Prevalence of type 2 diabetes mellitus in a representative sample of Greek adults and its association with modifiable risk factors: results from the Hellenic National Nutrition and Health Survey.

OBJECTIVE: Diabetes mellitus is a disease associated with many complications leading to premature death. The aim of this study was to estimate prevalence of type 2 diabetes (T2D), and the proportion of the population unaware of the condition, in association with modifiable risk factors. STUDY DESIGN: Data from the Hellenic National Nutrition and Health Survey were used (n = 3773 adults, 40.8% men) and were obtained by trained personnel. METHODS: Diabetes mellitus disease status was categorized as per the International Classification of Diseases codes (10th version). A subsample from the two main metropolitan areas was used to assess T2D and impaired fasting glucose (IFG) (n = 990; 38.2% men) from plasma analysis. RESULTS: The prevalence of T2D in the population was 5.2% in total, reaching 13.7% in adults aged >60 years (no sex differences). IFG was observed in 27.3% of adults in the two metropolitan areas, and 40% were unaware of having T2D in this subsample. The likelihood of having T2D significantly increased with age and body weight, whereas it decreased with higher educational level and physical activity (P for all <0.001). CONCLUSION: The high T2D prevalence in adults, especially among the older age-groups, suggests a major public health problem in Greece.

Association of meal and snack patterns with micronutrient intakes among Greek children and adolescents: data from the Hellenic National Nutrition and Health Survey.

BACKGROUND: The present study aimed to examine how different meal and snack patterns are associated with micronutrient intakes and diet quality among a nationally representative sample of Greek children and adolescents aged 1-19 years from the cross-sectional Hellenic National Nutrition and Health Survey (n = 598). METHODS: Meal and snack patterns were derived using 24-h dietary recalls. Mean adequacy ratio (MAR) was used as an overall measure of diet quality. Multiple linear regression adjusted for covariates was conducted to examine associations between eating patterns, nutrient intakes and MAR. RESULTS: Four most frequently reported eating schemes were identified including breakfast (B), lunch (L), dinner (D) and two snacks (S) (20.9%); B, L, D and 1S (16.2%); B, L, D and 3S (10.8%); and B, L and D (7.9%). Based on these schemes, the daily consumption of all main meals from the majority of the sample was highlighted. In children and adolescents aged 4-19 years, increasing snack frequency was positively associated with intakes of vitamin D, vitamin K, riboflavin, niacin, pantothenic acid, folate, magnesium, copper and selenium. An inverse association was recorded for vitamin E, vitamin B6 , calcium and iron. Among children aged 1-3 years, only niacin and copper were significantly associated with number of snacks, with the group of 'B-L-D-2S' presenting the highest intake. As for the overall diet quality, among all participants, there was no significant association of MAR with the type of meal and snack pattern, and thus the snack frequency. CONCLUSIONS: Snacking behaviour is a common practice among children and adolescents. Modifying current snack foods with nutrient-rich choices could lead to an improvement of their diet's nutritional quality.

Effectiveness and easiness of adherence to behavioural guidelines for diet and lifestyle changes for cholesterol-lowering: the Increasing Adherence of Consumers to Diet & Lifestyle Changes to Lower (LDL) Cholesterol (ACT) randomised controlled trial.

BACKGROUND: The present study aimed to assess perceived effectiveness and easiness of behavioural diet and lifestyle changes related to dyslipidaemia given by physicians or dieticians as a result of diet and lifestyle modifications being difficult to maintain. METHODS: One-hundred hypercholesterolaemic individuals were enrolled in a parallel, randomised 6-week study. Fifty were advised by dietitians (dietitian group: DG) in six weekly face-to-face behavioural therapy sessions and 50 received standard advice from physicians (physician group: PG). All individuals were followed-up for another 6 weeks under real-life conditions. Questionnaires regarding perceived effectiveness, easiness of adhering, forecasted and actual adherence to specific cholesterol-lowering advice were completed. RESULTS: Scores of perceived effectiveness of advice for sufficient exercise, limiting saturated fat (SFA) intake, eating fish twice a week, consuming plenty of fresh fruit and vegetables, and limiting salt intake different scientifically (all P < 0.05) in PG and DG between study phases. Scores of the individuals' perception of effectiveness at all study phases were higher in the DG compared to PG for sufficient exercise, limiting SFA intake, eating fish twice a week, eating plenty of fruits and vegetables, and limiting salt intake, whereas scores of easiness were significant only for fish consumption (P = 0.008) and using foods with added plant sterols (all P < 0.05). DG and PG significantly differed in forecasted (week 6) versus actual adherence (week 12) to various chances, with DG reporting higher adherence. CONCLUSIONS: Lifestyle and dietary changes related to dyslipidaemia can be achieved with continuous education, monitoring and follow-ups by dieticians, as well as potentially other trained healthcare professionals.

