Intake of fatty acids in western Europe with emphasis on trans fatty acids: the TRANSFAIR Study

Validity and reproducibility of the intake of trans-fatty acids estimated using a FFQ and characteristics of trans-fatty acid intake of the Japanese population: the JPHC FFQ Validation Study

We aimed to validate a method for assessing trans-fatty acid (TFA) intake in the Japanese population using the FFQ developed in the 1990s from a prospective study that was based on the Japan Public Health Center-based Prospective Cohort Study. For FFQ validation, we included 565 participants (Cohort I: n 215, Cohort II: n 350) aged 40-69 years. We used a 28-d dietary record (DR) over 1 year and two FFQ administered before and after DR assessment. We calculated total TFA intake, TFA from industrial oils (i-TFA) and TFA from ruminants (r-TFA) considering a database of measurements obtained mainly from Japan. Spearman's rank correlation coefficients (CC) were computed for validity and reproducibility. Energy adjustments were applied using two methods considering the TFA measurement: density method for TFA % of total energy and residual method for TFA g/d. The total TFA intake (% of the total energy intake) was 0·08-0·76 % (median, 0·27-0·37 %) in DR of both cohorts and was 0·00-1·13 % (median, 0·30-0·40 %) in FFQ. The i-TFA accounted for approximately 50 % of the total TFA intake in DR and approximately 40 % in FFQ. For total TFA (% of the total energy intake), CC were 0·54-0·69, and weighted κ coefficients were 0·88-0·92 for both cohorts. The de-attenuated CC was 0·46-0·62 for i-TFA (g/d) and 0·57-0·68 for r-TFA (g/d). Our study showed that the validity and reproducibility of TFA intake estimation using the FFQ were reasonable, suggesting its suitability among the Japanese population with low-TFA intake.

Trans-10 18:1 in ruminant meats: A review

Trans (t) fatty acids (TFA) from partially hydrogenated vegetable oils (i.e., industrial trans) have been phased out of foods in many countries due to their promotion of cardiovascular disease. This leaves ruminant-derived foods as the main source of TFA. Unlike industrial TFA where catalytic hydrogenation yields a broad distribution of isomers, ruminant TFA are enzymatically derived and can result in enrichment of specific isomers. Comparisons between industrial and ruminant TFA have often exonerated ruminant TFA due to their lack or at times positive effects on health. At extremes, however, ruminant-sourced foods can have either high levels of t10- or t11-18:1, and when considering enriched sources, t10-18:1 has properties similar to industrial TFA, whereas t11-18:1 can be converted to an isomer of conjugated linoleic acid (cis(c)9,t11-conjugated linoleic acid), both of which have potential positive health effects. Increased t10-18:1 in meat-producing ruminants has not been associated with negative effects on live animal production or meat quality. As such, reducing t10-18:1 has not been of immediate concern to ruminant meat producers, as there have been no economic consequences for its enrichment; nevertheless at high levels, it can compromise the nutritional quality of beef and lamb. In anticipation that regulations regarding TFA may focus more on t10-18:1 in beef and lamb, the present review will cover its production, analysis, biological effects, strategies for manipulation, and regulatory policy.

Serum non-esterified fatty acid levels and hip fracture risk: The Cardiovascular Health Study

Among elderly participants from the Cardiovascular Health Study, we found that non-esterified trans fatty acid levels had a significant prospective association with hip fracture risk. Other non-esterified fatty acid classes were not associated with hip fracture risk.

INTRODUCTION

Serum non-esterified fatty acids (NEFAs) are bioactive metabolic intermediates that can be taken up by bone tissue. Their associations with hip fracture risk have not been previously examined.

METHODS

Thirty-five individual NEFAs in five classes (saturated [SFA], mono-un-saturated [MUFA], poly-unsaturated n-6 and n-3 [PUFA], and trans-FA) were measured in Cardiovascular Health Study participants (n = 2139, mean age 77.8 years) without known diabetes. The multivariable associations of NEFA levels with hip fracture risk were evaluated in Cox hazards models.

RESULTS

We documented 303 incident hip fractures during 11.1 years of follow-up. Among the five NEFA classes, total trans FA levels were positively associated with higher hip fracture risk (HR 1.17 [95% CI, 1.04, 1.31; p = 0.01] per one standard deviation higher level). The SFA lignoceric acid (24:0) was positively associated with higher risk (HR 1.09 [1.04, 1.1]; p < 0.001), while behenic (22:0) and docosatetraenoic (22:4 n6) acids were associated with lower risk (HR 0.76 [0.61, 0.94]; p = 0.01; 0.84 [0.70, 1.00]; p = 0.05, respectively).

CONCLUSION

Total plasma trans NEFA levels are related to hip fracture risk, suggesting an unrecognized benefit of their systematic removal from food. Novel associations of individual NEFAs with hip fracture risk require confirmation in other cohort studies.

Trans fatty acid intake among Chinese population: a longitudinal study from 1991 to 2011

Objective

This study was aimed to roughly describe individual Trans Fatty Acids (TFAs) intake and the percentage of energy intake(E%), and identify major food sources in the Chinese population, taking gender, age, and regional distribution into the consideration, as well as examining temporal changes over the course of 20 years.

Method

This multi-center study, covering nine provinces among populations aged ≥ 3 in China, was conducted to collect food consumption information from 1991 to 2011. A classical assessment method was used to estimate the level of dietary TFA intake.

