Papaya (Carica papaya L.) is a highly nutritious and less-caloric fruit, commonly consumed for its minerals and vitamins and hence may help in controlling obesity and abdominal discomforts. The present study investigated the hypolipidaemic effects of papaya juice extract on male Albino Wistar rats (7 weeks old; 185 ± 17 g) fed on a high fat and fructose diet (HFFD) for 6 weeks. The rats were divided into groups I–IV of five rats each and fed on either a HFFD (i.e. the Control), HFFD + 200 mg papaya, HFFD + 350 mg papaya or a HFFD + 500 mg papaya. On day 34, after an overnight fast, blood samples were obtained by cardiac puncture under 99⋅8 % Chloroform anaesthesia for the determination of serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c) and high-density cholesterol (HDL-c). The atherogenic (AI) and coronary risk (CRI) indices were also calculated. Statistical analysis was performed using ANOVA where means were separated using Tukey's HSD test. Resulted showed that all rats given papaya juice had an increasing, non-significant HDL-c and reduced LDL-c levels while rats fed on HFFD had the highest TC (53⋅2 mg/dl) and TG (37⋅6 mg/dl) levels. Papaya juice statistically reduced the AI and CRI of the rats. In conclusion, consumption of HFFD + 500 mg was the most effective in the reduction of rats’ blood lipids and fats, due to its anti-obesity and hypolipidaemic properties, thus can be used in the management of dyspilidaemic disorders.

To assess the changes in the relationship between serum Mg and blood lipids of Chinese adults with type 2 diabetes (T2D) or central obesity, a total of 8163 subjects (mean age 59·6 years, 54·9 % men) were analysed. Participants were classified according to blood Mg (below 0·65 mmol/l, 0·65–0·95 mmol/l and above 0·95 mmol/l), T2D (yes/no) and central obesity (yes/no). Blood lipids (TAG, total cholesterol (TC), HDL-cholesterol and LDL-cholesterol) were determined by standardised methods and conditions. A significant increase in blood lipids, with the exception of HDL-cholesterol, across progressive Mg groups in all subjects was noted (P<0·05). TAG, TC, HDL-cholesterol and LDL-cholesterol were significantly higher among subjects with central obesity compared with those without central obesity (P<0·05). A significant increase in TAG, TC and LDL-cholesterol across progressive Mg groups was observed in subjects without T2D (P<0·05). However, no significant change of HDL-cholesterol and LDL-cholesterol across progressive Mg groups was observed in subjects with T2D (P>0·05). TAG, TC, HDL-cholesterol and LDL-cholesterol were significantly higher among subjects with T2D than those without T2D (P<0·05). Multivariable models for TAG and LDL-cholesterol failed to attain statistical significance in diabetics, by using a generalised linear or parsimonious model. TAG, TC, HDL-cholesterol and LDL-cholesterol were significantly higher among subjects with T2D or central obesity. Blood lipids, with the exception of HDL-cholesterol, were associated with serum Mg, but this association was somehow influenced by T2D in LDL-cholesterol. In addition, multivariable models for both TAG and LDL-cholesterol failed to attain statistical significance among subjects with T2D, different from subjects without T2D.

Randomised controlled trials comparing low- v. high-fat diets on cardiometabolic risk factors in people with overweight or obesity have shown inconsistent results, which may be due to the mixed metabolic status of people with excess adiposity. The role of dietary fat manipulation in modifying cardiometabolic indicators in people with overweight or obese without metabolic disturbance is unclear. Thus, meta-analysis was conducted to compare low- v. high-fat diets on cardiometabolic indicators in people who are overweight or obese without metabolic disturbance in the present study. Databases were searched until October 2016. The pooled effects of outcomes with heterogeneity were calculated with a random-effects model, heterogeneities were analysed by subgroup and meta-regression. As a result, twenty studies with 2106 participants were included in the meta-analysis. Total cholesterol and LDL-cholesterol levels were lower following low-fat diets compared with high-fat diets: weighted mean difference (WMD) was −7·05 mg/dl (−0·18 mmol/l; 95 % CI −11·30, −2·80; P=0·001) and −4·41 mg/dl (−0·11 mmol/l; 95 % CI −7·81, −1·00; P=0·011), respectively. Conversely, significant higher level of TAG (WMD: 11·68 mg/dl (0·13 mmol/l), 95 % CI 5·90, 17·45; P<0·001) and lower level of HDL-cholesterol (WMD: −2·57 mg/dl (−0·07 mmol/l); 95 % CI −3·85, −1·28; P<0·001) were found following low-fat diets compared with high-fat diets. In conclusion, dietary fat manipulation has a significant influence on blood lipid levels in people with overweight or obesity without metabolic disturbances.