Dietary patterns and lifestyle characteristics in adults: results from the Hellenic National Nutrition and Health Survey (HNNHS).

OBJECTIVES: The objective of this study was to identify and describe different dietary patterns in a nationally representative sample of Greek adults and to assess potential associations with lifestyle characteristics. STUDY DESIGN: This was a cross-sectional study. METHODS: Dietary patterns were derived by principal component analysis using individual dietary data (24-h recall) of 3552 participants of the Hellenic National Nutrition and Health Survey (HNNHS). Analysis of variance and chi-squared test were used to determine the lifestyle characteristics of the participants following each pattern. RESULTS: Three dietary patterns were identified explaining 16.5% of variance; a traditional pattern, loading positively on olive oil, non-starchy vegetables, and cheese; a Western pattern, loading positively on refined grains, processed meats, and animal fats; and a prudent pattern, loading positively on fruits, whole grains, and yoghurt and negatively on fast food. A fourth, snack-type pattern, loading positively on sweets, salty snacks, and nuts, was identified in women. Primary crude results revealed an association between dietary patterns and socio-economic status. In multivariate analysis, highest adherence to the prudent pattern was associated with higher protein and unsaturated fat intake and lower energy and saturated fat intake (all P ≤ 0.05); the Western and traditional patterns were associated with higher energy and total and saturated fat intake. The traditional pattern was additionally associated with higher monounsaturated fatty acids intake, whereas the Western pattern, with higher alcohol intake (all P ≤ 0.001). CONCLUSIONS: These findings are valuable for understanding the dietary behaviors of adults in Greece and enabling more focused public health policies for the promotion of healthier food behaviors in the future.

Structured advice provided by a dietitian increases adherence of consumers to diet and lifestyle changes and lowers blood low-density lipoprotein (LDL)-cholesterol: the Increasing Adherence of Consumers to Diet & Lifestyle Changes to Lower (LDL) Cholesterol (ACT) randomised controlled trial.

BACKGROUND: Evidence from healthcare professionals suggest that consumer compliance to healthy diet and lifestyle changes is often poor. The present study investigated the effect of advice provided by a physician or dietitian on consumer adherence to these measures combined with consuming foods with added plant sterols (PS) with the aim of lowering low-density lipoprotein cholesterol (LDL-C). METHODS: One hundred mildly-to-moderately hypercholesterolaemic individuals were enrolled into a parallel, randomised, placebo-controlled study. Dietitians (dietitian group; DG) advised 50 individuals in six weekly face-to-face behavioural therapy sessions, whereas the other 50 received standard advice from physicians (physician group, PG). Both groups consumed foods with added PS (three servings a day) for 6 weeks. Subsequently, all individuals were followed-up for another 6 weeks under real-life conditions. Blood lipids were measured at baseline and weeks 6 and 12 and 3-day diet diaries were taken at weeks 1, 6 and 12. RESULTS: Individuals in the DG significantly improved their dietary habits, physical activity and increased PS intake compared to the PG. After 6 weeks, LDL-C decreased in both groups compared to baseline without any significant differences between groups. At week 12, LDL-C was further significantly improved only in the DG (P = 0.006) compared to week 6. Total cholesterol, LDL-C and triglycerides were significantly lower in the DG compared to the PG at week 12 after adjusting for levels at week 6 (P < 0.001, P < 0.001 and P = 0.009, respectively). CONCLUSIONS: Although structured counselling by dietitians and common standard advice by physicians were equally effective with respect to improving blood cholesterol after 6 weeks, dietitians were more effective in the longer-term (i.e. 6 weeks after the end of the intervention period).

