Functional food science and the cardiovascular system

Low-density lipoprotein oxidation biomarkers in human health and disease and effects of bioactive compounds

Based on the significance of oxidized low-density lipoprotein (LDL) in health and disease, this review focuses on human studies addressing oxidation of LDL, including three lines of biomarkers, (i) ex vivo LDL resistance to oxidation, a "challenge test" model, (ii) circulating oxidized LDL, indicating the "current in vivo status", and (iii) autoantibodies against oxidized LDL as fingerprints of an immune response to oxidized LDL, along with circulating oxysterols and 4-hydroxynonenal as biomarkers of lipid peroxidation. Lipid peroxidation and oxidized LDL are hallmarks in the development of various metabolic, cardiovascular and other diseases. Changes further occur across life stages from infancy to older age as well as in athletes and smokers. Given their responsiveness to targeted nutritional interventions, markers of LDL oxidation have been employed in a rapidly growing number of human studies for more than 2 decades. There is growing interest in foods, which, besides providing energy and nutrients, exert beneficial effects on human health, such as protection of DNA, proteins and lipids from oxidative damage. Any health claim, however, needs to be substantiated by supportive evidence derived from human studies, using reliable biomarkers to demonstrate such beneficial effects. A large body of evidence has accumulated, demonstrating protection of LDL from oxidation by bioactive food compounds, including vitamins, other micronutrients and secondary plant ingredients, which will facilitate the selection of oxidation biomarkers for future human intervention studies and health claim support.

Lowering of platelet aggregation and serum eicosanoid levels in rats fed with a diet containing coconut oil blends with rice bran oil or sesame oil

The present investigation was undertaken to study the effects of feeding a diet containing blended and interesterified fat to rats on thrombotic parameters such as platelet aggregation and eicosanoid levels in blood serum. Male Wistar rats were fed with a diet containing 10% fat from native; coconut oil (CNO), rice bran oil (RBO), sesame oil (SESO), blended; (CNO+RBO blend (B), CNO+SESO(B), or interesterified oils; CNO+RBO interesterified (I), CNO+SESO(I) for a period of 60 days. Rats given a diet containing blended oil of CNO+RBO(B) or CNO+SESO(B) showed a decrease in rate of ADP induced aggregation of platelets by 34% and 30%, respectively, compared to those fed with CNO. Aggregation induced by collagen was also reduced similarly in rats given blended or interesterified oils of CNO with RBO or SESO. Feeding interesterified oil CNO+RBO(I), and CNO+SESO(I) to rats also resulted in decrease in rate of ADP induced platelet aggregation by 37% and 34%, respectively, compared to rats fed with CNO. The prostacyclin/thromboxane ratio in serum was increased in rats fed with blended and interesterified oil compared to those fed with CNO. These results indicated that CNO when blended or interesterified with RBO or SESO exhibit antithrombotic effects as compared to the effect observed by feeding rats with CNO.

Relationship between tap water hardness, magnesium, and calcium concentration and mortality due to ischemic heart disease or stroke in The Netherlands

BACKGROUND

Conflicting results on the relationship between the hardness of drinking water and mortality related to ischemic heart disease (IHD) or stroke have been reported.

OBJECTIVES

We investigated the possible association between tap water calcium or magnesium concentration and total hardness and IHD mortality or stroke mortality.

METHODS

In 1986, a cohort of 120,852 men and women aged 5569 years provided detailed information on dietary and other lifestyle habits. Follow-up for mortality until 1996 was established by linking data from the Central Bureau of Genealogy and Statistics Netherlands. We calculated tap water hardness for each postal code using information obtained from all pumping stations in the Netherlands. Tap water hardness was categorized as soft [< 1.5 mmol/L calcium carbonate (CaCO3)], medium hard (1.62.0 mmol/L CaCO3), and hard (> 2.0 mmol/L CaCO3). The multivariate case-cohort analysis was based on 1,944 IHD mortality and 779 stroke mortality cases and 4,114 subcohort members.

