Biomedical subjects

B Vessby

Publications and source records attributed to B Vessby.

At least 37 records · Page 2Linked to original sources

PubMed2002

Lipids and antioxidative effects of estradiol and sequential norethisterone acetate treatment in a 3-month randomized controlled trial.

OBJECTIVE: To determine the influence of hormone replacement therapy on serum lipids and antioxidative factors associated with the risk of coronary heart disease. METHODS: The effect of a sequential estradiol-norethisterone acetate regimen or placebo on lipid metabolism, antioxidative variables and fatty acid composition in serum was measured during the peak-estrogen phase in a randomized, double-blind, placebo-controlled study of 42 healthy postmenopausal women for 3 months. RESULTS: Active treatment significantly reduced lipoprotein(a) by 15% (p = 0.005, compared with placebo), low-density lipoprotein (LDL) cholesterol by 10% (p = 0.005) and the LDL cholesterol/high-density lipoprotein (HDL) cholesterol ratio by 11% (p = 0.016). Serum triglycerides increased by 21% (p = 0.045). No effect was observed on HDL cholesterol, on apolipoproteins apo A(1) or apo B, or on non-esterified fatty acids in serum. No treatment effect was seen in the proportions of monounsaturated and polyunsaturated fatty acids. The concentration of malondialdehyde in serum did not change with the estrogen-progestin treatment. CONCLUSIONS: This sequential estrogen-progestin therapy has a beneficial effect on apolipoprotein(a) and LDL cholesterol, but no effect on non-esterified fatty acids or the level of lipid peroxidation products in serum.

Administration, Oral↗

PubMed2001

Dyslipidemia and an unfavorable fatty acid profile predict left ventricular hypertrophy 20 years later.

BACKGROUND: -Left ventricular hypertrophy (LVH) is a common risk factor for cardiovascular mortality. Causes other than hypertension have not previously been investigated longitudinally. The aim of the present study was to determine hemodynamic, metabolic, and psychosocial predictors at 50 years of age for the prevalence of echocardiographic LVH and geometric subtypes at age 70 by use of a large sample of men from the general population followed up for 20 years. Methods and Results-In 1970 to 1973, all men born from 1920 to 1924 and residing in Uppsala County, Sweden, were invited to participate in a health survey aimed at identifying risk factors for cardiovascular disease. At a reinvestigation 20 years later, echocardiographic left ventricular mass index was determined in 475 subjects. A 1-SD increase in body mass index, systolic or diastolic blood pressure, fasting LDL/HDL cholesterol, serum triglycerides, or the serum cholesterol ester proportion of several saturated fatty acids or oleic acid at age 50 significantly increased the odds of having LVH at age 70 by 27% to 41%, whereas an increase in linoleic acid proportion was protective. Almost all metabolic predictors were independent of ischemic heart disease, valvular disease, and use of antihypertensive medication at age 70. CONCLUSIONS: -Dyslipidemia and indices of a low dietary intake of linoleic acid and high intake of saturated and monounsaturated fats, as well as hypertension and obesity, at age 50 predicted the prevalence of LVH 20 years later in this prospective longitudinal cohort study, thereby suggesting that lipids may be important in the origin of LVH.

Age Factors↗

PubMed2001

Vitamin E reduces lipid peroxidation in experimental hepatotoxicity in rats.

