Lipid-lowering effects of a modified butter-fat: a controlled intervention trial in healthy men

Metabolic effects of milk fatty acids: A literature review

Milk and dairy products are known to have a significant role in human development and tissue maintenance due to their high nutritional value. With the higher incidence of obesity and metabolic diseases, nutrition and public health authorities have recommended the intake of fat-free or low-fat dairy due to the saturated fatty acid content of whole-fat products and their effect on serum cholesterol levels. However, recent studies have questioned the association between milk fat consumption and cardiometabolic risk. This literature review aims to compile the scientific evidence of the metabolic effects of milk fatty acids in clinical and basic research studies, as well as their relationship with metabolic disorders and gut microbiota composition. Research shows that various milk fatty acids exert effects on metabolic alterations (obesity, type 2 diabetes and cardiovascular diseases) by modifying glucose homeostasis, inflammation and lipid profile-related factors. Additionally, recent studies have associated the consumption of milk fatty acids with the production of metabolites and the promotion of healthy gut microbiota. From mainly observational studies, evidence suggests that milk and dairy fatty acids are not directly linked to cardiometabolic risk, but further controlled research is necessary to clarify such findings and to assess whether dietary recommendations to choose low-fat dairy foods are necessary for the population for the prevention of obesity and cardiometabolic disease.

Butter from Different Species: Composition and Quality Parameters of Products Commercialized in the South of Spain

Butter is an important product for the dairy industry due to its particular sensory attributes and nutritional value, while the variability of the composition of the fatty acids in the milk can alter the nutritional and physical properties of butter and its acceptance by consumers. Butter is highly appreciated for its distinctive flavor and aroma; however, one of its main drawbacks lies in the difficulty in spreading it at low temperatures. Several types of butter that are present in the market were used in this study. We assessed the variability in the composition of the samples regarding their texture, color properties, and volatile organic compound profiles. We analyzed samples commercially produced from sheep's milk (SB), goat's milk (GB), and cow's milk (CB); samples from the latter species with (CSB) and without salt (CB); and the low-fat (CLB) version. All the physicochemical composition parameters were significantly affected by the effect of the type of butter, although only 29 out of the 45 fatty acids examined were identified in the butter samples analyzed. The textural properties of the butters were influenced by both their solid fat content and the fatty acid profile. In addition, the origin of the milk not only affected the texture parameters but also the color of the butters and the compounds associated with traits such as odor and flavor. Through the multivariate data analysis of butter fatty acids and volatile compound percentages, we observed a clear differentiation of the samples based on the species of origin.

Effect of Fish Oil and Linseed Oil on Intake, Milk Yield and Milk Fatty Acid Profile in Goats

This study aimed to evaluate the effect of incorporating linseed oil and fish oil in the diet on intake, ruminal fermentation, milk yield, and milk fatty acid profiles in dairy goats. Four crossbred Saanen lactating goats in mid-lactation and milking 1.30 ± 0.28 g/day were used in a 4 × 4 Latin square design. The basal diet contained concentrate and Para grass (C:F 40:60). Treatments included a basal diet without oil supplementation (Ctrl) or with 2.5% linseed oil (LO_2.5), 2.5% linseed oil and fish oil (3:2, w/w, LFO_2.5), and 4.16% linseed oil and fish oil (3:2, w/w, LFO_4.16). Diets had no effect on intake, milk yield, milk composition, or ruminal fermentation (p > 0.05). Compared with Ctrl, lower (p < 0.05) proportions of C10:0-C14:0 in milk fat were observed with LFO_4.16. Compared with the Ctrl and linseed oil added alone, feeding LFO_4.16 led to a greater (p < 0.01) concentration of C18:1 t11. Compared with both the Ctrl and LO_2.5 diets, milk c9,t11 CLA was 4.53 and 2.94 times greater with the LFO_4.16 diet. Compared with Ctrl and LO_2.5 diets (0.06% and 0.08%), goats fed LFO_2.5, and LFO_4.16 had greater (p < 0.001) concentrations of C22:6n-3 (0.63% and 0.87%). Overall, the combined data suggested that including 4.16% linseed oil and fish oil in the diet of dairy goats was effective in improving the concentrations of health-promoting fatty acids in milk without affecting milk production.

Cow's Milk and Dairy Consumption: Is There Now Consensus for Cardiometabolic Health?

Cow's milk and dairy products derived from this complex food source have long been proposed as beneficial to human health, yet underlying clinical evidence of direct benefit continues to raise controversy. Limited evidence supports positive cardiometabolic effects of a number of dairy macro- and micronutrient components including whey protein and casein, unsaturated fats, milk fat globule membrane (MFGM) and polar phospholipids, vitamin D and calcium, in addition to non-bovine components including bacterial and yeast probiotics. More controversial remain lipid components trans fats, including trans vaccenic acid, trans palmitoleic acid, and conjugated cis trans linoleic acid (CLA), plus medium-chain and odd-chain dairy fats. New evidence is rapidly identifying multiple pathways by which these dairy nutrients may effect health. Processing, including fermentation and homogenization, may also have positive effects. Conversely, the high saturated fat content of dairy has long raised concern, aligned with international guidelines to minimize dietary intake of animal-origin saturated fatty acids (SFA) to achieve better cardiometabolic health. However, led in part by observational studies and meta-analyses showing dairy to have no or even an inverse association with cardiometabolic health, evidence from randomized controlled trials (RCTs) has been scrutinized over the last 5 years, and focus on low-fat dairy has been challenged. Recent evidence supports the hypothesis that adverse effects of SFAs on metabolic health may be ameliorated when these fats are consumed within a complex matrix such as milk, cheese or yogurt, and that dairy food categories may influence outcomes as much as total fat content. For example, yogurt and high-fat, high-SFA cheese have a negative association with risk of type 2 diabetes (T2D) in many, not all, published trials. However, large sample dairy RCTs of long duration with CVD or T2D incidence as primary endpoints are lacking. This is a clear research gap, with these clinical studies required if a causative link between dairy and improved cardiometabolic health is to be confirmed and in turn promoted through dietary guidelines. Current advisories from national guidance groups such as American Heart Association (AHA) and European Society of Cardiology (ESC) continue to promote consumption of low-fat dairy products, whilst liquid milk and yogurt remain part of nutrition guidelines from joint American Diabetes Association (ADA)/European Association for Study of Diabetes (EASD) reports, and as part of a “no-one-size-fits-all” answer to diet and T2D by the ADA in their most recent 2019 Consensus Report.

