Dietary fats and hypertension. Focus on fish oil

Dietary modification for prevention and control of high blood pressure

Hypertension (HT) remains the leading cause of cardiovascular and premature death around the world. Diet is one of the important factors that contributes to the development of HT. We review the current evidence of how different dietary factors may influence blood pressure (BP) and consequent development of HT. There is evidence that BP is positively associated with higher consumption of sodium, alcohol, animal-based protein such as red meat, low-quality carbohydrates such as sugar-sweetened beverages, and saturated fatty acids. On the contrary, other dietary constituents have BP-lowering effects. These include potassium, calcium, magnesium, yogurt, eggs, plant-based proteins such as soy and legumes, mono- and polyunsaturated fatty acids, and high-quality carbohydrates such as whole grain and fruits. Dietary fibre is unrelated to BP lowering, possibly due to the different mechanisms of various types of fibre. The effects of caffeine, hibiscus tea, pomegranate, and sesame on BP are also unclear as evidence is hard to assess due to the varying concentrations and different types of drinks used in studies. Implementing dietary changes such as the Dietary Approaches to Stop Hypertension (DASH diet) or adopting a Mediterranean diet has been shown to reduce and control BP. Although the effect of diet on BP control has been established, the optimal amount of each dietary component and consequent ability to devise a personalized diet for HT prevention and BP control for different populations still require further investigation.

Potential roles of polyunsaturated fatty acid-enriched diets in modulating social stress-like features

Fish oil or its major constituents, namely omega-3 poly-unsaturated fatty acid (n3-PUFA), are popular supplements to improve neurogenesis, neuroprotection, and overall brain functions. Our objective was to probe the implications of fat enriched diet with variable PUFAs supplements in ameliorating social stress (SS). We fed mice on either of the three diet types, namely the n-3 PUFA-enriched diet (ERD, n3:n6= 7:1), a balanced diet (BLD, n3:n6= 1:1) or a standard lab diet (STD, n3:n6= 1:6). With respect to the gross fat contents, the customized special diets, namely ERD and BLD were extreme diet, not reflecting the typical human dietary composition. Aggressor-exposed SS (Agg-E SS) model triggered behavioral deficiencies that lingered for 6 weeks (6w) post-stress in mice on STD. ERD and BLD elevated bodyweights but potentially helped in building the behavioral resilience to SS. STD adversely affected the gene networks of brain transcriptomics associated with the cell mortality, energy homeostasis and neurodevelopment disorder. Diverging from the ERD's influences on these networks, BLD showed potential long-term benefits in combatting Agg-E SS. The gene networks linked to cell mortality and energy homeostasis, and their subfamilies, such as cerebral disorder and obesity remained at the baseline level of Agg-E SS mice on BLD 6w post-stress. Moreover, neurodevelopment disorder network and its subfamilies like behavioral deficits remained inhibited in the cohort fed on BLD 6w post Agg-E SS.

Saltwater fish consumption pattern and incidence of hypertension in adults: A study on the population of Gresik coast, Indonesia

Background: Hypertension is one of the main causes of morbidity and mortality in the Indonesian population, characterized by an increasing number of sufferers each year. Curtailing saltwater fish consumption pattern is an optional effort to prevent hypertension, as most users tend to attribute little or no attention to this possibility. Design and Methods: The purpose of this study, therefore, was to analyze the correlation between saltwater fish consumption pattern and the incidence of hypertension in adults, using analytic research design with cross sectional approach. Results: The analysis showed the dominance of female respondents (63%), aged 36-45 years (60%), graduated from senior high school (33.8%), working as housewives (32.5%), monthly income above the average (63.6%), absence of hypertension history (80.5%), eat sea fish often as a side dish (59.7%), and pre hypertension (59.1%). Furthermore, data analysis showed a Pvalue of 0.000, indicating the presence of a significant relationship between the consumption pattern of sea fish and the incidence of hypertension. Conclusions: The results of this study show the high consumption of saltwater fish by most people living in Kebungson, Gresik Village. This correlates with the incidence of hypertension in indigenous adults, as the majority was classified with prehypertension levels.