BACKGROUND AND AIMS: Lipid peroxidation is believed to be involved in the pathophysiology of a number of diseases and in the process of aging. This study investigates the effects of dietary supplementation with vitamin E (20 g/kg diet of all-rac-alpha-tocopheryl succinate for 3 weeks) on both non-enzymatic and enzymatic lipid peroxidation in experimental rats with carbon tetrachloride (CCl4)-induced hepatotoxicity (2.5 mL/kg body). METHODS: Plasma, urine and liver samples from control rats (n = 6), CCl4-treated rats (n = 6), and rats supplemented with vitamin E prior to CCl4 treatment (n = 8) were collected. Non-enzymatic lipid peroxidation induced by free radicals was investigated by measurement of a major F2-iso-prostane, 8-iso-prostaglandin F2 alpha (8-iso-PGF2 alpha). Cyclooxygenase-catalyzed enzymatic lipid peroxidation was measured with a major PGF2 alpha metabolite, 15-keto-13,14-dihydro-prostaglandin F2 alpha (15-K-DH-PGF2 alpha). Malondialdehyde and antioxidants in plasma were also quantified. RESULTS: CCl4 treatment alone resulted in significantly higher levels of plasma, urinary and liver 8-iso-PGF2 alpha, and of plasma and urinary 15-K-DH-PGF2 alpha compared to controls. Rats supplemented with vitamin E prior to CCl4 treatment had significantly lower levels of urinary and liver 8-iso-PGF2 alpha, urinary 15-K-DH-PGF2 alpha, and plasma malondialdehyde than rats treated with CCl4 alone. However, plasma 8-iso-PGF2 alpha and plasma 15-K-DH-PGF2 alpha were not affected by vitamin E supplementation. CONCLUSION: Thus, both non-enzymatic and enzymatic lipid peroxidation during experimental hepatic oxidative injury were suppressed by dietary vitamin E supplementation in rats.

Animals↗

PubMed2001

Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU Study.

AIMS/HYPOTHESIS: The amount and quality of fat in the diet could be of importance for development of insulin resistance and related metabolic disorders. Our aim was to determine whether a change in dietary fat quality alone could alter insulin action in humans. METHODS: The KANWU study included 162 healthy subjects chosen at random to receive a controlled, isoenergetic diet for 3 months containing either a high proportion of saturated (SAFA diet) or monounsaturated (MUFA diet) fatty acids. Within each group there was a second assignment at random to supplements with fish oil (3.6 g n-3 fatty acids/d) or placebo. RESULTS: Insulin sensitivity was significantly impaired on the saturated fatty acid diet (-10%, p = 0.03) but did not change on the monounsaturated fatty acid diet (+2%, NS) (p = 0.05 for difference between diets). Insulin secretion was not affected. The addition of n-3 fatty acids influenced neither insulin sensitivity nor insulin secretion. The favourable effects of substituting a monounsaturated fatty acid diet for a saturated fatty acid diet on insulin sensitivity were only seen at a total fat intake below median (37E%). Here, insulin sensitivity was 12.5% lower and 8.8% higher on the saturated fatty acid diet and monounsaturated fatty acid diet respectively (p = 0.03). Low density lipoprotein cholesterol (LDL) increased on the saturated fatty acid diet (+4.1%, p < 0.01) but decreased on the monounsaturated fatty acid diet (MUFA) (-5.2, p < 0.001), whereas lipoprotein (a) [Lp(a)] increased on a monounsaturated fatty acid diet by 12% (p < 0.001). CONCLUSIONS/INTERPRETATION: A change of the proportions of dietary fatty acids, decreasing saturated fatty acid and increasing monounsaturated fatty acid, improves insulin sensitivity but has no effect on insulin secretion. A beneficial impact of the fat quality on insulin sensitivity is not seen in individuals with a high fat intake (> 37E%).

Adult↗

PubMed2001

Conjugated linoleic acid supplementation in humans--metabolic effects.