Role of Fluid Milk in Attenuating Postprandial Hyperglycemia and Hypertriglyceridemia

Postprandial plasma glucose and triglyceride concentrations are predictive of relative cardiovascular disease (CVD) risk, and the pathogenesis of both insulin resistance and atherosclerosis has been attributed to acute states of hyperglycemia and hypertriglyceridemia. Postprandial lipemia and hyperglycemia suppress vascular reactivity and induce endothelial dysfunction. Epidemiological studies suggest that chronically-high consumption of milk and milk products is associated with a reduced risk of type 2 diabetes, metabolic syndrome, and CVD. The addition of dairy products to meals high in carbohydrates and fat may lessen these risks through reductions in postprandial glucose and triglyceride responses. Purported mechanisms include dairy proteins and bioactive compounds, which may explain the inverse relationship between dairy consumption and cardiometabolic diseases. The current review evaluates the available literature describing the relationships between metabolic dysfunction, postprandial metabolism, and vascular dysfunction and discusses the potential role of milk and dairy products in attenuating these impairments.

Effects of Breed and Stage of Lactation on Milk Fatty Acid Composition of Italian Goat Breeds

Fatty acid (FA) profile plays an important role on human health and on sensory quality of dairy products. There is few information about breed influence on milk FA profile of local goat breeds. This study aimed to characterize and compare the milk FA profile of 5 local endangered goat breeds (Garganica, Girgentana, Jonica, Maltese, and Mediterranean Red) and a cosmopolitan breed (Saanen) reared in the same farm during a complete lactation. A total of 252 milk samples were collected monthly from 42 goats (7 goats per breed) and analyzed for gross composition and FA profile. Individual FA was determined using gas-chromatography. Data were analyzed using a mixed model with repeated measures with breed and week of lactation as fixed effects. Results showed that the FA profile was significantly affected by week of lactation and only few FA by breed effect (p < 0.05). Overall, the main differences were found between Saanen and local breeds. This study contributed to the characterization of goat milk FA profile, and it may be of interest for the valorization of milk from local goat breeds which seem to have a healthier profile than milk of the cosmopolitan breed.

Fatty acids profile of Serra da Estrela PDO cheeses and respective atherogenic and thrombogenic indices

Purpose

This study aims to determine the physicochemical and fatty acids composition of Serra da Estrela cheese (SEC), as well as health-related lipid indices, like the atherogenic and thrombogenic indices, and to evaluate the influence of producer, geographical origin and production date.

Design/methodology/approach

All 24 SEC produced between November 2017 and March 2018 were collected at selected certified producers and analyzed by NIR spectrophotometer and by GC. Data were statistically evaluated by chemometric tools.

Findings

In all evaluated SEC, 23 fatty acids were quantified. Cheese origin influenced nutritional and health-related lipid indices). The cheeses were characterized by a relative high abundance of saturated fatty acids (67-76%), followed by a medium content of monounsaturated fatty acids (17-25%) and by low level of polyunsaturated fatty acids (5-7%). A putative positive association between cheese consumption and healthy lipid indices could be reached.

Practical implications

The contents of some medium and long chain fatty acids as well as of nutritional and health indices were influenced by cheese producer, geographical origin and production date pointing out the need for standardizing production procedures.

Social implications

The SEC plays a key role in the local economy, being an endogenous product with unique sensory characteristics and nutritional potential, for which the knowledge of the lipids profile and health indices is of utmost relevance.

Originality/value

SEC is an iconic Portuguese cheese with Protected Designation of Origin. Based on the results, like health-related lipid indices, evaluated for the first time, a positive association between cheese consumption and healthy lipid indices could be envisaged.

Adding heat-treated rapeseed to the diet of yak improves growth performance and tenderness and nutritional quality of the meat

Heat-treated rapeseed was supplemented to indoor fed yaks in winter to test the effect on dry matter intake (DMI), body mass change, and meat quality. Sixteen 3-year-old yak steers (124 ± 15.3 kg) were divided randomly into two groups and were offered either heat-treated rapeseed (HTR) or rapeseed meal (CONT). The yaks were allowed 14 days for adjustment and measurements were made over 120 d. There was no difference in DMI between groups (p = 0.67), but average daily gain tended to be higher (p < 0.056) and feed to gain ratio tended to be lower (p = 0.050) in HTR than in CONT yaks. Meat from HTR yaks was more tender (p = 0.006), had higher intramuscular fat (p = 0.013), and had lower cholesterol content (p = 0.009) than from CONT yaks. In addition, the atherogenic index was lower (0.37 vs. 0.43; p = 0.049), the PUFA:SFA ratio was higher (0.55 vs. 0.37; p = 0.049), and the n-6:n-3 (n-6 PUFA to n-3 PUFA) ratio was lower (2.76 vs. 4.78; p = 0.003) in HTR than in CONT yaks, which all favoured the HTR yaks. Meat from HTR yaks met human health standards of a PUFA:SFA ratio of above 0.4 and n-6:n-3 ratio of less than 4, whereas meat from CONT yaks just missed these standards.

