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

Comparison of the effect of medium-chain fatty acids and long-chain fatty acids on postprandial appetite and lipemia: a randomised crossover trial

Background

Postprandial lipemia (PPL) has been recognised as a cardiovascular disease risk factor. Appetite and PPL can be influenced by the length of saturated fatty acids (FAs). Thus, this study aims to investigate if different FA chain lengths have different impacts on appetite and PPL in healthy volunteers.

Methods

This is a randomised crossover single-blinded intervention study of 20 healthy adults. Coconut oil and palm oil were consumed in the form of biscuits. Blood serum samples were withdrawn after an overnight fast and 1, 2, 4 and 6 hours after eating the test meals and examined for blood lipid profile (total cholesterol (TC), high-density lipoprotein (HDL) and triglycerides (TG)), while Friedewald's equation was used to calculate low-density lipoprotein (LDL). Visual analogue scales were used by participants to rate their appetites, and an ad libitum meal was weighed to determine the energy intake.

Results

The net area under the curve of TG and TC following the coconut oil were significantly lower than following the palm oil (P value ≤0.05). In the mean of the change in TC, LDL and HDL from the baseline, a significant difference was found after 6 hours of eating the biscuits (P value ≤0.05). The perceptions of hunger and fullness did not significantly differ between the two types of FAs. Also, the energy and macronutrient intakes were not significantly different after the two types of oil, neither at the ad libitum meal nor on the day following the treatments.

Conclusion

The selection of FA chain length may influence PPL, and thus cardiovascular disease risk in a way that is functionally significant. However, this study detected no influence of FA chain length on appetite up to 40 hours post-treatment.

Trial registration number

NCT05539742.

Antihypertensive Therapy by ACEI/ARB Is Associated With Intestinal Flora Alterations and Metabolomic Profiles in Hypertensive Patients

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers (ACEI/ARB) are the first-line drugs for the treatment of essential hypertension (HTN), one of the most important risk factors for cardiovascular and cerebrovascular diseases. Intestinal flora and microbial metabolites have been demonstrated to play important roles in blood pressure (BP) regulation and HTN development. However, it remains elusive that intestinal bacteria and metabolites are associated with the protective effects of ACEI/ARB anti-hypertensive drugs against HTN. In this study, we evaluated the effect of ACEI/ARB on gut microbiome and metabolites in patients suffering from HTN. We performed 16S rRNA sequencing and fecal metabolomic analysis of 36 HTN patients placed on ACEI/ARB therapy and 19 newly diagnosed HTN patients with no history of anti-hypertensive treatment. Patients under medication treatment were further classified into well-controlled (n = 24) and poor-controlled (n = 12) groups according to their BP levels. The ACEI/ARB improved the intestinal microbiome of the HTN patients by reducing potentially pathogenic bacteria such as Enterobacter and Klebsiella and increasing beneficial bacteria such as Odoribacter. Moreover, ACEI/ARB therapy was correlated with significant metabolomic changes in the HTN patients, including progressively enhanced inositol from poor-controlled to well-controlled groups. The profiles of gut bacteria were linked to the production of metabolites, and inositol was negatively correlated with Klebsiella, Enterobacter, and Proteobacteria. Our study suggests that ACEI/ARB modulates gut microbial composition and functions and alters microbial metabolites in HTN patients.

Whole-Fat or Reduced-Fat Dairy Product Intake, Adiposity, and Cardiometabolic Health in Children: A Systematic Review

Dietary guidelines commonly recommend that children aged >2 y consume reduced-fat dairy products rather than regular- or whole-fat dairy. In adults, most studies have not found the consumption of whole-fat dairy products to be associated with increased cardiometabolic or adiposity risk. Associations in children could differ due to growth and development. We systematically reviewed the literature in indexed, peer-reviewed journals to summarize pediatric studies (children aged from 2 to 18 y) assessing associations between whole- and reduced-fat dairy intake and measures of adiposity as well as biomarkers of cardiometabolic disease risk, including the serum lipid profile, blood pressure, low-grade chronic inflammation, oxidative stress, and measures of glucose homeostasis. For the purposes of this review, a "whole-fat" dairy product was defined as a product with the natural fat content, whereas a "reduced-fat" dairy product was defined as a product with some or all of the fat removed (including "low-fat" and "skim" versions). A total of 29 journal articles met our criteria for inclusion. The majority were conducted in the United States and were prospective or cross-sectional observational studies, with only 1 randomized controlled trial. Studies were consistent in reporting that whole-fat dairy products were not associated with increased measures of weight gain or adiposity. Most evidence indicated that consumption of whole-fat dairy was not associated with increased cardiometabolic risk, although a change from whole-fat to reduced-fat dairy improved outcomes for some risk factors in 1 study. Taken as a whole, the limited literature in this field is not consistent with dietary guidelines recommending that children consume preferably reduced-fat dairy products. High-quality randomized controlled trials in children that directly compare the effects of whole-fat compared with reduced-fat dairy intake on measures of adiposity or biomarkers of cardiometabolic disease risk are needed to provide better quality evidence in this area.

Evaluation of plasma and erythrocyte fatty acids C15:0, t-C16:1n-7 and C17:0 as biomarkers of dairy fat consumption in adolescents

INTRODUCTION

Pentadecanoic (C15:0), heptadecanoic (C17:0) and trans-palmitoleic (t-C16:1n-7) fatty acids (FAs) are often used as biomarkers for dairy fat in adults. This study aimed to investigate the relationship between dairy product intake and these FAs in adolescents.

MATERIAL AND METHODS

Healthy adolescents were randomized to one of three groups (Group 1: control; Group 2: consume 3 dairy servings/day; and Group 3: consume ≥ 4 servings/d). C15:0, C17:0 and t-C16:1n-7 were quantified using gas chromatography. Dietary intakes were assessed by 24 h diet recalls.

RESULTS

No difference was observed in FAs at baseline or 6 months (mo), however, at 12 mo, erythrocyte C15:0 increased in group 3 (+0.37 µg/ml, p = 0.01). Dairy intake increased in both intervention groups (Group 2: +1.4 servings/d; Group 3: +2.4 servings/d, p < 0.0001) and positively correlated with erythrocyte C15:0 at 12 mo.

CONCLUSION

Erythrocyte FAs appear to be associated with increasing dairy intakes during adolescence.

Medium-chain fatty acids lower postprandial lipemia: A randomized crossover trial

Epidemiological and interventional studies have linked saturated fatty acids (SFA) with elevated levels of low-density lipoprotein cholesterol (LDL-C) and increased CVD risk. However, the effects of the SFA chain length on postprandial lipemia in humans are not well elucidated. The aim of this study was to investigate the impact of short, medium and long-chain SFA on postprandial blood lipids in healthy volunteers. Sixteen healthy volunteers consumed test biscuits containing 40 g of either butter (BB), coconut oil (CB) or lard (LB) in a single-blinded, randomized crossover design. Blood samples were collected fasting and 2, 3, 4, and 6 hours postprandially and assessed for blood lipids (total cholesterol, TC; high-density lipoprotein cholesterol, HDL-C; LDL-C and triglyceride, TG). The postprandial TG response following CB was 59.8% lower than following BB (p < 0.01) and 58.8% lower than LB (p < 0.01), although no difference was observed between the BB and the LB responses. The net area under the LDL-C concentration curve was significantly larger after consumption of the CB compared to the BB, despite no significant differences in postprandial net area under the TC and HDL-C concentration curves. Consumption of medium-chain SFA as CB resulted in lower postprandial TG excursions compared to short-chain SFA as BB and long-chain SFA as LB, despite their identical fat and caloric content. These results suggest that SFA differ in their potential to elevate postprandial lipid levels, and that coconut oil, a rich source of medium-chain SFA may not be as hyperlipidemic as animal fats rich in long chain SFA. ANZCTR IDENTIFIER: 12617000903381. CLINICAL TRIAL REGISTRY NUMBER: The study was registered with the Australia New Zealand Trial registry as ACTRN12617000903381.

