart disease. We therefore examined the effect of dietary fatty acid composition on serum Lp[a] levels in three strictly controlled experiments with healthy normocholesterolemic men and women. In Expt. I, 58 subjects consumed a control diet high in saturated fatty acids for 17 days. For the next 36 days, 6.5% of total energy intake from saturated fatty acids was replaced by monounsaturates plus polyunsaturates (monounsaturated fatty acid diet; n = 29) or by polyunsaturates alone (polyunsaturated fatty acid diet; n = 29). Both diets caused a slight, nonsignificant, increase in median Lp[a] levels, with no difference between diets. In Expt. II, 10% of energy from the cholesterol-raising saturated fatty acids (lauric, myristic, and palmitic acid) was replaced by oleic acid or by trans-monounsaturated fatty acids. Each of the 59 participants received each diet for 3 weeks in random order. The median level of Lp[a] was 26 mg/l on the saturated fatty acid diet; it increased to 32 mg/l (P less than 0.020) on the oleic acid diet and to 45 mg/l (P less than 0.001) on the trans-fatty acid diet. The difference in Lp[a] between the trans-fatty acid and the oleic acid diets was also highly significant (P less than 0.001). Expt. III involved 56 subjects; all received 8% of energy from stearic acid, from linoleic acid, or from trans-monounsaturates, for 3 weeks each. All other nutrients were equal.

Effect of a lipid-rich fraction from boiled coffee on serum cholesterol

Scandinavian-style boiled coffee, which raises serum cholesterol, was found to contain more lipid material than drip filter coffee, which does not. Ten volunteers consumed a lipid-enriched fraction from boiled coffee for six weeks: the supplement provided 77 g of water, 1?3 g of lipid, and 1?6 g of other solids per day. Serum cholesterol rose in every subject; the mean rise was 0?74 mmol/l after three weeks (range - 0?09 to 1?48 mmol/l) and 1 ?06 SD 0?37 mmol/l or 23% after six weeks (range 0?48 to 1?52 mmol/l). The increase was mainly due to low-density-lipoprotein cholesterol, which rose by 29%, but very-low-density lipoprotein cholesterol was also raised, as evidenced by a 55% rise in triglycerides. High-density-lipoprotein cholesterol was unchanged. After supplementation had ended, lipid levels returned to baseline. Boiled coffee thus contains a lipid that powerfully raises serum cholesterol