RESULTS

For both men and women, we observed no relationship between tap water hardness and IHD mortality [hard vs. soft water: hazard ratio (HR) = 1.03; 95% confidence interval (CI), 0.851.28 for men and HR = 0.93; 95% CI, 0.711.21 for women) and stroke mortality (hard vs. soft water HR = 0.90; 95% CI, 0.661.21 and HR = 0.86; 95% CI, 0.621.20, respectively). For men with the 20% lowest dietary magnesium intake, an inverse association was observed between tap water magnesium intake and stroke mortality (HR per 1 mg/L intake = 0.75; 95% CI, 0.610.91), whereas for women with the 20% lowest dietary magnesium intake, the opposite was observed.

CONCLUSIONS

We found no evidence for an overall significant association between tap water hardness, magnesium or calcium concentrations, and IHD mortality or stroke mortality. More research is needed to investigate the effect of tap water magnesium on IHD mortality or stroke mortality in subjects with low dietary magnesium intake.

Dietary palm olein oil augments cardiac antioxidant enzymes and protects against isoproterenol-induced myocardial necrosis in rats

Wistar rats, 150–200g, of either sex, were fed daily with commercial rat diet supplemented with palm olein oil in two doses (5% v/w (n = 16) and 10% v/w (n = 16) of diet) for 30 days. Control rats (n = 16) were fed with normal diet. On the 29th and 30th days, 8 rats from each group were administred isoproterenol (85 mg/kg, s.c., 24-h interval). On the 31st day, all rats were sacrificed and myocardial tissues were studied for thiobarbituric acid reactive substances (TBARS), antioxidant enzymes and light microscopic changes, along with the ferric-reducing ability of plasma (FRAP). A significant rise in myocardial superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) activity and FRAP level were observed in rats fed with palm olein oil. Isoproterenol caused an increase in myocardial oxidative stress in control rats, as evidenced by an increase in myocardial TBARS level, reduction in FRAP and myocardial SOD, catalase and GPx activity, along with focal necrosis of cardiac muscle fibres on light microscopy. The rise in myocardial TBARS and depletion of SOD and catalase activity following isoproterenol administration were prevented in palm-olein-oil-supplemented diet-fed rats at both doses. Isoproterenol-induced myocardial light-microscopic changes were also prevented in the treated groups. The results suggest that dietary palm olein oil caused augmentation of myocardial antioxidant enzymes and protected against isoproterenol-induced myocardial necrosis and associated oxidative stress.

Preventive effect of S-allyl cysteine sulphoxide (Alliin) on mitochondrial dysfunction in normal and isoproterenol induced cardiotoxicity in male Wistar rats: a histopathological study

This study was undertaken to evaluate the preventive role of S-allyl cysteine sulphoxide (SACS) in isoproterenol (ISO)-induced cardiotoxicity in male Wistar rats. Myocardial infarction was induced by subcutaneous injection of ISO (150 mg/kg) once a day for 2 days. SACS (40 and 80 mg/kg) was given as pretreatment orally daily for a period of 35 days using an intragastric tube. SACS pretreatment significantly lowered thiobarbituric acid reactive substances (TBARS) and increased the activities of mitochondrial superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione S-transferase (GST), and the concentration of reduced glutathione (GSH) in myocardial infarcted rats. SACS pretreatment also increased significantly the levels of mitochondrial phospholipids and decreased the levels of mitochondrial cholesterol, free fatty acids (FFAs), triglycerides (TGs) and calcium, and the activity of xanthine oxidase (XOD) in heart. Further, the activities of isocitrate dehydrogenase (ICDH), succinate dehydrogenase (SDH), alpha-ketoglutarate dehydrogenase (alpha-KGDH), NADH-dehydrogenase, and cytochrome C-oxidase were significantly elevated in the mitochondrial fraction of the heart in the SACS-pretreated ISO-induced rats. Oral administration of SACS for a period of 35 days to the normal control rats did not show any significant effect. Histopathological studies of the myocardial tissue showed a protective role of SACS in the myocardial-infarcted rats. The effect at a dose of SACS 80 mg/kg was more effective than the dose 40 mg/kg. The results of the study conclude that SACS protect the mitochondria of the ISO-induced myocardial-infarcted rats.

