In vivo oxidised cholesterol in atherosclerosis.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
M B Katan
Publications and source records attributed to M B Katan.
Trans monounsaturated fatty acids in nutrition and their impact on serum lipoprotein levels in man.
Trans-C18:1 in the diet originate predominantly from partially hydrogenated oils, with beef, mutton and dairy products being an additional source. These fatty acids are absorbed and incorporated into lipids. Their estimated consumption is about 5-7% of total fatty acids, although reliable data are lacking. In addition, large variations between individuals exist. There is no evidence that trans fatty acids accumulate in human tissues. Elaidic acid and its positional isomers do, however, raise LDL cholesterol and apoprotein B and Lp(a) and probably depress HDL cholesterol and apoprotein A-I, compared with the cis isomer, oleic acid. In view of these adverse effects, patients at high risk for atherosclerosis, in addition to reducing their intake of saturated fatty acids and of cholesterol might also do well to avoid excessive intakes of trans fatty acids. Still, trans fatty acids form only a minor component of the diets of most patients and therefore even marked relative reductions in intake will probably have less of an impact on LDL cholesterol than a sizeable reduction in saturated fatty acids and cholesterol will produce.
Diet↗
Intake of potentially anticarcinogenic flavonoids and their determinants in adults in The Netherlands.
Flavonoids are strong antioxidants that occur naturally in foods and can inhibit carcinogenesis in rodents. Accurate data on population-wide intakes of flavonoids are not available. Here, using data of the Dutch National Food Consumption Survey 1987-1988, we report the intake of the potentially anticarcinogenic flavonoids quercetin, kaempferol, myricetin, apigenin, and luteolin among 4,112 adults. The flavonoid content of vegetables, fruits, and beverages was determined by high-performance liquid chromatography. In all subjects, average intake of all flavonoids combined was 23 mg/day. The most important flavonoid was the flavonol quercetin (mean intake 16 mg/day). The most important sources of flavonoids were tea (48% of total intake), onions (29%), and apples (7%). Flavonoid intake did not vary between seasons; it was not correlated with total energy intake (r = 0.001), and it was only weakly correlated with the intake of vitamin A (retinol equivalents, r = 0.14), dietary fiber (r = 0.21), and vitamin C (r = 0.26). Our use of new analytic technology suggests that in the past flavonoid intake has been overestimated fivefold. However, on a milligram-per-day basis, the intake of the antioxidant flavonoids still exceeded that of the antioxidants beta-carotene and vitamin E. Thus flavonoids represent an important source of antioxidants in the human diet.
Adult↗
Stability of n-3 fatty acids in human fat tissue aspirates during storage.
The content of n-3 (omega 3) polyunsaturated fatty acids in fat tissue is an indicator of their long-term consumption. Therefore, a method for determining n-3 fatty acids in human fat tissue microbiopsies was validated and the stability of n-3 fatty acids in biopsies was checked under various conditions of storage. Methyl esters were prepared from 25 to 35 mg adipose tissue and separated by capillary gas chromatography. Recovery of added eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) was 98-105%. The change after storage of fat samples at room temperature or at 4, -20, or -80 degrees C for 3 mo averaged +3.3% for EPA and +2.1% for DHA, with no effect of temperature. Storage at +20 or -80 degrees C for 7 mo yielded no perceptible change in EPA, DHA, or five other n-3 polyunsaturated fatty acids. EPA and DHA concentrations in adipose tissue aspirates are remarkably stable and deserve attention as biomarkers in epidemiological studies.
Adipose Tissue↗
Dietary saturated fatty acids increase cholesterol synthesis and fecal steroid excretion in healthy men and women.
In a strictly controlled 6-week trial with 47 healthy volunteers we have determined the effect of replacement of polyunsaturated by saturated fatty acids on the fecal steroid excretion and on the rate of whole body cholesterol synthesis, as measured both by the sterol balance method and by the concentration of the cholesterol precursor lathosterol in serum. Subjects were fed mixed natural diets, of which the total fat content was kept constant at 45% energy. Consumption of polyunsaturated fatty acids, mainly linoleic acid, was 21% energy for the first 3-week period (P:S ratio 1.9), and 5% of energy (P:S ratio 0.2) for the next 3-week period, or vice versa. Cholesterol intake as determined by analysis of duplicate diets was 41 mg MJ-1 (about 500 mg day-1) during both periods. Feces were collected for 5 days at the end of both periods. The steroid composition of the feces was not affected by the change of diets. The fecal excretion of neutral steroids was significantly higher on the low P:S high-saturated-fat (2.25 +/- 0.68 mmol day-1) than on the high P:S high-linoleic-acid diet (2.00 +/- 0.69 mmol day-1; P < 0.01). The excretion of bile acids was similar (0.77 +/- 0.40 and 0.79 +/- 0.41 mmol day-1, respectively). The cholesterol balance and the rate of cholesterol synthesis were higher during the low P:S (1.86 +/- 0.83 mmol day-1) than during the high P:S period (1.55 +/- 0.85 mmol day-1; P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
The effect of a natural high-fibre diet on faecal and biliary bile acids, faecal pH and whole-gut transit time in man. A controlled study.
