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.

Substitution of dietary monounsaturated fatty acids for saturated fatty acids in a free-living population: a feasibility study

The fatty acid composition of the diet of seven free-living subjects (five men and two women) aged 41–56 years was altered for 1 month. The aim was to increase the intake of monounsaturated fatty acids (MUFAs) from subjects current habitual levels of 12% dietary energy to a target intake of 18% dietary energy, and to decrease saturated fatty acid (SFA) from habitual levels of 16% dietary energy to target levels of 10% dietary energy. The change in fatty acid intake was achieved by supplying volunteers with foods prepared using MUFA-containing spreads or olive oil (ready meals, sweet biscuits and cakes) and also by supplying spreads, cooking oil and MUFA-enriched milk for domestic use. Body weight and plasma total cholesterol measurements were made at baseline and at 2 and 4 weeks on the diet as an aid to maintaining subject compliance. MUFA consumption was significantly increased from 12% dietary energy to 16% dietary energy (P<0.01), and SFA intake was reduced from 16% dietary energy to 6% dietary energy (P<0.01) during the 4-week intervention. The diet failed to achieve the target increase in MUFA but exceeded the target reduction in SFA. This was due to the fact that subjects reduced their total fat intake from a mean habitual level of 38% dietary energy to a mean level of 30% dietary energy. During the dietary period, mean plasma cholesterol levels were lower at 2 weeks (P<0.01) and at 4 weeks (P<0.01) than the baseline, with a mean reduction of 20% over the dietary period. This study demonstrates the difficulty of achieving increased MUFA intakes (by SFA substitution) in free-living populations when only a limited range of fatty-acid modified food products are provided to volunteers.

Dietary monounsaturated fatty acids and haemostasis

Diets high in monounsaturated fatty acids (MUFA) are increasingly being recommended as a highly-effective cholesterol-lowering strategy in populations at risk of CHD. However, the need for a re-appraisal of the benefits of diets rich in MUFA became apparent as a result of recent studies showing that meals high in olive oil cause greater postprandial activation of blood coagulation factor VII than meals rich in saturated fatty acids. The present review evaluates the evidence for the effects of MUFA-rich diets on fasting and postprandial measurements of haemostasis, and describes data from a recently-completed long-term controlled dietary intervention study. The data show that a background diet high in MUFA has no adverse effect on fasting haemostatic variables and decreases the postprandial activation of factor VII in response to a standard fat-containing meal. Since the same study also showed a significant reduction in the ex vivo activation of platelets in subjects on the high-MUFA diet, the overall findings suggest that there is no reason for concern regarding adverse haemostatic consequences of high-MUFA diets.

Effects of dietary polyunsaturated fatty acid supplementation on fatty acid composition in muscle and subcutaneous adipose tissue of lambs

Lambs (n = 48) were used in a 2 × 2 factorial arrangement of treatments to evaluate effects of inclusion of oil containing PUFA in high-concentrate diets (with or without) and duration of oil supplementation (pre- vs. postweaning) on CLA concentration of muscle and adipose tissue. Lambs were fed preweaning creep diets (with or without oil) corresponding to the dietary lactation treatment diet (with or without oil) of the dam. Dams blocked by lambing date and rearing type were randomly assigned to 1 of 2 lactation dietary treatments with or without oil supplementation. Creep diets contained approximately 70% concentrate and 30% roughage and were provided to lambs for ad libitum intake. At weaning (58.7 ± 2.5 d of age), lambs (n = 48) were randomly assigned within preweaning treatment groups to 1 of 2 postweaning dietary treatments (with or without oil) and 16 pens in a randomized block design, blocked by sex and BW. Postweaning diets were formulated to contain approximately 80% concentrate and 20% roughage and were fed once daily for ad libitum intake. Soybean and linseed oil (2:1, respectively) replaced ground corn and provided 3% additional fat in pre- and postweaning diets. Lambs were slaughtered at 60.3 ± 4.2 kg of BW. A subcutaneous fat (SQ) sample was obtained within 1 h postmortem and a LM sample at the 12th rib was obtained 24 h postmortem, and both were analyzed for fatty acid profile. Feedlot performance and carcass measurements were not affected (P ≥ 0.26) by oil supplementation. Total CLA content of LM and SQ was not affected (P ≥ 0.08) by oil supplementation pre- or postweaning, but trans-10, cis-12 CLA was greater (P = 0.02) in SQ from lambs supplemented with oil postweaning. Total PUFA content in LM was greater (P = 0.02) in lambs supplemented with oil pre- or postweaning as a result of increased concentrations of 18:2cis-9, cis-12 and longer chain PUFA. Conversely, pre- and postweaning oil supplementation resulted in less (P = 0.04) MUFA content in LM. Only postweaning oil supplementation increased (P = 0.001) SQ PUFA content. Feeding oils containing PUFA to lambs pre- and postweaning did not increase CLA content of muscle, whereas postweaning oil supplementation minimally increased CLA concentration of SQ fat. Inclusion of soybean and linseed oil in pre- and postweaning diets increased total PUFA content of SQ fat and muscle tissue without adversely affecting growth performance or carcass characteristics.

