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1.
Fatty acid acylation of proteins corresponds to the co- or post-translational covalent linkage of a fatty acid, activated in the form of acyl-CoA, to an amino acid residue of the substrate protein. The cellular fatty acids which are involved in protein acylation are mainly saturated fatty acids. Palmitoylation (S-acylation) corresponds to the reversible attachment of palmitic acid (C16:0) to the side chain of a cysteine residue via a thioester bond. N-terminal myristoylation refers to the covalent attachment of myristic acid (C14:0) by an amide bond to the N-terminal glycine of many eukaryotic and viral proteins. Octanoylation (O-acylation) typically concerns the formation of an ester bond between octanoic acid (caprylic acid, C8:0) and the side chain of a serine residue of the gut and brain peptide ghrelin. An increasing number of proteins (enzymes, receptors, oncogenes, tumor suppressors, proteins involved in signal transduction, eukaryotic and viral structural proteins) have been shown to undergo fatty acid acylation. The acyl moiety can mediate protein subcellular localization, protein–protein interaction or protein–membrane interaction. Therefore, through the covalent modification of proteins, saturated fatty acids exhibit emerging specific and important roles in modulating protein functions. This review provides an overview of the recent findings on the various classes of protein acylation leading to the biological ability of saturated fatty acids to regulate many pathways. Finally, the links between these elucidated biochemical mechanisms and the physiological roles of dietary saturated fatty acids are discussed.  相似文献   

2.
Saturated fats: what dietary intake?   总被引:10,自引:0,他引:10  
Public health recommendations for the US population in 1977 were to reduce fat intake to as low as 30% of calories to lower the incidence of coronary artery disease. These recommendations resulted in a compositional shift in food materials throughout the agricultural industry, and the fractional content of fats was replaced principally with carbohydrates. Subsequently, high-carbohydrate diets were recognized as contributing to the lipoprotein pattern that characterizes atherogenic dyslipidemia and hypertriacylglycerolemia. The rising incidences of metabolic syndrome and obesity are becoming common themes in the literature. Current recommendations are to keep saturated fatty acid, trans fatty acid, and cholesterol intakes as low as possible while consuming a nutritionally adequate diet. In the face of such recommendations, the agricultural industry is shifting food composition toward lower proportions of all saturated fatty acids. To date, no lower safe limit of specific saturated fatty acid intakes has been identified. This review summarizes research findings and observations on the disparate functions of saturated fatty acids and seeks to bring a more quantitative balance to the debate on dietary saturated fat. Whether a finite quantity of specific dietary saturated fatty acids actually benefits health is not yet known. Because agricultural practices to reduce saturated fat will require a prolonged and concerted effort, and because the world is moving toward more individualized dietary recommendations, should the steps to decrease saturated fatty acids to as low as agriculturally possible not wait until evidence clearly indicates which amounts and types of saturated fatty acids are optimal?  相似文献   

3.
Dietary fat and its effects on health and disease has attracted interest for research and Public Health. Since the 1980s many bodies and organizations have published recommendations regarding fat intake. In this paper different sets of recommendations are analyzed following a systematic review process to examine dietary reference intakes, nutritional goals and dietary guidelines for fat and fatty acids. A literature search was conducted in relevant literature databases along a search for suitable grey literature reports. Documents were included if they reported information on either recommended intake levels or dietary reference values or nutritional objectives or dietary guidelines regarding fat and/or fatty acids and/or cholesterol intake or if reported background information on the process followed to produce the recommendations. There is no standard approach for deriving nutrient recommendations. Recommendations vary between countries regarding the levels of intake advised, the process followed to set the recommendations. Recommendations on fat intake share similar figures regarding total fat intake, saturated fats and trans fats. Many sets do not include a recommendation about cholesterol intake. Most recent documents provide advice regarding specific n-3 fatty acids. Despite efforts to develop evidence based nutrient recommendations and dietary guidelines that may contribute to enhance health, there are still many gaps in research. It would be desirable that all bodies concerned remain transparent about the development of dietary recommendations. In order to achieve this, the type of evidence selected to base the recommendations should be specified and ranked. Regular updates of such recommendations should be planned.  相似文献   