Supplementation with conjugated linoleic acid (CLA) induces a number of physiological effects in experimental animals, including reduced body fat content, decreased aortic lipid deposition, and improved serum lipid profile. Controlled trials on the effects of CLA in humans have hitherto been scarce. The aim of this study was to evaluate the effects of supplementation with CLA in healthy humans on anthropometric and metabolic variables and on the fatty acid composition of serum lipids and thrombocytes. Fifty-three healthy men and women, aged 23-63 yr, were randomly assigned to supplementation with CLA (4.2 g/d) or the same amount of olive oil during 12 wk in a double-blind fashion. The proportion of body fat decreased (-3.8%, P< 0.001) in the CLA-treated group, with a significant difference from the control group (P = 0.050). Body weight, body mass index, and sagittal abdominal diameter were unchanged. There were no major differences between the groups in serum lipoproteins, nonesterified fatty acids, plasma insulin, blood glucose, or plasminogen activator inhibitor 1 (PAI-1). In the CLA group the proportions of stearic, docosatetraenoic, and docosapentaenoic acids increased in serum lipids and thrombocytes, while proportions of palmitic, oleic, and dihomo-gamma-linolenic acids decreased, causing a decrease of the estimated delta-6 and delta-9 and an increase in the delta-5 desaturase activities. These results suggest that supplementation with CLA may reduce the proportion of body fat in humans and that CLA affects fatty acid metabolism. No effects on body weight, serum lipids, glucose metabolism, or PAI-1 were seen.

Adult↗

PubMed2001

Endothelium-dependent vasodilation is related to the fatty acid composition of serum lipids in healthy subjects.

The fatty acid (FA) composition of the serum lipids has been associated with cardiovascular disease (CVD). As an attenuated endothelium-dependent vasodilation (EDV) has been suggested as an early marker of atherosclerosis, we investigated the relationships between the proportion of FA in serum lipids (cholesterol esters and phospholipids) together with the levels of serum LDL- and HDL-cholesterol and triglycerides and EDV, as well as endothelium-independent vasodilation (EIDV). Fifty-six healthy subjects (31 men and 25 women), aged between 20 and 69 years, underwent measurements of forearm blood flow (FBF) at rest and during local infusion of 2 and 4 microg/min of metacholine (Mch, evaluating EDV), 5 and 10 microg/min of sodium nitroprusside (SNP, evaluating endothelium-independent vasodilation, EIDV) using venous occlusion plethysmography. An index of endothelial function was calculated as the ratio between EDV and EIDV. The proportion of palmitic (16:0) and palmitoleic (16:1) acids were inversely related (r=-0.35 and -0.35, P<0.01 for both), while linoleic acid (18:2 n6) and the HDL-cholesterol concentration were positively related (r=0.35 and 0.36, P<0.01 for both) to the endothelial function index. In multiple regression analysis also including age and gender, palmitoleic acid and HDL-cholesterol were significant independent predictors of endothelial function. Alfa-linolenic acid (18:3 n3) was positively correlated to both EDV and EIDV (r=0.40 and 0.43, P<0.01 for both), indicating a protective effect of this essential FA on vasodilation in general. It is concluded that the FA composition of serum lipids, partly reflecting the composition of dietary fat and previously associated with the development of CVD, was associated with endothelial function in apparently healthy subjects.

Adult↗

PubMed2001

A diet containing rapeseed oil-based fats does not increase lipid peroxidation in humans when compared to a diet rich in saturated fatty acids.