Single nucleotide polymorphisms at the ADIPOQ gene locus interact with age and dietary intake of fat to determine serum adiponectin in subjects at risk of the metabolic syndrome

Background: Adiponectin gene expression is modulated by peroxisome proliferator–activated receptor γ, which is a transcription factor activated by unsaturated fatty acids. Objective: We investigated the effect of the interaction between variants at the ADIPOQ gene locus, age, sex, body mass index (BMI), ethnicity, and the replacement of dietary saturated fatty acids (SFAs) with monounsaturated fatty acids (MUFAs) or carbohydrates on serum adiponectin concentrations. Design: The RISCK (Reading, Imperial, Surrey, Cambridge, and Kings) study is a parallel-design, randomized controlled trial. Serum adiponectin concentrations were measured after a 4-wk high-SFA (HS) diet and a 24-wk intervention with reference (HS), high-MUFA (HM), and low-fat (LF) diets. Single nucleotide polymorphisms at the ADIPOQ locus −11391 G/A (rs17300539), −10066 G/A (rs182052), −7734 A/C (rs16861209), and +276 G/T (rs1501299) were genotyped in 448 participants. Results: In white Europeans, +276 T was associated with higher serum adiponectin concentrations (n = 340; P = 0.006) and −10066 A was associated with lower serum adiponectin concentrations (n = 360; P = 0.03), after adjustment for age, BMI, and sex. After the HM diet, −10066 G/G subjects showed a 3.8% increase (95% CI: −0.1%, 7.7%) and G/A+A/A subjects a 2.6% decrease (95% CI: −5.6%, 0.4%) in serum adiponectin (P = 0.006 for difference after adjustment for the change in BMI, age, and sex). In −10066 G/G homozygotes, serum adiponectin increased with age after the HM diet and decreased after the LF diet. Conclusion: In white −10066 G/G homozygotes, an HM diet may help to increase adiponectin concentrations with advancing age. This trial was registered at clinicaltrials.gov as ISRCTN29111298.

Interaction of PPARG Pro12Ala with dietary fat influences plasma lipids in subjects at cardiometabolic risk

The PPARγ2 gene SNP Pro12Ala has shown variable association with metabolic syndrome traits in healthy subjects. We investigated the effect of interaction between genotype and the ratio of polyunsaturated:saturated (P:S) fatty acid intake on plasma lipids in 367 White subjects aged 30-70 y at increased cardiometabolic risk, in the RISCK study. Interaction was determined after habitual diet at recruitment, at baseline after a 4-week high-SFA (HS) diet and after 24-week reference (HS), high-MUFA (HM) and low-fat (LF) diets. At recruitment, there were no significant associations between genotype and plasma lipids, however, P:S x genotype interaction influenced plasma total cholesterol (TC) (P=0.02), LDL-cholesterol (LDL-C) (P=0.002) and triglyceride (TG) (P=0.02) concentrations. At P:S ratio ≤0.33, mean TC and LDL-C concentrations in Ala12 allele carriers were significantly higher than in non-carriers (respectively P=0.003; P=0.0001). Significant trends in reduction of plasma TC (P=0.02) and TG (P=0.002) concentrations occurred with increasing P:S (respectively ≤0.33 to >0.65 and 0.34 to >0.65) in Ala12 allele carriers. There were no significant differences between carriers and non-carriers after the 4-week HS diet or 24-week interventions. Plasma TC and TG concentrations in PPARG Ala12 allele carriers decrease as P:S increases, but are not dependent on a reduction in SFA intake.

Milk in the diet: good or bad for vascular disease?