Optimising Milk Composition

During recent decades, the UK dairy industry has had to adjust to the introduction of milk quotas in 1984, the deregulation of milk markets in 1994, and accommodate changes in the demand for dairy products. The combination of these factors, in addition to Bovine Spongiform Encephalopathy and Foot and Mouth disease, and a fall in milk price has inevitably resulted in a restructuring of the industry, but also reinforced the need for all sectors of the industry to respond to the prevailing economic climate and changes in consumer preferences.

Dietary Fatty Acids and Changes in Blood Lipids during Adolescence: The Role of Substituting Nutrient Intakes

The relevance of dietary fatty acids (FA) for blood lipids should be assessed in the context of substituting nutrients. Such evidence is lacking for adolescents. This study describes prospective associations of dietary FA with changes in serum lipids during adolescence, and considers the theoretical isocaloric replacements of saturated FA (SFA) with other FA or carbohydrates (CHO). Children from the GINIplus and LISAplus birth cohorts, with data on FA intakes (at age 10 years) and serum lipids (at age 10 and 15 years), were included (n = 1398). Associations of SFA, monounsaturated FA (MUFA), n-3 polyunsaturated FA (n-3 PUFA) and n-6 PUFA, with changes in low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TAG), and total cholesterol to HDL ratio (TOTAL:HDL), were assessed by linear regression. Substitution models assessed isocaloric replacements of SFA with MUFA, n-3 PUFA, n-6 PUFA or CHO. Higher SFA intakes were associated with decreasing TAG. No associations were observed for fatty acid intakes with LDL, HDL or TOTAL:HDL. In females, replacing SFA with CHO was associated with increasing LDL, TAG and TOTAL:HDL. Our findings confirm observations in adults, although sex-specific determinants seem relevant in our adolescent population. Overlooking the nutrient context when limiting SFA intakes might have detrimental consequences appreciable as early as adolescence.

Cheese and Cardiovascular Disease Risk: A Review of the Evidence and Discussion of Possible Mechanisms

Currently, the effect of dairy products on cardiovascular risk is a topic much debated and with conflicting results. The purpose of this review is to give an overview of the existing literature regarding the effect of cheese intake and risk of cardiovascular disease (CVD). Studies included reporting the intake of cheese and risk of CVD or risk markers of CVD represent four human intervention studies, nine prospective studies, one prospective case-cohort study, one prospective nested case-control study, five case-control studies, five cross-sectional studies and three correlation studies. The possible mechanisms that may be of importance include calcium, protein, fermentation and the fatty acid composition of cheese. Results from four prospective studies reported no association between cheese intake and CVD risk, whereas one reported an increased risk, two reported a decreased risk and one reported no association in men but a decreased risk in women. In addition, results from four intervention studies indicated no harmful effect on cholesterol concentrations when comparing fat intake from cheese with fat from butter. The underlying mechanisms for these findings still need to be elucidated.

Assessing the Fatty Acid, Carotenoid, and Tocopherol Compositions of Amaranth and Quinoa Seeds Grown in Ontario and Their Overall Contribution to Nutritional Quality

Various fatty acids, tocopherols, carotenoids, and their respective antioxidant contributions in 7 amaranth seed and 11 quinoa seed samples along with a new evaluation method are reported. The lipid yield was 6.98-7.22% in amaranth seeds and 6.03-6.74% in quinoa seeds, with unsaturated fatty acids (UFAs) being the predominant fatty acids, 71.58-72.44% in amaranth seeds and 81.44-84.49% in quinoa seeds, respectively. Carotenoids, mainly lutein and zeaxanthin, are confirmed for the first time in amaranth seeds, while β-carotene is reported first in quinoa seeds. The predominant tocopherols in amaranth seeds are δ- and α-tocopherol, whereas γ- and α-tocopherol are the primary tocopherols in quinoa seeds. UFAs, carotenoids, and tocopherols showed good correlation with antioxidant activity. All of the amaranth seeds demonstrated lower overall lipophilic quality than quinoa seeds, with the AS1 and QS10 cultivars providing the highest scores for amaranth and quinoa seeds, respectively. Results from this study will contribute to developing quinoa seeds and related functional foods with increased benefits.

The relation of saturated fatty acids with low-grade inflammation and cardiovascular disease

The mantra that dietary (saturated) fat must be minimized to reduce cardiovascular disease (CVD) risk has dominated nutritional guidelines for decades. Parallel to decreasing intakes of fat and saturated fatty acids (SFA), there have been increases in carbohydrate and sugar intakes, overweight, obesity and type 2 diabetes mellitus. The "lipid hypothesis" coined the concept that fat, especially SFA, raises blood low-density lipoprotein-cholesterol and thereby CVD risk. In view of current controversies regarding their adequate intakes and effects, this review aims to summarize research regarding this heterogenic group of fatty acids and the mechanisms relating them to (chronic) systemic low-grade inflammation, insulin resistance, metabolic syndrome and notably CVD. The intimate relationship between inflammation and metabolism, including glucose, fat and cholesterol metabolism, revealed that the dyslipidemia in Western societies, notably increased triglycerides, "small dense" low-density lipoprotein and "dysfunctional" high-density lipoprotein, is influenced by many unfavorable lifestyle factors. Dietary SFA is only one of these, not necessarily the most important, in healthy, insulin-sensitive people. The environment provides us not only with many other proinflammatory stimuli than SFA but also with many antiinflammatory counterparts. Resolution of the conflict between our self-designed environment and ancient genome may rather rely on returning to the proinflammatory/antiinflammatory balance of the Paleolithic era in consonance with the 21st century culture. Accordingly, dietary guidelines might reconsider recommendations for SFA replacement and investigate diet in a broader context, together with nondietary lifestyle factors. This should be a clear priority, opposed to the reductionist approach of studying the effects of single nutrients, such as SFA.

Effects of dietary saturated and n-6 polyunsaturated fatty acids on the incorporation of long-chain n-3 polyunsaturated fatty acids into blood lipids

BACKGROUND/OBJECTIVES

Omega-3 polyunsaturated fatty acids (n-3PUFA) are better absorbed when they are combined with high-fat meals. However, the role of different dietary fats in modulating the incorporation of n-3PUFA in blood lipids in humans has not been previously explored. Omega-6 polyunsaturated fatty acids (n-6PUFA) are known to compete with n-3PUFA in the metabolic pathways and for the incorporation into phospholipids, whereas saturated fats (SFA) may enhance n-3PUFA incorporation into tissues.

SUBJECTS/METHODS

In a randomized parallel-design trial, we aimed to investigate the long-term effects of n-3PUFA supplementation in subjects consuming a diet enriched with either SFA or n-6PUFA on fatty acid incorporation into plasma and erythrocytes and on blood lipid profiles (total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides).

RESULTS

Dietary supplementation with n-3PUFA co-administered with SFA for 6 weeks resulted in a significant rise in total cholesterol (0.46±0.60 mmol/L; P=0.020) and LDL-C (0.48±0.48 mmol/L; P=0.011) in comparison with combination with n-6PUFA. The diet enriched with SFA also induced a greater increase in eicosapentaenoic acid (2.07±0.79 vs 1.15±0.53; P=0.004), a smaller decrease in docosapentaenoic acid (-0.12±0.23 vs -0.30±0.20; P=0.034) and a similar increase in docosahexaenoic acid (3.85±1.14 vs 3.10±1.07; P=0.128) percentage in plasma compared with the diet enriched with n-6PUFA. A similar effect was seen in erythrocytes. N-3PUFA supplementation resulted in similar changes in HDL-C and triglyceride levels.