OBJECTIVE: To compare the effects of a rapeseed oil-based diet containing an increased proportion of easily oxidised polyunsaturated fatty acids such as alpha-linolenic acid with a diet rich in saturated fatty acids on the degree of lipid peroxidation in the human body. DESIGN: A randomised cross-over study. SUBJECTS AND INTERVENTIONS: Nineteen healthy moderately hyperlipidemic subjects (six women and 13 men, age 50+/-8 y and body mass index (BMI) 24.5+/-2.6 kg/m(2)) were given a rapeseed oil-based diet (RO) and a control diet (SAT) rich in saturated fatty acids during two consecutive 4 week periods separated by a 4 week wash-out period. Biomarkers of lipid peroxidation and antioxidants were analysed in plasma and urine. RESULTS: No significant differences in plasma or urinary levels of free 8-iso-prostaglandin F(2alpha), plasma total 8-iso-prostaglandin F(2alpha) plasma hydroperoxides or plasma malondialdehyde were observed between the RO and SAT diets (P=0.14-0.95). A higher concentration of serum gamma-tocopherol was detected after the RO diet compared to the SAT diet (P<0.001), whereas the serum alpha-tocopherol concentration and plasma antioxidative capacity did not differ between the two test diets. The total cholesterol, LDL cholesterol and LDL/HDL ratio were lower after the RO diet compared to the SAT diet (P<0.001), while HDL cholesterol and total triglyceride levels were similar after the two diets. CONCLUSION: These results suggest that a rapeseed oil-based diet rich in alpha-linolenic acid does not seem to increase the degree of lipid peroxidation in plasma and urine compared to a diet rich in saturated fats. This is possibly due to a sufficient content of antioxidants in the rapeseed oil diet to increase circulating concentrations of antioxidants that may protect unsaturated fatty acids from oxidation. SPONSORSHIP: Swedish Council for Forestry and Agricultural Research and Foundation for Geriatric Research.

Antioxidants↗

PubMed2001

Conjugated linoleic acid (CLA) reduced abdominal adipose tissue in obese middle-aged men with signs of the metabolic syndrome: a randomised controlled trial.

BACKGROUND: Abdominal obesity is strongly related to metabolic disorders. Recent research suggests that dietary conjugated linoleic acid (CLA) reduces body fat and may improve metabolic variables in animals. The metabolic effects of CLA in abdominally obese humans have not yet been tested. OBJECTIVE: To investigate the short-term effect of CLA on abdominal fat and cardiovascular risk factors in middle-aged men with metabolic disorders. METHODS: Twenty-five abdominally obese men (waist-to-hip ratio (WHR), 1.05+/-0.05; body mass index (BMI), 32+/-2.7 kg/m(2) (mean+/-s.d.)) who were between 39 and 64-y-old participated in a double-blind randomised controlled trial for 4 weeks. Fourteen men received 4.2 g CLA/day and 10 men received a placebo. The main endpoints were differences between the two groups in sagittal abdominal diameter (SAD), serum cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides, free fatty acids, glucose and insulin. RESULTS: At baseline, there were no significant differences between groups in anthropometric or metabolic variables. After 4 weeks there was a significant decrease in SAD (cm) in the CLA group compared to placebo (P=0.04, 95% CI; -1.12, -0.02). Other measurements of anthropometry or metabolism showed no significant differences between the groups. CONCLUSIONS: These results indicate that CLA supplementation for 4 weeks in obese men with the metabolic syndrome may decrease abdominal fat, without concomitant effects on overall obesity or other cardiovascular risk factors. Because of the limited sample size, the effects of CLA in abdominal obesity need to be further investigated in larger trials with longer duration.

Adipose Tissue↗

PubMed2001

The alpha and gamma tocopherol levels in serum are influenced by the dietary fat quality.

BACKGROUND: Alpha tocopherol in serum is thought to be of importance in protecting lipids against oxidation and low serum levels of alpha tocopherol has been suggested to increase the risk for coronary heart disease. However, low levels of gamma, rather than alpha, tocopherol have been found in patients with manifest coronary heart disease and in populations with a high incidence of coronary heart disease. AIM: The aim of this study was to determine the tocopherol concentrations in serum after two diets with identical nutrient content but with different fat quality, enriched in butter and rapeseed oil-based fats, respectively. METHOD: Twenty moderately hyperlipidemic, healthy subjects (six females and 14 males) participated in this double-blind cross-over study, where two isoenergetic diets were given in a randomized order during two 3-week periods, interrupted by a wash-out period of 3-4 weeks. RESULTS: The lipid-corrected serum concentrations of alpha and gamma tocopherol increased during the diet rich in rapeseed oil (by 7 and 23%, respectively) compared with on the baseline diet (P < 0.001), while these concentrations decreased (by 5 and 37%, respectively, P < 0.01) during the diet rich in saturated fat. The ratio between alpha and gamma tocopherol decreased significantly during the rapeseed oil diet (-23%, P < 0.01) and increased (+46%, P < 0.001) during the butter diet. CONCLUSION: Alpha and gamma tocopherol levels in serum are influenced by the type of fat used in the diet. The most unexpected finding is that the lipid-adjusted gamma tocopherol concentration significantly decreased by 37% during a diet rich in saturated fat with an increased ratio between alpha and gamma tocopherol, similar to the situation found in CHD patients.