Nonfat milk attenuates acute hyperglycemia in individuals with android obesity: A randomized control trial

BACKGROUND

Elevated android body fat increases the risk of developing cardiometabolic diseases. Postprandial hyperglycemia contributes to the proatherogenic metabolic state evident in android adiposity. Due to the insulinotropic effect of milk-derived proteins, postprandial hyperglycemia has been shown to be reduced with the addition of dairy products. The purpose of this study was to determine whether one serving of nonfat milk added to an oral glucose tolerance test (OGTT) could attenuate postprandial hyperglycemia in individuals with elevated android adiposity and whether these improvements would be associated with metabolic and/or peripheral hemodynamic effects.

METHODS

In this placebo-controlled, randomized, crossover experimental study, 29 overweight/obese adults (26 ± 1 year) consumed an OGTT beverage (75 g glucose) combined with either nonfat milk (227 g) or a placebo control (12 g lactose + 8 g protein + 207 g water) that was matched for both carbohydrate and protein quantities.

RESULTS

In the whole sample, blood glucose and insulin concentrations increased over time in both trials with no significant differences between trials. Relative increases in peak blood glucose response were significantly related to android body fat (p < 0.05). The subjects in the highest tertiles of android body fat displayed attenuated hyperglycemic responses as well as improvements in flow-mediated dilation (FMD) after milk intake.

CONCLUSIONS

A single serving of nonfat milk may attenuate acute hyperglycemia in individuals with elevated android body fat offering a simple and convenient option for managing elevations in blood glucose.

The health-nutrition dimension: a methodological approach to assess the nutritional sustainability of typical agro-food products and the Mediterranean diet

BACKGROUND

The aim of this paper is to provide a methodological approach to evaluate the nutritional sustainability of typical agro-food products, representing Mediterranean eating habits and included in the Mediterranean food pyramid.

RESULTS

For each group of foods, suitable and easily measurable indicators were identified. Two macro-indicators were used to assess the nutritional sustainability of each product. The first macro-indicator, called 'business distinctiveness', takes into account the application of different regulations and standards regarding quality, safety and traceability as well as the origin of raw materials. The second macro-indicator, called 'nutritional quality', assesses product nutritional quality taking into account the contents of key compounds including micronutrients and bioactive phytochemicals. For each indicator a 0-10 scoring system was set up, with scores from 0 (unsustainable) to 10 (very sustainable), with 5 as a sustainability benchmark value. The benchmark value is the value from which a product can be considered sustainable. A simple formula was developed to produce a sustainability index.

CONCLUSION

The proposed sustainability index could be considered a useful tool to describe both the qualitative and quantitative value of micronutrients and bioactive phytochemical present in foodstuffs. This methodological approach can also be applied beyond the Mediterranean, to food products in other world regions. © 2018 Society of Chemical Industry.

Chemical composition and seasonal changes in the fatty acid profile of Uruguayan “Colonia” Cheeses

The basic chemical composition and the fatty acid (FA) profile of Uruguayan Colonia cheese, consumed in the Mercosur region, were determined. 24 cheeses from different dairy farms: 10 elaborated in autumn and 14 in spring, were analyzed. Those cheeses are made from cow´s milk, whose diet was composed of 50% pasture system, 25% concentrate, and 25% silage reserves. The cheese making and ripening time were similar. Seasonal differences emerged in the profiles of saturated FA (SFA), unsaturated FA (UFA) and polyunsaturated FA (PUFA). The seasonal comparation of polyunsaturated FA (PUFA) as well as the CLA isomer such as C18:2 t10c12 showed significant differences (p < 0.05). CLA isomer such as C18:2 c9t11, showed no differences (p > 0.05). The atherogenesis index (AI) = 2.21 and thrombogenicity (IT) = 2.84, were calculated and discussed.

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.

Fatty acid profile of milk from Saanen and Swedish Landrace goats

Recent years have had an increased demand for goat milk and its products. The quality of goat milk is determined, in part, by the fatty acid (FA) profile, but there is little information about breed influence on the FA profile of goat milk. The aim of this study was to describe and compare FA profiles of goat milk produced by Saanen and Swedish Landrace breeds. FA profiles were analysed by gas chromatography with a flame ionisation detector using 100 m capillary column coated with ionic liquids of extreme polarity (SLB-IL111). The amounts of 19 FAs were measured. Analyses indicated that FA profile in the milk of Saanen goats differs from that of Swedish Landrace goats with the first having higher proportions of most SFA-s and the second having lower proportions of C16:0, C16:1 and C18:1. This knowledge enables the improvement of the quality of goat milk and goat milk-derived products.

Chemical composition and pharmacological significance of Anethum Sowa L. Root

BACKGROUND

Medicinal herbs are used for the treatment of different ailments since antiquity. Different parts of Anethum sowa L. is used in folk medicine as a carminative for the treatment of flatulence, colic and hiccups of infants and children, antioxidant, antimicrobial and antispasmodic agent. The aim of our present study is to evaluate the chemical composition of the essential oil, proximate and elemental composition, amino acid, fatty acid profile and thermal behaviour of its root part as well as different pharmacological activities like antioxidant, antimicrobial and cytotoxicity of the root essential oil.