Dietary fibre possibly protects against colonic cancer by effects on bile acid metabolism. We investigated the effect of a natural high-fibre diet on secondary bile acid formation. Twelve healthy subjects on an habitual low-fibre diet (for 4 weeks) consumed a high-fibre menu for 10 weeks (experimental group). A control group of 10 subjects consumed their regular high-fibre diet during this period. Faecal and biliary acid composition, faecal weight, faecal pH and gut transit time were studied before and after 6 and 10 weeks of fibre addition. Changes in the experimental group were compared to changes in the control group. The concentration, but not the excretion, of the secondary faecal bile acids was reduced in the experimental group. Faecal weight increased, faecal pH dropped and gut transit time was not altered. The biliary deoxycholic acid content decreased and the cholic acid content increased after 6 weeks, but returned to baseline values after 10 weeks of fibre addition. This study shows that a natural high-fibre diet lowers secondary faecal bile acid concentration through an increase in stool weight. The 7 alpha-dehydroxylation of primary bile acids is probably not or only transiently inhibited.
Adult↗
Effects of stearic acid and trans fatty acids versus linoleic acid on blood pressure in normotensive women and men.
The objective of this study was to compare the effect of linoleic acid (cis,cis-C18:2) with that of its hydrogenation products stearic acid (C18:0) and elaidic acid (trans-C18:1) on blood pressure levels in normotensive humans. We therefore measured the effects of these fatty acids on systolic and diastolic blood pressure in 30 women and 25 men. Three strictly controlled experimental diets were supplied to every subject for 3 weeks each, in different order (multiple cross-over). The composition of the three diets was constant, except for 8% of daily energy, which was provided by either linoleic acid, stearic acid, or monounsaturated trans fatty acids. The statistical power for detecting a true difference between two diets of 3 mmHg in systolic and diastolic blood pressure was over 90%. Mean systolic/diastolic blood pressure at the end of the dietary periods was 114/69 mmHg on the linoleic acid diet, 113/70 on the stearic acid diet, and 113/69 on the trans fatty acid diet. No significant differences were observed in blood pressure levels after 3 weeks on each diet. We conclude that a major increase in the intake of linoleic acid at the expense of stearic acid or trans fatty acids has no effect on blood pressure in normotensive young women and men.
Adult↗
Serum cholesteryl ester fatty acids and their relation with serum lipids in elderly men in Crete and The Netherlands.
This study describes dietary fatty acid intake, as assessed from serum cholesteryl ester composition, and its relation to serum lipoprotein levels in 100 age-matched elderly men from Crete and Zutphen. All were survivors of the respective cohorts of the Seven Countries Study [Keys A (1980) Seven countries: a multivariate analysis of death and coronary heart disease. Cambridge, MA: Harvard University Press]. A significantly higher percentage of oleic acid and a significantly lower percentage of linoleic acid in the cholesteryl esters was observed in the Cretan compared with the Zutphen men. The mean serum total cholesterol levels of the elderly men in Crete and Zutphen were similar (5.98 and 5.92 mmol/l, respectively), but in the Cretans the HDL cholesterol level was significantly higher (1.28 vs 1.09 mmol/l). The percentage of smokers and the average body mass index did not differ between the Cretan and Zutphen men, but the percentage of severely overweight men was three times higher in the Cretan cohort. Among men in Zutphen the oleic acid content of the cholesteryl esters was positively associated with the HDL cholesterol level, independent of the effects of age, body mass index, cigarette smoking and alcohol intake. However, the difference in HDL cholesterol level between Zutphen and Crete could be explained to only a minor extent by differences in serum cholesteryl oleic acid, smoking, or obesity.(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
Serum cholesterol and long-term death rates from suicide, accidents, or violence. Seven Countries Study Group.
Explore the source record for details and available documents.
Accidents↗
Boiled coffee does not increase serum cholesterol in gerbils and hamsters.
In contrast to drip filter coffee, boiled coffee increases the serum cholesterol level in man. To identify the substance(s) responsible for this effect, it is necessary to find an animal model sensitive to boiled coffee. In this study, three groups of 20 male gerbils and three groups of six male hamsters were fed a control diet or a control diet supplemented with either freeze-dried boiled coffee or freeze-dried filtered coffee. At the end of the 5-week feeding period serum cholesterol levels were not different in either species fed the different diets. These results suggest that these animal species are not sensitive to boiled coffee, or that the cholesterol-raising factor in boiled coffee is lost during the process of freeze-drying.