Newly derived children-based food index. An index that may detect childhood overweight and obesity.

A food index (FI) based on a priory knowledge was developed to assess the role of diet on overweight (OW) and obesity (OB) in school-aged children. This included «positive¼ and «negative¼ foods based on research evidence and food guidelines, with scores set accordingly. Statistical tests were used to strengthen the sensitivity of the index. The FI was validated using data from the GRECO study. The score ranged from 17 to 53.5 (mean 34.8 ± 5.01) and was inversely associated with body mass index (BMI) (-0.057 ± 0.02; 95% CI -0.098, -0.017) and waist circumference (WC) (-0.08 ± 0.03, 95% CI: -0.137, -0.022). Associations remained significant upon adjusting for age, gender and physical-inactivity (p = 0.02 ad 0.013, respectively). When stratified by gender, the association between FI and WC was not significant for boys (p = 0.08). The association with BMI remained significant for females and males (p = 0.047 and 0.037, respectively). The derived FI seems a valuable tool in detecting OW in children.

Evaluation of seasonality on total water intake, water loss and water balance in the general population in Greece.

BACKGROUND: Water balance is achieved when water intake from solid and fluid foods and drinking water meets water losses, mainly in sweat, urine and faeces. Seasonality, particularly in Mediterranean countries that have a hot summer, may affect water loss and consequently water balance. Water balance has not been estimated before on a population level and the effect of seasonality has not been evaluated. The present study aimed to compare water balance, intake and loss in summer and winter in a sample of the general population in Greece. METHODS: The Water Balance Questionnaire (WBQ) was used to evaluate water balance, estimating water intake and loss in summer (n = 480) and in winter (n = 412) on a stratified sample of the general population in Athens, Greece. RESULTS: In winter, mean (SD) water balance was -63 (1478) mL/day(-1) , mean (SD)water intake was 2892 (987) mL/day(-1) and mean (quartile range) water loss was 2637 (1810-3922) mL/day(-1) . In summer, mean (SD) water balance was -58 (2150) mL/day(-1) , mean (SD) water intake was 3875 (1373) mL/day(-1) and mean (quartile range) water loss was 3635 (2365-5258) mL/day(-1) . Water balance did not differ between summer and winter (P = 0.96); however, the data distribution was different; in summer, approximately 8% more participants were falling in the low and high water balance categories. Differences in water intake from different sources were identified (P < 0.05). CONCLUSIONS: Water balance in summer and winter was not different. However, water intake and loss were approximately 40% higher in summer than in winter. More people were falling in the low and high water balance categories in summer when comparing the distribution on water balance in winter.

Phytosterols supplementation decreases plasma small and dense LDL levels in metabolic syndrome patients on a westernized type diet.

BACKGROUND AND AIMS: Several studies have observed a hypocholesterolemic effect of plant sterols in hypercholesterolemic patients on a balanced diet. The aim of this study was to examine the effect of phytosterol supplementation on risk factors of coronary artery disease in metabolic syndrome patients on a Westernized type diet. METHODS AND RESULTS: In a randomized placebo-controlled design 108 patients with metabolic syndrome were assigned to consume either 2 plant sterol-enriched yogurt mini drink which provided 4 g phytosterols per day, or a yogurt beverage without phytosterols (control). The duration of the study was 2 months and the patients in both groups followed their habitual westernized type diet and recording it on food diaries. Blood samples were drawn at baseline and after 2 months of intervention. After 2 months supplementation with phytosterols, a significant reduction in total cholesterol, LDL-cholesterol, small and dense LDL (sdLDL) levels, as well as, apoB and triglycerides concentrations were observed in the intervention group (P < 0.05) compared to the control group. In addition, phytosterol supplementation lowered serum total cholesterol by 15.9%, LDL-cholesterol by 20.3% and triglyceride levels by 19.1% (P = 0.02, P < 0.001 and P < 0.001, respectively), although the patients kept their habitual westernized type diet. No differences were observed in HDL cholesterol, apoA1, glucose, C-reactive protein, fibrinogen levels and blood pressure. CONCLUSIONS: Phytosterol supplementation improves risk factors of coronary artery disease even if the diet is a westernized type.