Aged↗

PubMed2001

Several factors associated with the insulin resistance syndrome are predictors of left ventricular systolic dysfunction in a male population after 20 years of follow-up.

BACKGROUND: The epidemiologic data on heart failure are scarce. This study aimed at identifying predictors of left ventricular systolic dysfunction in a cohort of middle-aged men with a 20-year follow-up. METHODS: A population-based cohort of 431 50-year-old men was examined with blood pressure and anthropometric measurements together with lipid, glucose, and insulin determinations. A reinvestigation 20 years later also included echocardiography, ambulatory blood pressure monitoring, hyperinsulinemic euglycemic clamp, and oral glucose tolerance test. Sixteen subjects were found to have left ventricular systolic dysfunction at age 70 years, defined as an ejection fraction </=0.40. A control group of 48 subjects matched on myocardial infarction, hypertension, diabetes, and use of cardiovascular medication, but with an ejection fraction >0.40, was used in a nested case-control analysis. RESULTS: At age 50 years, heart rate (P <.01), plasma proinsulin (P <.05), and the proportion of dihomogammalinolenic acid in serum cholesterol esters (P <.05) were increased and serum phosphate decreased (P <.01) in the subjects identified with left ventricular systolic dysfunction at age 70 years compared with controls. No major metabolic abnormalities were associated with left ventricular systolic dysfunction at age 70 years compared with controls. CONCLUSION: Factors associated with insulin resistance precede left ventricular systolic dysfunction independently of ischemic heart disease and hypertension after 20 years of follow-up.

Age Factors↗

PubMed2001

Dietary fat intake in healthy adolescents: inverse relationships between the estimated intake of saturated fatty acids and serum cholesterol.

The objective of the present study was to describe the intake of dietary fatty acids among healthy 15-year-old boys and girls and to relate the intake of specific fatty acids and the fatty acid composition of the serum cholesterol esters to serum lipid, apolipoprotein (Apo) and insulin concentrations respectively. Fifty-two girls and forty-two boys were randomly selected from the official population register. Unexpectedly, significant inverse associations were found between the dietary content of saturated fatty acids with a chain length of four to fifteen C atoms, mainly derived from milk fat, as well as the corresponding fatty acids in the serum cholesterol esters, on the one hand and the serum concentrations of cholesterol and ApoB on the other. The estimated dietary intake of 4:0-10:0, 12:0 and 14:0 respectively, were all significantly inversely related to the serum cholesterol (r -0.32, r -0.31, r -0.30, all and ApoB (r -0.42, r -0.42, and r -0.40, all concentrations in girls and 12:0 to the ApoB concentration (r -0.55, in boys. The proportions of 12:0 and 15:0 in the serum cholesterol esters were negatively correlated with the serum cholesterol concentrations in both girls (r -0.34, r -0.32, and boys (r -0.53, r -0.32, and with the ApoB concentrations among boys (r -0.61, r -0.43, It is conceivable that milk fat contains or is associated with some component in the diet, or some other characteristics of the food intake, which counterbalances the expected positive relationships between saturated fat intake and lipid levels.

Adolescent↗

PubMed2001

Markers of high fish intake are associated with decreased risk of a first myocardial infarction.