METHODS

The air-dried roots of Anethum sowa L. were subjected to hydro-distillation to yield the essential oil. The antioxidant activity of the essential oil was studied by DPPH radical scavenging activity. The antimicrobial activity was tested against four Gram-positive, six Gram-negative bacteria and four fungi species. The minimum inhibitory concentration (MIC) and Minimum bacterial concentration (MBC) for each examined microorganism were determined using the micro-dilution method. The LC50 value of the oil was also evaluated by brine shrimp lethality assay. The subsequent proximate analysis was also done by AOAC methods. The elemental analysis of the root powder was analysed by ICP-MS, AAS and FP system. The fatty acid was extracted by hot and cold extraction method and the analyses were carried out by GC. The amino acid profile was done by the amino acid analyzer. The DTA, DTG and TG of the root powder were taken by the thermogravimetric analyzer.

RESULTS

A total of 24 constituents was identified and quantified in the essential oil and its water extract portion by GC and GC-MS. Apiol (81.99 and 74.779%) was found the highest phenylpropanoid constituent followed by m-diaminobenzene (10.446 and 8.778%) in the essential oil and aqueous extract portion. On the other hand, β-butyrolactone (5.13%) and isobutyl acetone (3.73%) were found in the major constituents in the water extract part. The IC50 value of the essential oil was found to be 3.07 mg/mL by DPPH radical assay methods. The LC50 value of the brine shrimp cytotoxicity assay of the essential oil was observed at 0.81 μg/mL. The essential oil showed better activity on Gram-negative bacteria than Gram-positive bacteria and fungi. The proximate composition showed that root contained 5.29% ash, 2.01% protein, 54.09% crude fibre, 0.15% essential oil and 1.14% fatty oil for hot extract and 0.23% for cold extract on the dried basis. The palmitic (33.81 & 31.58%) and linoleic acid (30.03 & 23.79%) were the major saturated and unsaturated fatty acids in the cold and hot extracted root powder respectively. Ca (23,600 mg/kg), Mg (7620.33 mg/kg) and K (1286.15 mg/kg) were the most predominant elements followed by Ni (1187.30 mg/kg), Se (913.79 mg/kg), Li (317.84 mg/kg), Na (288.72 mg/kg) and Fe (206.88 mg/kg). The toxic elements were found to be within the permissible limit. Glutamic acid (19.37%), glycine (14.53%) and lysine (17.08%) were found as the major amino acids. The decomposition rates were obtained by TG, DTG and DTA curve of the powder sample at various temperature ranges.

CONCLUSIONS

The results demonstrated that the root part of Anethum sowa L. is a rich source of mineral elements, essential amino acid and fatty acids. The essential oil is the highly potential as bioactive oil for pharmaceuticals and medical applications, possessing antioxidant, antimicrobial and cytotoxic activities. The thermal analysis suggested as a simple, effective and rapid method to characterize the Anethum sowa L. species as well as to assess for herbal formulation.

Quality characteristics, chemical composition, and sensory properties of butter from cows on pasture versus indoor feeding systems

This study evaluated the effects of 3 widely practiced cow feeding systems in the United States, Europe, and Southern Hemisphere regions on the characteristics, quality, and consumer perception of sweet cream butter. Fifty-four multiparous and primiparous Friesian cows were divided into 3 groups (n=18) for an entire lactation. Group 1 was housed indoors and fed a total mixed ration diet (TMR) of grass silage, maize silage, and concentrates; group 2 was maintained outdoors on perennial ryegrass-only pasture (GRS); and group 3 was maintained outdoors on a perennial ryegrass/white clover pasture (CLV). Mid-lactation butter was manufactured in triplicate with milk from each group in June 2015 (137±7d in milk) and was analyzed over a 6-mo storage period at 5°C for textural and thermal properties, fatty acid composition, sensory properties, and volatile compounds. The nutritional value of butters was improved by pasture feeding, and butter from pasture-fed cows had significantly lower thrombogenicity index scores compared with butters from TMR-fed cows. In line with these results, pasture-derived milks (GRS and CLV) produced butter with significantly higher concentrations of conjugated linoleic acid (cis-9,trans-11) and trans-β-carotene than TMR butter. Alterations in the fatty acid composition of butter contributed to significant differences in textural and thermal properties of the butters. Total mixed ration-derived butters had significantly higher hardness scores at room temperature than those of GRS and CLV. Onset of crystallization for TMR butters also occurred at significantly higher temperatures compared with pasture butters. Volatile analysis of butter by gas chromatography-mass spectrometry identified 25 compounds present in each of the butters, 5 of which differed significantly based on feeding system, including acetone, 2-butanone, 1-pentenol, toluene, and β-pinene. Toluene was very significantly correlated with pasture-derived butter. Sensory analysis revealed significantly higher scores for GRS-derived butter in several attributes including "liking" of appearance, flavor, and color over those of TMR butter. Partial least square regression plots of fatty acid profiles showed clear separation of butter derived from grazed pasture-based perennial ryegrass or perennial rye/white clover diets from that of a TMR system, offering further insight into the ability of fatty acid profiling to verify such pasture-derived dairy products.

Dairy food products: good or bad for cardiometabolic disease?

Prevalence of type 2 diabetes mellitus (T2DM) is rapidly increasingly and is a key risk for CVD development, now recognised as the leading cause of death globally. Dietary strategies to reduce CVD development include reduction of saturated fat intake. Milk and dairy products are the largest contributors to dietary saturated fats in the UK and reduced consumption is often recommended as a strategy for risk reduction. However, overall evidence from prospective cohort studies does not confirm a detrimental association between dairy product consumption and CVD risk. The present review critically evaluates the current evidence on the association between milk and dairy products and risk of CVD, T2DM and the metabolic syndrome (collectively, cardiometabolic disease). The effects of total and individual dairy foods on cardiometabolic risk factors and new information on the effects of the food matrix on reducing fat digestion are also reviewed. It is concluded that a policy to lower SFA intake by reducing dairy food consumption to reduce cardiometabolic disease risk is likely to have limited or possibly negative effects. There remain many uncertainties, including differential effects of different dairy products and those of differing fat content. Focused and suitably designed and powered studies are needed to provide clearer evidence not only of the mechanisms involved, but how they may be beneficially influenced during milk production and processing.