CONCLUSIONS

The results suggest that dietary substitution of SFA with n-6PUFA, despite maintaining low levels of circulating cholesterol, hinders n-3PUFA incorporation into plasma and tissue lipids.

Total and Full-Fat, but Not Low-Fat, Dairy Product Intakes are Inversely Associated with Metabolic Syndrome in Adults

BACKGROUND

Growing evidence suggests that dairy products may have beneficial cardiometabolic effects. The current guidelines, however, limit the intake of full-fat dairy products.

OBJECTIVE

We investigated the association of dairy consumption, types of dairy products, and dairy fat content with metabolic syndrome (MetSyn).

METHODS

We analyzed baseline data of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a multicenter cohort study of 15,105 adults aged 35-74 y. We excluded participants with known diabetes, cardiovascular diseases, or other chronic diseases, and those who had extreme values of energy intake, leaving 9835 for analysis. Dairy consumption was assessed by a food-frequency questionnaire. We computed servings per day for total and subgroups of dairy intake. We computed a metabolic risk score (MetScore) as the mean z score of waist circumference, systolic blood pressure, HDL cholesterol (negative z score), fasting triglycerides, and fasting glucose. We performed multivariable linear regression to test the association of servings per day of dairy products with MetScore.

RESULTS

In analyses that adjusted for demographics, menopausal status, family history of diabetes, dietary intake, nondietary lifestyle factors, and body mass index, we observed a graded inverse association for MetScore with total dairy (-0.044 ± 0.01, P = 0.009 for each additional dairy servings per day) and full-fat dairy (-0.126 ± 0.03, P < 0.001) but not with low-fat dairy intake. Associations were no longer present after additional adjustments for dairy-derived saturated fatty acids.

CONCLUSIONS

Total and especially full-fat dairy food intakes are inversely and independently associated with metabolic syndrome in middle-aged and older adults, associations that seem to be mediated by dairy saturated fatty acids. Dietary recommendations to avoid full-fat dairy intake are not supported by our findings.

Postprandial lipid responses do not differ following consumption of butter or vegetable oil when consumed with omega-3 polyunsaturated fatty acids

Dietary saturated fat (SFA) intake has been associated with elevated blood lipid levels and increased risk for the development of chronic diseases. However, some animal studies have demonstrated that dietary SFA may not raise blood lipid levels when the diet is sufficient in omega-3 polyunsaturated fatty acids (n-3PUFA). Therefore, in a randomised cross-over design, we investigated the postprandial effects of feeding meals rich in either SFA (butter) or vegetable oil rich in omega-6 polyunsaturated fatty acids (n-6PUFA), in conjunction with n-3PUFA, on blood lipid profiles [total cholesterol, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and triacylglycerol (TAG)] and n-3PUFA incorporation into plasma lipids over a 6-h period. The incremental area under the curve for plasma cholesterol, LDL-C, HDL-C, TAG and n-3PUFA levels over 6 h was similar in the n-6PUFA compared to SFA group. The postprandial lipemic response to saturated fat is comparable to that of n-6PUFA when consumed with n-3PUFA; however, sex-differences in response to dietary fat type are worthy of further attention.

Associations between macronutrient intake and serum lipid profile depend on body fat in European adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study

The present study aimed to investigate the relationships between macronutrient intake and serum lipid profile in adolescents from eight European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) cross-sectional study (2006-7), and to assess the role of body fat-related variables in these associations. Weight, height, waist circumference, skinfold thicknesses, total cholesterol, HDL-cholesterol (HDL-C), LDL-cholesterol, TAG, apoB and apoA1 were measured in 454 adolescents (44% boys) aged 12.5-17.5 years. Macronutrient intake (g/4180 kJ per d (1000 kcal per d)) was assessed using two non-consecutive 24 h dietary recalls. Associations were evaluated by multi-level analysis and adjusted for sex, age, maternal education, centre, sum of four skinfolds, moderate-to-vigorous physical activity, sedentary behaviours and diet quality index for adolescents. Carbohydrate intake was inversely associated with HDL-C (β = - 0.189, P< 0.001). An inverse association was found between fat intake and TAG (β = - 0.319, P< 0.001). Associations between macronutrient intake and serum lipids varied according to adiposity levels, i.e. an inverse association between carbohydrate intake and HDL-C was only observed in those adolescents with a higher waist:height ratio. As serum lipids and excess body fat are the major markers of CVD, these findings should be considered when developing strategies to prevent the risk of CVD among adolescents.

Cheese consumption in relation to cardiovascular risk factors among Iranian adults- IHHP Study

BACKGROUND/OBJECTIVE

It is expected that dairy products such as cheeses, which are the main source of cholesterol and saturated fat, may lead to the development or increase the risk of cardiovascular and metabolic diseases; however, the results of different studies are inconsistent. This study was conducted to assess the association between cheese consumption and cardiovascular risk factors in an Iranian adult population.

SUBJECTS/METHODS

Information from the Isfahan Healthy Heart Program (IHHP) was used for this cross-sectional study with a total of 1,752 participants (782 men and 970 women). Weight, height, waist and hip circumference measurement, as well as fasting blood samples were gathered and biochemical assessments were done. To evaluate the dietary intakes of participants a validated food frequency questionnaire, consists of 49 items, was completed by expert technicians. Consumption of cheese was classified as less than 7 times per week and 7-14 times per week.

RESULTS

Higher consumption of cheese was associated with higher C-Reactive Protein (CRP), apolipoprotein A and high density lipoprotein cholesterol (HDL-C) level but not with fasting blood sugar (FBS), total cholesterol, low density lipoprotein cholesterol (LDL-C), triglyceride (TG) and apolipoprotein B. Higher consumption of cheese was positively associated with consumption of liquid and solid oil, grain, pulses, fruit, vegetable, meat and dairy, and negatively associated with Global Dietary Index. After control for other potential confounders the association between cheese intake and metabolic syndrome (OR: 0.81; 96%CI: 0.71-0.94), low HDL-C level (OR: 0.87; 96%CI: 0.79-0.96) and dyslipidemia (OR: 0.88; 96%CI: 0.79-0.98) became negatively significant.

CONCLUSION

This study found an inverse association between the frequency of cheese intake and cardiovascular risk factors; however, further prospective studies are required to confirm the present results and to illustrate its mechanisms.

Saturated fat consumption may not be the main cause of increased blood lipid levels

Consumption of foods rich in saturated fatty acids (SFA) has often been associated with elevated blood lipid levels and consequently with risk for chronic diseases, including coronary heart disease. However, epidemiological and interventional studies on this topic are contradictory. While some studies have established a positive link, other studies have failed to show a significant association between saturated fat consumption and blood lipid levels, and others have even found an inverse association. Moreover, studies using animal models have demonstrated that dietary saturated fats raise blood lipid (cholesterol and triglycerides) levels only when the diet is deficient in omega-3 polyunsaturated fatty acids (n-3PUFA). The n-3PUFA are known for their potential in the management of hyperlipidaemia for the prevention of coronary heart disease, as well as for their anti-arrhythmic, anti-aggregatory and anti-inflammatory potential. We believe that with an adequate consumption of n-3PUFA dietary saturated fat may not result in elevated blood lipid levels. Therefore, we critically evaluated the literature regarding saturated fat and blood lipid level, with an emphasis on the role of n-3PUFA on this relationship. Evidence from animal studies and few clinical trials lead to the hypothesis that there are beneficial or neutral effects of saturated fatty acids when combined with recommended levels of n-3PUFA in the diet. However, an intervention focusing on the background fat when the volunteers' diet is supplemented with n-3PUFA is yet to be done. Proving the authenticity of this hypothesis would mean a substantial change in public health messages regarding saturated fats and their health effects; and also a change in the strategies related to prevention of chronic cardiac and artery diseases.