Detrimental Impact of Trans Fats on Human Health: Stearic Acid-Rich Fats as Possible Substitutes

  Strong evidence demonstrated the negative effect of trans fatty acid (TFA) intake on cardiovascular diseases (CVD), diabetes, systemic inflammation, and hemostasis. As a consequence, different regulatory actions have been developed around the world, aiming to reduce human consumption of TFA. Replacement for TFA functionality requires incorporation of plastic and stable saturated fats; the present options are palm or fully hydrogenated oils. Palm oil has been described as responsible for negative biological effects on serum cholesterol levels and CVD risk. Different epidemiological and clinical studies recommend reduction of saturated fatty acid (SFA) intake, mainly myristic and palmitic acids. Experimental evidence strongly suggests that stearic acid is a wholesome substitute for TFAs and other SFAs in food manufacturing. In this article, biological effects of stearic acid on human health are reviewed in comparison to TFAs, SFAs, and unsaturated fatty acids. Current revised understanding on dietary intake, digestion, and absorption is also covered.

Effect of dietary Rhodobacter capsulatus on cholesterol concentration and fatty acid composition in broiler meat

The study was designed to investigate the effects of dietary Rhodobacter capsulatus on cholesterol concentration and fatty acid composition in broiler meat. A total of 45 two-week-old male broiler chicks were randomly assigned into 3 treatment groups and fed ad libitum diets supplemented with 0 (control), 0.02, and 0.04% R. capsulatus for a 6-wk feeding period. The results of this study revealed that the supplementation of 0.04% R. capsulatus in diet reduced (P < 0.05) cholesterol and triglyceride concentrations in broiler meat. The concentrations (expressed as a percentage of total fatty acids) of oleic acid (18:1), linoleic acid (18:2), and linolenic (18:3) acid in thigh muscle and breast muscle were higher (P < 0.05) in the broilers fed the 0.04% R. capsulatus supplemented diet than in the broilers fed the control diet. The ratio of unsaturated fatty acids to saturated fatty acids was greater (P < 0.05) in both muscles of broilers fed the 0.04% R. capsulatus supplemented diet than the control diet. In addition, the concentrations of serum cholesterol and triglyceride, and hepatic cholesterol and triglyceride were also reduced (P < 0.05) by dietary R. capsulatus. Compared with the control diet, the 0.04% R. capsulatus supplemented diet reduced (P < 0.05) the ratio of low-density lipoprotein-cholesterol to high-density lipoprotein-cholesterol. Moreover, the supplementation of R. capsulatus in broiler diets did not show any adverse effect on production performance. Therefore, these results conclude that the application of R. capsulatus into diet may be feasible to reduce cholesterol concentration and improve the ratio of unsaturated fatty acids to saturated fatty acids in broiler meat.

Simulation of prospective phytosterol intake in Germany by novel functional foods

A blood cholesterol-lowering margarine containing plant sterolesters was the first functional food placed on the European food market pursuant to the regulation (EC) 258/97. In the following years nine further applicants submitted the request to add plant sterol compounds to dairy products, cheeses, bakery products, sausages, plant oils and other products. The European Scientific Committee on Food (SCF) declared a precautionary intake limit of 3 g plant sterols per d by multiple dietary sources. Using the consumption data of the German National Food Consumption Study, carried out from 1985 to 1988 with 23 209 participants, we hypothetically added 0·3–2 g plant sterols to usual daily servings of ten different food products, selected from the novel food applications. We calculated the prospective plant sterol intake regarding each kind of enriched food and by stepwise accumulation of different functional foods in three enrichment scenarios. Within our enrichment context we find a phytosterol intake satiation, if multiple plant sterol-enriched foods are eaten. An enrichment amount of 2 g plant sterols per proposed food serving size results in an intake maximum of 13 g/d.