New perspectives on dairy and cardiovascular health

CVD are the leading cause of mortality and morbidity worldwide. One of the key dietary recommendations for CVD prevention is reduction of saturated fat intake. Yet, despite milk and dairy foods contributing on average 27 % of saturated fat intake in the UK diet, evidence from prospective cohort studies does not support a detrimental effect of milk and dairy foods on risk of CVD. The present paper provides a brief overview of the role of milk and dairy products in the diets of UK adults, and will summarise the evidence in relation to the effects of milk and dairy consumption on CVD risk factors and mortality. The majority of prospective studies and meta-analyses examining the relationship between milk and dairy product consumption and risk of CVD show that milk and dairy products, excluding butter, are not associated with detrimental effects on CVD mortality or risk biomarkers that include serum LDL-cholesterol. In addition, there is increasing evidence that milk and dairy products are associated with lower blood pressure and arterial stiffness. These apparent benefits of milk and dairy foods have been attributed to their unique nutritional composition, and suggest that the elimination of milk and dairy may not be the optimum strategy for CVD risk reduction.

Bovine Peptic Casein Hydrolysate Ameliorates Cardiovascular Risk Factors in a Model of ApoE-deficient Mice but not Overweight, Mildly Hypercholesterolaemic Men

Associations have been shown between consumption of bovine dairy and decreased prevalence of metabolic related disorders. Milk peptides may promote both angiotensin-I- converting enzyme (ACE) inhibition for blood pressure (BP) lowering and insulin action for better glycaemic control. Less is known of other metabolic parameters. The aim of this study was to investigate effects of dairy peptic casein hydrolysate (CH) on markers of cardiovascular disease (CVD) risk in (1) an apolipoproteinE (ApoE) - deficient mouse model of high-fat fed hypercholesterolaem- ia, and, (2) a clinical study of moderate overweight and hypercholesterolaemia. In Trial 1, ApoE-deficient mice were supplemented with high dose CH (~1g/kg body weight) in a randomised, 9-wk, parallel design intervention, and blood and tissue samples harvested. In Trial 2, 24 mildly hypercholesterolaemic men were supplemented with lower dose CH (~0.1g/kg body weight, 10g/day, 3-wks) and matched whey protein control (WP, 10g/day, 3-wks) in a randomised, 9-wk, cross-over design intervention. Diets were separated by a 3-wk washout. Fasting blood and urine samples were collected, and blood pressure (BP) measured weekly. Clinical trial registration number, ACTRN 12611001013954. In ApoE-deficient mice, administration of CH significantly inhibited circulating total cholesterol concentrations by 37% (TC, P<0.01) and decreased aorta atherosclerotic lesion score by 25% (P<0.01). In the clinical study there were no significant differential effects of CH supplementation on CV markers, including serum lipids (TC, LDL-C, HDL-C, triglyceride), glucose and BP. Whilst high dose bovine peptic CH attenuated CVD risk in a murine ApoE deficient model of aggressive hypercholesterolaemia, no evidence of amelioration of risk by supplementation with a lower dose of CH in an overweight population of mildly hypercholesterolaemic men was found.

Effects of butter from mountain-pasture grazing cows on risk markers of the metabolic syndrome compared with conventional Danish butter: a randomized controlled study

Background

There is considerable interest in dairy products from low-input systems, such as mountain-pasture grazing cows, because these products are believed to be healthier than products from high-input conventional systems. This may be due to a higher content of bioactive components, such as phytanic acid, a PPAR-agonist derived from chlorophyll. However, the effects of such products on human health have been poorly investigated.

Objective

To compare the effect of milk-fat from mountain-pasture grazing cows (G) and conventionally fed cows (C) on risk markers of the metabolic syndrome.

Design

In a double-blind, randomized, 12-week, parallel intervention study, 38 healthy subjects replaced part of their habitual dietary fat intake with 39 g fat from test butter made from milk from mountain-pasture grazing cows or from cows fed conventional winter fodder. Glucose-tolerance and circulating risk markers were analysed before and after the intervention.

Results

No differences in blood lipids, lipoproteins, hsCRP, insulin, glucose or glucose-tolerance were observed. Interestingly, strong correlations between phytanic acid at baseline and total (P<0.0001) and LDL cholesterol (P=0.0001) were observed.

Conclusions

Lack of effects on blood lipids and inflammation indicates that dairy products from mountain-pasture grazing cows are not healthier than products from high-input conventional systems. Considering the strong correlation between LDL cholesterol and phytanic acid at baseline, it may be suggested that phytanic acid increases total and LDL cholesterol.

