Effects Of N-3 Polyunsaturated Fatty Acids On Post Surgical Atrial Fibrillation: A Prospective Randomised Study
Funder
National Health and Medical Research Council
Funding Amount
$536,529.00
Summary
Consumption of fish and fish oil has been associated with protective effects for deaths from heart disease in many studies. The effects are consistent and quite strong and appear to be unrelated to blood cholesterol levels. The effects are more likely due to the possibility that fish oil, which contains n-3 fats, can suppress abnormal heart rhythms which can cause 'sudden cardiac death'. This has been shown in animal studies, and recently we have shown that they can also suppress abnormal heart ....Consumption of fish and fish oil has been associated with protective effects for deaths from heart disease in many studies. The effects are consistent and quite strong and appear to be unrelated to blood cholesterol levels. The effects are more likely due to the possibility that fish oil, which contains n-3 fats, can suppress abnormal heart rhythms which can cause 'sudden cardiac death'. This has been shown in animal studies, and recently we have shown that they can also suppress abnormal heart rhythms in humans. Patients undergoing coronary bypass surgery are particularly susceptible to abnormal heart rhythms in the upper chambers of the heart in the days immediately following surgery. While these abnormal rhythms are rarely life threatening, they can result in increased post-surgical complications and a longer hospital stay with associated increased costs to the health system. In this study we will determine whether providing high dose fish oil for 3 weeks immediately preceding coronary bypass surgery, will result in a reduction in the proportion of patients experiencing post-surgical abnormal heart rhythms. We will also examine the effects of n-3 fats on the incidence of other complications following bypass surgery and also the length of hospital stay. In addition, we will gather data which will provide insight into the mechanisms by which n-3 fatty acids produce their well documented benefits to patients with cardiovascular disease. The significance of this study is its ability to provide a protective strategy in heart disease in which the mechanism is understood, which is effective, and importantly, which will have the potential to provide savings to the health care system through a reduction in hospital stay.Read moreRead less
N-3 LCPUFA Supplementation In Pregnancy To Reduce Allergies In Early Childhood
Funder
National Health and Medical Research Council
Funding Amount
$813,423.00
Summary
Over the last 20 years there has been a dramatic increase in allergic diseases in Australia as well as many other industrialised countries. This may be due to changes in our environment or diet. Over this period of time there has also been an increase in the dietary intake of n-6 fatty acids from vegetable oils and a corresponding decline in the intake of n-3 fatty acids from fish. Studies now indicate that there is a plausible link between these dietary changes and allergic diseases. Furthermor ....Over the last 20 years there has been a dramatic increase in allergic diseases in Australia as well as many other industrialised countries. This may be due to changes in our environment or diet. Over this period of time there has also been an increase in the dietary intake of n-6 fatty acids from vegetable oils and a corresponding decline in the intake of n-3 fatty acids from fish. Studies now indicate that there is a plausible link between these dietary changes and allergic diseases. Furthermore, emerging data suggest that the potential benefits of increasing n-3 fatty acids may be greatest during pregnancy and before allergic responses are established. Our project aims to minimise allergies in children from families where at least one parent has an allergy. We will assess whether dietary n-3 fatty acid supplementation of pregnant women will result in fewer children with allergies at 1 and 3 years of age. If the proposed intervention is successful, it would be a safe, cheap, acceptable and effective strategy to prevent allergies in children at high risk.Read moreRead less
Effect Of Lipid Mediators And Dietary Fats In Bone Remodelling
Funder
National Health and Medical Research Council
Funding Amount
$380,250.00
Summary
Osteoporosis in a major public health problem which directly affects about 10% of the population, which is currently around 2 million Australians. With aging of the population, it is projected that this proportion will increase to more than 13% over the next 20 years. When it is considered that the direct hospital and residential care costs attributable to osteoporotic fractures currently approaches $2 billion per annum, low-cost interventions for increasing bone strength which are easily applie ....Osteoporosis in a major public health problem which directly affects about 10% of the population, which is currently around 2 million Australians. With aging of the population, it is projected that this proportion will increase to more than 13% over the next 20 years. When it is considered