A systematic review and meta-analysis of randomised controlled trials was undertaken to determine the effects of almond consumption on blood lipid levels, namely total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), TAG and the ratios of TC:HDL-C and LDL-C:HDL-C. Following a comprehensive search of the scientific literature, a total of eighteen relevant publications and twenty-seven almond-control datasets were identified. Across the studies, the mean differences in the effect for each blood lipid parameter (i.e. the control-adjusted values) were pooled in a meta-analysis using a random-effects model. It was determined that TC, LDL-C and TAG were significantly reduced by −0·153 mmol/l (P < 0·001), −0·124 mmol/l (P = 0·001) and −0·067 mmol/l (P = 0·042), respectively, and that HDL-C was not affected (−0·017 mmol/l; P = 0·207). These results are aligned with data from prospective observational studies and a recent large-scale intervention study in which it was demonstrated that the consumption of nuts reduces the risk of heart disease. The consumption of nuts as part of a healthy diet should be encouraged to help in the maintenance of healthy blood lipid levels and to reduce the risk of heart disease.

We aimed to examine the contribution of blood lipids to the association between BMI and blood pressure (BP) in children with overweight and obesity. Data were collected in elementary and high schools of Chaoyang District, Beijing, China in 2012. Participants’ weight, height, BP and fasting plasma lipid profile were measured by standard protocols. Mediation analysis was used to examine the mediation role of blood lipids on the relation between BMI and BP, with age included as a covariate. We found that in boys 8·29 % (mediation effect=0·106, P=0·012) of the association between BMI and systolic BP was mediated through TAG. TAG mediated 12·53 % (mediation effect=0·093, P=0·018) and LDL-cholesterol mediated 7·75 % (mediation effect=0·57, P=0·046) of the association between BMI and diastolic BP was mediated by TAG and LDL-cholesterol, respectively. However, blood lipids did not show the mediation effect in girls. Our findings suggested that there was a sex difference in the contribution of blood lipids to the association between BMI and BP. Controlling TAG or LDL-cholesterol may be beneficial for reducing the risk of the BMI-related high BP in overweight boys; however, this outcome is not the case when controlling TAG or LDL-cholesterol in girls. This study may provide clues to explore the underlying mechanism of the association between obesity and hypertension.

Blood lipid response to a given dietary intervention could be determined by the effect of diet, gene variants or gene–diet interactions. The objective of the present study was to investigate whether variants in presumed nutrient-sensitive genes involved in lipid metabolism modified lipid profile after weight loss and in response to a given diet, among overweight European adults participating in the Diet Obesity and Genes study. By multiple linear regressions, 240 SNPs in twenty-four candidate genes were investigated for SNP main and SNP–diet interaction effects on total cholesterol, LDL-cholesterol, HDL-cholesterol and TAG after an 8-week low-energy diet (only main effect), and a 6-month ad libitum weight maintenance diet, with different contents of dietary protein or glycaemic index. After adjusting for multiple testing, a SNP–dietary protein interaction effect on TAG was identified for lipin 1 (LPIN1) rs4315495, with a decrease in TAG of − 0·26 mmol/l per A-allele/protein unit (95 % CI − 0·38, − 0·14, P= 0·000043). In conclusion, we investigated SNP–diet interactions for blood lipid profiles for 240 SNPs in twenty-four candidate genes, selected for their involvement in lipid metabolism pathways, and identified one significant interaction between LPIN1 rs4315495 and dietary protein for TAG concentration.