Intake of milk, but not total dairy, yogurt, or cheese, is negatively associated with the clustering of cardiometabolic risk factors in adolescents

Epidemiologic studies have reported an inverse association between dairy product consumption and cardiometabolic risk factors in adults, but this relation is relatively unexplored in adolescents. We hypothesized that a higher dairy product intake is associated with lower cardiometabolic risk factor clustering in adolescents. To test this hypothesis, a cross-sectional study was conducted with 494 adolescents aged 15 to 18 years from the Azorean Archipelago, Portugal. We measured fasting glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, triglycerides, systolic blood pressure, body fat, and cardiorespiratory fitness. We also calculated homeostatic model assessment and total cholesterol/high-density lipoprotein cholesterol ratio. For each one of these variables, a z score was computed using age and sex. A cardiometabolic risk score (CMRS) was constructed by summing up the z scores of all individual risk factors. High risk was considered to exist when an individual had at least 1 SD from this score. Diet was evaluated using a food frequency questionnaire, and the intake of total dairy (included milk, yogurt, and cheese), milk, yogurt, and cheese was categorized as low (equal to or below the median of the total sample) or "appropriate" (above the median of the total sample).The association between dairy product intake and CMRS was evaluated using separate logistic regression, and the results were adjusted for confounders. Adolescents with high milk intake had lower CMRS, compared with those with low intake (10.6% vs 18.1%, P = .018). Adolescents with appropriate milk intake were less likely to have high CMRS than those with low milk intake (odds ratio, 0.531; 95% confidence interval, 0.302-0.931). No association was found between CMRS and total dairy, yogurt, and cheese intake. Only milk intake seems to be inversely related to CMRS in adolescents.

An update on the cardiovascular pleiotropic effects of milk and milk products

Hypertension is a major risk factor in addition to atherosclerosis and type 2 diabetes mellitus for the development of coronary heart disease and strokes. Several prospective clinical studies have demonstrated a possible protective effect of milk and dairy product consumption on these conditions. The putative effects of milk and dairy products are possibly mediated through their mineral content of calcium, magnesium, potassium, and vitamin D. These dairy substances exercise their blood pressure-lowering effect either directly on the arterial wall by these minerals or indirectly through blockade of the angiotensin-converting enzyme (ACE) by the amino acids contained in the casein and whey of milk. The blockade of ACE results in the inhibition of production of angiotensin II, a potent vasoconstrictive peptide, and the prevention of degradation of bradykinin, a potent vasodilating peptide. For this concise review, a Medline search of the English language literature was conducted from 2006 to September 2012 and 16 pertinent papers were selected. The potential beneficial pleiotropic effects from these studies together with collateral literature will be discussed in this review.

Dietary fatty acid intake, its food sources and determinants in European adolescents: the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study

Dietary fatty acids (FA) play a role in several (patho)physiological processes at any age, and different FA have different effects on lipid status and health outcome. The present study aims to describe the FA intake and its main food sources in a population of healthy European adolescents and to assess the variation in intake as a function of non-dietary factors. FA intake was assessed with 24 h recall interviews in 1804 adolescents aged 12·5-17·5 years. Usual intakes were calculated using the multiple source method. Multilevel analyses, adjusting for study centre, were used to investigate the influence of non-dietary factors. The mean total fat intake was 33·3 (sd 1·2) % of total energy intake (%E). The mean SFA intake was 13·8 (sd 1·2) %E, with 99·8 % of the population exceeding the recommendations. SFA was mainly delivered by meat and cake, pies and biscuits. In most adolescents, the PUFA intake was too low, and 35·5 % of the population did not achieve the minimum recommended intake for α-linolenic acid (ALA). The main determinants of FA intake in the present study population were age and sex, as well as physical activity in the male subgroup. No contributions of body composition, socio-economic status or sexual maturation to the variance in FA intake were observed. In conclusion, the most important public health concerns regarding FA intake in this adolescent population were the low intake of ALA and the high intake of SFA, mainly seen in the younger-aged boys. In this group the major contributor to SFA was meat.

Obesity modifies the relations between serum markers of dairy fats and inflammation and oxidative stress among adolescents

Pentadecanoic acid (15:0) and heptadecanoic acid (17:0), the dairy-specific saturated fatty acids have been inversely, while inflammation and oxidative stress have been positively related to the risk of cardiovascular disease (CVD). Both fatty acid metabolism and inflammation and oxidative stress may be influenced by adiposity. In the current cross-sectional analyses among adolescents (mean age 15 years), we determined whether overweight status modified the associations between dairy fatty acids (pentadecanoic acid (15:0) and heptadecanoic acid (17:0)) represented in serum phospholipids (PL) and markers of inflammation and oxidative stress. Six biomarkers for inflammation and oxidative stress were analyzed, including circulating adiponectin, C-reactive protein (CRP), cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), and urinary 15-keto-dihydro-PGF2α (15-keto) and 8-iso-PGF2α (F2-iso). Generalized linear regression analyses, adjusted for age, gender, race, tanner score, total energy intake and physical activity, revealed that PL dairy fatty acids were inversely associated with CRP, F2-iso and 15-keto in overweight, but not in normal weight adolescents (all P(interaction) < 0.05). However, higher level of PL dairy fatty acids was associated with lower IL-6 among all adolescents. Further adjustment for dietary intake of calcium, vitamin D, protein, total flavonoids, and ω-3 fatty acids did not materially change the findings. Dairy-specific saturated fats, i.e., 15:0 and 17:0 fatty acids, may contribute to the potential health benefits of dairy products, especially for overweight adolescents.

Dairy consumption and the incidence of hyperglycemia and the metabolic syndrome: results from a french prospective study, Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR)

OBJECTIVE

In the French Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort, cross-sectional analyses have shown that a higher consumption of dairy products and calcium are associated with a lower prevalence of the metabolic syndrome (MetS). We assess the influence of dairy products on 9-year incident MetS and on impaired fasting glycemia and/or type 2 diabetes (IFG/T2D).

RESEARCH DESIGN AND METHODS

Men and women who completed a food frequency questionnaire at baseline and after 3 years were studied (n = 3,435). Logistic regression models were used to study associations between the average year 0 and year 3 consumption of milk and dairy products, cheese, dietary calcium density, and incident MetS and IFG/T2D after adjusting for 1) sex, age, alcohol, smoking, physical activity, fat intake and 2) additionally for BMI. Associations between dairy products and continuous variables were studied by repeated-measures ANCOVA, using the same covariates.

RESULTS

Dairy products other than cheese, and dietary calcium density, were inversely associated with incident MetS and IFG/T2D; cheese was negatively associated with incident MetS. All three parameters were associated with lower diastolic blood pressure, and with a lower BMI gain. Higher cheese intake and calcium density were associated with a lower increase in waist circumference and lower triglyceride levels. Calcium density was also associated with a lower systolic blood pressure and a lower 9-year increase in plasma triglyceride levels.

CONCLUSIONS

A higher consumption of dairy products and calcium was associated with a lower 9-year incidence of MetS and IFG/T2D in a large cohort drawn from the general population.