Omega-3 fatty acids as adjunctive therapeutics: prospective of nanoparticles in its formulation development

Omega-3 polyunsaturated fatty acids (ω-3-PUFAs) are dietary components that have been extensively recognized for their therapeutic value and have shown diverse therapeutic effects including anti-inflammatory, antiarrhythmic, antithrombotic, immunomodulatory and antineoplastic activities. Most of the ω-3-PUFAs are obtained through diet or supplements because the body does not synthesize them. The high instability of ω-3-PUFAs to oxidative deterioration, lower bioavailability at the target tissues and reduced bioactivity of ω-3-PUFAs is an impediment for achieving their therapeutic potential. The present review provides an overview of potential therapeutic activities of ω-3-PUFAs and different novel technical approaches based on nanotechnology, which have been emphasized to overcome instability problems as well as enhance the bioactivity of ω-3-PUFAs. Future prospects related to this area of research are also provided.

The Use of Nutraceuticals to Counteract Atherosclerosis: The Role of the Notch Pathway

Despite the currently available pharmacotherapies, today, thirty percent of worldwide deaths are due to cardiovascular diseases (CVDs), whose primary cause is atherosclerosis, an inflammatory disorder characterized by the buildup of lipid deposits on the inside of arteries. Multiple cellular signaling pathways have been shown to be involved in the processes underlying atherosclerosis, and evidence has been accumulating for the crucial role of Notch receptors in regulating the functions of the diverse cell types involved in atherosclerosis onset and progression. Several classes of nutraceuticals have potential benefits for the prevention and treatment of atherosclerosis and CVDs, some of which could in part be due to their ability to modulate the Notch pathway. In this review, we summarize the current state of knowledge on the role of Notch in vascular health and its modulation by nutraceuticals for the prevention of atherosclerosis and/or treatment of related CVDs.

The Use of Complementary and Alternative Medicine in Hospitalized Patients with Type 2 Diabetes Mellitus in Israel

INTRODUCTION

The use of complementary and alternative medicine (CAM) has been on the rise in recent years in the general population, as well as among patients with chronic diseases such as diabetes mellitus. The aim of this study was to add information regarding the use of CAM in patients with type 2 diabetes mellitus (DM2) in Israel and explore possible interactions between CAM and prescription medication (PM).

METHODS

This is a cross-sectional study based on questionnaires. The study included type 2 diabetic patients who were hospitalized in an internal medicine department at Assaf Harofeh Medical Center, Zerifin, Israel, between December 2013 and December 2014. Possible interactions between CAM and PM were evaluated by a clinical pharmacist and a clinical pharmacologist.

RESULTS

Out of 111 diabetic patients, 23.4% used CAM. There was no significant difference between the consumers and nonconsumers in terms of age, education, income, smoking, or alcohol habits. Only 11 of the 26 CAM consumers informed their physician regarding the use. We found possible drug-herb interactions in 19 of the 26 CAM consumers. A major interaction was found between omega-3 and antiaggregants and was encountered in 7 (26.9%) of the CAM consumers. Other minor and major interactions were found with vitamin E, ginkgo-biloba, co-enzyme Q10, green tea, fenugreek seeds, pyridoxine, and dandelion.

CONCLUSIONS

Since CAM consumption is on the rise, it is desirable to improve our knowledge concerning their potential effects and adverse effects, especially in conjunction with PM. Given the complexity of pharmaceutics in patients with chronic diseases, among them patients with DM, the use of supplementary medicine cannot be ignored.