Previous studies have suggested that the daidzein metabolite equol rather than daidzein itself contributes to the beneficial effect of soya foods in the prevention of CVD. The aim of the present study is to examine the proportion of equol excretion in Chinese adults and compare plasma lipids and carotid artery intima–media thickness (IMT) between equol excretors and non-excretors, and to evaluate the effect of soya isoflavone intakes on serum lipids and IMT in either equol excretors or non-excretors. Subjects (n 572; women n 362, men n 210) were recruited for the present study. An overnight urine sample was provided by each subject on their usual diet to quantify urinary concentrations of daidzein and equol. Far-wall IMT was determined by B-mode ultrasound in the right carotid at two sites, carotid bulb (CB-IMT) and common carotid artery (CCA-IMT), and fasting serum lipids were measured. Habitual dietary intakes were estimated with a FFQ, and soya isoflavone intake derived from the FFQ was assessed. Of the 572 subjects, the proportion of equol excretors on their usual diet was 25·0 % (n 143). Compared with non-excretors, equol excretors showed significantly lower serum TAG ( − 38·2 (95 % CI − 70·4, − 5·9) %, P = 0·012) and CCA-IMT ( − 4·9 (95 % CI − 9·7, − 0·3) %, P = 0·033). Equol excretors with higher daily isoflavone intakes ( − 5·4 mg/d) had significantly lower IMT ( − 16·2 %, P = 0·035) and tended to have higher HDL-cholesterol (P = 0·055) than did those with lower daily isoflavone intakes (1·5 mg/d), while no association was observed between soya isoflavone intakes and serum lipids or IMT in non-excretors. In conclusion, the benefits of soya isoflavones in preventing CVD may be apparent among equol excretors only.

The well-documented lipid-lowering effects of fibre may be related to its viscosity, a phenomenon that has been understudied, especially when fibre is given against the background of a typical North American (NA) diet. In this three-arm experiment, we compared the lipid-lowering effect of low-viscosity wheat bran (WB), medium-viscosity psyllium (PSY) and a high-viscosity viscous fibre blend (VFB), as part of a fibre intervention aimed at increasing fibre intake to recommended levels within the context of a NA diet in apparently healthy individuals. Using a randomised cross-over design, twenty-three participants (twelve males and eleven females; age 35 (sd 12) years; LDL-cholesterol (C) 2·9 (sem 0·6) mmol/l) consuming a typical NA diet received a standard, fibre-enriched cereal, where approximately one-third of the fibre was either a low-viscosity (570 centipoise (cP)) WB, medium-viscosity (14 300 cP) PSY or a high-viscosity (136 300 cP) novel VFB, for 3 weeks separated by washout periods of ≥ 2 weeks. There were no differences among the treatments in the amount of food consumed, total dietary fibre intake, reported physical activity and body weight. Final intake of the WB, PSY and VFB was 10·8, 9·0 and 5·1 g, respectively. Reduction in LDL-C was greater with the VFB compared with the medium-viscosity PSY ( − 12·6 (sem 3·5) %, P = 0·002) and low-viscosity WB ( − 14·6 (sem 4·2) %, P = 0·003). The magnitude of LDL-C reduction showed a positive association with fibre apparent viscosity (r − 0·41, P = 0·001). Despite the smaller quantity consumed, the high-viscosity fibre lowered LDL-C to a greater extent than lower-viscosity fibres. These data support the inclusion of high-viscosity fibre in the diet to reduce plasma lipids among apparently healthy individuals consuming a typical NA diet.

Intake of trans-fatty acids (TFA), especially industrially produced TFA (I-TFA), has been associated with the risk of CHD through influence on serum lipid levels. Other causal pathways remain less investigated. In the present cross-sectional study of middle-aged men representing a broad range of BMI, the association between intake of TFA, I-TFA and ruminant TFA (R-TFA) and obesity-associated risk markers of CHD was assessed. The study comprised 393 Danish men (median age 49 years) with a median BMI of 28·4 kg/m2. Intake of TFA was estimated based on 7 d dietary records, whereas outcomes of interest (waist circumference, sagittal abdominal diameter, percentage of truncal fat, C-reactive protein, IL-6, blood lipids, blood pressure, HbA1c and insulin sensitivity index) were obtained through clinical examination. The associations were assessed by linear regression analysis. The median intake of total TFA among the 393 men was 1·3 g/d, covering a daily I-TFA intake of 0·4 g (10–90th percentile 0·0–1·0) and R-TFA intake of 0·9 g (10–90th percentile 0·4–1·8). Intake of these amounts of TFA showed no significant associations with abdominal fatness, inflammatory markers, blood lipids, blood pressure and insulin homeostasis. Among middle-aged men with a generally low intake of TFA, neither I-TFA nor R-TFA was significantly related to obesity-associated risk markers of CHD. The decreased average intake of I-TFA in Denmark since 1995 is suggested to effectively prevent occurrence of the adverse metabolic changes and health consequences, which have formerly been observed in relation to, especially, I-TFA intake.

