Glucose and insulin responses to meals containing milk, lactose, glucose or fructose in subjects with non-insulin-dependent diabetes.

The postprandial blood glucose and serum insulin responses to liquid test meals containing 40 g carbohydrate from milk, lactose, glucose or fructose and equal amounts of energy were compared in 10 non-insulin-dependent (type 2) diabetic patients. The meals were consumed in random order on consecutive days after an overnight fast. Significant differences (p less than 0.001, ANOVA) were observed between the glucose and insulin responses to the meals. The glucose response was significantly higher after the glucose containing meal and lower after the fructose meal as compared with the other meals. The insulin response was significantly higher after the lactose and glucose meals than after the milk and fructose meals. After the milk and lactose meals the blood glucose responses were similar whereas the insulin response was significantly lower after the milk meal. As lactose apparently was similarly absorbed from the two meals the difference in the insulin response was probably due to different insulinogenic effects of the protein components or to differences in the physical properties of the respective meals.

Effects of dietary fat modifications on serum lipids and blood pressure in children.

Some recent studies have shown an extremely high level of serum cholesterol level among Finnish children. The aim of the present study was to test the effect of a "cholesterol lowering diet" on serum lipids and blood pressure among 36 children aged 8-18 years residing in two semirural communities in North Karelia, Finland. After a baseline period of two weeks on conventional diets, the proportion of energy derived from fat in the diet was reduced from the baseline level of 35% to 24%, and the ratio of polyunsaturated/saturated fats was increased from the baseline level of 0.18 to 0.61, during a 12-week intervention period. The children then changed back to their normal diet during a five-week switch-back period. The mean serum total cholesterol decreased 15% during the intervention, and then increased to nearly the initial level during the switch-back period. Similar changes were observed in HDL-cholesterol and also to some extent in apoproteins AI, AII and B. Blood pressure was not affected, although systolic blood pressure decreased during intervention. We conclude that the high level of serum cholesterol in Finnish children is to a great extent caused by the local dietary pattern and can be decreased by dietary modification.

Dietary fat and blood pressure: an intervention study on the effects of a low-fat diet with two levels of polyunsaturated fat.

The role of dietary fat in human blood pressure control was studied among 84 middle-aged subjects (mainly couples) in two semirural communities in North Karelia, Finland. The families were randomly allocated into two groups that, after a baseline period of 2 weeks, changed their diet for a 12-week intervention period so that the proportion of energy derived from fats was similarly reduced in both groups, from 38 to 24%, but the polyunsaturated/saturated fatty acid (P/S) ratio was increased--from 0.2 to 0.9 in group I and to 0.4 in group II. After the intervention period, both groups switched back to their usual diet for a period of 5 weeks. During the intervention period, total serum cholesterol was reduced by 16% in group I and 14% in group II. Mean body weight and urinary sodium, potassium, calcium, and magnesium excretion changes were small or nonexistent. Mean systolic blood pressure decreased 4 mm Hg in group I (P less than 0.01) and 3 mm Hg in group II (P less than 0.01), and mean diastolic blood pressure decreased 5 mm Hg (P less than 0.001) and 4 mm Hg (P less than 0.01), respectively. The reductions were reversed during the switch-back period (P less than 0.01). These results confirm previous findings of the blood-pressure-reducing effect of a low-fat/high-P/S diet. Although a number of possible confounding factors can be ruled out, the dietary constituent accounting for the blood pressure change cannot be ascertained definitely. The results showed no significant further blood pressure reduction with more than a moderately increased P/S ratio when the saturated fat intake was markedly reduced.

Concentration and composition of serum lipoproteins during a low-fat diet at two levels of polyunsaturated fat.

A 12-week dietary intervention was carried out among 40 families from North Karelia, a county in Finland with an exceptionally high rate of coronary heart disease and high serum cholesterol values. The proportion of dietary energy derived from fat was reduced during the 12-week intervention period from about 39% to 23% in all families. The families were randomly allocated into two groups. Twenty families consumed a diet with a polyunsaturated to saturated fat (P/S) ratio of 0.9 (group I), while the other 20 families had a diet with a P/S ratio of 0.4 (group II). Total serum cholesterol decreased by 16% and 9% in men of groups I and II, respectively, and by 16% in women of both groups. These changes were due to a decrease in both low density lipoprotein (LDL) and high density lipoprotein (HDL) cholesterol. LDL cholesterol and phospholipid reached minimum values after 6 weeks on both intervention diets, but LDL protein responded more slowly. Thus, after 6 weeks LDL had an altered composition containing less cholesterol and phospholipids and more protein and triglycerides than during the baseline diet. During the intervention, the linoleic acid content in the serum cholesteryl ester fraction increased, and the magnitude of this change correlated negatively with the changes in total and LDL cholesterol. The decrease in HDL cholesterol during the two intervention diets was due to a fall in the HDL2 cholesterol (29% and 24% in men, and 26% and 25% in women in groups I and II, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Relation of alcohol, physical activity, dietary fat and smoking to serum HDL and total cholesterol in young Finnish men.

