Atherosclerosis and Omega-3 Fatty Acids in Alaskan Natives
To determine whether there were differences in the prevalence and extent of atherosclerotic lesions in the coronaries and aortas between Alaskan natives and non-natives, and whether the extent of the lesions was related to omega-3 fatty acids in blood and tissues.
|Study Design:||Observational Model: Natural History|
|Study Start Date:||December 1988|
|Estimated Study Completion Date:||November 1994|
Purported low mortality from coronary heart disease in Eskimos from Greenland, Canada, or Alaska has been interpreted by many investigators as synonymous with the absence of or reduced amount of atherosclerotic lesions in the coronary arteries compared to populations with a high rate of coronary heart disease. It was thought that this study would help to clarify the role of omega-3 fatty acids in atherosclerosis but also would help in making a decision whether to recommend to the general public the inclusion of fish oils, which contain large amounts of these fatty acids in the diet, for prevention and/or reduction of atherosclerotic heart disease.
Coronary arteries, aortas, blood, adipose tissue, and liver were collected at autopsy from deceased Alaskan natives, aged 5 years and above, dying of all causes and from a similar number of age- and sex-matched non-native Alaskans. Tested standardized methods of gross evaluation, histomorphometry, and chemistry were used to characterize, measure, and evaluate the prevalence and extent of atherosclerosis in arteries. Chemical methods for determination of blood and tissue lipids and gas liquid chromatographic methods for determination of fatty acids in various lipid fractions in plasma and tissues were used. Risk factors for coronary artery disease were evaluated from tissues taken at autopsy. Hypertension was evaluated by an examination of kidney arterioles. Cigarette smoking was evaluated by measurement of thiocyanate in the blood and the presence or absence of diabetes was evaluated by measuring glycosylation of hemoglobin from red blood cells. Findings were compared with those studied in other populations such as Blacks and whites in New Orleans, and Japanese, Norwegians and nineteen other ethnic groups in the International Atherosclerosis Project.