[Diet for heart patients. A questionnaire study at Danish coronary care units]

A questionnaire survey of Danish hospitals showed that 70% of patients admitted for acute ischaemic heart disease were served the ordinary menu during their stay at the hospital. About 10% had a diabetic menu, while 20% had different kinds of lipid lowering diets. The ordinary menu contained 17 energy percent (E%) protein, 38 E% fat, and 46 E% carbohydrate. The amount of fibre was 3.1 g/MJ, the ratio of polyunsaturated to saturated fatty acids (P/S) was 0.4, and the total energy in a day's menu was 8.1 MJ. The ordinary high-fat hospital diets differ markedly from diets believed to be cardioprotective, contrast with the dietary counselling given during admission, and should be replaced by lipid lowering diets in most cases of acute ischaemic heart disease for educational and therapeutic reasons.

[Spontaneous weight loss in young subjects of normal weight after 11 weeks of unrestricted intake of a low-fat/high-fiber diet]

The present study investigated the spontaneous, unintended body weight changes observed during the first 11 weeks of an eight months' ad libitum low-fat/high-fibre diet (25.5 energy-% fat, 58.5 energy-% carbohydrate, 3.9 g dietary fiber/MJ), primarily aimed at investigating changes in blood lipid concentrations. Subjects were normal-weight, young, healthy students, 24 in the intervention group, and 24 in the control group (no diet). After 11 weeks, an overall decrease in body weight (1.3 +/- 0.4 kg) (mean +/- SEM) (p < 0.01) and fat mass (1.6 +/- 0.2 kg, p < 0.001) was observed in the intervention group. Fat-free mass remained unchanged. Initial body weight and fat mass correlated significantly to changes in body weight and fat mass. No changes were observed in the control group. In conclusion, the ad libitum intake of a low-fat/high-fibre diet led to a spontaneous, small loss of body weight and fat mass in young, normal-weight subjects.

Haemostatic variables in Pacific Islanders apparently free from stroke and ischaemic heart disease--the Kitava Study

We cross-sectionally measured plasminogen activator inhibitor-1 (PAI-1) activity, fibrinogen, factor VII (FVII:C) and VIII (FVIII:C) coagulant activity, and von Willebrand factor antigen (VWF:Ag) in 162 traditional horticulturalists older than 40 years from the tropical island of Kitava, Papua New Guinea, where the intake of western food is negligible and where stroke and ischaemic heart disease appear to be absent. Identical analyses were made in Swedish subjects of comparable ages. Kitavams had markedly lower PAI-1 activity, with 85% of males and 100% of females having PAI-1 activity < or = 5 U/ml, as compared with 22 and 14% in Swedish males and females (p < 0.0001). Surprisingly, Kitavans also had higher FVII:C. FVIII:C and VWF:Ag. Fibrinogen was 10% lower in Kitavan males while 25% higher in Kitavan females. The very low PAI-1 activity in Kitavans may explain some of their apparent freedom from cardiovascular disease and probably relates to their extreme leanness.

Spontaneous weight loss during 11 weeks' ad libitum intake of a low fat/high fiber diet in young, normal weight subjects

OBJECTIVE

During the first 11 weeks of 8 months' ad libitum intake of a low fat/high fiber diet (25.5 energy-% fat, 58.5 energy-% carbohydrate, 3.9 g dietary fiber/MJ) primarily aimed at investigating the effect on blood lipids, spontaneous, unintended body weight changes occurred. The objective of the present paper was to elaborate the analyses on changes in body weight and composition during the 11 weeks' intervention period.

MEASUREMENTS

Dietary intake, body weight and composition.

SUBJECTS

Subjects in the intervention (I) (n = 24) and control group (C) (n = 24) were normal weight, young, healthy students.

RESULTS

In the intervention group an overall decrease in body weight (-1.3 +/- 0.4 kg) (mean +/- s.e.m.) (P < 0.01) and fat mass (-1.6 +/- 0.2 kg, P < 0.001) occurred. Fat free mass remained unchanged (0.1 +/- 0.3 kg, n.s.). Subjects with the initially lowest level of body fat (n = 10) gained fat-free mass (0.6 +/- 0.2 kg) (n.s.) and lost fat mass (-0.9 +/- 0.2) (P < 0.01). In the intervention group initial body weight and fat mass correlated significantly to change in body weight (r = -0.59, P = 0.003 and r = -0.53, P = 0.008) and fat mass (r = -0.52, P = 0.01, and r = -0.50, P = 0.01). No changes were observed in the control group.