CVD still represent the greatest cause of death and disease burden in Europe and there remains uncertainty whether or not diets rich in milk and/or dairy products affect CVD risk. This paper reviews current evidence on this from prospective studies and the role of serum lipids and blood pressure as markers of CVD risk with such diets. Also the potential of animal nutrition-based approaches aimed at reducing CVD risk from consumption of milk and dairy products is outlined. Briefly, the evidence from prospective studies indicates that increased consumption of milk does not result in increased CVD risk and may give some long-term benefits, although few studies relate specifically to cheese and butter and more information on the relationship between milk/dairy product consumption and dementia is needed. Recent data suggest that the SFA in dairy products may be less of a risk factor than previously thought; although this is based on serum cholesterol responses which taken in isolation may be misleading. Milk and some dairy products have counterbalancing effects by reducing blood pressure and possibly BMI control. Despite this, animal nutrition strategies to replace some SFA in milk with cis-MUFA or cis-PUFA are extensive and intuitively beneficial, although this remains largely unproven, especially for milk. There is an urgent need for robust intervention studies to evaluate such milk-fat modifications using holistic markers of CVD risk including central arterial stiffness.

Insulin receptor substrate-2 gene variants in subjects with metabolic syndrome: association with plasma fatty acid levels and insulin resistance

Several insulin receptor substrate-2 (IRS-2) polymorphisms have been studied in relation to insulin resistance and type 2 diabetes. To examine whether the genetic variability at the IRS-2 gene locus was associated with the degree of insulin resistance and plasma fatty acid levels in metabolic syndrome (MetS) subjects. Methods and results: Insulin sensitivity, insulin secretion, glucose effectiveness, plasma fatty acid composition and three IRS-2 tag-single nucleotide polymorphisms (SNPs) were determined in 452 MetS subjects. Among subjects with the lowest level of monounsaturated (MUFA) (below the median), the rs2289046 A/A genotype was associated with lower glucose effectiveness (p<0.038), higher fasting insulin concentrations (p<0.028) and higher HOMA IR (p<0.038) as compared to subjects carrying the minor G-allele (A/G and G/G). In contrast, among subjects with the highest level of MUFA (above the median), the A/A genotype was associated with lower fasting insulin concentrations and HOMA-IR, whereas individuals carrying the G allele and with the highest level of ω-3 polyunsaturated fatty acids (above the median) showed lower fasting insulin (p<0.01) and HOMA-IR (p<0.02) as compared with A/A subjects. Conclusion: The rs2289046 polymorphism at the IRS2 gene locus may influence insulin sensitivity by interacting with certain plasma fatty acids in MetS subjects.

A gene variation (rs12691) in the CCAT/enhancer building α modulates glucose metabolism in metabolic syndrome

Background and aims CCAAT/enhancer-binding protein alpha (CEBPA) is a transcription factor involved in adipogenesis and energy homeostasis. Caloric restriction reduces CEBPA protein expression in patients with metabolic syndrome (MetS). A previous report linked rs12691 SNP in CEBPA to altered concentration of fasting triglycerides. Our objective was to assess the effects of rs12691 in glucose metabolism in Metabolic Syndrome (MetS) patients. Methods and results Glucose metabolism was assessed by static (glucose, insulin, adiponectin, leptin and resistin plasma concentrations) and dynamic (disposition index, insulin sensitivity index, HOMA-IR and acute insulin response to glucose) indices, performed at baseline and after 12 weeks of 4 dietary interventions (high saturated fatty acid (SFA), high monounsaturated fatty acid (MUFA), low-fat and low-fat-high-n3 polyunsaturated fatty acid (PUFA)) in 486 subjects with MetS. Carriers of the minor A allele of rs12691 had altered disposition index (p = 0.0003), lower acute insulin response (p = 0.005) and a lower insulin sensitivity index (p = 0.025) indicating a lower insulin sensitivity and a lower insulin secretion, at baseline and at the end of the diets. Furthermore, A allele carriers displayed lower HDL concentration. Conclusion The presence of the A allele of rs12691 influences glucose metabolism of MetS patients. Clinical Trials Registry number NCT00429195.