Effects of soy or milk protein durign a high-fat feeding challenge on oxidative stress, inflammation, and lipids in healthy men

Soy isoflavones may impede atherogenic processes associated with cardiovascular disease. Research suggests that the postprandial generation of TG-rich remnants contributes to the development of atherosclerosis. The purpose of the current study was to determine if 39 g soy (85 mg aglycone isoflavones, treatment) compared with 40 g milk protein (0 mg aglycone isoflavones, control) in combination with a high-fat meal can modify postprandial, atherogenic-associated events and biomarkers for oxidative stress, inflammation, and thrombosis. Fifteen healthy men (20-47 yr) participated in a double-blind cross-over meal-challenge study occurring on two nonconsecutive days. The study meals consisted of two high-fat apple muffins consumed with either a soy or milk shake (229 mL, 41% fat, 41% carbohydrate, and 18% protein). Blood samples were obtained at baseline (fasted) and hours two, four, and six postprandial. Plasma TG significantly increased in both treatment and control meal challenges compared with baseline. There were no significant differences (P > 0.05) between treatment (soy) and control (milk) for ex vivo copper-induced LDL oxidation, serum C-reactive protein, serum interleukin-6 (IL-6), serum fibrinogen, or plasma lipids (total cholesterol, HDL, LDL, TG). IL-6-concentrations significantly decreased as a function of time during either meal challenge (P = 0.005). These data suggest that consumption of soy or milk protein in conjunction with a high-fat meal does not acutely modify postprandial oxidative stress, inflammation, or plasma lipid concentrations in young, healthy men.

Stearic, oleic, and linoleic acids have comparable effects on markers of thrombotic tendency in healthy human subjects

Because human studies concerning the effects of stearic acid on thrombotic tendency are inconsistent, we compared the effects of stearic acid with those of its unsaturated derivatives, oleic acid and linoleic acid. In this randomized, crossover study, 45 subjects (27 women and 18 men) consumed, in random order, 3 experimental diets, each for 5 wk. Diets contained approximately 38% of energy as fat. Dietary compositions were the same except for 7% of energy from stearic, oleic, or linoleic acids. At the end of each period, ex vivo and in vitro platelet aggregation, and variables of coagulation, fibrinolysis, and hematology were evaluated. In men, ex vivo platelet aggregation time as measured by filtragometry (P = 0.036 for diet effects) was favorably prolonged during consumption of the linoleic acid diet compared with the stearic acid diet (P = 0.040), but there was no difference with consumption of the oleic acid diet (P = 0.198). In vitro platelet aggregation induced by collagen and ADP, and variables of coagulation (factor VII amidolytic activity and concentrations of fibrinogen and prothrombin fragment 1 and 2) and fibrinolysis [plasminogen activator inhibitor (PAI) activity and concentrations of tissue plasminogen activator (tPA)/PAI-1 complexes] did not differ among the 3 diets. The mean platelet volume of the subjects decreased during consumption of the stearic acid diet by 0.32 fL compared with the oleic acid diet (P < 0.001) and by 0.35 fL compared with the linoleic acid diet (P < 0.001). In conclusion, our results do not suggest that stearic acid is highly thrombogenic compared with oleic and linoleic acids.

Coenzyme Q10 Protects From Aging-Related Oxidative Stress and Improves Mitochondrial Function in Heart of Rats Fed a Polyunsaturated Fatty Acid (PUFA)-Rich Diet

Coenzyme Q(10) supplementation on age-related changes in oxidative stress and function of heart mitochondria in rats fed a polyunsaturated fatty acid (PUFA)-rich diet was investigated. Two groups of rats were fed for 24 months on a PUFA-rich diet, differing in supplementation or not with coenzyme Q(10). Animals were killed at 6, 12, or 24 months. Fatty-acid profile, hydroperoxides, alpha-tocopherol, coenzyme Q, catalase and glutathione peroxidase activities, and cytochromes a+a(3), b, c+c(1) and cytochrome c oxidase activity were measured. Coenzyme Q(10)-supplemented animals showed lower hydroperoxide levels; higher content and/or activity of alpha-tocopherol, coenzyme Q, and catalase; and a slightly lower decrease in mitochondrial function. According to that, previously reported positive effects of coenzyme Q supplementation on the life span of rats fed a PUFA-rich diet might be a consequence, at least in part, of a lower oxidative stress level and perhaps, to a minor extent, of a smaller decrease in mitochondrial function.