Trial registration

ClinicalTrials.gov, NCT01343589

The impact of substituting SFA in dairy products with MUFA or PUFA on CVD risk: evidence from human intervention studies

With the substantial economic and social burden of CVD, the need to modify diet and lifestyle factors to reduce risk has become increasingly important. Milk and dairy products, being one of the main contributors to SFA intake in the UK, are a potential target for dietary SFA reduction. Supplementation of the dairy cow's diet with a source of MUFA or PUFA may have beneficial effects on consumers' CVD risk by partially replacing milk SFA, thus reducing entry of SFA into the food chain. A total of nine chronic human intervention studies have used dairy products, modified through bovine feeding, to establish their effect on CVD risk markers. Of these studies, the majority utilised modified butter as their primary test product and used changes in blood cholesterol concentrations as their main risk marker. Of the eight studies that measured blood cholesterol, four reported a significant reduction in total and LDL-cholesterol (LDL-C) following chronic consumption of modified milk and dairy products. Data from one study suggested that a significant reduction in LDL-C could be achieved in both the healthy and hypercholesterolaemic population. Thus, evidence from these studies suggests that consumption of milk and dairy products with modified fatty acid composition, compared with milk and dairy products of typical milk fat composition, may be beneficial to CVD risk in healthy and hypercholesterolaemic individuals. However, current evidence is insufficient and further work is needed to investigate the complex role of milk and cheese in CVD risk and explore the use of novel markers of CVD risk.

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.

Differential impact of milk fatty acid profiles on cardiovascular risk biomarkers in healthy men and women

BACKGROUND/OBJECTIVES

The objective of this study was to evaluate the impact of three specific ruminant (R) milk fats resulting from modification of the cow's diet on cardiovascular risk factors in healthy volunteers. R-milk fats were characterized by increased content in total trans fatty acids (R-TFAs) and parallel decrease in saturated fatty acids (SFAs).

SUBJECTS/METHODS

A total of 111 healthy, normolipemic men and women have been recruited for a monocentric, randomized, double-blind and parallel intervention, 4-week controlled study. Volunteers consumed three experimental products (butter, dessert cream and cookies) made with one of the three specific milk fats (55 g fat per day). During the first week (run-in period), the subjects consumed on a daily basis dairy products containing 72% SFA/2.85% R-TFA (called 'L0'). For the next 3 weeks of the study (intervention period), the first group continued to consume L0 products. The second group received dairy products containing 63.3% SFA/4.06% R-TFA (called 'L4'), and the third group received dairy products containing 56.6% SFA/12.16% R-TFA (called 'L9').

RESULTS

Plasma concentrations of high-density lipoprotein (HDL)-cholesterol were not significantly altered by either diet (P=0.38). Compared to L0 diet, L4 diet contributed to reduce low-density lipoprotein (LDL)-cholesterol (-0.14+/-0.38 mmol/l, P=0.04), total cholesterol (-0.13+/-0.50 mmol/l, P=0.04), LDL-cholesterol/HDL-cholesterol (-0.14+/-0.36, P=0.03) and total cholesterol/HDL-cholesterol (-0.18+/-0.44, P=0.02).

CONCLUSIONS

Different milk fat profiles can change cardiovascular plasma parameters in human healthy volunteers. A limited increase of the R-TFA/SFA ratio in dairy products is associated with an improvement in some cardiovascular risk factors. However, a further increase in R-TFA/SFA ratio has no additional benefit.

No evidence of an effect of alterations in dietary fatty acids on fasting adiponectin over 3 weeks

OBJECTIVE

Little is known about the effects of alterations in fatty acid classes on adiponectin, a hormone secreted by the adipocyte known to be important in the development of diabetes and cardiovascular disease (CVD). Any factor, including diet, that may positively influence adiponectin gene expression or increase circulating levels might be useful for improving such metabolic abnormalities. We investigated the effects of alterations in dietary fatty acid saturation on fasting serum adiponectin and associated peptides.

METHODS AND PROCEDURES

Double-blind, randomized, crossover, 2 x 3-week residential intervention trial where 18 mildly hyperlipidemic adult men were provided with a high saturated:unsaturated fat (SFA:USFA) and lower SFA:USFA treatment separated by an uncontrolled 4-week washout. Only fatty acid profile was altered between treatments. Fasting blood samples were collected on days 0, 1, 7, 14, 21, 22 of each intervention period for the measurement of adiponectin, tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsC-RP), leptin, and ghrelin.

RESULTS

Body weight was kept constant (+/-1 kg) throughout each treatment. There was no detectable difference in fasting adiponectin at baseline (mean day 0 + day 1) between the treatment groups (mean +/- s.d.; high(SFA:USFA) = 7.0 +/- 1.7 vs. low(SFA:USFA) = 6.7 +/- 1.4 microg/ml, P > 0.05). There were neither significant between-treatment effects of fatty acid saturation (diet x time, P > 0.05) on serum adiponectin nor any significant between-treatment effects on serum TNF-alpha, IL-6, hsC-RP, leptin, or ghrelin (P > 0.05).

DISCUSSION

Fasting serum adiponectin was not detectably affected by alterations in dietary fatty acid profile in mildly hyperlipidemic men. There was no evidence that an increase in SFA content of the diet significantly worsened fasting serum adiponectin over a 3-week intervention period.

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.

Assessment of erythrocyte phospholipid fatty acid composition as a biomarker for dietary MUFA, PUFA or saturated fatty acid intake in a controlled cross-over intervention trial

Background

Dietary intervention trials rely on self-reported measures of intake for assessment of energy and macronutrient composition. Dietary fat intake is of particular interest due to strong associations with pathophysiology. In epidemiological trials phospholipid fatty acid composition may reflect composition of habitual diet, although strong correlations have been identified only for essential polyunsaturated fatty acids (PUFAs). Preliminary evidence shows that saturated fatty acids (SFA) C15:0 and C17:0 may be acceptable biomarkers. This study measured changes in erythrocyte membrane fatty acids during a period of strictly controlled fat feeding to investigate their use as a short-term marker of compliance, particularly for intake of SFAs.