Obesity and body fat classification in the metabolic syndrome: impact on cardiometabolic risk metabotype

Obesity is a key factor in the development of the metabolic syndrome (MetS), which is associated with increased cardiometabolic risk. We investigated whether obesity classification by body mass index (BMI) and body fat percentage (BF%) influences cardiometabolic profile and dietary responsiveness in 486 MetS subjects (LIPGENE dietary intervention study). Anthropometric measures, markers of inflammation and glucose metabolism, lipid profiles, adhesion molecules and haemostatic factors were determined at baseline and after 12 weeks of 4 dietary interventions (high saturated fat (SFA), high monounsaturated fat (MUFA) and 2 low fat high complex carbohydrate (LFHCC) diets, 1 supplemented with long chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs)). 39% and 87% of subjects classified as normal and overweight by BMI were obese according to their BF%. Individuals classified as obese by BMI (± 30 kg/m2) and BF% (± 25% (men) and ± 35% (women)) (OO, n = 284) had larger waist and hip measurements, higher BMI and were heavier (P < 0.001) than those classified as non-obese by BMI but obese by BF% (NOO, n = 92). OO individuals displayed a more pro-inflammatory (higher C reactive protein (CRP) and leptin), pro-thrombotic (higher plasminogen activator inhibitor-1 (PAI-1)), pro-atherogenic (higher leptin/adiponectin ratio) and more insulin resistant (higher HOMA-IR) metabolic profile relative to the NOO group (P < 0.001). Interestingly, tumour necrosis factor alpha (TNF-α) concentrations were lower post-intervention in NOO individuals compared to OO subjects (P < 0.001). In conclusion, assessing BF% and BMI as part of a metabotype may help identify individuals at greater cardiometabolic risk than BMI alone.

Fatty acid composition of cooked chicken meat and chicken meat products as influenced by price range at retail

The primary objective was to determine fatty acid composition of skinless chicken breast and leg meat portions and chicken burgers and nuggets from the economy price range, standard price range (both conventional intensive rearing) and the organic range from four leading supermarkets. Few significant differences in the SFA, MUFA and PUFA composition of breast and leg meat portions were found among price ranges, and supermarket had no effect. No significant differences in fatty acid concentrations of economy and standard chicken burgers were found, whereas economy chicken nuggets had higher C16:1, C18:1 cis, C18:1 trans and C18:3 n-3 concentrations than had standard ones. Overall, processed chicken products had much higher fat contents and SFA than had whole meat. Long chain n-3 fatty acids had considerably lower concentrations in processed products than in whole meat. Overall there was no evidence that organic chicken breast or leg meat had a more favourable fatty acid composition than had meat from conventionally reared birds.

Is fatty acid intake a predictor of arterial stiffness and blood pressure in men? Evidence from the Caerphilly Prospective Study

Background and aims: Arterial stiffness is an independent predictor of cardiovascular disease (CVD) events and all-cause mortality and may be differentially affected by dietary fatty acid (FA) intake. The aim of this study was to investigate the relationship between FA consumption and arterial stiffness and blood pressure in a community-based population. Methods and results: The Caerphilly Prospective Study recruited 2398 men, aged 45-59 years, who were followed up at 5-year intervals for a mean of 17.8-years (n 787). A semi-quantitative food frequency questionnaire estimated intakes of total, saturated, mono- and poly-unsaturated fatty acids (SFA, MUFA, PUFA). Multiple regression models investigated associations between intakes of FA at baseline with aortic pulse wave velocity (aPWV), augmentation index (AIx), systolic and diastolic blood pressure (SBP, DBP) and pulse pressure after a 17.8-year follow-up - as well as cross-sectional relationships with metabolic markers. After adjustment, higher SFA consumption at baseline was associated with higher SBP (P = 0.043) and DBP (P = 0.002) and after a 17.8-year follow-up was associated with a 0.51 m/s higher aPWV (P = 0.006). After adjustment, higher PUFA consumption at baseline was associated with lower SBP (P = 0.022) and DBP (P = 0.036) and after a 17.8-year follow-up was associated with a 0.63 m/s lower aPWV (P = 0.007). Conclusion: This study suggests that consumption of SFA and PUFA have opposing effects on arterial stiffness and blood pressure. Importantly, this study suggests that consumption of FA is an important risk factor for arterial stiffness and CVD.