CONCLUSION

The ad libitum intake of a low fat/high fiber diet lead to a spontaneous loss of body weight and fat mass in young, normal weight subjects.

Biomarkers of habitual fish intake in adipose tissue

The association between habitual fish and marine n-3 polyunsaturated fatty acid (PUFA) intake, and the fatty acid composition of subcutaneous fat was studied in 24 healthy young volunteers. Habitual dietary intakes were estimated from three 7-d weighted food records made at months 0, 5, and 8 of the 8-mo study period. The adipose tissue fatty acid composition of each individual was determined by gas chromatography as the mean of two gluteal biopsies, obtained in the first and the last month of the study. The daily consumption of fish and of marine n-3 PUFAs in absolute terms (g/d) was significantly associated with adipose tissue docosahexaenoic acid content (DHA; r = 0.55 and 0.58, respectively, P < 0.001), but not with eicosapentaenoic and docosapentaenoic acid contents. Our study indicates that the adipose tissue DHA content is the biomarker of choice for the assessment of long-term habitual dietary intakes of fish and marine n-3 PUFAs.

Effect of fats high in individual saturated fatty acids on plasma lipoprotein[a] levels in young healthy men

Plasma lipoprotein[a] (Lp[a]) is associated with atherogenesis and thrombogenesis. We examined how plasma Lp[a] in healthy young men was affected by fats high in stearic (C18), palmitic (C16), and lauric+myristic (C12+ C14) acid (experiment I, 15 subjects), and by fats high in myristic (C14) and palmitic (C16) acid (experiment II, 12 subjects). Strictly controlled isocaloric diets with 36% of energy from test fats were served in random order for 3 weeks separated by wash-out period(s). Diets high in C18 gave significantly higher levels of Lp[a] (51(12-560) mg/L) than diets high in C16 (38(12-533 mg/L) (P = 0.020) and C12 + C14 (34(12-534) mg/L) (P = 0.002). These differences were observed in several of the subjects in experiment I. In experiment II we saw no difference in plasma Lp[a] after diets high in C16 and C14. Our observations suggest that a fat high in stearic acid might affect Lp[a] in a different way than fats high in palmitic and myristic+lauric acid. Lp[a] concentrations were not associate with changes in tissue-plasminogen activator (t-PA) activity, factor VII coagualant activity, or plasma LDL cholesterol.

[Food intake of Danes and cardiac risk factors]

We served a low-fat (28% of energy) high-fibre (3.3 g/MJ) diet according to Nordic Nutrition Recommendations (REC diet), and a high-fat diet (39% of energy) corresponding to the average Danish diet (DANE diet) to 21 healthy middle-aged individuals in a two times two weeks cross-over study. The REC diet resulted in lower serum concentrations of low density lipoprotein (LDL) cholesterol (medians: 2.77 vs 3.04 mmol/l, p < 0.001), and high-density lipoprotein (HDL) cholesterol (1.08 vs 1.24 mmol/l, p < 0.001), and higher fasting triglycerides (1.11 vs 0.86 mmol/l, p = 0.04) than the DANE diet. Furthermore, the REC diet lowered plasma factor VII coagulant activity (FVIIc) (88 vs 96%, p = 0.002) and raised plasma fibrinolytic activity. Our observations indicate that a low-fat high-fibre diet may not only reduce the atherogenic, but also the thrombogenic tendency of an individual compared with a diet corresponding to the average Danish diet.

Dietary changes in fasting levels of factor VII coagulant activity (FVII:C) are accompanied by changes in factor VII protein and other vitamin K-dependent proteins

The mechanisms behind dietary effects on fasting coagulant activity of factor VII (FVII:C) are not clarified. In the present study of 15 young volunteers, two experimental diets differing in composition of saturated fatty acids (C18:0 [diet S] or C12:0 + C14:0 [diet ML]) were served for 3 weeks each. Fasting blood samples were collected before and after the dietary regimen and analysed for triglycerides, FVII:C, and protein concentrations of FVII, FII, FX, protein C, CRP, albumin, fibrinogen, and F1 + 2. FVII:C was significantly reduced on diet S compared with diet ML. This was accompanied by a decrease in FVII protein, F1 + 2 and the vitamin K-dependent proteins FII, FX, and protein C. In contrast, no changes were observed in triglycerides, FVII:C/FVII:Ag, albumin and CRP. Fibrinogen was increased on diet S compared with diet ML. Our findings suggest that the change in fasting FVII:C was part of a general change in concentrations of vitamin K-dependent proteins.