High intake of fish has been associated with reduced risk of CHD. The high content of n-3 polyunsaturated fatty acids (PUFA) in fish has been suggested to be a protective factor. In addition, fish is the entirely dominating source of methylmercury for the general population, and the concentration of Hg in erythrocytes (Ery-Hg) is often used as an index of fish consumption. Our aim was to study the relationships between a first-ever myocardial infarction, Ery-Hg, activity of gluthathione peroxidase in erythrocytes (Ery-GSH-Px) and plasma concentration of the n-3 PUFA eicosapentaenoic and docosahexaenoic acids (P-PUFA). In a population-based prospective nested case-control study within Northern Sweden seventy-eight cases of a first-ever myocardial infarction were compared with 156 controls with respect to Ery-Hg, P-PUFA and Ery-GSH-Px. Both Ery-Hg and P-PUFA, but not Ery-GSH-Px, were significantly higher in subjects reporting high fish intake (at least one meal per week) than in those with lower intake. This finding suggests that Ery-Hg and P-PUFA reflect previous long-term fish intake. Low risk of myocardial infarction was associated with high Ery-Hg or high P-PUFA. In a multivariate model the risk of myocardial infarction was further reduced in subjects with both high Ery-Hg and high P-PUFA (odds ratio 0.16, 95 % CI 0.04, 0.65). In conclusion, there is a strong inverse association between the risk of a first myocardial infarction and the biomarkers of fish intake, Ery-Hg and P-PUFA, and this association is independent of traditional risk factors.

Biomarkers↗

PubMed2001

Education, lifestyle factors and mortality from cardiovascular disease and cancer. A 25-year follow-up of Swedish 50-year-old men.

BACKGROUND: There is a well-established inverse relation between education and mortality from cardiovascular disease and cancer. The reasons for this are still in part unclear. We aimed to investigate whether differences in traditional vascular risk factors, adult height, physical activity, and biomarkers of fatty acid and antioxidant intake, could explain this association. METHODS: In all, 2301 50-year-old men in Uppsala, Sweden (82% of the background population) were examined with regard to educational level, blood pressure, blood glucose, body mass index, serum lipids, smoking, body height, physical activity, serum beta carotene, alpha tocopherol, selenium, and serum fatty acids in cholesterol esters. Cause-specific mortality was registered 25 years later. RESULTS: Low education was associated with a higher rate of mortality from cardiovascular disease (crude relative risk [RR] = 1.67, 95% CI : 1.17-2.39), and from cancer (crude RR = 1.94, 95% CI : 1.21-3.10), compared to high educational attainment. Men with high education had an overall more beneficial risk factor profile concerning traditional cardiovascular risk factors, physical activity, and biomarkers of dietary intake of antioxidants and fat. After adjustment for all examined risk factors, the inverse gradient between education and cardiovascular mortality disappeared (RR in low education = 1.01. 95% CI : 0.67-1.52). Controlling for smoking, physical activity and dietary biomarkers explained less than half of the excess cancer mortality in the lower educational groups. Smoking (adjusted RR = 1.89, 95% CI : 1.37-2.61), and high proportions of palmitoleic acid in serum cholesterol esters (adjusted RR per 1 SD = 1.39, 95% CI : 1.07-1.82) predicted cancer mortality, independently of all other factors. There were no independent relations between serum antioxidants and mortality. CONCLUSIONS: These data indicate that modifiable lifestyle factors mediate the inverse gradient between education and death from cerebro- and cardiovascular disease. Smoking, physical activity and dietary factors explained half of the excess cancer mortality in lower educated groups. Further studies are needed to explore the proposed association between palmitoleic acid, a marker of high intake of animal and dairy fat, and cancer.

Antioxidants↗

PubMed2001

Fatty acid composition of adipose tissue and serum lipids are valid biological markers of dairy fat intake in men.