Incremental effect of a calcium salt of cis-monounsaturated fatty acids supplement on milk fatty acid composition in cows fed maize silage-based diets

In most Western countries, saturated fatty acid (SFA) intake exceeds recommended levels, which is considered a risk factor for cardiovascular disease (CVD). As milk and dairy products are major contributors to SFA intake in many countries, recent research has focused on sustainable methods of producing milk with a lower saturated fat concentration by altering dairy cow diets. Human intervention studies have shown that CVD risk can be reduced by consuming dairy products with reduced SFA and increased cis-monounsaturated fatty acid (MUFA) concentrations. This milk fatty acid profile can be achieved by supplementing dairy cow diets with cis-MUFA-rich unsaturated oils. However, rumen exposure of unsaturated oils also leads to enhanced milk trans fatty acid (TFA) concentrations. Because of concerns about the effects of TFA consumption on CVD, feeding strategies that increase MUFA concentrations in milk without concomitant increases in TFA concentration are preferred by milk processors. In an attempt to limit TFA production and increase the replacement of SFA by cis-MUFA, a preparation of rumen-protected unsaturated oils was developed using saponification with calcium salts. Four multiparous Holstein-Friesian cows in mid-late lactation were used in a 4 × 4 Latin square design with 21-d periods to investigate the effect of incremental dietary inclusion of a calcium salt of cis-MUFA product (Ca-MUFA; 20, 40, and 60 g/kg of dry matter of a maize silage-based diet), on milk production, composition, and fatty acid concentration. Increasing Ca-MUFA inclusion reduced dry matter intake linearly, but no change was observed in estimated ME intake. No change in milk yield was noted, but milk fat and protein concentrations were linearly reduced. Supplementation with Ca-MUFA resulted in a linear reduction in total SFA (from 71 to 52 g/100 g of fatty acids for control and 60 g/kg of dry matter diets, respectively). In addition, concentrations of both cis- and trans-MUFA were increased with Ca-MUFA inclusion, and increases in other biohydrogenation intermediates in milk fat were also observed. The Ca-MUFA supplement was very effective at reducing milk SFA concentration and increasing cis-MUFA concentrations without incurring any negative effects on milk and milk component yields. However, reduced milk fat and protein concentrations, together with increases in milk TFA concentrations, suggest partial dissociation of the calcium salts in the rumen

Seasonal variation in the fatty acid composition of milk available at retail in the United Kingdom and implications for dietary intake

Milk and dairy products are major sources of fat in the human diet, but there are few detailed reports on the fatty acid composition of retail milk, trans fatty acids in particular, and how these change throughout the year. Semi-skimmed milk was collected monthly for one year from five supermarkets and analysed for fatty acid composition. Relative to winter, milk sold in the summer contained lower total saturated fatty acid (SFA; 67 vs 72 g/100 g fatty acids) and higher cis-monounsaturated fatty acid (MUFA; 23 vs 21 g/100 g fatty acids) and total trans fatty acid (6.5 vs 4.5 g/100 g fatty acids) concentrations. Concentrations of most trans-18:1 and -18:2 isomers also exhibited seasonal variation. Results were applied to national dietary intakes, and indicated that monthly variation in the fatty acid composition of milk available at retail has limited influence on total dietary fatty acid consumption by UK adults.

Impact of geographical region on urinary metabolomic and plasma fatty acid profiles in subjects with the metabolic syndrome across Europe: the LIPGENE study

The application of metabolomics in multi-centre studies is increasing. The aim of the present study was to assess the effects of geographical location on the metabolic profiles of individuals with the metabolic syndrome. Blood and urine samples were collected from 219 adults from seven European centres participating in the LIPGENE project (Diet, genomics and the metabolic syndrome: an integrated nutrition, agro-food, social and economic analysis). Nutrient intakes, BMI, waist:hip ratio, blood pressure, and plasma glucose, insulin and blood lipid levels were assessed. Plasma fatty acid levels and urine were assessed using a metabolomic technique. The separation of three European geographical groups (NW, northwest; NE, northeast; SW, southwest) was identified using partial least-squares discriminant analysis models for urine (R 2 X: 0•33, Q 2: 0•39) and plasma fatty acid (R 2 X: 0•32, Q 2: 0•60) data. The NW group was characterised by higher levels of urinary hippurate and N-methylnicotinate. The NE group was characterised by higher levels of urinary creatine and citrate and plasma EPA (20 : 5 n-3). The SW group was characterised by higher levels of urinary trimethylamine oxide and lower levels of plasma EPA. The indicators of metabolic health appeared to be consistent across the groups. The SW group had higher intakes of total fat and MUFA compared with both the NW and NE groups (P≤ 0•001). The NE group had higher intakes of fibre and n-3 and n-6 fatty acids compared with both the NW and SW groups (all P< 0•001). It is likely that differences in dietary intakes contributed to the separation of the three groups. Evaluation of geographical factors including diet should be considered in the interpretation of metabolomic data from multi-centre studies.