Cytomegalovirus infection aggravates atherogenesis in apoE knockout mice by both local and systemic immune activation

Since the 1970s, cytomegalovirus (CMV) infection has been associated with atherosclerotic disease. However, the exact contribution of the virus remains uncertain. In this article we describe both a direct and indirect immune-mediated effect of the virus on the disease process. Eight-week-old apolipoprotein E (apoE) knockout mice were infected with mouse CMV (MCMV) or mock injected, and they were sacrificed at 2 and 20 weeks post-injection (p.i.) to study atherosclerosis, vascular wall IFNgamma and TNFalpha expression and MCMV spread. To study plasma IFNgamma and TNFalpha levels, blood was collected at 1, 2, 4 and 6 days p.i. in addition to days of sacrifice. Plasma cytokine levels were increased after MCMV infection at early time points and decreased to mock levels at 2 and 20 weeks p.i. At 2 weeks p.i., more aortic arch samples showed local cytokine expression after MCMV infection. The number of early atherosclerotic lesions and the percentage of mice containing early lesions were increased at 2 weeks p.i., while at 20 weeks p.i., the MCMV-induced effect on atherogenesis was seen on the late lesions. In conclusion, MCMV infection induces a systemic immune response reflecting an indirect effect of MCMV infection on atherosclerosis in addition to a local aortic immune response reflecting a direct effect of the virus on the atherosclerotic process.

Lipolytic PPAR activation: new insights into the intersection of triglycerides and inflammation?

PURPOSE OF REVIEW

To examine connections between triglyceride metabolism and inflammation, especially as they relate to transcriptional regulation through peroxisomal proliferator activated receptors activation.

RECENT FINDINGS

Peroxisomal proliferator activated receptors, members of the steroid hormone nuclear receptor family, have been of particular interest as a mechanism through which different dietary components might control gene expression. Extensive prior work has defined the central role peroxisomal proliferator activated receptors play in many key metabolic responses, including glucose control and lipid metabolism. Emerging evidence suggests peroxisomal proliferator activated receptor activation may limit inflammation and atherosclerosis. The demonstration that certain fatty acids can activate peroxisomal proliferator activated receptors belies the potential link between nutritional components and peroxisomal proliferator activated receptor responses. Interest in this connection had been heightened by recent evidence that lipolysis in certain situations can both generate peroxisomal proliferator activated receptor ligands and limit some known inflammatory responses.

SUMMARY

Lipolytic peroxisomal proliferator activated receptor activation suggests new ways in which to reconsider triglycerides and the distal consequences of their metabolism, including the possible effects on inflammation and atherosclerosis.

Chronic oral administration of raw garlic protects against isoproterenol-induced myocardial necrosis in rat

Wistar albino rats (150-200 g) were fed raw garlic homogenate orally in three different doses (125, 250, 500 mg/kg/day) for 30 days. Isoproterenol (85 mg/kg, s.c. 2 doses at 24-h interval, animals sacrificed after 24 h of last injection) induced myocardial necrosis in control rats and after 30 days of garlic feeding. Myocardial oxidative stress was evident following isoproterenol administration by reduction in myocardial superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities along with a rise in plasma thiobarbituric acid reactive substances (TBARS). Myocardial necrosis was evident from the light microscopic and ultrastructural changes, along with a rise in plasma lactate dehydrogenase (LDH). Significant preservation of myocardial SOD activity was observed in all the garlic-fed rats. However, there was no significant change in myocardial reduced glutathione level and GPx activity in any of the treated groups. Significant reduction in plasma TBARS and LDH levels was observed in the 500 mg/kg garlic treated group. Isoproterenol-induced myocardial morphological changes were least in the 250 and 500 mg/kg garlic treated groups. The results suggest that chronic oral administration of raw garlic offered protection against isoproterenol-induced myocardial necrosis and associated oxidative stress.