The study was based on 471 men, aged 19 to 20 years, who started their compulsory military service in three military bases in Southwest, Southeast and Northern Finland in February 1982. The data were gathered by means of self-administered questionnaires. A fasting venous blood specimen was taken to determine serum HDL and total cholesterol, gamma-glutamyltransferase and thiocyanate. In this cross-sectional study a few variables based on the self-administered questionnaire explained 8% and 7% of the variation in serum HDL and total cholesterol, respectively. Our results show that easily measurable behavioural factors do contribute to serum HDL and total cholesterol levels in young men. In our study the impact of alcohol consumption on serum HCL cholesterol was greater than in most previous studies. Our findings give additional support to the hypothesis that even a very modest amount of regular physical exercise has the effect of increasing the serum HDL cholesterol level.

Effect of a diet low in saturated fatty acids on plasma lipids, lipoproteins, and HDL subfractions.

The effect on serum high density lipoprotein subfractions of a low fat diet with a high ratio of polyunsaturated-to-saturated fatty acids was studied in 38 middle-aged volunteers (19 men and 19 women) in North Karelia, Finland. The mean serum HDL2 cholesterol decreased from 32 +/- 2 mg/dl (mean +/- SE) to 28 +/- 2 mg/dl (p less than 0.001) during the experimental diet and returned to 33 +/- 2 mg/dl (p less than 0.001) after a return to the original diet. No changes were observed in the concentration of HDL3 cholesterol. A highly significant decrease was observed in serum apoprotein A-I concentration, but not in apoprotein A-II concentration during the experimental diet. It is concluded that a low-fat, high-P/S ratio diet lowers LDL and HDL2 cholesterol in healthy volunteers, but does not influence the level of HDL3 subfraction.

Dietary intervention study among 30 free-living families in Finland.

A dietary intervention study to reduce risk factors for coronary heart disease was carried out among 30 free-living middle-aged couples in North Karelia, Eastern Finland. During the study, the subjects changed their normal diet for six weeks. The main changes in the diet were decrease in the consumption of fat (from 39% to 24% of total calories), increase in the P:S ratio from 0.15 to 1.22, and increased consumption of fruit and vegetables. The changes in the food consumption pattern were facilitated by giving the families free food items, such as skim milk, vegetable margarine, vegetables, and fruit. The food consumption and nutrient intakes were measured by food consumption records kept every other day. Also, duplicate diets were collected once during each study period for chemical analysis. Compliance with the dietary changes was better than expected, and the acceptability and the palatability of the diet were reported to be good. The decrease in the fat content of the diet increased the nutrient density of the diet; i.e., the concentration of vitamins and minerals improved. This study showed how even more drastic dietary changes than those recommended by health authorities can be realized among ordinary Finnish people.

Effect of dietary fat on blood pressure in a rural Finnish population.

Thirty couples living in Liperi, a community of North Karelia, aged 40 to 50 yr participated in a dietary intervention study to assess the influence of dietary fat on blood pressure and other parameters. After a weeklong base-line period the subjects consumed a low fat diet (24% of energy) with a polyunsaturated/saturated fat ratio (P/S) of 1.2 for 6 wk. After this 6-wk intervention period the subjects resumed their normal diets (36% energy from fat, P/S 0.15) for an additional 6-wk period. Body weight remained constant throughout the study and salt intakes were approximately 12 g/day. During the low fat, high P/S period a decrease of 7.5 and 2.8 mm Hg pressure occurred for systolic and diastolic blood pressure from the base-line level. When the normal diet was resumed, systolic and diastolic blood pressures increased by 7.7 and 6.3 mm Hg, respectively, from the levels observed at the end of the intervention period.

Controlled, randomised trial of the effect of dietary fat on blood pressure.

57 couples living in two communities of North Karelia, aged 30-50 years, were randomly allocated to three groups. After a 2-week baseline period group I followed a diet low in fat (23% of energy) with a high polyunsaturated/saturated (P/S) ratio (1 . 0), group II reduced daily salt intake from 192 mmol to 77 mmol, and group III (control group) continued the usual diet. After the 6-week intervention period groups I and II reverted to their usual diets. In group I systolic blood pressure declined from 138 . 4 to 129 . 5 mm Hg and diastolic blood pressure from 88 . 9 to 81 . 3 mm Hg during the intervention period; the values rose during switch-back. The fall was greater among hypertensive than among normotensive subjects. In groups II and III the mean blood pressure changed very little during the study.

Effect of diet on serum lipoproteins in a population with a high risk of coronary heart disease.

The population of North Karelia, a county in Finland, has a high rate of coronary heart disease. It also has a high prevalence of hypercholesterolemia, but whether this reflects a diet rich in animal fats or is a result of genetic factors is unclear. We studied the effect on serum lipoproteins of a low-fat diet with a high ratio of polyunsaturated to saturated fatty acids in 54 middle-aged volunteers in North Karelia. Total serum cholesterol decreased, from 263 +/- 8 mg per deciliter (mean +/- S.E.) to 201 +/- 5 mg in men (P less than 0.0001) and from 239 +/- 8 to 188 +/- 8 mg in women (P less than 0.0001), along with low-density-lipoprotein cholesterol and apoprotein B. High-density lipoprotein decreased from 54 +/- 2 mg per deciliter to 44 +/- 2 in men (P less than 0.0001) and from 56 +/- 3 to 47 +/- 2 mg in women (P less than 0.0001). A small but significant reduction occurred in serum apoprotein A-I, whereas apoprotein A-II increased slightly. The individual changes in low-density-lipoprotein cholesterol correlated with those in high-density-lipoprotein cholesterol. The changes in serum lipids and apoproteins were reversed when the participants returned to their original diets. Our results suggest that the hypercholesterolemia characteristic of this population is due at least in part to dietary factors.