Short chain saturated fatty acids decrease circulating cholesterol and increase tissue PUFA content in the rat

This study investigates the effect of various dietary saturated fatty acid (SFA) profiles on plasma lipid parameters and tissue fatty acid composition in rats. The experiment was designed to monitor polyunsaturated fatty acids (PUFA) levels, while examining different amounts and types of SFA. Four isocaloric diets were prepared, containing 10-11 mol% of fatty acids (FA) as linoleic acid (LNA) and 2.5 mol% as α-linolenic acid (ALA), leading to an identical and well-balanced LNA/ALA ratio. The initial rapeseed oil/corn oil mixture providing ALA and LNA was enriched with olive oil to prepare the olive oil diet. The butterfat diet was supplemented with butterfat, containing short-chain SFA (C4:0-C10:0, 17 mol% of FA), lauric acid (C12:0, 3.2 mol%), myristic acid (C14:0, 10.5 mol%) and palmitic acid (C16:0, 14.5 mol%). The saturates diet was supplemented with trilaurin, trimyristin and tripalmitin to obtain the same level of lauric, myristic and palmitic acids as the butterfat diet, without the short-chain SFA. The trimyristin diet was enriched with trimyristin only. The results showed that the butterfat diet contributed to specific effects, compared to the olive oil diet and the saturates and trimyristin diets: a decrease in plasma total, LDL- and HDL-cholesterol, higher tissue storage of ALA and LNA, and a higher level of (n-3) highly unsaturated fatty acids in some tissues. This study supports the hypothesis that in diets with identical well-balanced LNA/ALA ratios, short chain SFA may decrease circulating cholesterol and increase tissue polyunsaturated fatty acid content in the rat.

Biomarkers of milk fat and the risk of myocardial infarction in men and women: a prospective, matched case-control study

BACKGROUND

High intakes of saturated fat have been associated with cardiovascular disease, and milk fat is rich in saturated fat.

OBJECTIVE

The objective of this study was to investigate the association between the serum milk fat biomarkers pentadecanoic acid (15:0), heptadecanoic acid (17:0), and their sum (15:0+17:0) and a first myocardial infarction (MI).

DESIGN

The study design was a prospective case-control study nested within a large population-based cohort in Sweden. Included in the study were 444 cases (307 men) and 556 controls (308 men) matched on sex, age, date of examination, and geographic region. Clinical, anthropometric, biomarker fatty acid, physical activity, and dietary data were collected. The odds of a first MI were investigated by using conditional logistic regression.

RESULTS

In women, proportions of milk fat biomarkers in plasma phospholipids were significantly higher (P < 0.05) in controls than in cases and were, in general, negatively, albeit weakly, correlated with risk factors for metabolic syndrome. The crude standardized odds ratios of becoming an MI case were 0.74 (95% CI: 0.58, 0.94) in women and 0.91 (95% CI: 0.77, 1.1) in men. After multivariable adjustment for confounders, the inverse association remained in both sexes and was significant in women. In agreement with biomarker data, quartiles of reported intake of cheese (men and women) and fermented milk products (men) were inversely related to a first MI (P for trend < 0.05 for all).

CONCLUSIONS

Milk fat biomarkers were associated with a lower risk of developing a first MI, especially in women. This was partly confirmed in analysis of fermented milk and cheese intake. Components of metabolic syndrome were observed as potential intermediates for the risk relations.

Dairy food consumption and obesity-related chronic disease

Dairy food comprises a range of different products with varying nutritional components. In the context of a healthy diet, dairy food may provide protection against and amelioration of chronic diseases related to obesity. These include overweight, insulin resistance/metabolic syndrome/type 2 diabetes, hypertension/stroke, and cardiovascular disease. Eliciting how dairy food may have this impact represents a challenge for modern nutritional science and requires an integration of knowledge from observational studies of population dietary patterns and disease prevalence, and experimental studies testing the effect of dairy food consumption. It also benefits from the recent identification of biomarkers of dairy fat intake and from mechanistic studies that support the plausibility of the observed effects. Future research might discriminate between types of dairy foods and focus on the synergy provided by the food matrix, rather than simply the component parts of the food.

Sources of saturated fat and sucrose in the diets of Swedish children and adolescents in the European Youth Heart Study: strategies for improving intakes

OBJECTIVE

To compare macronutrient intakes of Swedish children and adolescents to population goals; to identify the major sources of energy, fat, saturated fat and sucrose; and to simulate the effect adherence to current food-based dietary guidelines (FBDG) would have on saturated fat and sucrose intakes.

DESIGN

Cross-sectional study. From 24 h recall data, food groups contributing most to energy, fat, saturated fat and sucrose were identified. Based on the prevailing consumption of foods mentioned in the FBDG, we simulated five scenarios: changes in milk and yoghurt; cheese; energy-dense, nutrient-dilute foods; soft drinks; and burger and sausage consumption.

SETTING

Stockholm and Örebro (Sweden) in 1998-1999.

SUBJECTS

Children (n 551, 9·6 years) and adolescents (n 569, 15·5 years) participating in the European Youth Heart Study.

RESULTS

Intakes of saturated fat and sucrose exceeded population goals in all age and gender subgroups. Compliance to the goal for saturated fat was lower in children, particularly boys. Compliance to the sucrose goal was lower among adolescents. The major sources of energy, fat, saturated fat and sucrose in the diet reflect not only the traditional Swedish diet but also the influence of energy-dense, nutrient-dilute foods. The simulations suggest that a combination of FBDG is required to bring both saturated fat and sucrose intakes in line with recommendations.

CONCLUSIONS

Widespread adherence to a combination of FBDG could theoretically bring mean intakes in line with population goals. The effect on overall nutrient intakes as well as consumer acceptance of such changes needs to be considered.

Dairy consumption and patterns of mortality of Australian adults

BACKGROUND/OBJECTIVES

Dairy foods contain various nutrients that may affect health. We investigated whether intake of dairy products or related nutrients is associated with mortality due to cardiovascular disease (CVD), cancer and all causes.

SUBJECTS/METHODS

We carried out a 16-year prospective study among a community-based sample of 1529 adult Australians aged 25-78 years at baseline. Habitual intakes of dairy products (total, high/low-fat dairy, milk, yoghurt and full-fat cheese), calcium and vitamin D were estimated as mean reported intake using validated food frequency questionnaires (FFQs) self-administered in 1992, 1994 and 1996. National Death Index data were used to ascertain mortality and cause of death between 1992 and 2007. Hazard ratios (HRs) were calculated using Cox regression analysis.

RESULTS

During an average follow-up time of 14.4 years, 177 participants died, including 61 deaths due to CVD and 58 deaths due to cancer. There was no consistent and significant association between total dairy intake and total or cause-specific mortality. However, compared with those with the lowest intake of full-fat dairy, participants with the highest intake (median intake 339 g/day) had reduced death due to CVD (HR: 0.31; 95% confidence interval (CI): 0.12-0.79; P for trend=0.04) after adjustment for calcium intake and other confounders. Intakes of low-fat dairy, specific dairy foods, calcium and vitamin D showed no consistent associations.

CONCLUSIONS

Overall intake of dairy products was not associated with mortality. A possible beneficial association between intake of full-fat dairy and cardiovascular mortality needs further assessment and confirmation.

The effects of probiotic and conventional yoghurt on lipid profile in women

Many studies have been done on the hypocholesterolaemic effect of probiotic yoghurt. The results, however, are not conclusive. The aim of the present study was to test the effect of probiotic and conventional yoghurt on the lipid profile in women. In a randomised trial, ninety female volunteers aged 19–49 years were assigned to three groups. Subjects consumed daily 300 g probiotic yoghurt containingLactobacillus acidophilusLa5 andBifidobacterium lactisBb12 or 300 g conventional yoghurt or no yoghurt for 6 weeks. Fasting blood samples, 3 d dietary records and anthropometric measurements were collected at baseline (T1), end of week 3 (T2) and end of week 6 (T3). Lipid profile parameters were determined by enzymic methods. Results showed no significant difference in lipid profile within any group throughout the study. Comparing mean differences (T1 − T3) among the three groups showed: no difference in TAG and LDL-cholesterol, a decrease in cholesterol in both conventional (P < 0·05) and probiotic yoghurt groups (P < 0·005) compared with the control group, a decrease in total:HDL-cholesterol ratio for conventional (P < 0·05) and probiotic yoghurt groups (P < 0·001) compared with the control group, and an increase in HDL-cholesterol in the probiotic yoghurt group (P < 0·05) compared with the control group. Positive changes in lipid profile were observed in both yoghurt groups. Any added effect, therefore, is due to the consumption of fermented milk products.