Dietary modulators of statin efficacy in cardiovascular disease and cognition

Cardiovascular disease remains the leading cause of morbidity and mortality in the United States and other developed countries, and is fast growing in developing countries, particularly as life expectancy in all parts of the world increases. Current recommendations for the prevention of cardiovascular disease issued jointly from the American Academy of Cardiology and American Heart Association emphasize that lifestyle modification should be incorporated into any treatment plan, including those on statin drugs. However, there is a dearth of data on the interaction between diet and statins with respect to additive, complementary or antagonistic effects. This review collates the available data on the interaction of statins and dietary patterns, cognition, genetics and individual nutrients, including vitamin D, niacin, omega-3 fatty acids, fiber, phytochemicals (polyphenols and stanols) and alcohol. Of note, although the available data is summarized, the scope is limited, conflicting and disparate. In some cases it is likely there is unrecognized synergism. Virtually no data are available describing the interactions of statins with dietary components or dietary pattern in subgroups of the population, particularly those who may benefit most were positive effects identified. Hence, it is virtually impossible to draw any firm conclusions at this time. Nevertheless, this area is important because were the effects of statins and diet additive or synergistic harnessing the effect could potentially lead to the use of a lower intensity statin or dose.

Blood pressure decrease with ingestion of a soya product (kinako) or fish oil in women with the metabolic syndrome: role of adiponectin and nitric oxide

The aim of the present study was to verify the effects of fish oil and a soya-based product on inflammatory markers and endothelial function measured by NO in women with the metabolic syndrome (MetS). A total of sixty-five women (mean age: 47·9 (sd9·98) years) were studied in a 90-d parallel, randomised design. A control group maintained their usual diet; the second group received 29 g/d of soyabean (kinako); the third group received 3 g/d of fish oiln-3 fatty acids; and the fourth group received fish oil (3 g/d) and kinako (29 g/d). Anthropometric, blood pressure (BP), inflammatory markers, anti-inflammatory marker (adiponectin) and NO concentrations were evaluated. In relation to the baseline values, the group that received fish oil and kinako concomitantly presented a statistically significant decrease in systolic BP (SBP;P < 0·05), whereas there was a significant decrease in diastolic BP (DBP) in the control group (P < 0·05), kinako group (P < 0·01) and fish oil group (P < 0·01) after 90 d. There was a significant increase in adiponectin (P < 0·01) and NO values (P < 0·05) after 90 d in the kinako and fish oil groups. Differences between treatment groups verified a significant decrease (P < 0·05) in DBP in the kinako group after 90 d when compared to the results obtained from the fish oil and kinako groups. In conclusion, the findings of increased serum adiponectin and NO metabolite levels after 90 d, both in the fish oil and soya groups, reinforce the importance of the influence of adiponectin and NO levels on BP decrease in patients with the MetS.

Fish oil, selenium and mercury in relation to incidence of hypertension: a 20-year follow-up study

OBJECTIVES

Long-chain omega-3 polyunsaturated fatty acids (LCω3PUFAs), selenium (Se) and mercury (Hg) are three important components in fish. The cardioprotective effect of LCω3PUFA intake has been recognized; however, the hypothesis that this benefit may be greatest with high Se and low Hg levels has not been investigated.

DESIGN

A cohort of 4508 American adults aged 18-30, without hypertension at baseline in 1985, were enrolled. Six follow-ups were conducted at examinations in 1987, 1990, 1992, 1995, 2000 and 2005. Diet was assessed by a validated interviewer-administered quantitative food frequency questionnaire at exams in 1985, 1992 and 2005. Incident hypertension was defined as first occurrence at any follow-up examination of systolic blood pressure (BP) ≥ 140 mmHg, diastolic BP ≥ 90 mmHg or taking antihypertensive medication. Toenail clippings were collected in 1987, and Se and Hg levels were quantified by instrumental neutron-activation analysis.

RESULT

Participants in the highest LCω3PUFA intake quartile had a significantly lower incidence of hypertension (hazard ratio: 0.65; 95% CI: 0.53-0.79; P(trend) < 0.01) compared to those in the lowest quartile after adjustment for potential confounders. Docosahexaenoic acid showed a greater inverse association than eicosapentaenoic acid. The inverse association of LCω3PUFA intake with hypertension appeared more pronounced at higher Se and lower Hg levels, although interaction tests were statistically nonsignificant.