Effect on blood lipids, coagulation, and fibrinolysis of a fat high in myristic acid and a fat high in palmitic acid

The hypothesis that myristic acid (C14:0) has a stronger cholesterol-increasing potential than does palmitic acid is based on very few experimental observations. A randomized, strictly controlled dietary study was therefore designed to investigate the effect of a synthetic fat that was high in myristic acid, and palm oil, which is high in palmitic acid, on lipoproteins and hemostatic variables. Twelve men were served two diets (40% of energy as fat) with 41% of fat as myristic (diet M) or palmitic acid (diet P) for 3 wk with 1 mo between the two dietary schedules. Plasma HDL cholesterol was 8% higher with diet M than with diet P: 1.10 +/- 0.06 (mean +/- SEM) vs 1.01 +/- 0.05 mmol/L (P < 0.006). Diet M raised factor VII coagulant (F VIIc) activity to 98% (77-117%) vs 96% (71-109%) (medians and ranges) after diet P (P = 0.02). Total and LDL-cholesterol concentrations did not differ between the diets. In conclusion, the myristic acid test fat was not more cholesterolemic than was palm oil, but it did induce a minor rise in F VIIc activity.

Non-fasting factor VII coagulant activity (FVII:C) increased by high-fat diet

Preliminary observations have suggested that non-fasting factor VII coagulant activity (FVII:C) may be related to the dietary fat content. To confirm this, we performed a randomised cross-over study. Seventeen young volunteers were served 2 controlled isoenergetic diets differing in fat content (20% or 50% of energy). The 2 diets were served on 2 consecutive days. Blood samples were collected at 8.00 h, 16.30 h and 19.30 h, and analysed for triglycerides, FVII coagulant activity using human (FVII:C) or bovine thromboplastin (FVII:Bt), and FVII amidolytic activity (FVII:Am). The ratio FVII:Bt/FVII:Am (a measure of FVII activation) increased from fasting levels on both diets, but most markedly on the high-fat diet. In contrast, FVII:Am (a measure of FVII protein) tended to decrease from fasting levels on both diets. FVII:C rose from fasting levels on the high-fat diet, but not on the low-fat diet. The findings suggest that high-fat diets increase non-fasting FVII:C, and consequently may be associated with increased risk of thrombosis.

The effect of ephedrine plus caffeine on plasma lipids and lipoproteins during a 4.2 MJ/day diet

The effect of treatment with a combination of ephedrine and caffeine during eight weeks' energy restriction (4.2 MJ/day) on the fasting plasma lipid profile was studied in obese women. Thirty-two women were randomly assigned to either ephedrine 20 mg plus caffeine 200 mg (EC) or placebo three times per day. Weight loss (7.8 +/- 0.63 kg) and loss of fat mass (6.2 +/- 0.49 kg) did not differ significantly between the two groups. Total cholesterol concentration declined from baseline to week 8 (0.58 +/- 0.13 mmol/l) with no significant difference between the two groups. HDL-cholesterol concentration was decreased by 0.14 +/- 0.03 mmol/l at week 4 and week 8 in the placebo group (P < 0.05) but remained unchanged in the EC group. No effect of dieting was seen on plasma triglyceride concentration in the placebo group but a decrease was observed in the EC group at week 8. It is suggested that EC combinations abolish the decline in HDL-cholesterol during active weight loss due to the beta-agonistic properties of ephedrine.

Low-fat, high-fiber diet favorably affects several independent risk markers of ischemic heart disease: observations on blood lipids, coagulation, and fibrinolysis from a trial of middle-aged Danes

We served a low-fat (28% of energy), high-fiber (3.3 g/MJ) diet according to Nordic nutrition recommendations (Rec diet), and a high-fat diet (39% of energy) corresponding to the average Danish diet (Dane diet) for periods of 2 wk in a randomized crossover study of 21 healthy middle-aged individuals. The Rec diet resulted in lower serum concentrations of low-density-lipoprotein (LDL) cholesterol (medians: 2.77 vs 3.04 mmol/L, P < 0.001) and high-density-lipoprotein (HDL) cholesterol (1.08 vs 1.24 mmol/L, P < 0.001), and higher fasting triglycerides (1.11 vs 0.86 mmol/L, P = 0.04) than did the Dane diet. Furthermore, the Rec diet lowered plasma factor VII coagulant activity (FVIIc) (88% vs 96%, P = 0.002) and raised plasma fibrinolytic activity. Our observations indicate that a low-fat, high-fiber diet may not only reduce the atherogenic but also the thrombogenic tendency of an individual compared with a diet corresponding to the average Danish diet.