Dietary risk markers that contribute to the aetiology of hypertension in black South African children: the THUSA BANA study

Although clinical hypertension occurs less frequently in children than in adults, ample evidence supports the concept that the roots of essential hypertension extend back to childhood. Since little is available in the literature on causal dietary factors of hypertension in children, this study hypothesised that certain dietary factors can be identified as risk markers that might contribute to the aetiology of hypertension in black children. Children aged 10-15 years were randomly selected from 30 schools in the North West Province from 2000 to 2001. These children comprised 321 black males and 373 females from rural to urbanised communities, of which 40 male and 79 female subjects were identified with high-normal to hypertensive blood pressure. Blood pressure was measured with a Finapres apparatus and data were analysed with the Fast Modelflo software program to provide systolic, diastolic and mean blood pressure. A 24-h dietary recall questionnaire and weight and height measurements were taken. In a stepwise regression analysis, the following variables were significantly associated (P < or = 0.05) with blood pressure parameters of hypertensive males: biotin, folic acid, pantothenic acid, zinc and magnesium. Energy, biotin and vitamin A intakes were significantly associated with blood pressure parameters of hypertensive females. No significant dietary markers were indicated for any of the normotensive groups. Dietary intakes of all of these nutrients were well below the dietary reference intakes. In conclusion, the dietary results coupled with the cardiovascular parameters of this study identified folic acid and biotin as risk markers that could contribute to the aetiology of hypertension in black persons. The low intakes of these nutrients, among others, is a matter of serious concern, as is the increasing tendency towards urbanisation.

Nutrição e exercício na prevenção e controle das doenças cardiovasculares

As doenças cardiovasculares constituem a principal causa de mortalidade no mundo e o seu crescimento significativo nos países em desenvolvimento alerta para o potencial impacto nas classes menos favorecidas. São influenciadas por um conjunto de fatores de risco, alguns modificáveis mediante alterações no estilo de vida, como a dieta adequada e o exercício regular. O objetivo da presente revisão é abordar esses aspectos a fim de prevenir e controlar as doenças cardiovasculares. O consumo de vegetais, frutas, grãos integrais, soja, azeite e peixes deve ser aumentado, ainda que limitando a quantidade de gordura. Os alimentos ricos em ácidos graxos saturados e trans devem ser evitados, assim como o uso excessivo de sal e bebidas alcoólicas. Além do exercício aeróbio, as atividades contra resistência vêm aumentando sua importância na reabilitação cardíaca. Essas mudanças de estilo de vida deveriam ser prioridades na Saúde Pública a fim de deter o avanço das doenças cardiovasculares em nosso país.

Consumption of added fats and oils in the European Prospective Investigation into Cancer and Nutrition (EPIC) centres across 10 European countries as assessed by 24-hour dietary recalls

OBJECTIVE

To evaluate the consumption of added fats and oils across the European centres and countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC).

DESIGN AND SETTING

24-Hour dietary recalls were collected by means of standardised computer-guided interviews in 27 redefined EPIC centres across 10 European countries.

SUBJECTS

From an initial number of 36 900 subjects, single dietary recalls from 22 924 women and 13 031 men in the age range of 35-74 years were included.

RESULTS

Mean daily intake of added fats and oils varied between 16.2 g (Varese, Italy) and 41.1 g (Malmö, Sweden) in women and between 24.7 g (Ragusa, Italy) and 66.0 g (Potsdam, Germany) in men. Total mean lipid intake by consumption of added fats and oils, including those used for sauce preparation, ranged between 18.3 (Norway) and 37.2 g day-1 (Greece) in women and 28.4 (Heidelberg, Germany) and 51.2 g day-1 (Greece) in men. The Mediterranean EPIC centres with high olive oil consumption combined with low animal fat intake contrasted with the central and northern European centres where fewer vegetable oils, more animal fats and a high proportion of margarine were consumed. The consumption of added fats and oils of animal origin was highest in the German EPIC centres, followed by the French. The contribution of added fats and oils to total energy intake ranged from 8% in Norway to 22% in Greece.