Results

Over the 20-year period, the intake of TFAs in Chinese populations had increased, but remained at a relatively lower level (from 0.25 g/d(0.11% for E%) to 0.53 g/d(0.24% for E%)) compared with that of other countries and the World Health Organization (WHO) recommended level. Collectively, males and participants aged 19–60 generally consumed more TFA-containing foods. People in eastern regions consumed more TFAs and had a higher E% than those in western area. Industrial sources of TFAs, especially vegetable oil, ranked as the principal food sources of TFAs in the Chinese population. Natural sources of TFAs have gradually increased in proportion among children and adolescents.

Conclusions

TFA intake and the E% are commonly under the recommended level in the general population in China. Presently, restriction of vegetable oil could be a crucial method to reduce TFA intake. It would be critical to facilitate and promote public health that food recommendations might be based on the dietary preferences for population separated by different ages and regions.

Eighteen‑carbon trans fatty acids and inflammation in the context of atherosclerosis

Endothelial dysfunction is a pro-inflammatory state characterized by chronic activation of the endothelium, which leads to atherosclerosis and cardiovascular disease (CVD). Intake of trans fatty acids (TFAs) is associated with an increased risk of CVD. This risk is usually associated with industrial TFAs (iTFAs) rather than ruminant TFAs (rTFAs); however it is not clear how specific TFA isomers differ in their biological activity and mechanisms of action with regard to inflammation. Here we review the literature on 18‑carbon TFAs, including the research associating their intake or levels with CVD and studies relating 18‑carbon TFA exposure to modulation of inflammatory processes. The evidence associating iTFAs with CVD risk factors is fairly consistent and studies in humans usually show a relation between iTFAs and higher levels of inflammatory markers. In contrast, studies in humans, animals and in vitro suggest that rTFAs have null or mildly beneficial effects in cardiovascular health, metabolic parameters and inflammatory markers, although the evidence is not always consistent. More studies are needed to better identify the beneficial and detrimental effects of the different TFAs, including those with 18 carbons.

Plant-derived polyunsaturated fatty acids and markers of glucose metabolism and insulin resistance: a meta-analysis of randomized controlled feeding trials

The objective of this meta-analysis was to investigate the effects of plant-derived polyunsaturated fatty acids (PUFAs) on glucose metabolism and insulin resistance. Scopus and PubMed databases were searched until January 2018. Eligible studies were randomized controlled feeding trials that investigated the effects of a diet high in plant-derived PUFA as compared with saturated fatty acids (SFA) or carbohydrates and measured markers of glucose metabolism and insulin resistance as outcomes. Data from 13 relevant studies (19 comparisons of plant-derived PUFA with control) were retrieved. Plant-derived PUFA did not significantly affect fasting glucose (-0.01 mmol/L (95 % CI - 0.06 to 0.03 mmol/L)), but lowered fasting insulin by 2.6 pmol/L (-4.9 to -0.2 pmol/L) and homeostatic model assessment-insulin resistance (HOMA-IR) by 0.12 units (-0.23 to - 0.01 units). In dose-response analyses, a 5% increase in energy (En%) from PUFA significantly reduced insulin by 5.8 pmol/L (95% CI -10.2 to -1.3 pmol/L), but not glucose (change -0.07, 95% CI -0.17 to 0.04 mmol/L) and HOMA-IR (change - 0.24, 95% CI -0.56 to 0.07 units). In subgroup analyses, studies with higher PUFA dose (upper tertiles) reduced insulin (-6.7, -10.5 to -2.9 pmol/L) and HOMA-IR (-0.28, -0.45 to -0.12 units), but not glucose (-0.09, 95% CI -0.18 to 0.01 mmol/L), as compared with an isocaloric control. Subgroup analyses showed no differences in effects between SFA and carbohydrates as replacement nutrients (p interaction ≥0.05). Evidence from randomized controlled trials indicated that plant-derived PUFA as an isocaloric replacement for SFA or carbohydrates probably reduces fasting insulin and HOMA-IR in populations without diabetes.

Effects of diets containing linseed oil or lard and supplemented with pumpkin seeds on oxidative status, blood serum metabolites, growth performance, and meat quality of naked neck chickens

This study investigates the effect of two dietary fats, namely linseed oil (LO) and lard (LF), and supplementation with pumpkin seeds (PS) on the performance, oxidative status, and blood serum metabolites of broilers, along with the composition, oxidative stability, and fatty acid (FA) profile of broiler meat. Ninety-six 64-d-old naked neck chickens were randomly distributed into four groups of 24 chickens each (8 chickens per cage, three cages per treatment) and fed a LO diet, a LO diet supplemented with 50 g PS kg−1, a LF diet, and a LF diet supplemented with 50 g PS kg−1. The antioxidant system is increased and reactive oxygen species decreased in chickens fed PS diets. Glycemia and cholesterol levels were significantly lower in the chickens fed PS diets than in those given diets without supplementation; the cholesterol levels were also significantly lower in the chickens fed LO diets than those fed LF diets. However, the LO diet affected the fresh meat quality by decreasing pH values of the meat at 24 h after slaughter. Adding PS to the LO diet improved the oxidative stability of the muscle at day 3 of refrigerated storage. The use of LO instead of LF favourably modulates the FA profile of meat, by increasing both linoleic and α-linolenic acid content and reducing the n-6/n-3 polyunsaturated FA ratio, atherogenic and thrombogenic index.