Erythrocyte fatty acid composition and insulin sensitivity in daughters of Type 2 diabetic patients and women with no family history of diabetes.

BACKGROUND: There is evidence that the impact of environmental factors on insulin sensitivity is modified by the presence of family history of diabetes. AIM: To compare the association between the erythrocyte phospholipid fatty acid composition (a biomarker of dietary fatty acids) and insulin sensitivity in daughters of Type 2 diabetic patients with the corresponding association in women without family history of diabetes. MATERIAL/SUBJECTS AND METHODS: Eighteen offspring of Type 2 diabetic patients [age 30+/-6.5 yr; body mass index (BMI) 22.2+/-2.5 kg/m2; body fat 31.8+/-5.1%] and 18 matched women (age 30.1+/-6.8 yr; BMI 22.2+/-1.8 kg/m2; body fat 32.2+/-6.0%) participated in the study. RESULTS: Insulin Sensitivity Index (ISI)-Matsuda tended to be lower (p=0.06) in the Offspring than the control group. Weight proportions of erythrocyte phospholipid saturated (SFA), polyunsaturated (PUFA), and monounsaturated fatty acids (MUFA) were similar between the two groups. In the offspring, erythrocyte total SFA were negatively correlated with ISI-Matsuda [r=-0.47, p<0.05), ISI(gly)-Belfiore (r=-0.52, p<0.05) and ISI(ffa)-Belfiore (r=-0.53, p<0.05)], whereas total PUFA were positively correlated with insulin sensitivity [ISI-Matsuda, r=0.46, p<0.05; ISI(gly)-Belfiore, r=0.53, p<0.05; ISI(ffa)-Belfiore, r=0.54, p<0.05]. No significant correlations were observed in the control group. CONCLUSIONS: The associations between erythrocyte fatty acid composition and insulin sensitivity are distinct between daughters of Type 2 diabetic patients and women without family history of diabetes.

A high protein low fat meal does not influence glucose and insulin responses in obese individuals with or without type 2 diabetes.

BACKGROUND: When substituted for carbohydrate in a meal, dietary protein enhances glycaemic control in subjects with type 2 diabetes (DM2). It is unknown whether the effect is a result of increased protein or reduced carbohydrate. The present study aimed to compare the effects of two meals differing in protein to fat ratios on post-prandial glucose and insulin responses. METHODS: This was a crossover, blind study in which obese subjects with (n = 23) and without (n = 26) DM2 consumed two meals in random order with equal amounts of energy (3.1 MJ, 741 kcal), fibre and carbohydrates and a 1-week washout period. Meals were a high protein, low fat (30% protein, 51% carbohydrates, 19% fat) meal and a low protein, high fat (15% protein, 51% carbohydrates, 34% fat) meal. Subjects were matched for age and body mass index. Plasma glucose and insulin were measured at fasting, 30, 60, 90, 120 min post-prandially. Insulin resistance and insulin sensitivity were assessed. RESULTS: There was no significant meal effect on glucose and insulin responses within groups. Glucose response was higher in diabetic (120 min 11 +/- 0.7 mmol L(-1)) compared to nondiabetic (120 min 5 +/- 0.2; P < 0.001) subjects. Diabetic subjects had significantly higher insulin resistance (P < 0.001) and lower insulin sensitivity (P < 0.001) than nondiabetics. Although peak insulin levels, 60 min post-prandially, did not differ between groups (81 +/- 9 pmol L(-1) for diabetic versus 79 +/- 7 pmol L(-1) for nondiabetic subjects), they were achieved much later, 90 min post-prandially, in diabetic, (99 +/- 8 pmol L(-1)) compared to nondiabetic (63 +/- 7 pmol L(-1), P = 0.002) subjects. CONCLUSIONS: Manipulating protein to fat ratio in meals does not affect post-prandial plasma blood glucose or insulin responses in obese people with and without DM2.