CONCLUSIONS

The results demonstrate a high variation in dietary intake of added fats and oils in EPIC, providing a good opportunity to elucidate the role of dietary fats in cancer aetiology.

Drinking water and cardiovascular disease

A link between cardiovascular disease (CVD) mortality and the hardness of drinking water (DW) is suggested by about 30 epidemiological studies performed worldwide in the general population since 1957. This review examines the main ecological studies, case-control studies and cohort studies, published between 1960 and 2000. Attention is paid to the problem of interpretation of this typical result of environmental epidemiology. Some studies focused on the role played by inorganic elements known as DW contaminants (mainly, As, Pb) and above all on the role of the magnesium content of DW and its cardioprotective effects. To date, it would be impossible to understand this environmental findings without large intervention studies performed in well-controlled public health programs.

Chia seed (Salvia hispanica L.) as an omega-3 fatty acid source for broilers: influence on fatty acid composition, cholesterol and fat content of white and dark meats, growth performance, and sensory characteristics

Five thousand four hundred, 1-d-old, male, Ross 308, broiler chicks were fed for 49 d to compare diets containing 10 and 20% chia (Salvia hispanica L.) seed to a control diet. Cholesterol content, total fat content, and fatty acid composition of white and dark meats were determined at the end of the trial. A taste panel assessed meat flavor and preference. Cholesterol content was not significantly different among treatments; however, the 10% chia diet produced a lower fat content in the dark meat than did the control diet. Palmitic fatty acid content was less in both meat types when chia was fed, with differences being significant (P < 0.05), except for the white meat and the 20% chia diet. alpha-Linolenic fatty acid was significantly higher (P < 0.05) in the white and dark meats with the chia diets. Chia significantly lowered the saturated fatty acid content as well as the saturated:polyunsaturated fatty acid and omega-6:omega-3 ratios of the white and dark meats compared to the control diet. No significant differences in flavor or preference ratings were detected among diets. Body weight and feed conversion were significantly lower with the chia diets than with the control, with weight reductions up to 6.2% recorded with the 20% chia diet.

A critical assessment of some biomarker approaches linked with dietary intake

In this review many examples are given of the complexities involved in using some biomarkers in relation to assessing the effects of dietary exposure, when there is frequently a need to determine changes following long-term low level exposure to dietary components. These range from understanding why the biomarker might be valuable and how best it can be measured, to the pitfalls which can occur in the interpretation of data. Analytical technique is considered in relation to folate and selenium, and flavonoid and carotenoid species are used to illustrate how the metabolism of a compound may alter the validity or adequacy of a marker. Vitamin A is discussed in relation to the difficulties which can arise when there are several biomarkers that may be available to assess exposure to one nutrient. Vitamin B12 is discussed in relation to the dietary choices made by individuals. Possible interactions and the role of measuring total antioxidant capacity is considered in some detail. In contrast to most nutrients, there is a marked lack of biomarkers of either exposure or effect for most non-nutrients. The role of biological effect monitoring is considered for dietary contaminants, fumonisins and polyhalogenated aromatic hydrocarbons. Aflatoxins are discussed to exemplify food contaminants for which the biomarker approach has been extensively studied. Finally some compounds which are deliberately added to foods and some which appear as processing contaminants are each considered briefly in relation to the requirement for a biomarker of exposure to be developed.

A review of latest research findings on the health promotion properties of tea

Important progress has been made in the past five years concerning the effects of green and black tea on health. Experimentation with new accurate tools provide useful information about the metabolism of tea components in the body, their mode of action as antioxidants at the cellular level and their protective role in the development of cancer, cardiovascular disease and other pathologies. The use of tea components as nutraceuticals and functional foods are also discussed.