that the direct hospital and residential care costs attributable to osteoporotic fractures currently approaches $2 billion per annum, low-cost interventions for increasing bone strength which are easily applied to the elderly population have enormous potential for health benefits in Australia. Thus study will examine the effects of dietary omega-3 fats, of the kind found in fish and fish oil, on the biology of bone metabolism and on bone strength. The results will provide information which may be used in developing simple drug or dietary strategies for large-scale use for increasing bone mass and strength in the elderly population. A strength of the study arises from the combination of research expertise in (a) dietary fats, and (b) molecular biology of bone cells, and (c) animal models of bone metabolism which are amenable to dietary interventions. This combination is unique, but builds on well established systems which hitherto have existed in separate research paradigms. The Chief Investigator has considerable experience in development of diets enriched in omega-3 fats which are practical and suitable for daily use on a long-term basis. This adds considerably to the potential significance of the outcomes because, if favourable effects of omega-3 fats are observed and are characterised with regard to mechanisms, the results can be rapidly translated into large-scale clinical use.Read moreRead less
The Effect Of Dietary Fatty Acids On Cellular Calcium Handling Mechanisms In Cardiac Muscle
Funder
National Health and Medical Research Council
Funding Amount
$275,765.00
Summary
A major health problem in the developed countries is cardiovascular disease, which is manifest as high blood pressure, stroke, heart attack and abnormalities of heart rhythm, or cardiac arrhythmias. A western diet, ie. one high in animal fat, or saturated fats, may be to blame. Human epidemiological studies have shown that consumption of a diet high in saturated fats is correlated with a propensity to arrhythmias while a diet high in polyunsaturated fatty acids (PUFAs) can confer protection from ....A major health problem in the developed countries is cardiovascular disease, which is manifest as high blood pressure, stroke, heart attack and abnormalities of heart rhythm, or cardiac arrhythmias. A western diet, ie. one high in animal fat, or saturated fats, may be to blame. Human epidemiological studies have shown that consumption of a diet high in saturated fats is correlated with a propensity to arrhythmias while a diet high in polyunsaturated fatty acids (PUFAs) can confer protection from coronary heart disease and cardiac arrhythmias. The mechanisms underlying these effects are not fully understood. The contraction of the heart depends on changes in calcium inside the individual muscle cells. Abnormalities of the way calcium is handled in the cells leads to abnormalities of contraction and to a certain types of arrhythmia. Over the last 5 to 10 years, technological developments have enabled us to examine changes in calcium in living heart cells at microscopic level. It is possible to fill individual living cells with a fluorescent dye which changes either the magnitude or the wavelength of its fluorescence according to the ambient calcium concentration. Cells filled with these dyes are examined with a laser scanning confocal microscope, in which a very tightly focussed laser beam excites the dye and the resulting fluorescence is gathered by a computer controlled image analysis system. In this way we can measure the calcium concentration within the cells with a spatial resolution of about 1-1000 of a millimetre, and a time resolution of about 1-100 of a second. Using these techniques, we have found that supplementing the diet of rats with either PUFAs or saturated fats produces a dramatic change in the way that calcium is stored and released in their heart cells. This effect of dietary fats has not been reported before, and it may represent an important clue as to how these substances protect against many cardiac arrhythmias.Read moreRead less
Regulation And Activity Of Fatty Acid Delta-6 Desaturase (D6D)
Funder
National Health and Medical Research Council
Funding Amount
$527,683.00
Summary
Fish and fish oils contain fats known as omega-3 fats. These have health benefits in adult conditions such as rheumatoid arthritis and heart disease, and they are necessary for proper brain and eye development in infants. However, much of the population does not like to eat fish and also, world fish stocks are under stress. Thus, a sustainable alternative source of omega-3 fats needs to be explored. Some vegetable oils such as canola, echium, and flaxseed oils have omega-3 fats. However, these a ....Fish and fish oils contain fats known as omega-3 fats. These have health benefits in adult conditions such as rheumatoid arthritis and heart disease, and they are necessary for proper brain and eye development in infants. However, much of the population does not like to eat fish and also, world fish stocks are under stress. Thus, a sustainable alternative source of omega-3 fats needs to be explored. Some vegetable oils