The fatty acid intake is in part reflected by the fatty acid composition of adipose tissue and serum lipids. We evaluated whether the proportions of myristic (14:0), pentadecanoic (15:0) and heptadecanoic (17:0) fatty acids in the adipose tissue triacylglycerols and serum cholesterol esters and phospholipids reflect long-term dairy fat consumption in free-living men. In 114 healthy men aged 40-76 y, we compared the relative content of 14:0, 15:0 and 17:0 in subcutaneous adipose tissue and in serum lipids with relative intake (g/100 g of total fat) assessed by two 1-wk weighed food records made 6 mo apart and assessed by fourteen 24-h dietary recall interviews equally distributed during 1 y. According to food records, the mean +/- SD dairy fat intake was 24.9 +/- 13.1 g/d (29.6 +/- 10.5 g/100 g total fat); intake of 14:0, 15:0 and 17:0 was 4.6, 0.23 and 0.16 g/100 g total fat, and the content in adipose tissue was 3.6, 0.36 and 0.25 g/100 g fatty acids, respectively. Pearson correlation coefficients between intake of dairy fat (based on 24-h recalls) and fatty acid composition of adipose tissue were 0.64 (P: < 0.001) for 14:0, 0.74 (P: < 0.001) for 15:0 and 0.60 (P: < 0.001) for 15:0 + 17:0. Corresponding correlations with serum cholesterol esters were 0.34 (P: < 0.001) (14:0), 0.45 (P: < 0.001) (15:0) and 0.56 (P: < 0.001) (15:0 + 17:0), and with serum phospholipids the values were 0.30 (P: < 0.01) (14:0), 0.50 (P: < 0.001) (15:0) and 0.50 (P: < 0.001) (15:0 plus 17:0). In our study population, the relative content of 15:0 or 14:0 in adipose tissue is a valid biomarker for long-term dairy fat intake in free-living individuals. When adipose tissue is not available, 15:0 content in serum cholesterol esters or phospholipids might be used. Intake data based on repeated 24-h recalls are equally informative and may be an equivalent choice in nutritional studies.

Adipose Tissue↗

PubMed2001

Corn and sesame oils increase serum gamma-tocopherol concentrations in healthy Swedish women.

We studied the effects of dietary intervention with three vegetable oils (Linola, corn or sesame oil, all good sources of gamma-tocopherol) on absolute and relative concentrations of alpha- and gamma-tocopherol in human serum. The oils contained only small amounts of linolenic acid but varying amounts of oleic and linoleic acids, and they had different concentrations of alpha-tocopherol. Forty healthy female students (mean age 26 y) were randomly assigned to one of three groups and consumed a diet that contained one of the three oils for 4 wk. Refined oils were distributed as ingredients in specially prepared buns, in margarine or as dressing. Serum tocopherols, serum lipoproteins and plasma malondialdehyde concentrations were measured. The gamma-tocopherol concentrations normalized to serum lipids increased significantly in the corn and sesame oil groups (P < 0.01), and the alpha-/gamma-tocopherol ratios decreased significantly from baseline concentrations in all groups (P < 0.05). The alpha-tocopherol concentrations did not change during the diet period in any of the three groups. Serum cholesterol, serum apolipoprotein B and plasma malondialdehyde concentrations decreased significantly only in the Linola oil group (P < 0.05). These data show that a moderately modified natural diet that contains both alpha- and gamma-tocopherol increases the serum gamma-tocopherol concentration in healthy women without affecting the serum alpha-tocopherol concentration.

Adult↗

PubMed2001

Plasminogen activator inhibitor-1 and relations to fatty acid composition in the diet and in serum cholesterol esters.