Effect of a whey protein and rapeseed oil gel feed supplement on milk fatty acid composition of Holstein cows

Isoenergetic replacement of dietary saturated fatty acids (SFA) with cis-monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) can reduce cardiovascular disease risk. Supplementing dairy cow diets with plant oils lowers milk fat SFA concentrations. However, this feeding strategy can also increase milk fat trans fatty acids (FA) and negatively affect rumen fermentation. Protection of oil supplements from the rumen environment is therefore needed. In the present study a whey protein gel (WPG) of rapeseed oil (RO) was produced for feeding to dairy cows, in 2 experiments. In experiment 1, four multiparous Holstein-Friesian cows in mid-lactation were used in a change-over experiment, with 8-d treatment periods separated by a 5-d washout period. Total mixed ration diets containing 420 g of RO or WPG providing 420 g of RO were fed and the effects on milk production, composition, and FA concentration were measured. Experiment 2 involved 4 multiparous mid-lactation Holstein-Friesian cows in a 4 × 4 Latin square design experiment, with 28-d periods, to investigate the effect of incremental dietary inclusion (0, 271, 617, and 814 g/d supplemental oil) of WPG on milk production, composition, and FA concentration in the last week of each period. Whey protein gel had minimal effects on milk FA profile in experiment 1, but trans-18:1 and total trans-MUFA were higher after 8 d of supplementation with RO than with WPG. Incremental diet inclusion of WPG in experiment 2 resulted in linear increases in milk yield, cis- and trans-MUFA and PUFA, and linear decreases in SFA (from 73 to 58 g/100 g of FA) and milk fat concentration. The WPG supplement was effective at decreasing milk SFA concentration by replacement with MUFA and PUFA in experiment 2, but the increase in trans FA suggested that protection was incomplete.

Replacement of saturated and trans-fatty acids in the diet v. CVD risk in the light of the most recent studies

OBJECTIVE

To present and discuss results of the most recent studies pertaining to the effects of consumption of different types of fatty acids on the risk of CVD. The aim was also an attempt to answer the question of whether a revision of the current recommendations is necessary.

DESIGN

A review of prospective cohort studies, systematic reviews and meta-analyses published in 2014-2017 on the effects of SFA and trans-fatty acid (TFA) intakes as well as various models of their replacement in the diet on CVD risk.

RESULTS

Results of the new large prospective cohort studies pertaining to the effect of SFA consumption on CVD risk are contradictory. Similarly, the recent meta-analyses of clinical trials related to the effects of SFA substitution on CVD risk provided extremely different results, which is related to the application of different inclusion and exclusion criteria. Differences in results of randomised controlled trials may be caused by different methodologies of dietary parameter changes, varying duration of studies, as well as the time at which they were carried out.

CONCLUSIONS

It is extremely difficult to extrapolate results of recent studies to contemporary recommendations. It seems that there is a need for properly randomised studies on large groups, with good control of dietary and non-dietary parameters, which account for not only the sum of SFA and TFA, but also their source. Only such studies will allow for full evaluation of an effect of substituting SFA and TFA on cardiovascular risk.

Differential effects of oilseed supplements on methane production and milk fatty acid concentrations in dairy cows

It is known that supplementing dairy cow diets with full-fat oilseeds can be used as a strategy to mitigate methane emissions, through their action on rumen fermentation. However, direct comparisons of the effect of different oil sources are very few, as are studies implementing supplementation levels that reflect what is commonly fed on commercial farms. The objective was to investigate the effect of feeding different forms of supplemental plant oils on both methane emissions and milk fatty acid (FA) profile. Four multiparous, Holstein-Friesian cows in mid-lactation were randomly allocated to one of four treatment diets in a 4×4 Latin square design with 28-day periods. Diets were fed as a total mixed ration with a 50 : 50 forage : concentrate ratio (dry matter (DM) basis) with the forage consisting of 75 : 25 maize silage : grass silage (DM). Dietary treatments were a control diet containing no supplemental fat, and three treatment diets containing extruded linseed (EL), calcium salts of palm and linseed oil (CPLO) or milled rapeseed (MR) formulated to provide each cow with an estimated 500 g additional oil/day (22 g oil/kg diet DM). Dry matter intake (DMI), milk yield, milk composition and methane production were measured at the end of each experimental period when cows were housed in respiration chambers for 4 days. There was no effect of treatment diet on DMI or milk protein or lactose concentration, but oilseed-based supplements increased milk yield compared with the control diet and milk fat concentration relative to control was reduced by 4 g/kg by supplemental EL. Feeding CPLO reduced methane production, and both linseed-based supplements decreased methane yield (by 1.8 l/kg DMI) and intensity (by 2.7 l/kg milk yield) compared with the control diet, but feeding MR had no effect on methane emission. All the fat supplements decreased milk total saturated fatty acid (SFA) concentration compared with the control, and SFA were replaced with mainly cis-9 18:1 but also trans FA (and in the case of EL and CPLO there were increases in polyunsaturated FA concentration). Supplementing dairy cow diets with these oilseed-based preparations affected milk FA profile and increased milk yield. However, only the linseed-based supplements reduced methane production, yield or intensity, whereas feeding MR had no effect.

Inadequate daily intakes of n-3 polyunsaturated fatty acids (PUFA) in the general French population of children (3-10 years) and adolescents (11-17 years): the INCA2 survey

PURPOSE

This paper deals with the dietary daily intakes of main polyunsaturated fatty acids (PUFA) in French children and adolescents.