Intervention studies have demonstrated that saturated fat increases total and LDL-cholesterol concentrations, and it is therefore recommended that the intake of high-fat dairy products be limited. However, observational studies have found an inverse relationship between the intake of dairy products and incidence of CVD. We aimed to study whether the Ca content of dairy products influences the effect of dairy fat on the lipid profile. The study had a randomised cross-over design. Subjects (n 9) were randomised to one of the sequence of four isoenergetic 10 d diets: low Ca and low fat (LC/LF: approximately 700 mg Ca/d, 25 % of energy (fat); high Ca and LF (HC/LF: approximately 2800 mg Ca/d, 25 % of energy fat); LC and high fat (LC/HF: approximately 700 mg Ca/d, 49 E% fat); or HC and HF (approximately 2800 mg Ca/d, 49 E% fat). Blood variables were measured before and after each diet period, and faeces and urine were collected at the end of each diet period. A two-way ANOVA was used to examine the effect of Ca and fat intake. Independent of Ca intake, the HF diet increased the concentrations of total (9 %; P < 0·0001), LDL (14 %; P < 0·0001)- and HDL (13 %; P = 0·0002)-cholesterol compared with the LF diet. However, independent of fat intake, the HC diet decreased the concentrations of total (4 %; P = 0·0051) and LDL-cholesterol (10 %; P < 0·0001) but not HDL-cholesterol compared with the LC diet. In addition, total:HDL-cholesterol was decreased (5 %; P = 0·0299), and HDL:LDL was increased (12 %; P = 0·0097) by the HC diet compared with the LC diet. Faecal fat excretion was increased by both the HC (P < 0·0001) and HF (P = 0·0052) diets. In conclusion, we observed that dairy Ca seems to partly counteract the raising effect of dairy fat on total and LDL-cholesterol, without reducing HDL-cholesterol.

Previous studies have suggested that daidzein's metabolites, equol and O-desmethylangolensin (O-DMA), rather than daidzein itself may contribute to the beneficial effects of soya foods in the prevention of CVD. The present study aims to assess the proportion of equol and O-DMA producers, and to compare differences in anthropometric factors, serum lipids, glucose and uric acid between producers and non-producers in Chinese adults aged 20–69 years. For the present cross-sectional study, 202 subjects (100 women and 102 men) were recruited. Twenty-four-hour urinary daidzein and its metabolites were determined in these subjects while on their usual diet and again after a 3-d isoflavone challenge. Fasting serum lipids, glucose and uric acid were examined on their usual diet. Three days of 24 h dietary recalls were used to assess dietary intakes. Of the 202 subjects, 27 (13·4 %) and 27 (13·4 %) excreted equol and O-DMA on their usual diet, and 101 (50 %) and 94 (46·5 %) produced equol and O-DMA after a load of 80 mg/d isoflavones. Equol producers showed lower serum uric acid ( − 10·2 %, P = 0·001), TAG ( − 29·5 %, P = 0·007) and waist:hip ratio ( − 2·6 %, P = 0·032), and tended to have higher HDL cholesterol (6·3 %, P = 0·069) compared with equol non-producers. There were no significant differences in serum lipids, glucose and uric acid between O-DMA producers and non-producers. In conclusion, equol phenotypes might influence cardiovascular risk.