Animals↗
Isomeric fatty acids and serum lipoproteins.
Explore the source record for details and available documents.
Animals↗
Effects of a monounsaturated rapeseed oil and a polyunsaturated sunflower oil diet on lipoprotein levels in humans.
The effects of high oleic acid rapeseed oil compared with polyunsaturated fats on serum lipoprotein levels are largely unknown. Therefore, we fed 30 women and 29 men a baseline diet rich in saturated fat, which was followed by a diet rich in high oleic and low erucic acid rapeseed oil (total energy content of fat, 38%; saturates, 12.4%; monounsaturates, 16%; n-6 polyunsaturates, 6%; and n-3 polyunsaturates, 2%) and one rich in sunflower oil (total energy content of fat, 38%; saturates, 12.7%; monounsaturates, 10%; n-6 polyunsaturates, 13%; and n-3 polyunsaturates, 0%). The oils were incorporated into mixed natural diets that were dispensed in a random order for 3.5 weeks each in a blinded crossover design. The diet composition was confirmed by analysis of duplicate diets. Both test diets reduced serum total cholesterol (TC) and low density lipoprotein (LDL) cholesterol levels from baseline, the monounsaturated rapeseed oil diet more than the polyunsaturated sunflower oil diet (TC: -15% versus -12%, p less than 0.01; LDL cholesterol: -23% versus -17%, p less than 0.01). Very low density lipoprotein (VLDL) cholesterol and total, VLDL, and LDL triglyceride levels were lower during the sunflower oil diet compared with the rapeseed oil diet. Total high density lipoprotein (HDL) cholesterol levels remained unchanged by both diets. The consumption of rapeseed oil resulted in a more favorable HDL2 to LDL cholesterol ratio (0.43 +/- 0.19 versus 0.39 +/- 0.18, p less than 0.01) and an apolipoprotein A-I to B ratio (3.0 +/- 1.4 versus 2.4 +/- 1.6, p less than 0.001) than did the sunflower oil.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Does body fatness modify the association between dietary cholesterol and risk of coronary death? Results from the Chicago Western Electric Study.
The hypothesis that body fatness modifies the relation between dietary cholesterol and 25-year coronary mortality was examined in a cohort of 1,792 middle-aged men employed by the Western Electric Company in Chicago. Relative risks of coronary death (and 95% confidence intervals) associated with a 225 mg/day greater intake of dietary cholesterol for men with a subscapular skinfold thickness less than or equal to 14, 15-20, and greater than or equal to 21 mm were 1.44 (1.10-1.90), 1.07 (0.84-1.36), and 0.95 (0.76-1.20), respectively, after adjustment for age; serum total cholesterol level; systolic blood pressure; cigarette smoking; family history of cardiovascular disease; evidence of major organ system disease at baseline; and intake of saturated fatty acids, polyunsaturated fatty acids, energy, and ethanol. Adjusted relative risks associated with a 15-mm greater subscapular skinfold thickness for men with a dietary cholesterol intake less than or equal to 649, 650-799, and greater than or equal to 800 mg/day were 1.76 (1.04-2.98), 1.64 (1.04-2.57), and 1.00 (0.69-1.55), respectively. Fatter men apparently did not benefit from a diet lower in cholesterol, while men who ate a diet high in cholesterol apparently did not benefit from leanness. These results support the hypothesis that body fatness modifies the relation between dietary cholesterol and coronary mortality, perhaps because leaner men are more responsive than fatter men to the effects of dietary cholesterol on the concentration of low density lipoprotein cholesterol.
Adipose Tissue↗
Effect of dietary fatty acids on serum lipids and lipoproteins. A meta-analysis of 27 trials.