Effects of red wine on endothelial function: postprandial studies vs clinical trials.

AIMS: There are several epidemiological studies suggesting that moderate daily consumption of red wine may reduce cardiovascular risk. Additionally, results from a great number of in vitro studies indicate that constituents found in red wine are responsible for quite a few beneficial effects on endothelial cells. However, comparison of postprandial studies and clinical trials concerning red wine consumption leads to controversial results about its effect on endothelial function and especially flow-mediated dilatation (FMD). Endothelial function is an early indicator of atherosclerosis and vessel damage and at the same time, it is an independent prognostic factor for cardiovascular risk. Therefore, it is very important to investigate the known acute postprandial effects of red wine consumption, which is highly advised by dieticians and doctors, especially in high-risk populations, such as patients with coronary artery disease (CAD). DATA SYNTHESIS: This is a review of studies investigating acute and short-term effects of red wine on endothelial function, as well as relevant in vitro studies. CONCLUSION: Analysis of all data about the acute effects of red wine constituents on endothelial function, is inconclusive and it is obvious that new studies are necessary in order to elucidate this matter. Undoubtedly, one should be very careful in suggesting red wine consumption in high-risk populations, as its acute postprandial effect is not yet clear.

Dietary supplementation with flaxseed oil lowers blood pressure in dyslipidaemic patients.

OBJECTIVE: Alpha-linolenic acid (ALA) is the natural precursor of the cardioprotective long-chain n-3 fatty acids. Available data indicate a possible beneficial effect of ALA on cardiovascular disease (CVD), but the response of various CVD risk factors to increased ALA intake is not well characterized. The purpose of the present study was to examine the effect of increased ALA intake on blood pressure in man. DESIGN, SETTING, SUBJECTS AND INTERVENTIONS: We used a prospective, two-group, parallel-arm design to examine the effect of a 12-week dietary supplementation with flaxseed oil, rich in ALA (8 g/day), on blood pressure in middle-aged dyslipidaemic men (n=59). The diet of the control group was supplemented with safflower oil, containing the equivalent n-6 fatty acid (11 g/day linoleic acid (LA); n=28). Arterial blood pressure was measured at the beginning and at the end of the dietary intervention period. RESULTS: Supplementation with ALA resulted in significantly lower systolic and diastolic blood pressure levels compared with LA (P=0.016 and P=0.011, respectively, from analysis of variance (ANOVA) for repeated measures). CONCLUSIONS: We observed a hypotensive effect of ALA, which may constitute another mechanism accounting in part for the apparent cardioprotective effect of this n-3 fatty acid.

Nutrition and inflammatory load.

Chronic inflammation has been suggested to play an important role in metabolic diseases, such as atherothrombosis and type 2 diabetes. A lot of research has focused on the immunomodulatory effects of several nutrients, such as fatty acids, antioxidants, carbohydrates, specific amino acids, micronutrients, and alcohol, which play a crucial role in the maintenance of an "optimal" immune response. In addition, specific dietary patterns, such as the Mediterranean diet, are evolving as protective against cardiovascular disease, because of their anti-inflammatory properties. In this article, the existing data concerning the nutrients' pro- and anti-inflammatory properties are presented, as well as dietary patterns that could protect from chronic inflammation and its metabolic and atherothrombotic complications.

The effect of MTHFR(C677T) genotype on plasma homocysteine concentrations in healthy children is influenced by gender.