Recent investigations on the effects of phyto-oestrogens on various tissues have revealed that these diverse molecules may improve human health, particularly by protecting against certain chronic diseases. After a brief examination of the food sources, structures, and general cellular actions of the major phyto-oestrogens, current research findings on cardiovascular disease, skeletal tissues, and reproductive cancers are reviewed. Phyto-oestrogen concentrations in blood may be maintained at high levels in those consuming soyabean (Glycine max)-based food daily at several meals and exert their effects on target cells through either genomic effects via the classical oestrogen receptors or non-genomic effects mediated by membrane-bound oestrogen receptors or other cellular proteins. The expression of oestrogen receptor (OR) subtypes alpha (a) and beta (β) varies across tissues, and cells that preferentially express OR-β, which may include bone cells, are more likely to respond to phyto-oestrogens. Conversely, reproductive tissues contain relatively more OR-a and may, thus, be differently affected by phyto-oestrogens. Soyabean phyto-oestrogens appear to prevent the progression of atherosclerosis through multiple interactions, including lowering of plasma lipids and lipoproteins, increased vasodilatation and, possibly, decreased activation of blood platelets and vascular smooth muscle cells. However, a favourable impact on cardiovascular disease morbidity and mortality by a soyabean-enriched western-type diet remains to be shown, and unresolved questions remain regarding dose and form of the phyto-oestrogens in relation to risks and benefits. The isoflavones of soyabean have been shown consistently to have bone-retentive effects in animal studies by several investigators using rodent models, although intakes must be above a relatively high threshold level for a lengthy period of time, and little or no extra benefit is observed with intakes above this threshold level. The reports of modest or no effects on prevention of bone loss in human and non-human primate studies respectively, may be due to the limited doses tested so far. The relationship between soyabean-food intake and cancer risk has been more extensively investigated than for any other disease, but with less certainty about the benefits of long-term consumption of phyto-oestrogen-containing foods on prevention of cancer. The observations that breast and prostate cancer rates are lower in Asian countries, where soyabean foods are consumed at high levels, and the high isoflavone content of soyabeans have led to examination of the potential protective effects of phyto-oestrogens. Establishing diet-cancer relationships has proved difficult, in part because of the conflicting data from various studies of effects of soyabean-diets on cancer. Epidemiological evidence, though not impressive, does suggest that soyabean intake reduces breast cancer risk. The isoflavone genistein has a potent effect on breast cancer cells in vitro, and early exposure of animals to genistein has been effective in reducing later development of mammary cancer. Thus, continuous consumption of soyabean foods in early life and adulthood may help explain the low breast cancer mortality rates in Asian countries. Although the evidence for a protective effect against prostate cancer may be slightly more supportive, more research is needed before any firm conclusions can be made about the phyto-oestrogen-cancer linkages.

The aim of the present study was to compare individual associations of BMI, triceps skinfold (TSF), waist circumference (WC) and percentage fat mass (%FM) with blood pressure (BP) and blood lipids in children and adolescents. Cross-sectional data on BMI, TSF, WC, %FM as well as on BP, TAG and HDL were analysed in 4220 (BP) and 729 (lipids) 9–11-year-old children and 3174 (BP) and 536 (lipids) 13–16-year-old adolescents as part of the Kiel Obesity Prevention Study. All obesity indices were similarly associated with BP and blood lipids. In girls, WC had closer correlations to BP than BMI (systolic BP: 0·27 and 0·24 for BMI, 0·34 and 0·28 for WC in 9–11- and 13–16-year-olds). Subjects with an obesity index ≥ 90th percentile had higher prevalences of elevated BP and blood lipids than subjects with a normal index. In children with normal BMI or WC, an additionally elevated second obesity index was associated with a 2·5–7·4-fold higher prevalence of high BP when compared with children with normal indices. In adolescents, an elevated WC plus an elevated second obesity index was associated with a 2·6–8·2-fold higher prevalence of high BP when compared with adolescents with an elevated WC plus a normal second index. We conclude that (i) both BMI and WC are appropriate to estimate CVD risk, (ii) the use of a second obesity index is recommended in children with normal BMI or normal WC as well as in adolescents with elevated WC and (iii) all obesity indices seemed to be appropriate for risk assessment.