To calculate the effect of changes in carbohydrate and fatty acid intake on serum lipid and lipoprotein levels, we reviewed 27 controlled trials published between 1970 and 1991 that met specific inclusion criteria. These studies yielded 65 data points, which were analyzed by multiple regression analysis using isocaloric exchanges of saturated (sat), monounsaturated (mono), and polyunsaturated (poly) fatty acids versus carbohydrates (carb) as the independent variables. For high density lipoprotein (HDL) we found the following equation: delta HDL cholesterol (mmol/l) = 0.012 x (carb----sat) + 0.009 x (carb----mono) + 0.007 x (carb---- poly) or, in milligrams per deciliter, 0.47 x (carb----sat) + 0.34 x (carb----mono) + 0.28 x (carb----poly). Expressions in parentheses denote the percentage of daily energy intake from carbohydrates that is replaced by saturated, cis-monounsaturated, or polyunsaturated fatty acids. All fatty acids elevated HDL cholesterol when substituted for carbohydrates, but the effect diminished with increasing unsaturation of the fatty acids. For low density lipoprotein (LDL) the equation was delta LDL cholesterol (mmol/l) = 0.033 x (carb----sat) - 0.006 x (carb----mono) - 0.014 x (carb----poly) or, in milligrams per deciliter, 1.28 x (carb----sat) - 0.24 x (carb----mono) - 0.55 x (carb---- poly). The coefficient for polyunsaturates was significantly different from zero, but that for monounsaturates was not. For triglycerides the equation was delta triglycerides (mmol/l) = -0.025 x (carb----sat) - 0.022 x (carb----mono) - 0.028 x (carb---- poly) or, in milligrams per deciliter, -2.22 x (carb----sat) - 1.99 x (carb----mono) - 2.47 x (carb----poly).(ABSTRACT TRUNCATED AT 250 WORDS)
Cholesterol↗
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.(ABSTRACT TRUNCATED AT 250 WORDS)
Dietary Fats↗
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 normolipemic and apparently healthy, completed the trial. Three experimental diets were supplied to every subject for 3 weeks each, in random order (multiple cross-over). The Linoleate-diet provided 12.0% of total energy intake as linoleic acid, 2.8% as stearic acid, and 0.1% as trans fatty acids. The Stearate-diet supplied 3.9 energy % as linoleic acid, 11.8% stearic acid, and 0.3% trans fatty acids. The Trans-diet provided 3.8 energy % as linoleic acid, 3.0% stearic acid, and 7.7% as monounsaturated trans fatty acids, largely elaidic acid (trans-C18:1(n-9)). Other nutrients were constant. Fasting blood was sampled at the end of each dietary period. Mean (+/- SD) serum LDL cholesterol was 109 +/- 24 mg/dl (2.83 +/- 0.63 mmol/l) on the Linoleate-diet. It rose to 116 +/- 27 mg/dl (3.00 +/- 0.71 mmol/l) on the Stearate-diet (change, 7 mg/dl or 0.17 mmol/l, P = 0.0008) and to 119 +/- 25 mg/dl (3.07 +/- 0.65 mmol/l) on the Trans-diet (change, 9 mg/dl or 0.24 mmol/l, P less than 0.0001). High density lipoprotein (HDL) cholesterol decreased by 2 mg/dl (0.06 mmol/l, P less than 0.0001) on the Stearate-diet and by 4 mg/dl (0.10 mmol/l, P less than 0.0001) on the Trans-diet, both relative to linoleic acid. Our findings show that 7.7% of energy (mean, 24 g/day) of trans fatty acids in the diet significantly lowered HDL cholesterol and raised LDL cholesterol relative to linoleic acid. Combination with earlier results (Mensink, R. P., and M. B. Katan. 1990. N. Engl. J. Med. 323: 439-445) suggests a linear dose-response relation. Replacement of linoleic acid by stearic acid also caused somewhat lower HDL cholesterol and higher LDL cholesterol levels. Hydrogenation of linoleic acid to either stearic or trans fatty acids produces fatty acids that may increase LDL and decrease HDL cholesterol relative to linoleic acid itself.
Adolescent↗
[Costs of the diet in hypercholesterolemia].
Explore the source record for details and available documents.
Adult↗
Diet-induced alteration in the activity of plasma lipid transfer protein in normolipidemic human subjects.
Studies were performed to investigate the effect of diets rich in oleic or linoleic acids on the activity of plasma cholesteryl ester transfer protein (CETP) in normolipidemic subjects. Previous to the test diets, all subjects consumed a baseline diet rich in saturated fatty acids ("sat-diet") for 17 days. The test diets, rich in either monounsaturated fatty acids ("mono-diet") or rich in polyunsaturated fatty acids ("poly-diet"), were given for 5 weeks to 52 normolipidemic healthy volunteers. The activity of CETP was measured, using a method independent of endogenous plasma lipoproteins, as the rate of exchange of radioactive cholesteryl oleate between labelled LDL and unlabelled HDL. The "mono-diet" induced a statistically significant decrease in CETP activity (from 115 +/- 20 to 102 +/- 19 units/ml plasma, P less than 0.01), while the small decrease on the "poly-diet" (from 111 +/- 23 to 107 +/- 22 units/ml plasma) did not reach significancy. The percentual decrease in CETP activity induced by the "mono-diet" was higher than that induced by the "poly-diet" as was also found for the decrease in LDL cholesterol. In both diet groups a positive correlation was found between changes in CETP activity and changes in plasma total or (VLDL + LDL) cholesterol. The results suggest that high levels of dietary monounsaturated fatty acids may result in decreased plasma CETP activity, as well as LDL cholesterol levels. The mechanisms of these effects, and their possible interrelations, remain to be established.
Adult↗