CONCLUSIONS

Our findings indicated that LCω3PUFA intake was inversely associated with incidence of hypertension. The prior hypothesis that the potential antihypertensive effect of LCω3PUFA intake varies depending on joint levels of Se and Hg received modest support and cannot be ruled out.

The cardiovascular effects of flaxseed and its omega-3 fatty acid, alpha-linolenic acid

Preventing the occurrence of cardiovascular disease (CVD) with nutritional interventions is a therapeutic strategy that may warrant greater research attention. The increased use of omega (&omega;)-3 fatty acids is a powerful example of one such nutritional strategy that may produce significant cardiovascular benefits. Marine food products have provided the traditional dietary sources of &omega;-3 fatty acids. Flaxseed is an alternative to marine products. It is one of the richest sources of the plant-based &omega;-3 fatty acid, alpha-linolenic acid (ALA). Based on the results of clinical trials, epidemiological investigations and experimental studies, ingestion of ALA has been suggested to have a positive impact on CVD. Because of its high ALA content, the use of flaxseed has been advocated to combat CVD. The purpose of the present review was to identify the known cardiovascular effects of flaxseed and ALA and, just as importantly, what is presently unknown.

Rat heart cannot synthesize docosahexaenoic acid from circulating alpha-linolenic acid because it lacks elongase-2

The extent to which the heart can convert alpha-linolenic acid (alpha-LNA, 18:3n-3) to longer chain n-3 PUFAs is not known. Conversion rates can be measured in vivo using radiolabeled alpha-LNA and a kinetic fatty acid model. [1-(14)C]alpha-LNA was infused intravenously for 5 min in unanesthetized rats that had been fed an n-3 PUFA-adequate [4.6% alpha-LNA, no docosahexaenoic acid (DHA, 22:6n-3)] or n-3 PUFA-deficient diet (0.2% alpha-LNA, nor DHA) for 15 weeks after weaning. Arterial plasma was sampled, as was the heart after high-energy microwaving. Rates of conversion of alpha-LNA to longer chain n-3 PUFAs were low, and DHA was not synthesized at all in the heart. Most alpha-LNA within the heart had been beta-oxidized. In deprived compared with adequate rats, DHA concentrations in plasma and heart were both reduced by >90%, whereas heart and plasma levels of docosapentaenoic acid (DPAn-6, 22:5n-6) were elevated. Dietary deprivation did not affect cardiac mRNA levels of elongase-5 or desaturases Delta6 and Delta5, but elongase-2 mRNA could not be detected. In summary, the rat heart does not synthesize DHA from alpha-LNA, owing to the absence of elongase-2, but must obtain its DHA entirely from plasma. Dietary n-3 PUFA deprivation markedly reduces heart DHA and increases heart DPAn-6, which may make the heart vulnerable to different insults.

Fatty acid consumption and metabolic syndrome components: the GOCADAN study

Fatty acids (FAs) have been related to changes in glucose and lipid metabolism. In this article, the authors assess the association between intake of specific FAs and components of the metabolic syndrome (MS) in adult Eskimos. A total of 691 Inupiat Eskimos (325 men and 366 women), aged 34 to 75 years, were examined as part of the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) study. The investigation included a physical examination, blood pressure measurements, blood sampling under fasting conditions, 2-hour oral glucose tolerance test, and a personal interview including a validated food frequency questionnaire. Components of MS were defined according to the Third Report of the National Cholesterol Education Program Adult Treatment Panel criteria. Consumption of individual FAs showed associations with MS components. Long-chain omega-3 FAs, from fish and sea mammals, were associated with lower blood pressure, serum triglycerides, and 2-hour glucose and higher high-density lipoprotein cholesterol, fasting insulin, and homeostasis model assessment. Saturated fat consumption was associated with higher triglyceride levels and blood pressure. Trans-FA consumption was associated with higher blood pressure. Consumption of long-chain omega-3 FAs from marine sources may improve certain MS components, and thus may reduce risk for cardiovascular disease. High consumption of saturated FAs and trans-FAs may have an adverse effect on MS.