4.
Saturated and trans-fatty acids raise total cholesterol and LDL-cholesterol and are known to increase the risk of CHD, while dietary unsaturated fatty acids play important roles in maintaining cardiovascular health. Replacing saturated fats with unsaturated fats in the diet often involves many complex dietary changes. Modifying the composition of foods high in saturated fat, particularly those foods that are consumed daily, can help individuals to meet the nutritional targets for reducing the risk of CHD. In the 1960s the Dutch medical community approached Unilever about the technical feasibility of producing margarine with a high-PUFA and low-saturated fatty acid composition. Margarine is an emulsion of water in liquid oil that is stabilised by a network of fat crystals. In-depth expertise of fat crystallisation processes allowed Unilever scientists to use a minimum of solid fat (saturated fatty acids) to structure a maximum level of PUFA-rich liquid oil, thus developing the first blood-cholesterol-lowering product, Becel. Over the years the composition of this spread has been modified to reflect new scientific findings and recommendations. The present paper will briefly review the developments in fat technology that have made these improvements possible. Unilever produces spreads that are low in total fat and saturated fat, virtually free of trans-fatty acids and with levels of n-3 and n-6 PUFA that are in line with the latest dietary recommendations for the prevention of CHD. Individuals with the metabolic syndrome have a 2-4-fold increased risk of developing CHD; therefore, these spreads could make a contribution to CHD prevention in this group. In addition, for individuals with the metabolic syndrome the spreads could be further modified to address their unique dyslipidaemia, i.e. elevated blood triacylglycerols and low HDL-cholesterol. Research conducted in the LIPGENE study and other dietary intervention studies will deliver the scientific evidence to justify further modifications in the composition of spreads that are healthy for the heart disease risk factors associated with the metabolic syndrome.  相似文献   

5.
Abstract

This narrative review summarises the main studies of the role of the different fatty acids in coronary heart disease (CHD) and cardiovascular disease (CVD) risk and the current scientific debate on dietary recommendations. Reduction and substitution of the saturated fatty acids (SFAs) with the polyunsaturated fatty acids (PUFAs) are still the main dietary recommendation to prevent CHD and CVD. In the last few years, however, the strength of the scientific evidence underlying this dietary advice has been questioned. Recent investigations reappraise the previously declared deleterious role of the SFAs and reduce the positive role of PUFAs, mainly the omega-6, whereas the role of monounsaturated fatty acids (MUFAs) remains unclear. In contrast, the negative effects of trans fatty acids (TFAs) seem stronger than previously thought. Finally, criticisms have emerged from a dietary recommendation approach focussed on individual components rather than on wide food items and eating habits.  相似文献   

6.
It is the position of the Academy of Nutrition and Dietetics (the Academy) that dietary fat for the healthy adult population should provide 20% to 35% of energy, with an increased consumption of n-3 polyunsaturated fatty acids and limited intake of saturated and trans fats. The Academy recommends a food-based approach through a diet that includes regular consumption of fatty fish, nuts and seeds, lean meats and poultry, low-fat dairy products, vegetables, fruits, whole grains, and legumes. These recommendations are made within the context of rapidly evolving science delineating the influence of dietary fat and specific fatty acids on human health. In addition to fat as a valuable and calorically dense macronutrient with a central role in supplying essential nutrition and supporting healthy body weight, evidence on individual fatty acids and fatty acid groups is emerging as a key factor in nutrition and health. Small variations in the structure of fatty acids within broader categories of fatty acids, such as polyunsaturated and saturated, appear to elicit different physiological functions. The Academy recognizes that scientific knowledge about the effects of dietary fats on human health is young and takes a prudent approach in recommending an increase in fatty acids that benefit health and a reduction in fatty acids shown to increase risk of disease. Registered dietitian nutritionists are uniquely positioned to translate fat and fatty acid research into practical and effective dietary recommendations.  相似文献   