Serum lipids, glucose and insulin levels in healthy schoolchildren aged 9 and 15 years from central Sweden: Reference values in relation to biological, social and lifestyle factors

BACKGROUND

There is a shortage of reference values for cardiovascular risk factors such as serum lipids, glucose and insulin related to biological, social and lifestyle factors for Swedish children and adolescents. Such values are needed for planning and evaluation of public health activities, and for clinical use.

DESIGN AND METHODS

Data for this cross-sectional, school-based study were collected during a school year (September to May). A random sample of 1137 girls and boys aged 9 and 15 years from two locations in central Sweden participated in the study, and blood samples were taken from 969 of them.

METHODS

Fasting serum blood samples were analysed for triglycerides, total cholesterol, high-density lipoprotein cholesterol, glucose and insulin. Physical examination included measurement of height, weight and pubertal status. Questionnaires provided family background data. Total physical activity was measured by accelerometer registration.

RESULTS

Serum levels differed significantly between age and gender groups and were correlated to pubertal status. Neither genetic nor socio-economic background nor smoking status influenced the serum levels. Insulin levels were elevated in subjects with a body mass index in the highest decentile, compared with the levels in the rest of the subjects. The insulin levels were inversely associated with total physical activity, and physical activity varied with season.

CONCLUSIONS

Pubertal status (biological age) should to be considered in the interpretation of serum values in schoolchildren rather than chronological age. The interpretation of insulin values should include both body mass index and physical activity level, and perhaps also season. Previously described regional differences in serum lipid levels in Swedish adults seem to be present also in children.

A reappraisal of the impact of dairy foods and milk fat on cardiovascular disease risk

Background

This review provides a reappraisal of the potential effects of dairy foods, including dairy fats, on cardiovascular disease (CVD)/coronary heart disease (CHD) risk. Commodities and foods containing saturated fats are of particular focus as current public dietary recommendations are directed toward reducing the intake of saturated fats as a means to improve the overall health of the population. A conference of scientists from different perspectives of dietary fat and health was convened in order to consider the scientific basis for these recommendations.

Aims

This review and summary of the conference focus on four key areas related to the biology of dairy foods and fats and their potential impact on human health: (a) the effect of dairy foods on CVD in prospective cohort studies; (b) the impact of dairy fat on plasma lipid risk factors for CVD; (c) the effects of dairy fat on non-lipid risk factors for CVD; and (d) the role of dairy products as essential contributors of micronutrients in reference food patterns for the elderly.

Conclusions

Despite the contribution of dairy products to the saturated fatty acid composition of the diet, and given the diversity of dairy foods of widely differing composition, there is no clear evidence that dairy food consumption is consistently associated with a higher risk of CVD. Thus, recommendations to reduce dairy food consumption irrespective of the nature of the dairy product should be made with caution.

The association of desaturase 9 and plasma fatty acid composition with insulin resistance-associated factors in female adolescents

Desaturase 9 (Delta 9), which converts saturated fatty acids (SFAs) into monounsaturated fatty acids, is an important component in leptin-mediated energy homeostasis in rodent models. Few human studies, however, have been performed regarding the clinical relevance of Delta 9, particularly whether Delta 9 is involved in the relationship between blood fatty acid profiles and insulin resistance-associated factors. The aim of the present study was to examine fatty acid data from 178 apparently healthy female adolescents and determine whether (a) Delta 9 has independent associations with adiposity, insulin resistance level, and fasting plasma polyunsaturated fatty acids (PUFAs); (b) Delta 9 is a predictor of fasting blood lipid profile; and (c) the associations between fasting plasma fatty acid component and insulin resistance level are independent of abdominal obesity level. Desaturase 9-16 (surrogate of Delta 9 as calculated by plasma ratio C16:1 n-7/C16:0) correlated with waist girth (r = .160, P < .05), homeostasis model assessment of insulin resistance (HOMA-IR) (r = .201, P < .01), plasma PUFAs (eg, C20:4 n-6 [r = -.269, P < .001], C22:6 n-3 [r = -.274, P < .001]). After adjustment for dietary SFAs, Delta 9-16 had stronger correlation with waist (r = .227, P < .01) and significant correlation with PUFAs, whereas it had a nonsignificant correlation with HOMA-IR. The same pattern was observed with Delta 9-18 (surrogate of Delta 9 as calculated by plasma ratio C18:1 n-9/C18:0). After adjustment for dietary SFAs, waist, and HOMA-IR, Delta 9-16 and Delta 9-18 were still positive predictors of triglyceride (both P < .001) and apolipoprotein B (Delta 9-18, P < .001; Delta 9-16, P = .052). After adjustment for waist, HOMA-IR only remained a positive determinant of medium-chain SFAs (C14:0, P < .001; C16:0, P < .05); but it emerged to be inversely related to C20:4 n-6 (P < 0.1). The positive and independent associations of medium-chain SFAs with insulin resistance level suggest their vital roles in diabetes pathogenesis, whereas certain PUFAs such as C20:4 n-6 appear to be protective. The observed associations of Delta 9 with adiposity and plasma lipid profile in these apparently healthy female adolescents support the concept derived from rodent models that Delta 9 activity is independently reflective of higher body mass index and higher circulatory triglyceride levels.

Intake of dairy fat and dairy products, and risk of myocardial infarction: a case-control study

The role of dairy fat in the aetiology of myocardial infarction (MI) is controversial. The aim of this study was to evaluate the association between intake of dairy fat and dairy products, and risk of a first acute MI. A total of 111 MI patients with a first acute MI and 107 population controls (men and women, age 45 75 years) were studied. Diet was assessed using a 180-item food frequency questionnaire. The MI cases had higher intake of total fat, but lower intake of saturated fat and dairy fat than the control persons. No effect of dairy fat or saturated fat on the odds ratio for MI was observed, however. A significant inverse trend in odds of MI for intake of cheese was observed, but the trend was no longer significant after adjustment for smoking. The results suggest that intake of fat from dairy products may not be associated with increased risk of having a first MI. The healthy control persons had a diet that differed from the diet of the MI patients in many aspects, and dairy products were a part of this diet. This may have protected them from having a first MI.

Saturated fatty acids: simple molecular structures with complex cellular functions

PURPOSE OF REVIEW

This review summarizes recent findings on the biological functions of saturated fatty acids. Some of these findings suggest that saturated fatty acids may have important and specific regulatory roles in the cells. Until now these roles have largely been outweighed by the negative impact of dietary saturated fatty acids on atherosclerosis biomarkers. Elucidated biochemical mechanisms like protein acylation (N-myristoylation, S-palmitoylation) and putative physiological roles are described.

RECENT FINDINGS

The review will focus on the following topics: new aspects on the metabolism of saturated fatty acids; recent reports on the biochemical functions of saturated fatty acids; current investigations on the physiological roles (elucidated and putative) of saturated fatty acids; and a discussion of the nutritional dietary recommendations (amounts and types) of saturated fatty acids.

SUMMARY

Dietary saturated fatty acids are usually associated with negative consequences for human health. Experimental results on the relationship between doses, physiological effects, specificities and functions of individual saturated fatty acids are, however, conflicting. In this context, this review describes emerging recent evidence that some saturated fatty acids have important and specific biological roles. Such data are needed to allow a balanced view in terms of potential nutritional benefits of saturated fatty acids, and, if necessary, reassessment of the current nutritional dietary recommendations.

Dietary fat in infancy should be more focused on quality than on quantity

OBJECTIVE

The primary aim was to assess, the association of the quantity and quality of dietary fat intake from 6 to 12 months of age and serum lipids at 12 months.

SUBJECTS/METHODS

Three hundred healthy term Swedish infants were recruited in a longitudinal prospective study at the age of 6 months; 276 remained in the study at 12 months. Food records and anthropometric data were collected monthly from 6 to 12 months; serum lipids were analysed at 6 and 12 months.