Cardiovascular and endothelial effects of fish oil supplementation in healthy volunteers

Consumption of fish oil (FO) is associated with reduced adverse cardiovascular events. In a randomized, blinded, placebo-controlled trial, 26 subjects (17 men and 9 women; mean age [+/- SD] 31 +/- 3.7 years) received 1 g FO capsule (n = 14) or placebo (1 g of corn oil, n = 12) for 14 days. At day 0 and day 14, heart rate (HR), blood pressure, endothelium-dependent brachial artery flow-mediated vasodilation (EDV), and endothelium-independent nitroglycerin-mediated vasodilation (EIDV) were assessed with ultrasound. FO supplementation resulted in a significant increase in EDV (20.4% +/- 13.2% vs 9.9% +/- 5.4%; P = .036) and EIDV (32.6% +/- 16.8% vs 18.0% +/- 14.9%; P = .043). Resting HR decreased by a mean of 5.9 +/- 9.4 bpm (FO) compared with placebo (mean increase of 0.73 +/- 4.8 bpm [P = .05]). FO supplementation in healthy subjects is associated with improved endothelial function and decreased resting HR.

Fatty acids and CHD

During the last century much evidence has accumulated to suggest that from a public health perspective the type of fat is more important than the amount of fat. Saturated andtrans-fatty acids increase and bothn-6 andn-3 PUFA decrease the risk of CHD. Most of the knowledge about the effects of dietary fatty acids on CHD risk is based on observational studies and controlled dietary experiments with intermediate end points (e.g. blood lipoprotein fractions). Information from high-quality randomised controlled trials on fatty acids and CHD is lacking. The Netherlands Institute for Public Health has calculated the potential health gain that can be achieved if the fatty acid composition of the current Dutch diet is replaced by the recommended fatty acid composition. The recommendations of The Netherlands Health Council are: saturated fatty acids <10% energy intake;trans-fatty acids <1% energy intake; fish consumption (an indicator ofn-3 PUFA) once or twice weekly. Implementation of this recommendation could reduce the incidence of CHD in The Netherlands by about 25 000/year and the number of CHD-related deaths by about 6000/year and increase life expectancy from age 40 years onwards by 0.5 year. These projections indicate the public health potential of interventions that modify the fatty acid composition of the diet.

Current clinical applications of omega-6 and omega-3 fatty acids

BACKGROUND

Recent years have brought a resurgence of research interest in fatty acids, with studied fields running the gamut of human disease. This movement has run in parallel with an increased interest in using nutrition modalities as therapeutic measures, as opposed to their conventional role as energy sources. The aim of this manuscript is to provide a basic review of current clinical applications of omega-6 and omega-3 fatty acids, with a particular focus on the latter.

METHODS

A selective review of the voluminous literature, including randomized controlled trials, meta-analyses, population studies, and case reports, was used to compile data and identify trends in pertinent clinical applications of fatty acid therapy.

CONCLUSIONS

There are a myriad of disorders and maladies that seem to benefit from fatty acid supplementation, specifically omega-3 fatty acids. It has clearly been shown that omega-3 fatty acid supplementation provides a protective benefit in heart disease, and in particular sudden cardiac death. Rheumatoid arthritis (RA) is another disease entity that has been proven to benefit from this nutrition intervention, with improvement in symptoms and diminished nonsteroidal antiinflammatory drug (NSAID) usage. In addition, many psychiatric disorders, particularly schizophrenia and major depressive disorder (MDD), have shown positive results when supplementation has been used as an adjunct to standard pharmacotherapy. The remainder of clinical applications for omega-3 fatty acids requires further investigation. Specifically, according to preliminary clinical evidence, parenteral administration of fatty acids warrants further study.