Results

This was a randomised cross-over trial in which diet was provided and strictly controlled. 20 healthy, male subjects were given a 40 energy % (en%) fat diet, high in saturated (high-SFA, 20 en%) or unsaturated (high-USFA, 24 en%) fatty acids for 2 periods of 3 weeks. Subjects were residential during intervention with all food and beverages provided. Dietary composition was verified by direct chemical analysis. Blood samples were collected on days 1,7,14, 21 and analysed for red blood cell (RBC) membrane fatty acid composition. Pearson correlation showed RBC fatty acid composition to mimic dietary composition by 3 weeks, but the relationships were weak. Of the SFAs only RBC C16:0 decreased in response to decreased dietary content on high-USFA treatment (ANOVA, diet, P < 0.05). Of the USFAs, higher levels of C18:1 MUFA, C20:4 and C22:6 long chain PUFA on high-USFA diet lead to higher C18:1, C20:4 and C22:6 within RBCs (ANOVA, time*diet, P < 0.05). Pearson's correlation was significant between dietary and RBC fatty acids during the 21d dietary manipulation for C18:1, and C20:5, C22:6 only (P < 0.05).

Conclusion

RBC membrane fatty acids cannot reliably be used as an independent measure of compliance for dietary SFA intake in short-term studies. The MUFA oleic acid and PUFAs EPA and DHA may be more useful as markers of compliance during short term intervention trials.

Effects of Fat-Modified Dairy Products on Blood Lipids in Humans in Comparison with Other Fats

BACKGROUND/AIM

Due to its high content of LDL-raising saturated fatty acids (SFA), milk fat has been considered to be hypercholesterolaemic, but it also contains fatty acids and other constituents which seem to have a hypocholesterolaemic effect. Milk fat was modified by feeding cows rapeseed cake, resulting in a reduced content of SFA and an increased content of unsaturated fatty acids. The objective of this study was to investigate the effects of modified milk fat (ModFat) on serum cholesterol fractions, triacylglycerides (TAG) and lipoprotein(a) [LP(a)], compared with regular milk fat (RegFat) and with soft margarine (Marg).

METHOD

Fifteen women and 16 men were enrolled in the intervention study. Nine of the participants were hypercholesterolaemic. Nutrient intake parameters, serum lipids and LP(a) were determined.

RESULTS

The serum concentration of HDL cholesterol increased in the ModFat period, leading to a decreased LDL/HDL ratio in this period. The lowest LP(a) concentrations were measured at the end of the control phase and at the end of the ModFat period. A decreasing tendency of serum TAG concentration was observed in the ModFat period.

CONCLUSION

The fat-modified milk seems to have positive effects on the LDL/HDL ratio and the LP(a) concentrations, both of which have been established as risk factors for coronary heart disease.

Rumen protected protein and fat produced from oilseeds and/or meals by formaldehyde treatment; their role in ruminant production and product quality: a review

The nutritional characteristics of rumen-protected protein and fat supplements produced by formaldehyde treatment of oilseeds and meals are reviewed. The proportion of rumen undegraded protein (RUP) in different protein sources can be controlled by this process, bio-available lysine is 82–84% and the proportions of acid detergent and neutral detergent insoluble nitrogen are unchanged by formaldehyde treatment; this is in contrast to heat treatment of proteins where significant increases in these nitrogen components can occur if the RUP content exceeds 60% of the crude protein (CP). A RUP content of 75–80% of CP is optimal when using protein supplements for milk production, and for body growth in steers a lower RUP content is desirable (i.e. 50–55% of CP). Both the fat and protein constituents in rumen-protected fat supplements derived from the emulsification and formaldehyde treatment of oilseeds are highly protected from ruminal metabolism (75–90%) and are readily digested in the small intestine (90% for C18 unsaturated fatty acids, 82% for the essential amino acids). Protected fat/protein supplements are designed and fed to lactating and non-lactating ruminants to increase efficiency of production, enhance product quality, augment n-3, n-6 and n-9 fatty acid content of meat and milk, and to improve reproductive performance. The challenges and potential role for these protected fat/protein supplements in improving productivity and quality of ruminant derived foods are discussed.

Physical and sensory properties of dairy products from cows with various milk fatty acid compositions

Dairy products from milk of cows fed diets rich in polyunsaturated fatty acids have a more health-promoting fatty acid composition and are softer but often have oxidized flavors. Dairy products made from cow's milk that has more- or less-unsaturated fatty acid compositions were tested for differences in texture and flavor from those made from bulk-tank milk. The milk was manufactured into butter, vanilla ice cream, yogurt, Provolone cheese, and Cheddar cheese. The products were analyzed for fatty acid composition, physical properties, and flavor. Milk of cows with a more monounsaturated fatty acid composition yielded products with a more monounsaturated fatty acid composition that were softer and had a satisfactory flavor. Thus, selection of cows for milk fatty acid composition can be used to produce dairy products that are probably more healthful and have a softer texture.

Double-blind, randomized feedback control fails to improve the hypocholesterolemic effect of a plant-based low-fat diet in patients with moderately elevated total cholesterol levels

OBJECTIVE

To determine whether the cholesterol-lowering effect of a plant-based low-fat diet can be improved by a flexible control design that controls the extent of fat reduction based on the individual response of blood cholesterol.

DESIGN

Randomized, double-blind intervention study.

SETTING

A hotel in Prerow, Germany.

SUBJECTS

A total of 32 participants (21 female and 11 male participants) with total cholesterol level > 5.7 mmol/l.

INTERVENTION

The control group consumed a plant-based low-fat diet with constantly 20% of energy as fat; the intervention group received a diet with either 20 or 15% of energy as fat, depending on the serum cholesterol response of the preceding week. A flexible control design based on the individual cholesterol response during a run-in period of 1 week was used within a low-fat intervention.