RESULTS

Swedish infants had a total fat intake within the Nordic recommendations, but intake of polyunsaturated fatty acids (PUFA) was low (5.6 percent of total energy (E%)) and intake of saturated fatty acids (SAFA) was high (15.1 E%). Higher PUFA intake was associated with lower total serum cholesterol (TC, B=-0.13, P=0.003), lower low-density-lipoprotein cholesterol (LDL-C, B=-0.12, P=0.004) and apolipoprotein B (B=-0.03) (P=0.034) in girls but not in boys. When data from the present study were compared to data from similar studies in Finland and Iceland, it appears that the quality of the dietary fat has greater impact on serum lipid levels than the quantity of fat in the diet.

CONCLUSIONS

Higher PUFA and lower SAFA intakes may reduce TC and LDL-C early in life, particularly in girls. Further, with respect to lowering serum lipid concentrations in early childhood it seems appropriate to set focus on fat quality rather than the quantity.

SPONSORSHIPS

Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (Formas), Swedish Research Council, Medicine, Stiftelsen Oskar Foundation, Sven Jerring Foundation, Samariten Foundation, Stiftelsen Goljes minne and Semper AB.

Dietary intake and nutritional status of children and adolescents in Europe

The objective of this project was to collect and evaluate data on nutrient intake and status across Europe and to ascertain whether any trends could be identified. Surveys of dietary intake and status were collected from across Europe by literature search and personal contact with country experts. Surveys that satisfied a defined set of criteria – published, based on individual intakes, post-1987, adequate information provided to enable its quality to be assessed, small age bands, data for sexes separated above 12 years, sample size over 25 and subjects representative of the population – were selected for further analysis. In a small number of cases, where no other data for a country were available or where status data were given, exceptions were made. Seventy-nine surveys from 23 countries were included, and from them data on energy, protein, fats, carbohydrates, alcohol, vitamins, minerals and trace elements were collected and tabulated. Data on energy, protein, total fat and carbohydrate were given in a large number of surveys, but information was very limited for some micronutrients. No surveys gave information on fluid intake and insufficient gave data on food patterns to be of value to this project. A variety of collection methods were used, there was no consistency in the ages of children surveyed or the age cut-off points, but most surveys gave data for males and females separately at all ages. Just under half of the surveys were nationally representative and most of the remainder were regional. Only a small number of local surveys could be included. Apart from anthropometric measurements, status data were collected in only seven countries. Males had higher energy intakes than females, energy intake increased with age but levelled off in adolescent girls. Intakes of other nutrients generally related to energy intakes. Some north–south geographical trends were noted in fat and carbohydrate intakes, but these were not apparent for other nutrients. Some other trends between countries were noted, but there were also wide variations within countries. A number of validation studies have shown that misreporting is a major problem in dietary surveys of children and adolescents and so all the dietary data collected for this project should be interpreted and evaluated with caution In addition, dietary studies rely on food composition tables for the conversion of food intake data to estimated nutrient intakes and each country uses a different set of food composition data which differ in definitions, analytical methods, units and modes of expression. This can make comparisons between countries difficult and inaccurate. Methods of measuring food intake are not standardised across Europe and intake data are generally poor, so there are uncertainties over the true nutrient intakes of children and adolescents across Europe. There are insufficient data on status to be able to be able to draw any conclusions about the nutritional quality of the diets of European children and adolescents.

Estimated intake of milk fat is negatively associated with cardiovascular risk factors and does not increase the risk of a first acute myocardial infarction. A prospective case–control study

Milk fat is high in saturated fatty acids (SFA) and high intakes of SFA are associated with cardiovascular diseases. The aim of the present study was to prospectively evaluate the potential risk of a first-ever acute myocardial infarction (AMI) in relation to the estimated milk-fat intake, reflected as the proportions of pentadecanoic acid (15:0) and heptadecanoic acid (17:0) in serum lipid esters. This was evaluated in a study population selected within the Västerbotten Intervention Program and the northern Sweden ‘Monitoring of Trends and Determinants in Cardiovascular disease’ survey populations. A prospective case–control design was used. The proportions of the biomarkers were lower in the cases (n78) than in the controls (n156), who were matched for age, sex, sampling time and geographical region. The standardised odds ratios of becoming an AMI case were between 0·7 and 0·8 for the biomarkers. The proportions of 15:0 and 17:0 in serum phospholipids were significantly and negatively correlated to serum concentrations of plasminogen activator inhibitor-1, tissue-type plasminogen activator, triacylglycerols, insulin, specific insulin, pro-insulin and leptin (allP<0·0001), suggesting a negative relationship to the insulin-resistance syndrome and the risk of CHD. Adjustment for BMI did not materially change the relationships. Although there seems to be a negative association between milk-fat intake as mirrored by the proportions of 15:0 and 17:0 in serum lipid esters and a first-ever AMI, adjustment for clinical risk factors removed this relationship.

The role of animal nutrition in improving the nutritive value of animal-derived foods in relation to chronic disease

Foods derived from animals are an important source of nutrients in the diet; for example, milk and meat together provide about 60 and 55% of the dietary intake of Ca and protein respectively in the UK. However, certain aspects of some animal-derived foods, particularly their fat and saturated fatty acid (SFA) contents, have led to concerns that these foods substantially contribute to the risk of CVD, the metabolic syndrome and other chronic diseases. In most parts of Europe dairy products are the greatest single dietary source of SFA. The fatty acid composition of various animal-derived foods is, however, not constant and can, in many cases, be enhanced by animal nutrition. In particular, milk fat with reduced concentrations of the C12–16SFA and an increased concentration of 18:1 MUFA is achievable, although enrichment with very-long-chainn-3 PUFA is much less efficient. However, there is now evidence that some animal-derived foods (notably milk products) contain compounds that may actively promote long-term health, and research is urgently required to fully characterise the benefits associated with the consumption of these compounds and to understand how the levels in natural foods can be enhanced. It is also vital that the beneficial effects are not inadvertently destroyed in the process of reducing the concentrations of SFA. In the future the role of animal nutrition in creating foods closer to the optimum composition for long-term human health is likely to become increasingly important, but production of such foods on a scale that will substantially affect national diets will require political and financial incentives and great changes in the animal production industry.

Milk and the metabolic syndrome

The metabolic syndrome is a cluster of metabolic disorders, namely dyslipidaemia, hypertension, obesity and glucose intolerance. Insulin resistance is the core phenomenon. Co-occurrence is associated with increased cardiovascular disease (CVD) risk. Observational studies found no increased CVD risk with increasing consumption of milk and other dairy products. In several studies dairy consumption was inversely associated with the occurrence of one or several facets of the metabolic syndrome. Many dairy components may contribute to the beneficial effects. Milk and particularly whey appeared insulinotropic when given in a single meal, but not in longer-term intervention. Medium chain fatty acids improve insulin sensitivity. Whey proteins, amino acids, medium chain fatty acids and in particular calcium and other minerals may contribute to the beneficial effect of dairy products on body weight and body fat. Peptides, calcium and other minerals reduce blood pressure. Fermented products and probiotic bacteria decrease absorption of cholesterol, sphingomyelin of cholesterol and fat, calcium of cholesterol, bile acids and fat. Proteins, peptides and bacteria may also reduce plasma cholesterol. Lactose, citrate, proteins and peptides improve weight control, blood pressure and plasma lipids indirectly, by improving calcium bioavailability. Furthermore, dairy consumption improves the bioavailability of folate and other secondary plant components.

Modelling dairy intake on the development of acute coronary syndromes: the CARDIO2000 study

BACKGROUND

Dairy consumption may be associated with a small but worthwhile reduction in cardiovascular disease risk, but results from epidemiological studies are inconsistent. The aim of the present study was to evaluate the association between dairy consumption and the prevalence of a first, non-fatal event of an acute coronary syndrome, in a Greek sample.