n-3 fatty acids and cardiovascular disease

The results of prospective cohort studies indicate that consuming fish or fish oil containing the n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is associated with decreased cardiovascular death, whereas consumption of the vegetable oil-derived n-3 fatty acid a-linolenic acid is not as effective. Randomized control trials (RCTs) in the context of secondary prevention also indicate that the consumption of EPA plus DHA is protective at doses <1 g/d. The therapeutic effect appears to be due to suppression of fatal arrhythmias rather than stabilization of atherosclerotic plaques. At doses >3 g/d, EPA plus DHA can improve cardiovascular disease risk factors, including decreasing plasma triacylglycerols, blood pressure, platelet aggregation, and inflammation, while improving vascular reactivity. Mainly on the basis of the results of RCTs, the American Heart Association recommends that everyone eat oily fish twice per week and that those with coronary heart disease eat 1 g/d of EPA plus DHA from oily fish or supplements. Directions for future research include (1) RCTs to confirm the initial trials showing that EPA plus DHA decreases cardiovascular death and additional studies to determine whether this effect is due to EPA, DHA, or the combination; the dosage of the effective components; and whether the mechanism of action in humans is prevention of fatal arrhythmias. (2) Clinical studies to determine whether the reduction in cardiovascular disease risk factors is due to EPA, DHA, or the combination and the dosage of the effective components. (3) Clinical studies to determine whether vegetable oil-derived alpha-linolenic acid added to a diet enriched in n-6 fatty acids can effectively substitute for fish oil-derived EPA plus DHA.

Hypertension prevention: from nutrients to (fortified) foods to dietary patterns. Focus on fatty acids

Diet affects significantly the incidence and severity of cardiovascular diseases and fatty acid intake, in its qualitative as well as quantitative aspects, and influences several risk factors including cholesterol (total, LDL and HDL), triglycerides, platelet aggregation and blood pressure, as evidenced in the 2001 WHO report. This review focuses on the qualitative concern of lipid intake, the various classes of fatty acids of the lipid fraction of the diet, saturated, monounsaturated and polyunsaturated, and their effects on blood pressure. Saturated fat have a bad file and several experimental studies in the rat showed a progressive increase in blood pressure in response to a highly saturated diet. Moreover, a highly saturated diet during gestation led to offspring which, when adults, presented a gender-related hypertension. The mechanism of this effect may be related to the polyunsaturated/saturated ratio (p/s). During the past 20 years, trans fatty acids have been suspected of deleterious health effects, but the investigations have shown that these fatty acids display a biological behaviour close to that of saturated fatty acids (SFA). Moreover, epidemiological investigations did not confirm the relationship between trans fatty acids and cardiovascular pathology. Polyunsaturated fatty acids have been shown to exert a positive action on hypertension. This effect could be attributed to the alteration of the p/s, but mainly to the omega3 polyunsaturated fatty acids (PUFAs). The comparison of several animal models led to the conclusion that long-chain omega3 PUFAs (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) can prevent the increase in blood pressure and reduce established hypertension, but the efficient dose remains an object of discussion. Moreover, the two long-chain omega3 PUFAs, EPA and DHA, display specific effects, which vary with the aetiology of hypertension, because their mechanism of action is different. DHA acts on both blood pressure and heart function (heart rate and ECG) and interferes with the adrenergic function. Conversely, EPA, which is not incorporated in cardiac phospholipids, has no effect on the heart and its mechanism of action is largely unknown. Although it is accepted by the scientific community that the intake of EPA and DHA needs to be increased, we will have to discover new ways to do it, since marine products are the main source of these fatty acids, and this source is not inexhaustible.

The role of omega-3-fatty acids in the prevention of cardiac events

Cardiac disease continues to be a major cause of death in the Western world. Several preventive measures can be implemented to reduce the risk of a cardiac event. One of these measures is diet. A diet that is rich in fatty fish provides a considerable quantity of omega-3-fatty acids. These fatty acids have been shown to reduce the risk of cardiac events such as arrhythmias, stroke and thrombosis. The nurse has a key health education role to play in the promotion of healthy eating in order to reduce the incidence of cardiac events in patients with existing cardiac disease.