RESULTS

During the run-in period, the consumption of a plant-based low-fat diet led to a reduction in total cholesterol by 18+/-6 mmol/l (P < 0.001), in LDL cholesterol by 19+/-9 mmol/l (P < 0.001) and triglycerides by 13+/-3 mmol/l (P < 0.001). During the feedback control period, an additional reduction in total cholesterol by 13+/-8 (P < 0.001) and in LDL cholesterol by 17+/-11 (P < 0.001) was observed compared to 15+/-15 and 7+/-18 in the control group. The effect of an additional feedback control was only marginal and not statistically significant compared to the effect of the low-fat diet alone.

CONCLUSIONS

On a level of fat intake already reduced to 20% of energy, the use of a feedback control to adapt the fat content of the diet depending on the individual serum cholesterol response was not more effective in reducing blood cholesterol levels than a plant-based low-fat diet alone.

Effect of moderate changes in dietary fatty acid profile on postprandial lipaemia, haemostatic and related CVD risk factors in healthy men

OBJECTIVE

To investigate the effect of moderate changes in dietary fatty acid profile on postprandial risk factors for cardiovascular disease (CVD).

DESIGN

Double-blind, randomised, crossover, intervention trial.

SETTING

: University of Auckland Human Nutrition Unit, New Zealand.

SUBJECTS

A total of 18 lean healthy men.

INTERVENTION

A dairy butter fat modified to reduce the saturated:unsaturated fatty acid ratio and a conventional high saturated butter fat were given on two separate occasions as a high-fat test meal (59+/-4 g fat; 71 en% fat) at breakfast. A fat exclusion lunch, dinner and snacks were also given. Blood samples were collected at 0 (baseline), 1, 3, 6, 10 and 24 h.

RESULTS

Maximum peak in total triacylglycerol (TAG) occurred 3 h postprandially and was highest on modified treatment (diet, P<0.05) due predominantly to increased TAG within the chylomicron-rich fraction. Transient peaks in total-, LDL- and HDL-cholesterol occurred postprandially, but did not differ between dietary treatments (P>0.05). There were no differential effects of diet on postprandial free fatty acids, apo A, apo B, glucose, insulin, amylin or haemostatic clotting factors (P>0.05).

CONCLUSIONS

In a group of healthy young men, replacement of 16% of total saturated fatty acids by mono- and polyunsaturated fats within a dairy lipid did not induce postprandial changes in CVD risk that may be considered beneficial for health.

SPONSORSHIP

Fonterra, Wellington; New Zealand.

Replacing cows' with sheep's dairy fat lowers plasma cholesterol concentration in participants consuming dairy fat-rich diets

OBJECTIVE

To determine the effects on plasma cholesterol concentration of replacing cows' dairy fat with sheep's dairy fat.

DESIGN

Randomised crossover dietary intervention.

SETTING

General community, Dunedin, New Zealand.

SUBJECTS

Volunteer sample of 41 healthy adults with initial plasma cholesterol concentration between 4.8 and 7.8 mmol/l.

INTERVENTIONS

Participants were asked to follow a self-selected low-fat background diet throughout the study to which, during each of the 2, 3-week dairy diets, they were asked to add sheep's or cows' dairy products.

MAIN OUTCOME MEASURES

Energy and nutrient intakes, plasma triacylglycerol fatty acids, and plasma cholesterol.

RESULTS

Energy and nutrient intakes on the sheep-dairy and cow-dairy diets were very similar, with total, saturated, monounsaturated and polyunsaturated fat contributing 34, 18-19, 9, and 3% of total energy intake, respectively. Participants consumed approximately 50 g/day of dairy fat on each diet. Replacing cows' with sheep's dairy fat led to a 0.33 (0.11-0.56, 95% CI) mmol/l decrease (6%) in plasma total cholesterol concentration, from 5.53 (0.90, s.d.) to 5.20 (0.90) mmol/l. Plasma low-density lipoprotein (LDL) cholesterol was 0.18 (0.02-0.33) mmol/l lower on the sheep-dairy diet as was the concentration of plasma high-density lipoprotein (HDL) cholesterol, 0.11 (0.02-0.20) mmol/l. The LDL to HDL cholesterol ratio at the end of the sheep-dairy diet, 2.91 (1.10), was not significantly different (P>0.05) from the cow-dairy diet, 2.73 (0.83).

CONCLUSIONS

Within the context of a diet high in dairy fat (50 g/day), replacing cows' milk fat with sheep's milk fat leads to a small reduction in plasma cholesterol concentration, but no change in the ratio of LDL to HDL cholesterol.

Texture of butter from cows with different milk fatty acid compositions

Milk fatty acid composition and textural properties of butter are known to be affected by the cows' diets. We examined the phenotypic variation in milk fatty acid composition among cows fed the same diet to see if the variation was sufficient to produce butter with different textural properties. Ten cows were selected that tested higher (n = 5) or lower (n = 5) in their proportion of milk unsaturated fatty acids. Milk samples were collected a week after testing, and butter was prepared from the individual samples. Milk and butter samples were again analyzed for fatty acid composition. Butter at 5 degrees C was evaluated by a sensory panel for spreadability and by a texture analyzer at both 5 and 23 degrees C for hardness and adhesiveness. Milk and butter samples from cows with a more unsaturated milk fatty acid composition had a lower atherogenic index, and the butter samples were more spreadable, softer, and less adhesive. Thus, phenotypic variation in milk fatty acid composition among cows fed the same diet is sufficient to produce butter with different textural properties.