DESIGN

Seven hundred male and 148 female patients with first event of an acute coronary syndrome and 1078 population-based controls, age and sex matched, were randomly selected.

METHODS

Detailed information regarding their medical records, alcohol intake, physical activity and smoking habits was recorded. Nutritional habits were evaluated with a semi-quantitative food-frequency questionnaire. Multiple logistic regression analysis estimated the odds ratio of having acute coronary syndrome by level of dairy intake, after taking into account the effect of several confounders.

RESULTS

An inverse relationship was observed between dairy products consumption and odds of having acute coronary syndrome. One portion increase in weekly dairy products intake was associated with 12% lower likelihood of having acute coronary syndrome, after controlling for various potential confounders (P<0.001). Cut-off analysis showed that 7.4 portions per week are the optimal consumption that benefits people from having acute coronary syndrome.

CONCLUSIONS

Dairy consumption seems to offer significant protection against coronary heart disease, irrespective of various clinical, lifestyle and other characteristics of the participants.

Evaluation of the odd fatty acids 15:0 and 17:0 in serum and adipose tissue as markers of intake of milk and dairy fat

BACKGROUND

There is a need for biomarkers of dietary saturated fatty acids, because several diseases have been related to intake of these fatty acids.

OBJECTIVE

To examine the relation between intake of dairy fat and the proportion of pentadecanoic (15:0) and heptadecanoic (17:0) acid in serum and adipose tissue.

DESIGN

Healthy men aged 21-55 y provided serum (n = 110) and adipose tissue samples (n = 107) and completed both 14 days weighed records (WR) and a 180-item food frequency questionnaire (FFQ). The proportions of 15:0 and 17:0 acid in serum and adipose tissue as measured by gas liquid chromatography were evaluated as biomarkers for fat intake from dairy products using Pearsons correlation coefficient and the method of triads.

RESULTS

The strongest correlation coefficients were observed between total intake of dairy fat estimated from WR and relative content of 15:0 in adipose tissue (0.52, 95% CI: 0.37, 0.65) and total serum (0.43, 95% CI 0.26, 0.57). A consistent inverse association was observed between the intake of milk fat and relative serum content of 17:0. The validity coefficients observed for the intake of dairy fat estimated from weighed records, the 180-item FFQ and by the relative content of 15:0 in serum and adipose tissue were 0.94 (95% CI: 0.68, 1.00), 0.50 (95% CI: 0.29, 0.67), 0.49 (95% CI: 0.32, 0.67) and 0.56 (95% CI: 0.28, 0.82), respectively.

CONCLUSION

Relative content of 15:0 in serum and adipose tissue may be a useful biomarker for the intake of total dairy fat, whereas FFQs and WRs may provide better estimates of the intake of fat from milk.

Dairy products and cardiovascular disease

PURPOSE OF REVIEW

Although it has often been postulated that the consumption of dairy products is associated with a high risk of coronary heart disease, study results have been conflicting. This review summarizes recent observational and human intervention trial findings on dairy products and cardiovascular disease.

RECENT FINDINGS

Results from more recent observational studies on dairy products and milk disagree. This may be because of the very different methods used combined with several methodological problems. A somewhat surprising beneficial association between the intake of dairy products and the metabolic syndrome was observed in some studies, although not in a single study of elderly women. Milk may have the same cholesterol-raising properties as butter, whereas cheese does not seem to increase plasma cholesterol. Some milk products fermented by specific bacterial strains have been shown to have rather moderate cholesterol-reducing properties. There is also good evidence that certain fermented products (especially by Lactobacillus helveticus) have a mildly decreasing effect on hypertension, probably because of bioactive peptides.

SUMMARY

When guiding principles such as balance, variety and moderation are stressed, there is no strong evidence that dairy products increase the risk of coronary heart disease in healthy men of all ages or young and middle-aged healthy women. Human studies should investigate the role of dairy products with respect to sex and age by including classic and novel risk markers of coronary heart disease. Specific fermented milks may be beneficial in the future prevention of hypertension. The beneficially neutral effect of cheese on coronary heart disease risk factors should be elucidated further.

Plasma fatty acid composition is associated with the metabolic syndrome and low-grade inflammation in overweight adolescents

BACKGROUND

Together with adiposity, plasma fatty acid (FA) composition can modulate the development of the metabolic syndrome (MS).

OBJECTIVE

Our aim was to investigate the relations of FA composition in plasma phospholipids and cholesterol esters (CEs) with weight status, MS, and inflammation in adolescents.

DESIGN

Plasma FA composition was measured by gas-liquid chromatography in 120 (60 normal-weight and 60 overweight) 12-y-old adolescents. We also measured the presence of MS, insulin resistance with the homeostasis model assessment, and interleukin 6 and C-reactive protein concentrations in the adolescents.

RESULTS

MS was present in 25% of the overweight adolescents but in none of the normal-weight adolescents. Compared with overweight adolescents, normal-weight adolescents had lower saturated FAs (SFAs) in both phospholipids (P < 0.001) and CEs (P < 0.01) and higher docosahexaenoic acid in phospholipids (P < 0.001). In overweight subjects, FA composition was associated with MS features independent of body fat. The odds ratios of MS for a 0.1 increase in the ratio of polyunsaturated FAs (PUFA) to SFAs (PUFA:SFA) were 0.91 in phospholipids (P = 0.03) and 0.90 in CEs (P = 0.06). In phospholipids, PUFA:SFA and linoleic acid were associated positively with HDL cholesterol (P < 0.01 for both). PUFA:SFA in phospholipids and CEs were associated inversely with interleukin 6 (P < 0.05 for both). Eicosapentaenoic acid in phospholipids (P = 0.06) and CEs (P < 0.05) and linolenic acid in CEs (P < 0.05) were inversely related to C-reactive protein. These relations remained significant after adjustment for the waist-to-hip ratio. No significant relation between FA composition and the homeostasis model assessment was observed.

CONCLUSIONS

Plasma FA composition is associated with weight status in healthy adolescents. High intake of long-chain PUFAs, especially n-3 PUFAs, may protect obese subjects against MS and low-grade inflammation as early as adolescence.

Intake of milk fat, reflected in adipose tissue fatty acids and risk of myocardial infarction: a case–control study

OBJECTIVE

To study the association between content of fatty acids from milk fat (14:0, 15:0 and 17:0) in adipose tissue and risk of a first myocardial infarction (MI).

DESIGN AND SUBJECTS

A case-control study with 99 patients and 98 population controls both men and postmenopausal women, age 45-75 year. Adipose tissue fatty acids were determined by gas-liquid chromatography.

RESULTS

The content of 14:0, 14:1, 15:0, 17:0 and 17:1 were all significantly higher in adipose tissue of controls than of the patients. Age and sex adjusted odds ratios (OR) for MI were significantly reduced with increasing quartiles of 14:0, 14:1, 15:0 and 17:1 in adipose tissue, but except for 15:0 (OR = 0.36, 95% CI 0.13-0.99), the trend was no longer significant after further adjustment for waist-to-hip ratio, smoking and family history for coronary heart disease. Correlations between 14:0 and 15:0 in adipose tissue, and waist-to-hip ratio were significantly negative (r = -0.22 for both, P < 0.01).

CONCLUSION

Our study suggests that intake of dairy fat or some other component of dairy products, as reflected by C15:0 as marker in adipose tissue, may protect persons at increased risk from having a first MI, and that the causal effects may rely on other factors than serum cholesterol.

SPONSORSHIP

Throne Holst's foundation for Nutrition Research, Research Council of Norway, The Norwegian Association of Margarine Producers, DeNoFa Fabriker A/S, TINE BA.