7.
The role that diet plays in the management of plasma lipid levels is discussed in this review. It has long been recognized that saturated fatty acids and cholesterol raise the plasma cholesterol level whereas polyunsaturated fatty acids lower it. Recently, the effects of other dietary constituents in the management of plasma lipid levels have been established. In particular, monounsaturated fatty acids, soluble fiber, and vegetarian diets favorably affect plasma lipid levels. Overweight and obesity adversely affect plasma lipid levels. Omega-3 fatty acids are hypotriglyceridemic, and high carbohydrate diets low in saturated fatty acids are hypocholesterolemic. Further work is required to establish the long-term consequences of alcohol and coffee consumption on the plasma lipid response. A variety of alternative dietary strategies can be employed in conjunction with traditional dietary recommendations (i.e., reduce total fat, especially saturated fatty acids and dietary cholesterol) for the management of plasma lipid levels. The expected plasma total cholesterol (specifically low-density-lipoprotein cholesterol) reduction is approximately 10% to 20% when dietary saturated fatty acids and cholesterol are decreased to less than or equal to 7% of calories and less than or equal to 200 mg of cholesterol per day. Further dietary modifications, such as increasing soluble fiber, may lead to additional reductions of 1% to 10% in plasma total cholesterol.  相似文献   

8.
PURPOSE OF REVIEW: Given the pathophysiological importance of insulin resistance, the potential impact of dietary fatty acids is highly relevant. The effects of different types of dietary fatty acids on insulin sensitivity in humans are discussed, with focus on recent controlled studies. RECENT FINDINGS: Observational studies assessing fatty acid composition in serum or tissues suggest that insulin resistance is associated with relatively high intakes of saturated fat (e.g. palmitic acid) and low intakes of polyunsaturated fat (e.g. linoleic acid), findings that are supported by recent clinical data. Most controlled studies have hitherto examined the effect of monounsaturated fat on insulin sensitivity, several indicating that it has beneficial effects when substituted for saturated fat. More clinical data comparing n-6 polyunsaturated, monounsaturated and saturated fat are needed to identify the optimal dietary fat composition, especially in patients with insulin resistance/obesity and diabetes. The total fat content of the background diet should also be considered in future studies. Finally, we and others hypothesize that dietary fatty acids may partly mediate their effects on insulin action by regulating the activity of lipogenic enzymes and desaturases. SUMMARY: Substituting saturated fat with unsaturated fat seems to have beneficial effects on insulin sensitivity, although the clinical significance of modifying fat quality alone is still unclear.  相似文献   

9.
What are the health effects of fat?   总被引:1,自引:0,他引:1  
In order to answer the question which health benefits are to be expected from dietary fat, we have to differentiate between different kinds of fat with varying fatty acid composition. Saturated fatty acids are commonly judged to have a negative health impact as they lead to increased serum cholesterol levels and a higher risk of coronary heart disease. Therefore, all recommendations stress the importance to limit the intake of saturated fatty acids. Monounsaturated fatty acids, on the other hand, have a positive impact on the serum lipid profile, lead to decreased LDL-oxidation and favorably influence the metabolism of diabetics. However, it is essential that monounsaturated fatty acids be mainly supplied by plant oils like rape seed or olive oil and not by foods that are simultaneously rich in saturated fatty acids. Concerning polyunsaturated fatty acids, it is important to increase the supply of n-3 fatty acids (ratio of n-6:n-3: about 5:1) as there is substantial evidence for their protective effects. If the fatty acid composition of the diet is optimized, even a total dietary fat content of 35% of total energy intake can be adequate as long as there is enough physical activity and the diet is rich in plant-derived foods like vegetables, fruits, cereals, potatoes, beans and legumes.  相似文献   

10.
OBJECTIVES: To assess the dietary intakes and diet quality of menopausal women relative to premenopausal women, and to determine whether their diets are compatible with reducing risks of cardiovascular disease (CVD) and osteoporosis. DESIGN: Cross-sectional study using 3-day food records and anthropometric measurements. Subjects Thirty apparently healthy, nonoestrogen using and nonsupplemented women menopausal since 3-5 years and 30 well-matched premenopausal women. Outcome measures Nutrient intakes, diet nutrient density, body mass index (BMI), waist circumference, waist-to-hip ratio and serum oestradiol. RESULTS: Energy intake and body weight of pre- and postmenopausal women were comparable. Their BMI, waist circumference and waist-to-hip ratios were within healthy ranges. The diet of postmenopausal women was compatible (less total lipids and saturated fatty acids; more fibres, antioxidant vitamins and potassium) with North American nutritional recommendations linked to cardiovascular health. Their dietary iron intakes exceeded their reduced physiological need, which may jeopardize their cardiovascular system. Their calcium and vitamin D intakes were far below recommendations for healthy bones. Five other nutrients were also suboptimal. Phosphorus intake (high in both groups) correlated with dietary proteins, sulphur amino acids and calcium. CONCLUSIONS: The diet of the postmenopausal women studied were more compatible with national nutritional recommendations than that of premenopausal controls. However, these postmenopausal women, not taking hormone replacement therapy (HRT) and having inadequate dietary calcium and vitamin D intakes, may be at increased risk of osteoporotic fracture later in life. More studies on CVD risk inherent to body iron accumulation involving a large number of postmenopausal women are warranted before planning public health measures regarding dietary iron intake.  相似文献   