METHODS

Dietary intakes of main PUFA were determined from a general French population of 1500 children (3-10 years) and adolescents (11-17 years) by using the most recent set of national robust data on food (National Survey INCA 2 performed in 2006 and 2007).

RESULTS

Main results showed that mean daily intakes of total fat and n-6 PUFA linoleic acid (LA, 18:2n-6) were close to current recommended values for children and adolescent populations. However, 80% (children) to 90% (adolescents) of our French populations not only ingested low quantities of n-3 long-chain PUFA (docosahexaenoic (22:6n-3) and eicosapentaenoic (20:5n-3) acids) but also very low quantities of alpha-linolenic acid (ALA, 18:3n-3) at the origin of a non-balanced n-6/n-3 ratio. Inadequate consumption of EPA + DHA was also observed in subgroups of infants and adolescent who consumed more than two servings/week of fish.

CONCLUSIONS

Such disequilibrium in PUFA dietary intakes in favor of n-6 PUFA could have adverse impact on cell membrane incorporation of long-chain n-3 PUFA and deleterious impacts on the health of children and adolescents. Promoting the consumption of both vegetable oils and margarines rich in ALA, and oily fish rich in long-chain n-3 PUFA might improve such PUFA disequilibrium.

An exploration of socio-economic and food characteristics of high trans fatty acid consumers in the Dutch and UK national surveys after voluntary product reformulation

Trans fatty acids (TFA) increase the risk of mortality and chronic diseases. TFA intakes have fallen since reformulation, but may still be high in certain, vulnerable, groups. This paper investigates socio-economic and food consumption characteristics of high TFA consumers after voluntary reformulation in the Netherlands and UK. Post-reformulation data of adults aged 19-64 was analysed in two national surveys: the Dutch National Food Consumption Survey (DNFCS) collected 2007-2010 using 2*24hr recalls (N = 1933) and the UK National Diet and Nutrition Survey (NDNS) years 3&4 collected 2010/11 and 2011/12 using 4-day food diaries (N = 848). The socio-economic and food consumption characteristics of the top 10% and remaining 90% TFA consumers were compared. Means of continuous data were compared using t-tests and categorical data means using chi-squared tests. Multivariate logistic regression models indicated which socio-demographic variables were associated with high TFA consumption. In the Dutch analyses, women and those born outside the Netherlands were more likely to be top 10% TFA consumers than men and Dutch-born. In the UK unadjusted analyses there was no significant trend in socio-economic characteristics between high and lower TFA consumers, but there were regional differences in the multivariate logistic regression analyses. In the Netherlands, high TFA consumers were more likely to be consumers of cakes, buns & pastries; cream; and fried potato than the remaining 90%. Whereas in the UK, high TFA consumers were more likely to be consumers of lamb; cheese; and dairy desserts and lower crisps and savoury snack consumers. Some socio-demographic differences between high and lower TFA consumers were evident post-reformulation. High TFA consumers in the Dutch 2007-10 survey appeared more likely to obtain TFA from artificial sources than those in the UK survey. Further analyses using more up-to-date food composition databases may be needed.

Progressing Insights into the Role of Dietary Fats in the Prevention of Cardiovascular Disease

Dietary fats have important effects on the risk of cardiovascular disease (CVD). Abundant evidence shows that partial replacement of saturated fatty acids (SAFA) with unsaturated fatty acids improves the blood lipid and lipoprotein profile and reduces the risk of coronary heart disease (CHD). Low-fat diets high in refined carbohydrates and sugar are not effective. Very long-chain polyunsaturated n-3 or omega-3 fatty acids (n-3 VLCPUFA) present in fish have multiple beneficial metabolic effects, and regular intake of fatty fish is associated with lower risks of fatal CHD and stroke. Food-based guidelines on dietary fats recommend limiting the consumption of animal fats high in SAFA, using vegetable oils high in monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA), and eating fatty fish. These recommendations are part of a healthy eating pattern that also includes ample intake of plant-based foods rich in fiber and limited sugar and salt.

Production of trans and conjugated fatty acids in dairy ruminants and their putative effects on human health: A review

Consumption of milk and dairy products is important in Western industrialised countries. Fat content is an important constituent contributing to the nutritional quality of milk and dairy products. In order to improve the health of consumers, there is high interest in improving their fatty acid (FA) composition, which depends principally on rumen and mammary metabolism. This paper reviews the lipid metabolism in ruminants, with a particular focus on the production of trans and conjugated linoleic acids (CLA) and conjugated linolenic acids (CLnA) in the rumen. After the lipolysis of dietary lipids, an extensive biohydrogenation of unsaturated FA occurs by rumen bacteria, leading to numerous cis and trans isomers of 18:1, non-conjugated of 18:2, CLA and CLnA. The paper examines the different putative pathways of ruminal biohydrogenation of cis9-18:1, 18:2n-6, 18:3n-3 and long-chain FA and the bacteria implicated. Then mechanisms relative to the de novo mammary synthesis are presented. Ruminant diet is the main factor regulating the content and the composition of milk fat. Effects of nature of forage and lipid supplementation are analysed in cows and small ruminants species. Finally, the paper briefly presents the effects of these FA on animal models and human cell lines. We describe the properties of ruminant trans 18:1, when compared to industrial trans 18:1, CLA and CLnA on human health from meta-analyses of intervention studies and then explore the underlying mechanisms.