The present paper provides a comprehensive review of the literature pertaining to the impact of alcohol intake on cardiovascular disease. Both cross-sectional and prospective studies have disclosed a negative association between moderate intake of alcoholic beverages and cardiovascular disease. The relationship appears to be present for both wine, beer and spirits. Effects of alcohol itself and also the role of different cardio-protective substances in alcoholic beverages are discussed. Alcohol has been suggested to beneficially affect the blood lipid profile, as it increases plasma HDL-cholesterol level. Furthermore, it may inhibit thrombogenesis by reducing thromboxan formation and decreasing the plasma level of fibrinogen. However, high blood concentrations of alcohol may impair fibrinolysis by increasing plasma plasminogen activator inhibitor-1 level. This action could contribute to explaining the ‘U’-shaped association between alcohol intake and cardiac events. Alcohol seems to promote abdominal fat distribution, but the importance of this effect in non-obese individuals is uncertain. Wine in particular, but also beer, contains polyphenols which act as antioxidants. Their action could maintain the integrity of the endothelial function by reducing the formation of superoxide. Moreover, these antioxidants may protect against LDL oxidation and modulate the macrophage attack on the endothelium. Although the cardio-protective effect of alcohol can hardly be addressed in healthy individuals by intervention studies with hard end points, there are many observational and experimental findings indicating that moderate alcohol drinking possesses properties preventive of cardiovascular disease.

Increased Se intakes have been associated with decreased risk of cancer and CVD. Several mechanisms have been proposed, including antioxidant effects through selenoproteins, induction of carcinogen metabolism and effects on the blood lipid profile. In a 4 × 1 week randomised, double-blind cross-over study, healthy young men supplemented their usual diet with selenate, Se-enriched yeast, Se-enriched milk or placebo (Se dose was 300 μg/d for selenate and Se-enriched yeast, and about 480 μg/d for Se-enriched milk) followed by 8-week washout periods. All Se sources increased serum Se levels after supplementation for 1 week. The effect of the organic forms did not differ significantly and both increased serum Se more than selenate. Conversely, thrombocyte glutathione peroxidase (GPX) was increased in the periods where subjects were supplemented with selenate but not in those where they were given Se-enriched yeast or Se-enriched milk. We found no effect on plasma lipid resistance to oxidation, total cholesterol, TAG, HDL- and LDL-cholesterol, GPX, glutathione reductase (GR) and glutathione S-transferase (GST) activities measured in erythrocytes, GPX and GR activities determined in plasma, or GR and GST activities in thrombocytes. Leucocyte expression of genes encoding selenoproteins (GPX1, TrR1 and SelP), and of electrophile response element-regulated genes (GCLC, Fra1 and NQO1) were likewise unaffected at all time points following intervention. We conclude that thrombocyte GPX is specifically increased by short-term selenate supplementation, but not by short-term supplementation with organic Se. Short-term Se supplementation does not seem to affect blood lipid markers or expression and activity of selected enzymes and a transcription factor involved in glutathione-mediated detoxification and antioxidation.

Plant sterols (PS) and MUFA are well-documented cholesterol lowering agents. We aimed to determine the effect of PS esterified to olive oil fatty acids (PS-OO) on blood lipid profile and lipid peroxidation in hypercholesterolaemic subjects. Twenty-one moderately overweight, hypercholesterolaemic subjects consumed three consecutive treatment diets, each lasting 28 d and separated by 4-week washout periods, using a randomized crossover design. Diets contained 30 % energy as fat, 70 % of which was provided by olive oil (OO), and differed only in the treatment oils: OO, PS esterified to sunflower oil fatty acids (PS-SO), and PS-OO. Both PS-SO and PS-OO treatments provided 1·7 g PS /d. PS-OO and PS-SO consumption resulted in a decrease (P = 0·0483) in LDL-cholesterol (LDL-C) concentrations compared with the OO diet. Although total cholesterol and apo B-100 levels were not significantly affected, PS-SO and, to some extent, PS-OO reduced the total:HDL-cholesterol (HDL-C) ratio (P = 0·0142) and the apo B-100:apo A-I ratio (P = 0·0168) compared with the OO diet. There were no differences across diets in lipoprotein(a) (Lp(a)) and lipid peroxidation levels. However, following consumption of OO and PS-SO, Lp(a) concentrations increased (P = 0·0050 and 0·0421, respectively), while PS-OO treatment did not affect Lp(a) levels. Furthermore, there was a decrease (P = 0·0097) in lipid peroxidation levels with PS-OO treatment during the supplementation phase. Our results suggest that supplementing an OO-rich diet with PS-OO favourably alters the plasma lipid profile and may decrease the susceptibility of LDL-C to lipid peroxidation in hypercholesterolaemic subjects.