11.
The last decade has seen nearly 20 papers reviewing the totality of the data on saturated fats and cardiovascular outcomes, which, altogether, have demonstrated a lack of rigorous evidence to support continued recommendations either to limit the consumption of saturated fatty acids or to replace them with polyunsaturated fatty acids. These papers were unfortunately not considered by the process leading to the most recent U.S. Dietary Guidelines for Americans, the country’s national nutrition policy, which recently reconfirmed its recommendation to limit saturated fats to 10% or less of total energy intake, based on insufficient and inconsistent evidence. Continuation of a cap on saturated fat intake also fails to consider the important effects of the food matrix and the overall dietary pattern in which saturated fatty acids are consumed.  相似文献   

12.
Types of dietary fat and risk of coronary heart disease: a critical review   总被引:15,自引:0,他引:15  
During the past several decades, reduction in fat intake has been the main focus of national dietary recommendations to decrease risk of coronary heart disease (CHD). Several lines of evidence. however, have indicated that types of fat have a more important role in determining risk of CHD than total amount of fat in the diet. Metabolic studies have long established that the type of fat, but not total amount of fat, predicts serum cholesterol levels. In addition, results from epidemiologic studies and controlled clinical trials have indicated that replacing saturated fat with unsaturated fat is more effective in lowering risk of CHD than simply reducing total fat consumption. Moreover, prospective cohort studies and secondary prevention trials have provided strong evidence that an increasing intake of n-3 fatty acids from fish or plant sources substantially lowers risk of cardiovascular mortality. In this article, we review evidence from epidemiologic studies and dietary intervention trials addressing the relationship between dietary fat intake and risk of CHD, with a particular emphasis on different major types of fat, n-3 fatty acids and the optimal balance between n-3 and n-6 fatty acids. We also discuss the implications of the available evidence in the context of current dietary recommendations.  相似文献   

13.
Currently available epidemiological evidence suggested that an increase of saturated fatty acids (SFA) could have negative effects on cognitive functions, while increased polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA) may be protective against cognitive decline. In a Southern Italian elderly population from the Italian Longitudinal Study on Aging (ILSA), a clear reduction of risk of age-related cognitive decline (ARCD) has been found with elevated intake of PUFA and MUFA. Furthermore, in the ILSA, while dietary fatty acids intakes were not associated with incident mild cognitive impairment (MCI), high PUFA intake appeared to have borderline non-significant trend for a protective effect against the development of MCI. These epidemiological findings on predementia syndromes, i.e. MCI or ARCD, together with a recent randomised controlled trial on a possible effect on cognitive and depressive symptoms of ω-3 PUFA supplementation in patients with very mild AD, suggested a possible role of fatty acids intake in maintaining adequate cognitive functioning and possibly in preventing or delaying the onset of dementia.  相似文献   