Trends in dietary fat and fatty acid intakes and related food sources among Chinese adults: a longitudinal study from the China Health and Nutrition Survey (1997–2011)

Objective

Few studies have evaluated the intake trends of fatty acids in China. The present study aimed to describe the profile of longitudinal dietary fat and fatty acid intakes and their related food sources in Chinese adults.

Design

A longitudinal study using data from the China Health and Nutrition Survey (1997–2011) was conducted. Dietary intake was estimated using 24 h recalls combined with a food inventory for three consecutive days. Linear mixed models were used to calculate the adjusted mean intake values.

Setting

Urban and rural communities in nine provinces (autonomous regions), China.

Subjects

Adults (n 19 475; 9420 men and 10 055 women).

Results

Fat intake among men in 1997 was 73·4 g/d (28·1 % of total energy (%TE)), while in 2011 it increased to 86·3 g/d (33·2 %TE). Similarly, for women, this intake increased from 62·7 g/d (28·4 %TE) in 1997 to 74·1 g/d (33·7 %TE) in 2011. Energy intake from SFA grew from 6·8 to 7·6 %TE for both sexes. PUFA intake increased from 18·4 to 22·5 g/d for men and from 15·7 to 19·7 g/d for women, and was above 6 %TE in all survey periods. Intakes of 18:2 and 18:3 fatty acids showed significant upward trends in both sexes. Participants consumed less animal fats and more vegetable oils, with more PUFA intake and less energy from SFA. EPA and DHA intakes fluctuated around 20 mg/d.

Conclusions

Fatty acid intakes and profile in Chinese adults are different from those reported in other countries.

Trans Fat Intake and Its Dietary Sources in General Populations Worldwide: A Systematic Review

After the discovery that trans fat increases the risk of coronary heart disease, trans fat content of foods have considerably changed. The aim of this study was to systematically review available data on intakes of trans fat and its dietary sources in general populations worldwide. Data from national dietary surveys and population studies published from 1995 onward were searched via Scopus and websites of national public health institutes. Relevant data from 29 countries were identified. The most up to date estimates of total trans fat intake ranged from 0.3 to 4.2 percent of total energy intake (En%) across countries. Seven countries had trans fat intakes higher than the World Health Organization recommendation of 1 En%. In 16 out of 21 countries with data on dietary sources, intakes of trans fat from animal sources were higher than that from industrial sources. Time trend data from 20 countries showed substantial declines in industrial trans fat intake since 1995. In conclusion, nowadays, in the majority of countries for which data are available, average trans fat intake is lower than the recommended maximum intake of 1 En%, with intakes from animal sources being higher than from industrial sources. In the past 20 years, substantial reductions in industrial trans fat have been achieved in many countries.

Seasonal variation in fatty acid profile in the milk of different species under popularly followed feeding system in India

The aim of the study was to evaluate the seasonal variation in fatty acid profile in the milk of different species during summer and winter seasons. Samples were collected in months of summer and winter. Total saturated fatty acids (SFA) content (g/100g of fat) was 13-14% higher in summer than winter in all species. Total monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA) and conjugated linoleic acid (CLA) concentration (g/100g fat) were 10-12%, 3-4%, 30-40% respectively and, higher in winter than summer. MUFA, PUFA and CLA were considerably altered among seasons and species. It was concluded that PUFA and CLA in milk of different species increased during winter season than summer and this may be attributed to the seasonal availability of green fodder.

Diet-induced milk fat depression is associated with alterations in ruminal biohydrogenation pathways and formation of novel fatty acid intermediates in lactating cows

The biohydrogenation theory of milk fat depression (MFD) attributes decreases in milk fat in cows to the formation of specific fatty acids (FA) in the rumen. Trans-10, cis-12-CLA is the only biohydrogenation intermediate known to inhibit milk fat synthesis, but it is uncertain if increased ruminal synthesis is the sole explanation of MFD. Four lactating cows were used in a 4×4 Latin square with a 2×2 factorial arrangement of treatments and 35-d experimental periods to evaluate the effect of diets formulated to cause differences in ruminal lipid metabolism and milk fat synthesis on the flow of FA and dimethyl acetal at the omasum. Treatments comprised total mixed rations based on grass silage with a forage:concentrate ratio of 35:65 or 65:35 containing 0 or 50 g/kg sunflower oil (SO). Supplementing the high-concentrate diet with SO lowered milk fat synthesis from -20·2 to -31·9 % relative to other treatments. Decreases in milk fat were accompanied by alterations in ruminal biohydrogenation favouring the trans-10 pathway and an increase in the formation of specific intermediates including trans-4 to trans-10-18 : 1, trans-8, trans-10-CLA, trans-9, cis-11-CLA and trans-10, cis-15-18 : 2. Flow of trans-10, cis-12-CLA at the omasum was greater on high- than low-concentrate diets but unaffected by SO. In conclusion, ruminal trans-10, cis-12-CLA formation was not increased on a diet causing MFD suggesting that other biohydrogenation intermediates or additional mechanisms contribute to the regulation of fat synthesis in the bovine mammary gland.