OBJECTIVE: To explore the influence of gender, together with folate status, on the relation between the common methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and plasma total homocysteine (tHcy) concentrations in healthy children. DESIGN: Cross-sectional study by face-to-face interview. SETTING AND SUBJECTS: A total of 186 sixth-grade students participated from twelve randomly selected primary schools in Volos, Greece. METHODS: Fasting tHcy, folate, and vitamin B(12) were measured in plasma. The MTHFR genotypes were determined. Anthropometric and dietary intake data by 24-h recall were collected. RESULTS: Geometric means for plasma tHcy, plasma folate and energy-adjusted dietary folate did not differ between females and males. The homozygous mutant TT genotype was associated with higher tHcy only in children with lower plasma folate concentrations (<19.9 nmol/l, P = 0.012). As a significant gender interaction was observed (P = 0.050), we stratified the lower plasma folate group by gender and found that the association between the genotype and tHcy was restricted to males (P = 0.026). Similar results were obtained when folate status was based on estimated dietary folate. Specifically, only TT males that reported lower dietary folate consumption (<37 microg/MJ/day) had tHcy that was significantly higher than tHcy levels of C-allele carriers (P = 0.001). CONCLUSIONS: Under conditions of lower folate status (as estimated by either plasma concentration or reported dietary consumption), gender modifies the association of the MTHFR(C677T) polymorphism with tHcy concentrations in healthy children. SPONSORSHIP: Kellog Europe.

Effect of meal frequency on glucose and insulin levels in women with polycystic ovary syndrome: a randomised trial.

BACKGROUND/OBJECTIVES: The aim of the study was to compare the effect of two-meal patterns (three vs six meals per day) on glucose and insulin levels in women with polycystic ovary syndrome (PCOS). SUBJECTS/METHODS: In a randomised, crossover, 24-week study, 40 women with PCOS, aged 27±6 years, body mass index 27±6 kg/m(2), followed a weight maintenance diet (% carbohydrates:protein:fat, 40:25:35), consumed either as a three- or a six-meal pattern, with each intervention lasting for 12 weeks. Anthropometric measurements, diet compliance and subjective hunger, satiety and desire to eat were assessed biweekly. All women underwent an oral glucose tolerance test (OGTT) with 75 g glucose for measurement of plasma glucose and insulin at the beginning and end of each intervention. HaemoglobinA1c (HbA1c), blood lipids and hepatic enzymes were measured at the beginning and end of each intervention. RESULTS: Body weight remained stable throughout the study. Six meals decreased significantly fasting insulin (P=0.014) and post-OGTT insulin sensitivity (Matsuda index, P=0.039) vs three meals. After incorporation of individual changes over time, with adjustment for potential confounders, the only variable that remained significant was the Matsuda index, which was then used in multivariate analysis and general linear models. Six meals improved post-OGTT insulin sensitivity independently of age and body weight vs three meals (P=0.012). No significant differences were found between six and three meals for glucose, HbA1c, blood lipids, hepatic enzymes, subjective desire to eat and satiety. CONCLUSIONS: Six meals had a more favourable effect on post-OGTT insulin sensitivity in women with PCOS compared with isocaloric three meals.

Differences in glucose-dependent insulinotrophic polypeptide hormone and hepatic lipase in subjects of southern and northern Europe: implications for postprandial lipemia.

BACKGROUND: This study was an extension of a previous study that showed different lipemic responses to standard test meals in subjects from southern and northern Europe. OBJECTIVE: The aim was to determine in 32 healthy young men from northern and southern Europe whether differences in the secretion of insulin and glucose-dependent insulinotrophic polypeptide (GIP) might explain these findings through the actions of these hormones on lipoprotein lipase. DESIGN: We investigated in a randomized, single-blind, crossover study the effects of 2 test meals of identical macronutrient composition but different saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) contents on postprandial GIP, insulin, the ratio of incremental triacylglycerol to apolipoprotein B-48 (a marker of chylomicron size), and the activity of postheparin lipases. RESULTS: Fasting and postprandial GIP concentrations and postheparin hepatic lipase activities were significantly higher in the southern Europeans (P < 0.001 and P < 0.02, respectively). Lipoprotein lipase activity after the SFA-rich meal was significantly higher in the northern Europeans (P < 0.01). HL activity 9 h after the SFA-rich meal and the area under the curve (AUC) for the postprandial insulin response correlated with the AUC for the postprandial GIP response [r = 0.44 (P < 0.04) and r = 0.46 (P < 0.05), respectively]. There were no significant differences in chylomicron size between the 2 groups for either meal, but when the groups were combined there was a significant difference in chylomicron size between the SFA- and MUFA-rich meals (P < 0.05), which could be due to the formation of larger chylomicrons after the MUFA-rich meal. CONCLUSION: The significantly higher GIP and insulin responses and HL activities in southern Europeans may provide an explanation for our previous report of attenuated postprandial triacylglycerol and apolipoprotein B-48 responses in them.