High plasminogen activator inhibitor (PAI)-1 levels and poor dietary fat quality are potential risk factors for cardiovascular disease. The aim was to investigate the cross-sectional associations between PAI-1 activity and dietary nutrient intake, focusing on fat quality, in a population-based study of 871 men aged 70 years. The relationship between PAI-1 and the fatty acid composition in serum cholesterol esters (n=381 men) was also studied. The estimated total fat intake was positively associated with PAI-1 activity. The intake of both monounsaturated and polyunsaturated fatty acids was positively associated with PAI-1 activity, whereas the intake of saturated fatty acids was not. In serum cholesterol esters, higher proportions of palmitoleic and dihomo-gamma-linolenic acid, a lower proportion of linoleic acid, and reduced estimated Delta5-desaturase activity were associated with higher PAI-1 levels. These associations were confounded by factors representing the insulin resistance syndrome. PAI-1 activity was positively associated with gamma-linolenic and arachidonic acid, independent of potential confounders. In conclusion, this study demonstrates that dietary intake of unsaturated fatty acids is positively associated with PAI-1 activity, whereas intake of saturated fatty acids is not. The associations present between PAI-1 activity and the fatty acid proportions in serum cholesterol esters are partly influenced by metabolic syndrome-related factors.

Aged↗

PubMed2000

Serum concentrations of organochlorines in men: a search for markers of exposure.

Analysis of single marker substances in serum could provide cost-effective assessment of human exposure to complex mixtures of organochlorines. We studied the serum concentrations of 10 polychlorinated biphenyl (PCB) congeners and 11 chlorinated pesticides and some of their metabolites in samples collected from 120 Swedish men (mean age 63 years, range 40-74 years) from the general Swedish population. The median concentrations of individual PCB congeners increased in the order PCB 52 < PCB 101 < or = PCB28 < PCB 105 < PCB 167 < PCB 156 < PCB 118 < PCB 138 < PCB 180 < PCB 153. The concentrations of o,p'-DDT, o,p'-DDE, p,p'-DDD, alpha-HCH and gamma-HCH were in most cases below the quantification limit (2-4 ng/g lipid). Among the other chlorinated pesticides the median concentration increased in the order oxychlordane (12 ng/g lipid) < p,p'-DDT < trans-nonachlor < beta-HCH < HCB < p,p'-DDE (586 ng/g lipid). The observed concentrations of PCB and chlorinated pesticides were in the same range as those found in similar groups of men from Sweden and Norway, but lower than those found in male populations with recent occupational exposure or high environmental exposure. Strong relationships were found between the concentrations of single mono- and di-ortho PCB congeners and groups of PCB congeners in serum. In our group of men PCB 153 was a good marker substance for the concentration of sigma PCB and sigma di-ortho PCB concentrations in serum. Moreover, among the mono-ortho PCB congeners analyzed, PCB 156 could be used as a marker for the sigma mono-ortho PCB TEQ concentrations in serum in the studied group. No useful marker substances were found among DDT compounds and other chlorinated pesticides and metabolites, except for trans-nonachlor which predicted the concentration of the metabolite oxychlordane fairly well.

Adult↗

PubMed2000

Conjugated linoleic acid induces lipid peroxidation in humans.

Conjugated linoleic acid (CLA) is shown to have chemoprotective properties in various experimental cancer models. CLA is easily oxidised and it has been suggested that an increased lipid oxidation may contribute to the antitumorigenic effects. This report investigates the urinary levels of 8-iso-PGF(2alpha), a major isoprostane and 15-keto-dihydro-PGF(2alpha), a major metabolite of PGF(2alpha), as indicators of non-enzymatic and enzymatic lipid peroxidation after dietary supplementation of CLA in healthy human subjects for 3 months. A significant increase of both 8-iso-PGF(2alpha) and 15-keto-dihydro-PGF(2alpha) in urine was observed after 3 months of daily CLA intake (4.2 g/day) as compared to the control group (P<0.0001). Conjugated linoleic acid had no effect on the serum alpha-tocopherol levels. However, gamma-tocopherol levels in the serum increased significantly (P=0. 015) in the CLA-treated group. Thus, CLA may induce both non-enzymatic and enzymatic lipid peroxidation in vivo. Further studies of the mechanism behind, and the possible consequences of, the increased lipid peroxidation after CLA supplementation are urgently needed.

Adult↗