Evaluation of the Impact of Ruminant Trans Fatty Acids on Human Health: Important Aspects to Consider

The definition and evaluation of trans fatty acids (TFA) with regard to foodstuffs and health hazard are not consistent. Based on the current situation, the term should be restricted only to TFA with isolated double bonds in trans-configuration. Conjugated linoleic acids (CLA) should be separately assessed. Ideally, the origin of the consumed fat should be declared, i.e., ruminant TFA (R-TFA) and industrial TFA (non-ruminant; I-TFA). In ruminant fat, more than 50% of R-TFA consists of vaccenic acid (C18:1 t11). In addition, natural CLA, i.e., c9,t11 CLA is also present. Both are elevated in products from organic farming. In contrast to elaidic acid (t9) and t10, which occur mainly in partially hydrogenated industrial fat, t11 is partially metabolized into c9,t11 CLA via Δ9-desaturation. This is the major metabolic criterion used to differentiate between t11 and other trans C18:1. t11 indicates health beneficial effects in several studies. Moreover, CLA in milk fat is associated with the prevention of allergy and asthma. An analysis of the few studies relating to R-TFA alone makes clear that no convincing adverse physiological effect can be attributed to R-TFA. Only extremely high R-TFA intakes cause negative change in blood lipids. In conclusion, in most European countries, the intake of R-TFA is assessed as being low to moderate. Restriction of R-TFA would unjustifiably represent a disadvantage for organic farming of milk.

Effect of oilseed type on milk fatty acid composition of individual cows, and also bulk tank milk fatty acid composition from commercial farms

Supplementing dairy cow diets with oilseed preparations has been shown to replace milk saturated fatty acids (SFA) with mono- and/or polyunsaturated fatty acids (MUFA, PUFA), which may reduce risk factors associated with cardio-metabolic diseases in humans consuming milk and dairy products. Previous studies demonstrating this are largely detailed, highly controlled experiments involving small numbers of animals, but in order to transfer this feeding strategy to commercial situations further studies are required involving whole herds varying in management practices. In experiment 1, three oilseed supplements (extruded linseed (EL), calcium salts of palm and linseed oil (CPLO) and milled rapeseed (MR)) were included in grass silage-based diets formulated to provide cows with ~350 g oil/day, and compared with a negative control (Control) diet containing no supplemental fat, and a positive control diet containing 350 g/cow per day oil as calcium salt of palm oil distillate (CPO). Diets were fed for 28-day periods in a 5×4 Latin Square design, and milk production, composition and fatty acid (FA) profile were analysed at the end of each period. Compared with Control, all lipid supplemented diets decreased milk fat SFA concentration by an average of 3.5 g/100 g FA, by replacement with both cis- and trans-MUFA/PUFA. Compared with CPO, only CPLO and MR resulted in lower milk SFA concentrations. In experiment 2, 24 commercial dairy farms (average herd size±SEM 191±19.3) from the south west of the United Kingdom were recruited and for a 1 month period asked to supplement their herd diets with either CPO, EL, CPLO or MR at the same inclusion level as the first study. Bulk tank milk was analysed weekly to determine FA concentration by Fourier Transform mid-IR spectroscopy prediction. After 4 weeks, EL, CPLO and MR all decreased herd milk SFA and increased MUFA to a similar extent (average -3.4 and +2.4 g/100 g FA, respectively) when compared with CPO. Differing responses observed between experiments 1 and 2 may be due in part to variations in farm management conditions (including basal diet) in experiment 2. This study demonstrates the importance of applying experimental research into commercial practice where variations in background conditions can augment different effects to those obtained under controlled conditions.

Glycemia Influences on Glucose Metabolism in Sepsis During Hyperinsulinemic Clamp

BACKGROUND

We investigated glucose metabolism in septic patients during hyperglycemic clamps and compared the different levels of insulinemia and glycemia.

METHODS

In 10 non-diabetic stable septic patients on mechanical ventilation with baseline glycemia >6 mmol/L and continuous insulin infusion, 3 steps of hyperinsulinemic clamp were performed after 8 hours without caloric intake. In step 1, the targets were insulinemia of 250 mIU/L and glycemia of 5 mmol/L; in step 2, insulinemia of 250 mIU/L and glycemia of 10 mmol/L; in step 3, insulinemia of 1250 mIU/L and glycemia of 5 mmol/L. Glucose uptake was calculated as the amount of glucose per time needed to maintain the target level of glycemia. Glucose oxidation was calculated from indirect calorimetry and urinary nitrogen losses. Values are provided as means +/- SD. A two-way analysis of variance and Scheffe's method were used for statistical analysis and p < .05 was considered significant.

RESULTS

At step 1, glucose uptake was lower than at step 2 (3.8 +/- 2.48 mg/kg/min and 7.9 +/- 3.45 mg/kg/min, respectively; p < .001). Glucose oxidation was also lower at step 1 (2.6 +/- 0.98 and 4.2 +/- 1.85 mg/kg/min, respectively; p < .01). Glucose storage was low at step 1 (0.7 +/- 1.39) and increased at step 2 (3.5 +/- 2.18; p < .05). In step 3, glucose uptake was 7.0 +/- 2.1, oxidation was 3.6 +/- 1.37, and storage was 2.9 +/- 2.79. There was no significant difference in all these parameters between steps 2 and 3. Energy expenditure between steps 1, 2 and 3 did not change (2294 + 307.42, 2334 + 341.53, and 2342 + 426.67 kcal/day, respectively). Alanine in plasma dropped significantly (p < .05): 10 mmol/L (311 +/- 55.88 mmol/L) at glycemia compared with 5 mmol/L (390 +/- 76 micromol/L) at insulinemia 250 mIU/L. It did not differ significantly from the values obtained at glycemia 5 mmol/L and insulinemia 1250 mIU/L (348 +/- 70.68 mmol/L). Even if the level of cytokines in sepsis was higher, there was no correlation between the insulin level in plasma (250 and 1250 mIU/L), glycemia (5 and 10 mmol/L) and cytokine level (IL-1beta, IL-2, IL-6, IL-8 and TNFalpha).

