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
L-amino Acid Sensing By The Extracellular Calcium-sensing Receptor: Molecular, Cellular And In Vivo Studies
Funder
National Health and Medical Research Council
Funding Amount
$362,545.00
Summary
Recent work by Dr Conigrave and colleagues demonstrates for the first time that protein and calcium metabolism are linked at the molecular level by the widely distributed calcium-sensing receptor. The project will aim to demonstrate the physiological significance of this finding by testing whether L-amino acids, the building blocks of body protein, exert receptor-dependent control over the secretion and blood levels of hormones that regulate body calcium levels. It will further test the hypothes ....Recent work by Dr Conigrave and colleagues demonstrates for the first time that protein and calcium metabolism are linked at the molecular level by the widely distributed calcium-sensing receptor. The project will aim to demonstrate the physiological significance of this finding by testing whether L-amino acids, the building blocks of body protein, exert receptor-dependent control over the secretion and blood levels of hormones that regulate body calcium levels. It will further test the hypothesis by determining whether amino acids exert receptor-dependent control over the proliferation of bone forming cells and urinary excretion of calcium.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
Immunomodulatory Effects Of Omega-3 Polyunsaturated Fatty Acids : Role In Allergy Prevention In Infancy
Funder
National Health and Medical Research Council
Funding Amount
$537,600.00
Summary
The dramatic increase in asthma and allergic disease over the last 20-30 years has highlighted the urgent need to identify associated environmental changes that may also be logical targets for disease prevention. Although this is likely to be multifactorial, one significant change during this period has been a progressive decline in the intake of dietary anti-inflammatory n-3 polyunsaturated fats (PUFA) in Western diets, with a corresponding increase in n-6 PUFA fatty acids. We recently showed f ....The dramatic increase in asthma and allergic disease over the last 20-30 years has highlighted the urgent need to identify associated environmental changes that may also be logical targets for disease prevention. Although this is likely to be multifactorial, one significant change during this period has been a progressive decline in the intake of dietary anti-inflammatory n-3 polyunsaturated fats (PUFA) in Western diets, with a corresponding increase in n-6 PUFA fatty acids. We recently showed for the first time that n-3 PUFA may have more significant effects in very early life before immune responses are fully established. We confirmed that maternal fish oil supplementation (n-40) resulted in significantly higher n-3 PUFA levels in newborns (compared to those with no supplements, n-43), and this was related to reduced immune responses to allergens (such as house dust mite, cat and egg). These observations suggest that n-3 PUFA can modify early immune development. Although this previous study was designed to assess immune outcomes (rather than clinical outcomes) we collected preliminary clinical data for the purposes of this application. We observed a consistent trend for less allergic symptoms and sensitisation in the supplementation group. These observations clearly warrant this proposed study to confirm these clinical effects, and to assess the mechanisms of action in considerably more detail. In this proposed study we will compare the effects of fish oil (n-165) or placebo (n-165) in early infancy (from 0-6 months of age). This much larger population will allow us to determine if increasing dietary n-3 PUFA is a way of reducing the chance of allergy in families where there is a high genetic risk. Approximately 40% of infants in Australia will go on to develop asthma or allergies. Strategies such as this that reduce the risk (even slightly) or the severity of disease expression could have enormous impact in this global context at relatively little cost.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