Effect of long-term olive oil dietary intervention on postprandial triacylglycerol and factor VII metabolism.

Although the beneficial effects of Mediterranean-type diets, which are rich in olive oil, a good source of monounsaturated fatty acids (MUFAs), are generally accepted, little is known about the effects of long-term dietary MUFA intake on postprandial lipoprotein metabolism and hemostasis. This study used a single-blind, randomized, crossover design to investigate the relative effects of a long-term dietary olive oil intervention and a control [saturated fatty acid (SFA)-enriched] diet on postprandial triacylglycerol metabolism and factor VII activity. The postprandial response to a standard test meal was investigated in 23 healthy men who adhered to both diets for 8 wk. cis-MUFAs were successfully substituted for SFAs in the MUFA diet without affecting total dietary fat or energy intakes. The long-term dietary MUFA intervention significantly reduced plasma and LDL-cholesterol concentrations (P = 0.01). Postprandial triacylglycerol concentrations were significantly greater in the early postprandial period after the MUFA diet (P = 0.003). Postprandial factor VII activation and the concentration of the factor VII antigen were significantly lower after the MUFA diet (P = 0.04 and P = 0.006, respectively). This study showed that isoenergetic substitution of MUFAs for SFAs reduces plasma cholesterol and reduces the degree of postprandial factor VII activation. The alterations in the postprandial triacylglycerol response suggest a greater rate of dietary fat absorption and postprandial triacylglycerol metabolism after a diet rich in MUFAs. This study presents new insights into the biochemical basis of the beneficial effects associated with long-term dietary MUFA consumption, which may explain the lower rates of coronary mortality in Mediterranean regions.

Differences in postprandial lipaemic response between Northern and Southern Europeans.

Postprandial lipaemic responses to two test meals were investigated in 30 Northern (15 British and 15 Irish), and 30 Southern (Greeks from Crete) healthy male Europeans. The meals were a saturated fatty acid (SFA) meal, which resembled the fatty acid composition of an average UK diet, and a monounsaturated fatty acid (MUFA) meal in which the fat consisted of olive oil. Habitual diets of the two groups differed, with higher total fat, (P < 0.03) and MUFA (P < 0.0001) and lower polyunsaturated fatty acid (PUFA) (P < 0.0001) intakes in Southern than Northern Europeans. Levels of total MUFA (P < 0.02) and oleic acid (P < 0.004) were also higher in adipose tissue of Southern in comparison to Northern Europeans. In both European groups there were no significant differences in postprandial triglyceride response between the two meal types, SFA or MUFA. However, Northern and Southern Europeans showed significant differences in their patterns of postprandial response in plasma triglycerides (P < 0.0001), apolipoprotein B-48 (P < 0.0001), NEFA (P < 0.0001), insulin (P < 0.0007), and factor VII activity (P-0.03). In the case of NEFA, areas under the response curve were higher following the SFA than the MUFA meal for both groups, (P < 0.003) and were greater in Southern than Northern Europeans (P < 0.002) and apo B-48 responses were lower (P < 0.005). Some of these differences may reflect differences in fasting levels since fasting apolipoprotein B-48 levels were lower (P < 0.01) and fasting NEFA (P < 0.02) and insulin (P < 0.005) were higher in the Southern than in the Northern Europeans. In addition, 9 h postprandial post-heparin lipoprotein lipase activity was lower in the Southern than in the Northern Europeans (P < 0.0006). This is the first report of differences in postprandial lipid, factor VII and insulin responses in Southern and Northern Europeans which may be of importance in explaining the different susceptibilities of these two populations to risk of coronary artery disease.

Postprandial lipoprotein lipase, insulin and gastric inhibitory polypeptide responses to test meals of different fatty acid composition: comparison of saturated, n-6 and n-3 polyunsaturated fatty acids.