CONCLUSION

At insulinemia 250 mIU/L, a glucose level of 10 mmol/L seems to increase glucose uptake, oxidation, and storage compared with glycemia 5 mmol/L. This glucose uptake and oxidation at glycemia 10 mmol/L is comparable with the effect of extremely high insulinemia (1250 mIU/L) clamped at glycemia 5 mmol/L. A higher level of blood glucose or a high level of insulinemia significantly increases glucose uptake but not energy expenditure.

Multivariate characterization of salt and fat content, and the fatty acid profile of pastry and bakery products

The content of salt, fat and fatty acid profile of pastry and bakery products commercialised in Portugal was evaluated.

trans Fatty Acids in Colostrum, Mature Milk and Diet of Lactating Adolescents

The purpose of this study was to investigate the trans fatty acids (TFA) content and distribution in colostrum, mature milk, and diet of adolescent mothers, after TFA declaration in food labels became mandatory in Brazil. Participants were healthy adolescents (n 54, 15-19 years, 1-90 days postpartum) practicing exclusive breastfeeding. Milk samples were collected 3 days after delivery (colostrum) and in the third month postpartum (mature milk) by hand expression. The fatty acid composition of the milk samples was determined by gas chromatography. TFA intake corresponded to 1.23 % of total energy value. Total 18:2 TFA accounted for less than 0.5 % of the energy intake. The amount of total 18:1 TFA (mean ± SEM) was 1.9 % ± 0.14 in colostrum and 1.5 % ± 0.2 in mature milk. The total content of n-3 PUFA was inversely correlated with the total content of 18:1 TFA in colostrum. Both in colostrum and in mature milk, vaccenic acid (11t-18:1) was found to be the most abundant 18:1 trans isomer, followed by elaidic acid (9t-18:1), whereas rumenic acid (9c,11t-18:2 CLA) was the predominant 18:2 trans isomer. In conclusion, the levels of TFA of industrial sources found in the mother's diet and breast milk (colostrum and mature milk) showed a decrease in relation to those observed in studies conducted prior to the TFA labeling resolution in Brazil. However, the current low intake levels of n-3 LCPUFA and DHA content in the milk of lactating adolescents may be insufficient for supporting adequate neurological development of the infants.

Public health economic evaluation of different European Union-level policy options aimed at reducing population dietary trans fat intake

BACKGROUND

The adverse relation between dietary trans fatty acid (TFA) intake and coronary artery disease risk is well established. Many countries in the European Union (EU) and worldwide have implemented different policies to reduce the TFA intake of their populations.

OBJECTIVE

The aim of this study was to assess the added value of EU-level action by estimating the cost-effectiveness of 3 possible EU-level policy measures to reduce population dietary TFA intake. This was calculated against a reference situation of not implementing any EU-level policy (i.e., by assuming only national or self-regulatory measures).

DESIGN

We developed a mathematical model to compare different policy options at the EU level: 1) to do nothing beyond the current state (reference situation), 2) to impose mandatory TFA labeling of prepackaged foods, 3) to seek voluntary agreements toward further reducing industrially produced TFA (iTFA) content in foods, and 4) to impose a legislative limit for iTFA content in foods.

RESULTS

The model indicated that to impose an EU-level legal limit or to make voluntary agreements may, over the course of a lifetime (85 y), avoid the loss of 3.73 and 2.19 million disability-adjusted life-years (DALYs), respectively, and save >51 and 23 billion euros when compared with the reference situation. Implementing mandatory TFA labeling can also avoid the loss of 0.98 million DALYs, but this option incurs more costs than it saves compared with the reference option.

CONCLUSIONS

The model indicates that there is added value of an EU-level action, either via a legal limit or through voluntary agreements, with the legal limit option producing the highest additional health benefits. Introducing mandatory TFA labeling for the EU common market may provide some additional health benefits; however, this would likely not be a cost-effective strategy.

Red blood cell oleic acid levels reflect olive oil intake while omega-3 levels reflect fish intake and the use of omega-3 acid ethyl esters: The Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico-Heart Failure trial

The Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico-Heart Failure (GISSI-HF) study reported benefits of n-3 fatty acid (FA) treatment on cardiovascular (CV) events, but the effects of treatment on a putative CV disease risk factor, the red blood cell (RBC) n-3 FA level (the omega-3 index), have not been examined in this context. We hypothesized that treatment with prescription omega-3 acid ethyl esters (O3AEE) would increase the omega-3 index to the proposed cardioprotective value of 8%. RBCs were collected from a subset of patients participating in the GISSI-HF study (n=461 out of 6975 randomized), at baseline and after 3 months of treatment with either an olive oil placebo or O3AEE (1 g/d). RBC FA levels were expressed as a percentage of total FA. Patients also reported their typical olive oil and fish intakes. RBC oleic acid levels were directly correlated with reported frequency of olive oil consumption, and the omega-3 index was correlated with reported fish intake (P for trends <0.001 for both). After treatment, the omega-3 index increased from 4.8±1.7% to 6.7±1.9% but was unchanged in the placebo group (4.7±1.7 to 4.8±1.5%) (P<.0001 for changes between groups). At 3 months, more patients reached the proposed target omega-3 index level of 8%-12% in the treated vs placebo group (22.6% vs. 1.3%, P<.0001), however, what omega-3 index levels were ultimately achieved after four years in this trial are unknown.