such as canola, echium, and flaxseed oils have omega-3 fats. However, these are not the same as the omega-3s in fish oil. In general, vegetable omega-3s are known as short-chain omega-3s whereas those in fish are long-chain. When the vegetable oil omega-3s are consumed in the diet, the body must convert them to the fish-type, or long-chain, omega-3s in order to gain the health benefits. Currently, human metabolism is poor at doing this conversion. Our studies suggest that the amounts and blends of fats in most diets are well below optimal for conversion to long-chain omega-3s in the body. In particular, our studies show that there may be no point in simply adding more vegetable omega-3 fats to the diet. This project will examine the enzymes that convert the short-chain to the long-chain omega-3 fats. In particular, it will examine how the dietary fats interact with each other in detrimental ways to suppress activity of the conversion enzymes necessary for long-chain omega-3 formation. Evidence for the health benefits of fish-based omega-3 fats is very strong and it is an approach to health that most people can undertake on their own. Our lack of knowledge of the best way to use plant-based omega-3 fats is a large impediment for a more sustainable and broader based use of omega-3 fats. The results from this study will begin to fill in this knowledge gap. The results will be useful across a range of activities that are determinants of the kinds of fat that we eat. These include oil seed breeding, food manufacture, and dietetics.Read moreRead less
Identification Of The Mechanisms Of Lipotoxicity Within The Bone Marrow Milieu
Funder
National Health and Medical Research Council
Funding Amount
$416,007.00
Summary
Obesity and osteoporosis two major epidemics of our time. Bone and fat communicate with each other in two different ways. A hormonal communication links bone and fat in a positive manner. In contrast, at the local level, increasing levels of marrow fat with aging affect bone quality through the local release of toxic factors. We will identify these factors and will assess the potential reversibility of lipotoxicity in bone, as a new therapeutic approach to osteoporosis in the elderly.
This project examines how high fat diets affect inflammation and asthma outcomes. Research regarding the relationship between asthma and obesity is inconclusive. This project examines high fat intake as an initiator of both these conditions. We explore statins as a treatment for diet-induced inflammation. By increasing our understanding of how fat affects inflammation, we will be able to plan a dietary approach to improve asthma outcomes.
Obesity is an important cause of disease, including liver disease. Obesity-associated liver disease occurs when the liver becoming resistance to the effects of insulin, the hormone that controls blood sugar (glucose). In muscle and fat, insulin causes glucose to be taken into the tissues and stored. Glucose is made in the liver and the actions of insulin here are to turn off the release of glucose into the circulation and increase uptake and storage of glucose. Insulin resistance occurs in a num ....Obesity is an important cause of disease, including liver disease. Obesity-associated liver disease occurs when the liver becoming resistance to the effects of insulin, the hormone that controls blood sugar (glucose). In muscle and fat, insulin causes glucose to be taken into the tissues and stored. Glucose is made in the liver and the actions of insulin here are to turn off the release of glucose into the circulation and increase uptake and storage of glucose. Insulin resistance occurs in a number of situations but the most important of these is obesity, particularly when there is accumulation of fat inside the abdominal cavity. Although the liver has a central role in co-ordinating the bodies response to insulin, the mechanisms of insulin resistance in human liver are unknown. One prominent hypothesis is that fat molecules released by intra-abdominal fat deposits are responsible. Intra-abdominal fat stores are important because fatty acids from these deposits can travel directly to the liver with the blood supply from the gut. However the precise effects of these on insulin action in the liver are unknown. Fat tissue is actively involved in the regulation of metabolism and releases a number of regulatory proteins. One of these, adiponectin, appears to have an important role in improving insulin sensitivity in the liver. The production of adiponectin decreases as obesity increases, providing another link between obesity and insulin resistance in the liver. This project will examine insulin action and the signalling molecules responsible for this in human liver tissue. The project aims to determine the effect of obesity, particularly intra-abdominal fat deposits, on insulin responses in liver tissue. The studies also aim to confirm (or otherwise) the role of free fatty acids and adiponectin on insulin action in human liver. The data from these studies will contribute to our understanding of insulin resistance and obesity-related liver disease.Read moreRead less