Conjugated linoleic acid (CLA) is a collective term for a mixture of positional and geometric isomers of conjugated dienoic derivatives of linoleic acid. CLA has received considerable attention as a result of animal experiments that report anti-carcinogenic, anti-atherogenic and anti-diabetic properties, and modulation of body composition and immune function. Several studies of CLA supplementation in human subjects have now been published, but in contrast to animal studies there has been marked variation between reports on the health-related outcomes. The consensus from seventeen published studies in human subjects is that CLA does not affect body weight or body composition. Some detrimental effects of the trans-10,cis-12 CLA isomer have also been reported in terms of altered blood lipid composition and impaired insulin sensitivity. Finally, CLA has only limited effects on immune functions in man. However, there have been reports of some interesting isomer-specific effects of CLA on the blood lipid profile, but not on immune function. These isomer-specific effects need further investigation. Until more is known, CLA supplementation in man should be considered with caution.

The present study investigated whether consuming dairy products naturally enriched in cis-9, trans-11 (c9, t11) conjugated linoleic acid (CLA) by modification of cattle feed increases the concentration of this isomer in plasma and cellular lipids in healthy men. The study had a double-blind cross-over design. Subjects aged 34–60 years consumed dairy products available from food retailers for 1 week and then either control (0·17 g c9, t11 CLA/d; 0·31 g trans-vaccenic acid (tVA)/d) or CLA-enriched (1·43 g c9, t11 CLA/d; 4·71 g tVA/d) dairy products for 6 weeks. After 7 weeks washout, this was repeated with the alternate products. c9, t11 CLA concentration in plasma lipids was lower after consuming the control products, which may reflect the two-fold greater c9, t11 CLA content of the commercial products. Consuming the CLA-enriched dairy products increased the c9, t11 CLA concentration in plasma phosphatidylcholine (PC) (38%; P=0·035), triacylglycerol (TAG) (22%; P<0·0001) and cholesteryl esters (205%; P<0·0001), and in peripheral blood mononuclear cells (PBMC) (238%; P<0·0001), while tVA concentration was greater in plasma PC (65%; P=0·035), TAG (98%; P=0·001) and PBMC (84%; P=0·004). Overall, the present study shows that consumption of naturally enriched dairy products in amounts similar to habitual intakes of these foods increased the c9, t11 CLA content of plasma and cellular lipids.

We investigated the feasibility of increasing ursodeoxycholic acid (UDCA) in the enterohepatic circulation of pigs by administering living bacteria capable of epimerising endogenous amidated chenodeoxycholic acid (CDCA) to UDCA. We first demonstrated that combining Bifidobacterium animalis DN-173 010, as a bile salt-hydrolysing bacterium, and Clostridium absonum ATCC 27555, as a CDCA to UDCA epimerising bacterium, led to the efficient epimerisation of glyco- and tauro-CDCA in vitro, with respective UDCA yields of 55·8 (se 2·8) and 36·6 (se 1·5)%. This strain combination was then administered to hypercholesterolaemic pigs over a 3-week period, as two daily preprandial doses of either viable (six experimental pigs) or heat-inactivated bacteria (six controls). The main effects of treatment were on unconjugated bile acids (P=0·035) and UDCA (P<0·0001) absorbed into the portal vein, which increased 1·6–1·7- and 3·5–7·5-fold, respectively, under administration of living compared with inactivated bacteria. In bile, UDCA did not increase significantly, but the increase in biliary lithocholic acid with time in the controls was not observed in the experimental pigs (P=0·007), and the same trend was observed in faeces. All other variables (biliary lipid equilibrium, plasma lipid levels and partition of cholesterol between the different lipoprotein classes) remained unaffected by treatment throughout the duration of the experiment. In conclusion, it is feasible to increase the bioavailability of UDCA to the intestine and the liver by administering active bacteria. This may represent an interesting new probiotic activity, provided that in future it could be expressed by a safe food micro-organism.