Is vaccenic acid (18:1t n-7) associated with an increased incidence of hip fracture? An explanation for the calcium paradox

High calcium intake may increase hip fracture (HF) incidence. This phenomenon, known as the calcium paradox, might be explained by vaccenic acid (18:1t n-7, VA), the highly specific trans fatty acid (TFA) present in dairy products. First, we ecologically investigated the relationship between 18:1 TFA intake and HF incidence using data from 12 to 13 European countries collected before 2000; then we measured the effects of VA and elaidic acid (18:1t n-9, EA) on osteoblasts from goldfish scales (tissues very similar to mammalian bone), with alkaline phosphatase as a marker; and finally we measured the effect of VA on mRNA expression in the scales for the major bone proteins type I collagen and osteocalcin. HF incidence was significantly correlated with 18:1 TFA intake in men (r=0.57) and women (r=0.65). Incubation with 1μmol/L VA and EA for 48h significantly decreased alkaline phosphatase activity by 25% and 21%, respectively. Incubation of scales with 10μmol/L VA for 48h significantly decreased mRNA expression for type I collagen and osteocalcin (by about 50%). In conclusion, VA may be causatively related to HF and could explain the calcium paradox. It may be prudent to reduce 18:1 TFA intake, irrespective of trans positions, to prevent HF.

Trans fatty acids in the Portuguese food market

Consistent evidence exist on the harmful health effects of industrial trans fatty acids (TFA). In order to have accurate data on TFA intake and implement adequate measures to reduce their intake, each country should have updated estimates of TFA content in the diet. The objective of the present study was to provide data on the TFA content in food commercialized in the Portuguese market. The results on the TFA content of 268 samples acquired between October and December 2013 are reported. Samples were categorized as margarines and shortenings (n = 16), spreadable chocolate fats (n = 6), fried potatoes and chips (n = 25), industrial bakery (n = 4), breakfast cereals (n = 3), pastry products (n = 120), seasonings (n = 5), instant soups (n = 5), instant desserts (n = 6), chocolate snacks (n = 4), microwave popcorn (n = 4), cookies, biscuits and wafers (n = 53), and fast-food (n = 13), with butter (n = 4) included for comparison purposes. TFA were quantified by gas chromatography. Total TFA content in the fat ranged from 0.06% to 30.2% (average 1.9%), with the highest average values in the “biscuits, wafers and cookies” group (3.4% TFA), followed by the pastry group (2.0%). Fifty samples (19%) had TFA superior to 2% in the fat. These findings highlight there is still much need for improvement in terms of the TFA content in Portuguese foods, particularly in traditional pastry.

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Trans fatty acids content in Portuguese food is updated.

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Most food categories have very low TFA contents.

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Some fats used in local pastry have high TFA contents.

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Inaccurate fat designations might induce incorrect choices.

The Contribution of Modern Margarine and Fat Spreads to Dietary Fat Intake

The study of dietary fat consumption and its resultant effects on human health has been one of the most investigated topics in the field of human nutrition. Based on the results obtained from such studies, specific dietary recommendations on fat intake (both in terms of quantity and quality) have been established by health organizations around the globe. Among the various food industry sectors, the margarine manufacturers have also responded to these guidelines and now offer improved formulations with a desirable balance of fat contents and fat types. The main aim of this article is to provide an overview on how these modern margarines can contribute towards reaching the dietary guidelines relating to fat intake. In particular, the dietary recommendations with respect to the specific fatty acid types are comprehensively detailed along with an emphasis on the role of modern margarines in providing balanced fat types (more polyunsaturated fats, less saturated fats and a near-complete absence of trans fats) in the daily diet.

The Deep Correlation between Energy Metabolism and Reproduction: A View on the Effects of Nutrition for Women Fertility

In female mammals, mechanisms have been developed, throughout evolution, to integrate environmental, nutritional and hormonal cues in order to guarantee reproduction in favorable energetic conditions and to inhibit it in case of food scarcity. This metabolic strategy could be an advantage in nutritionally poor environments, but nowadays is affecting women's health. The unlimited availability of nutrients, in association with reduced energy expenditure, leads to alterations in many metabolic pathways and to impairments in the finely tuned inter-relation between energy metabolism and reproduction, thereby affecting female fertility. Many energetic states could influence female reproductive health being under- and over-weight, obesity and strenuous physical activity are all conditions that alter the profiles of specific hormones, such as insulin and adipokines, thus impairing women fertility. Furthermore, specific classes of nutrients might affect female fertility by acting on particular signaling pathways. Dietary fatty acids, carbohydrates, proteins and food-associated components (such as endocrine disruptors) have per se physiological activities and their unbalanced intake, both in quantitative and qualitative terms, might impair metabolic homeostasis and fertility in premenopausal women. Even though we are far from identifying a "fertility diet", lifestyle and dietary interventions might represent a promising and invaluable strategy to manage infertility in premenopausal women.