14.
OBJECTIVE: Diet therapy is the cornerstone for the management of gestational diabetes mellitus (GDM). Women with GDM are commonly given dietary advice that broadly focuses on a reduction of total energy and fat consumption. We compared nutrient intake and specifically fatty acids of women with GDM who had received individualized nutritional counseling with those of non-diabetic women who did not. METHOD: Women with GDM (n=44) and healthy pregnant women (n=44) with uncomplicated singleton pregnancies were recruited during the third trimester. Women with GDM were given consultation on diet, health, and macronutrient content of foods commonly consumed by the individual. The non-diabetic group did not receive any dietary advice. Both groups were asked to keep a detailed record of all of foods and fluid consumed over a 4-d period. RESULTS: After dietary counseling, the GDM group had lower intakes of energy (P<0.05), refined sugar (P<0.0001), total and saturated fats (P<0.0001), and monounsaturated (P<0.01) and trans (P<0.0001) fatty acids and higher levels of docosahexaenoic acid and fiber (P<0.05) compared with the non-diabetic group. CONCLUSIONS: Individualized dietary advice was associated with a lower consumption of the target nutrients in women with GDM. Another benefit of the advice was a slight increase in intake of eicosapentaenoic and docosahexaenoic acids, although consumption of omega-3 fatty acids by both groups was well below the recommendations for pregnancy. There is evidence that docosahexaenoic acid modulates insulin resistance and that it is vital for neurovisual development. We suggest that dietary management for women with GDM should foster the current recommendations for essential fatty acids in pregnancy.  相似文献   

15.
A recent meta-analysis of prospective cohort studies has not found an association between dietary saturated fat intake and CHD incidence. This funnelled the discussion about the importance of the recommendation to lower the intake of saturated fat for the prevention of CHD. At the same time a document of the European Food Safety Authority has suggested that specific quantitative recommendations are not needed for individual fatty acids but that more general statements can suffice. In this review, we discuss methodological aspects of the absence of association between SFA intake and CHD incidence in prospective cohort studies. We also summarise the results of the controlled dietary experiments on blood lipids and on CHD incidence in which saturated fat was replaced by either cis-unsaturated fat or carbohydrates. Finally, we propose a nutritionally adequate diet with an optimal fatty acid composition for the prevention of CHD in the context of dietary patterns. Such diets are characterised by a low intake of saturated fat, and as low as possible intake of trans-fat and fulfil the requirements for the intake of n-6 and n-3 fatty acids. No recommendation is needed for the intake of cis-MUFA.  相似文献   

16.
OBJECTIVES: To investigate the relation between (1) cardiorespiratory fitness and plasma saturated, monounsaturated and polyunsaturated fatty acids and (2) the interactions between cardiorespiratory fitness, dietary fat intake and plasma fatty acid composition. DESIGN: Cross-sectional analysis. SETTING AND SUBJECTS: The subjects were randomly selected, 127 middle-aged Finnish men participating in the DNASCO exercise intervention study. INTERVENTIONS: Cardiorespiratory fitness was determined spiroergometrically, dietary intake of macro- and micronutrients by 4-day food records and plasma fatty acids by gas chromatography. The subjects were divided into tertiles of aerobic fitness. RESULTS: Differences between fitness tertiles were not observed for dietary intake of total fat, and saturated, monounsaturated or polyunsaturated fatty acids (percent of total energy). In contrast, plasma saturated fatty acids were significantly lower (P <0.01) and polyunsaturated fatty acids significantly higher (P <0.05) in the highest fitness tertile compared to the lowest tertile. Dietary saturated fat intake was positively associated with plasma saturated fatty acids (r=0.342; P <0.05) and inversely with plasma polyunsaturated fatty acids (r=-0.453; P <0.01) only in the lowest fitness tertile. In addition, a positive correlation between body mass index and plasma saturated fatty acids (r=0.516; P <0.01) as well as a negative correlation between body mass index and plasma polyunsaturated fatty acids (r=-0.516; P <0.01) was observed in the lowest tertile solely. CONCLUSION: Different levels in cardiorespiratory fitness are associated with different levels in plasma saturated and polyunsaturated fatty acids and lead to modifications in the association between dietary and plasma fatty acids. These findings can perhaps be explained by a reduced hepatic fatty acid and lipoprotein synthesis as well as by an enhanced muscular lipid utilization, which are commonly seen in those who are physically active and who exhibit a higher level of fitness.  相似文献   