The mechanism of action of omega-3 fatty acids in secondary prevention post-myocardial infarction

BACKGROUND

Omega-3 fatty acids from fish and fish oils can protect against coronary heart disease (CHD), which is still the most common cause of death in the Western economies. Evidence from epidemiological and case cohort studies indicate that consumpton of fatty fish and omega-3 fatty acids reduces the risk of cardiovascular mortality.

OBJECTIVE

This article briefly reviews the evidence regarding omega-3 fatty acids and CHD and outlines the mechanisms through which omega-3 fatty acids might confer cardiac benefits over and above the standard secondary prevention strategies.

CONCLUSION

The conclusion reached is that omega-3 fatty acids play a significant role in secondary prevention post-myocardial infarction. The mechanisms through which two of these omega-3 fatty acids, eicosapentaenoic acid and docosahexanoic acid, exert their action appear to be distinct and adjuvant to the available standard secondary prevention therapies. The role to be played by the administration of a newly licensed 90% concentrate EPA + DHA formulation (1 g/day capsule: Omacor) is explored.

Effects of fish oil on hypertension, plasma lipids, and tumor necrosis factor-α in rats with sucrose-induced metabolic syndrome

Dietary fish oil rich in (n-3) fatty acids plays an important role in reducing abnormalities associated with the metabolic syndrome and mortality from coronary heart disease. We investigated the effects of dietary fish oil on the metabolic syndrome in a high-sucrose-fed rat model. The model was achieved by the administration of 30% sucrose in drinking water in male Wistar rats during 21 weeks. After the metabolic syndrome rat model was established, fish oil was administered during 6 weeks. The metabolic syndrome rats showed significant increases in body weight, systolic blood pressure, serum insulin, total lipids, triacylglycerols, cholesterol, free fatty acids, LDL, total proteins, albumin, and serum tumor necrosis factor-alpha (TNF-alpha). They also presented abdominal and epididymal fat accumulation and fatty liver. After fish oil diet administration, metabolic syndrome rats had a significant reduction in blood pressure, serum insulin, triacylglycerols, cholesterol, free fatty acids, and total lipids, but no change was observed in TNF-alpha concentration or fat accumulation. In conclusion, fish oil reversed the alterations on metabolic parameters and blood pressure exerted by sucrose administration, although it had no effect on TNF-alpha production and adiposity. This confirms the theory that the molecular etiology of the metabolic syndrome is multifactorial, as is the effect of n-3 polyunsaturated fatty acids (PUFAs) upon it, having complex and multifaceted actions.

Feeding Laying Hens Seal Blubber Oil: Effects on Egg Yolk Incorporation, Stereospecific Distribution of Omega-3 Fatty Acids, and Sensory Aspects

Seventy-two 26-wk-old Single Comb White Leghorn laying hens were randomly assigned to 36 cages (2 per cage) in a 3-orthogonal 4 x 4 latin square, with the fourth row suppressed, to assess the effect of feeding refined seal blubber oil (SBO, containing 22.2% omega-3 fatty acids) on the fatty acid composition and position in the egg yolk lipids. The experiment was conducted over a period of 9 wk. Eggs were collected and numbered, and the weights were recorded for each week and cage. Eggs collected at wk 5 and 9 were used for total lipid, lipid class, fatty acid, and positional analyses. Sensory evaluation was carried out on eggs collected at wk 6 and 7. Feeding SBO at 1.25% led to an increase (P < 0.0001) in the long-chain omega-3 polyunsaturated fatty acids (LCn3PUFA) and a concomitant decrease (P < 0.0001) in arachidonic acid (ARA) in the egg yolk lipids. Yet this amount of SBO in the diet had no effect (P > 0.1) on the sensory attributes of the egg and on production parameters such as egg weight, number of eggs laid, and feed intake (P > 0.05). When feeding SBO in amounts higher than 1.25% proportionately, a plateau effect of the LCn3PUFA content of the eggs was observed. This appears to be because the PUFA content in the sn-2 position of the phospholipids cannot exceed a certain amount. When this amount is reached, the LCn3PUFA will be increasingly stored in triglycerides. The results presented here clearly indicate how eggs can be produced with optimized composition of LCn3PUFA without affecting (P > 0.1) the sensory properties of the eggs. The procedures elaborated herein provide directly applicable consequences for the food industry.