OBJECTIVE: The present study was carried out to investigate effects of meals, rich in either saturated fatty acids (SFA), or n-6 or n-3 fatty acids, on postprandial plasma lipid and hormone concentrations as well as post-heparin plasma lipoprotein lipase (LPL) activity. DESIGN: The study was a randomized single-blind study comparing responses to three test meals. SETTING: The volunteers attended the Clinical Investigation Unit of the Royal Surrey County Hospital on three separate occasions in order to consume the meals. SUBJECTS: Twelve male volunteers with an average age of 22.5 +/- 1.4 years (mean +/- SD), were selected from the University of Surrey student population; one subject dropped out of the study because he found the test meal unpalatable. INTERVENTIONS: Three meals were given in the early evening and postprandial responses were followed overnight for 11h. The oils used to prepare each of the three test meals were: a mixed oil rich in saturated fatty acids (SFA) which mimicked the fatty acid composition of the current UK diet, corn oil, rich in n-6 fatty acids and a fish oil concentrate (MaxEPA) rich in n-3 fatty acids. The oil under investigation (40 g) was incorporated into the test meals which were otherwise identical [208 g carbohydrates, 35 g protein, 5.65 MJ (1350 kcal) energy]. Postprandial plasma triacylglycerol (TAG), gastric inhibitory polypeptide (GIP), and insulin responses, as well as post-heparin LPL activity (measured at 12 h postprandially only) were investigated. RESULTS: Fatty acids of the n-3 series significantly reduced plasma TAG responses compared to the mixed oil meal (P < 0.05) and increased post-heparin LPL activity 15 min after the injection of heparin (P < 0.01). A biphasic response was observed in TAG, with peak responses occurring at 1 h and between 3-7 h postprandially. GIP and insulin showed similar responses to the three test meals and no significant differences were observed. CONCLUSION: We conclude that fish oils can decrease postprandial plasma TAG levels partly through an increase in post-heparin LPL activity, which however, is not due to increased GIP or insulin concentrations.

Polyunsaturated fatty acids of the n-6 and n-3 series: effects on postprandial lipid and apolipoprotein levels in healthy men.

OBJECTIVE: The present study was carried out to determine effects of test meals of different fatty acid compositions on postprandial lipoprotein and apolipoprotein metabolism. DESIGN: The study was a randomized, single blind design. SETTING: The study was carried out in the Clinical Investigation Unit of the Royal Surrey County Hospital. SUBJECTS: Twelve male normal subjects with an average age of 22.4 +/- 1.4 years (mean +/- SD) were selected from the student population of the University of Surrey; one subject dropped out of the study because he found the test meal unpalatable. INTERVENTIONS: The subjects were given three evening test meals on three separate occasions, in which the oils used were either a mixed oil (rich in saturated fatty acids and approximated the fatty acid intake of the current UK diet), corn oil (rich in n-6 fatty acids), or fish oil (rich in n-3 fatty acids) 40 g of the oil under investigation were incorporated into a rice-based test meal. Triacylglycerol-rich lipoproteins-triacylglycerol (TRL-TAG), TRL-cholesterol (TRL-cholesterol), plasma-TAG, plasma cholesterol (T-C), and serum apolipoprotein A-I and B (apo A-I and B) responses were measured. Postprandial responses were followed for 11 h. RESULTS: Postprandial plasma-TAG responses, calculated as incremental areas under the response curves (IAUC) were significantly reduced following the fish oil meal [365.5 +/- 145.4 mmol/l x min (mean +/- SD)[ compared with the mixed oil meal (552.0 +/- 141.7 mmol/l x min) (P < 0.05) and there was a strong trend towards the same direction in the TRL-TAG responses. In all instances, plasma-and TRL-TAG showed a biphasic response with increased concentrations occurring at 1h and between 3 and 7h postprandially. TRL-cholesterol, T-C, and serum apo A-I and B responses to the three meals were similar. CONCLUSIONS: The findings support the view that fish oils decrease postprandial lipaemia and this may be an important aspect of their beneficial effects in reducing risk of coronary heart disease (CHD). Further work is required to determine the mechanisms responsible for this effect.