17.
In 2008, the Food and Agricultural Organization (FAO)/World Health Organization (WHO) reviewed its recommendations on dietary fat and fatty acids in light of the growing evidence base on dietary fatty acids and health outcomes. These new FAO/WHO recommendations are considerably broader than the current UK recommendations, in that the FAO/WHO report makes separate recommendations for adults and children and sets ranges of intake for n‐3 and n‐6 polyunsaturated fatty acids (PUFAs) based, not only on prevention of deficiency, but also on their role in contributing to optimum and long‐term health. The key recommendation of this report is that saturated fatty acids (SFAs) should be limited to 10% of dietary energy intake and, compared with the UK recommendations, there is a stronger emphasis on replacing excess dietary SFAs with PUFAs (both n‐3 and n‐6) because of convincing evidence that this dietary exchange reduces low density lipoprotein cholesterol and the risk of coronary heart disease. It may therefore be timely to consider the need for a modification of the UK dietary guidelines on dietary fat and fatty acid intake to take account of the growing evidence base for the potential benefit of replacing SFAs with PUFAs.  相似文献   

18.
Development of type 2 diabetes mellitus and insulin resistance is associated with a quality of dietary fatty acids such as saturated and unsaturated fatty acids. Dietary fatty acids also include transform of unsaturated fatty acids and intake of transform of oleate (elaidate) is associated with cardiovascular disease. However, little is known about the roles of elaidate in insulin responsiveness. We show here that elaidate impairs insulin-dependent glucose uptake in adipocytes. Differentiation with 10?μM elaidate, which is close to physiological plasma concentration, reduces insulin-dependent glucose uptake. Furthermore, insulin-dependent GLUT4 translocation is disturbed in adipocytes differentiated with elaidate. In addition, analysis of lipolysis and gene expression shows that deteriorative effects of elaidate on insulin responsiveness are limited but not general. Thus, our findings reveal that differentiation with elaidate tends to affect insulin-dependent glucose uptake through alternation of GLUT4 translocation from cytosol to the plasma membrane.  相似文献   

19.
Data on market size, market share, and compositional changes of various products made from partially hydrogenated fats and oils were used to estimate current, previous, and predicted levels of trans fatty acids in the US diet. Recent literature and various perceptions of the toxicological, physiological, and nutritional effects of trans fatty acids were reviewed. Trans acid availability has changed little during the last 15-20 yr and currently is estimated to be approximately 7.6 g X person-1 X day-1. Modest decreases in total fat intake, including trans fatty acid intake, may occur in the future if consumers adopt certain dietary recommendations. We believe that concerns about possible relationships of trans fatty acids to development of atherosclerotic disease or cancer are not supported by reliable data. Numerous literature accounts support the conclusion that trans fatty acids do not pose any harm to humans or animals consuming a balanced diet containing adequate linoleic acid.  相似文献   

20.
In view of the high omega-3 poly unsaturated fatty acid content of the brain, it is evident that these fats are involved in brain biochemistry, physiology and functioning; and thus in some neuropsychiatric diseases and in the cognitive decline of ageing. Though omega-3 fatty acids (from fatty fish in the human diet) appear effective in the prevention of stress, their role as regulator of mood and of libido is a matter for discussion pending experimental proof in animal and human models. Dietary omega-3 fatty acids play a role in the prevention of some disorders including depression, as well as in dementia, particularly Alzheimer's disease. Their direct role in major depression, bipolar disorder (manic-depressive disease) and schizophrenia is not yet established. Their deficiency can prevent the renewal of membranes, and thus accelerate cerebral ageing; none the less, the respective roles of the vascular component on one hand (where the omega-3's are active) and the cerebral parenchyma itself on the other, have not yet been clearly resolved. The role of omega-3 in certain diseases such as dyslexia and autism is suggested. In fact, omega-3 fatty acids participated in the first coherent experimental demonstration of the effect of dietary substances (nutrients) on the structure and function of the brain. Experiments were first of all carried out one x-vivo cultured brain cells (1), then on in vivo brain cells(2), finally on physiochemical, biochemical, physiological, neurosensory, and behavioural parameters (3). These findings indicated that the nature of poly unsaturated fatty acids(in particular omega-3) present in formula milks for infants (both premature and term) determines the visual, cerebral,and intellectual abilities, as described in a recent review (4). Indeed,the insufficient dietary supply of omega-3 fatty acids in today's French and occidental diet raises the problem of how to correct dietary habits so that the consumer will select foods that are genuinely rich in omega-3/ the omega-3 family ; mainly rapeseed, (canola) and walnut oils on one hand and fatty fish on the other.  相似文献   

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