Bioanalysis of PUFA metabolism and lipid peroxidation in coronary atherosclerosis

Twenty eight men (age 34-77 years) who underwent an elective coronary angiography for coronary artery disease (CAD), were studied. They were divided into group A (luminal narrowing < 50%; n = 11) and group B (luminal narrowing > 50%; n = 17). Capillary gas chromatography was used for determination of fatty acids. Retinol and alpha-tocopherol were analyzed by reversed-phase high-performance liquid chromatography (HPLC), other parameters were determined spectrofluorometrically and spectrophotometrically. Severe coronary atherosclerosis in group B was associated with higher serum low density lipoprotein/high density lipoprotein (LDL/HDL) cholesterol ratio, triacylglycerols, and phospholipids (P < 0.05). Erythrocyte membrane fatty acids C14:0, C16:1 and C22:6n3 were significantly higher in group B (P < 0.05). We found significantly higher plasma polyunsaturated fatty acids (PUFA) C18:3n6 in group B, whereas plasma linoleic acid was not changed significantly. There was a significant increase of IDL-C18:0, LDL-C14:0 and HDL-C22:6n3 PUFA in group B. We conclude that disturbances in saturated fatty acids (SUFA) and PUFA metabolism are associated with coronary atherogenesis. Such abnormalities may include enhanced extrahepatic transport of C14:0 SUFA via LDL and its incorporation into cell membranes, and enhanced clearance of anti atherosclerotic C22:6n3 PUFA via serum HDL.

Dietary treatment of the metabolic syndrome--the optimal diet

The treatment of the metabolic syndrome aims to improve insulin sensitivity and correct/prevent the associated metabolic and cardiovascular abnormalities. Since many individuals with the metabolic syndrome are overweight, dietary treatment should be primarily focused on weight reduction. This approach can improve insulin sensitivity and exert beneficial effects on all the other abnormalities clustering in the syndrome. Insulin sensitivity can also be influenced by diet composition. In this respect, the specific effects of the quality of dietary fat are of great interest, given the considerable evidence in experimental animals that saturated fat in the diet may lead to insulin resistance. In man, there is indirect evidence that a higher saturated fat intake is associated with impaired insulin action. Human studies have also attempted to evaluate the relationship between total fat intake and insulin sensitivity. They are consistent in showing that fat intake is correlated with both plasma insulin values (positively) and insulin sensitivity (negatively). However, these correlations are largely mediated by body weight. Conversely, intervention studies are consistent in showing that when total fat intake is moderately increased (from 20 to 40%), no major effect is observed on insulin sensitivity. We have recently undertaken a large, multicentre intervention study in 162 healthy individuals given either a high-saturated-fat or a high-monounsaturated-fat diet for 3 months. It shows that a high-monounsaturated-fat diet significantly improves insulin sensitivity compared to a high-saturated-fat diet. However, this beneficial effect of monounsaturated fat disappears when total fat intake exceeds 38% of total energy. Independently of its effects on insulin sensitivity, diet composition can influence the factors clustering in the metabolic syndrome. Dietary carbohydrate increases blood glucose levels, particularly in the postprandial period, and consequently also insulin levels and plasma triglycerides. The detrimental effects of a high-carbohydrate diet on plasma glucose/insulin, triglyceride/HDL or fibrinolysis occur only when carbohydrate foods with a high glycaemic index are consumed, while they are abolished if the diet is based largely on fibre-rich, low-glycaemic-index foods. In conclusion, weight reduction is a powerful measure for the treatment of metabolic syndrome. Moreover, the diet for the treatment of the metabolic syndrome should be limited in the intake of saturated fat, while high fibre/low-glycaemic-index foods should be used without specific limitations. Moderate amounts of monounsaturated fat could be permitted as they do not induce detrimental metabolic effects.

Functional food science and substrate metabolism

The present review addresses the role of food constituents in the aetiology of metabolic conditions and chronic diseases, mostly related to energy metabolism and substrate regulation, such as obesity and non-insulin-dependent diabetes mellitus. Second, attention is paid to malnutrition, a major cause of mortality and morbidity in developing countries, which may be a cause of concern in Europe because of the increasing number of elderly people in the population. Finally, the role of diet during exercise, a condition of enormous substrate demands, is evaluated. Based on a critical evaluation of the existing knowledge in the literature, implications for future research in relation to functional foods are discussed.