Dietary n-3 PUFAs affect the blood pressure rise and cardiac impairments in a hyperinsulinemia rat model in vivo

The cardiovascular consequences of eicosapentaenoic acid (EPA)- and docosahexaenoic acid (DHA)-specific intake were evaluated in vivo in a hyperinsulinemia (HI) model induced by dietary fructose intake. Wistar rats were fed a diet containing (or not for control) either EPA or DHA. The rise in blood pressure (BP), heart rate, and ECG were continuously monitored using an intra-abdominal telemetry system. The myocardial phospholipid fatty acid profile was significantly affected by DHA intake but less by EPA intake. The data indicated a reduced rise in BP in both DHA and EPA HI groups compared with controls. This result was confirmed by tail-cuff measurement after 5 wk [133.3 +/- 1.67 and 142.5 +/- 1.12 mmHg in n-3 polyunsaturated fatty acid (PUFA) and control groups, respectively], whereas n-3 PUFA did not affect BP in non-HI rats (116.3 +/- 3.33 mmHg). The heart rate was lower in the HI DHA group than in the other two dietary HI groups. Moreover, DHA induced a significantly shorter QT interval. It is concluded that the cardioactive component of fish oils is DHA through a mechanism that may involve the cardiac adrenergic system.

Role of weight loss and polyunsaturated fatty acids in improving metabolic fitness in moderately obese, moderately hypertensive subjects

OBJECTIVE

While the exact regulatory interactions between blood pressure (BP) and obesity are not completely understood, weight loss provides an alternative to pharmacological treatment of hypertension. The intent of this repeated measures study of mild-moderate hypertensive, moderately obese subjects (34 females/18 males) was to determine if the reduction in BP following weight loss could be further affected by modifying the fatty acid (FA) composition of the hypocaloric diet.

METHODS

BP, insulin sensitivity (Si), and lipid parameters were assessed before and after a 10-week calorie-restricted period. Subjects were randomized to one of three dietary groups differing in FA composition. Reduced body weight was maintained for a further 4 weeks and body composition assessment, BP and heart rate measurements were repeated.

RESULTS

Weight loss (10%) in obese hypertensive subjects resulted in substantial improvements in BP, Si and lipid profile. There was no additional effect on the reduction in BP by the type of FA consumed in the diet. Following weight loss, there was a trend for omega-3 FAs to have a protective effect on fat-free mass loss (compared to omega-6 FA Group and saturated FA Group) and a trend to further enhance Si. There were significant improvements in circulating lipid profiles independent of the dietary FA intervention following the weight loss. The improvements in BP and body composition were maintained during the weight-loss maintenance period. The type of fat consumed had minor differential effects on some of the measured metabolic outcomes.

CONCLUSION

These results provide strong support for modest weight loss as a treatment for hypertension.

Dietary fatty acids effects on sucrose-induced cardiovascular syndrome in rats

Cardiovascular disease is one of the leading causes of morbidity and mortality in Mexico. We investigated the effects of omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids on the metabolic syndrome associated with cardiovascular disease in a high-sucrose-fed rat model. The metabolic syndrome-induced rats showed a significant increase in systolic blood pressure, serum insulin, nonfasting serum triglyceride and serum cholesterol levels. Experimental high-sucrose-fed animals received either a n-3 or n-6 enriched diet or a control diet during 6 weeks. Animals fed the n-3 enriched diet had a significant reduction in blood pressure and serum insulin and triglyceride levels. Serum triglyceride levels were also significantly reduced in the n-6-rich diet animals.