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Shrimp is very low in total fat, yet it has a high cholesterol content. Although shrimp is a popular food in the American diet, many people avoid it because of its high cholesterol content. The objective of this study was to test the effect of the addition of cholesterol from shrimp to a low-fat baseline diet as well as to compare the effect of an equal amount of dietary cholesterol derived from shrimp or egg on the plasma lipoprotein pattern of normolipidemic subjects. In a randomized crossover trial, a diet containing 300 g shrimp/d, which supplied 590 mg dietary cholesterol/d, significantly increased low-density-lipoprotein (LDL) cholesterol by 7.1% (P = 0.014) and high-density-lipoprotein (HDL) cholesterol by 12.1% (P = 0.0001) when compared with a baseline diet matched for fat content but containing only 107 mg cholesterol/d. However, because the percentage increase in LDL cholesterol was less than for HDL cholesterol, the shrimp diet did not worsen the ratio of total cholesterol to HDL cholesterol or the ratio of LDL to HDL cholesterol. Moreover, shrimp consumption decreased triacylglycerol (triglyceride) concentrations by 13% (P = 0.004). The diet containing two large eggs per day with 581 mg dietary cholesterol/d also raised LDL-and HDL-cholesterol concentrations compared with baseline, but the percentage increase in LDL cholesterol (10.2%, P = 0.0001) was more than for HDL cholesterol (7.6%, P = 0.004) and there was a trend toward worse lipoprotein ratios. In a comparison of the two high-cholesterol diets, the shrimp diet produced significantly lower ratios of total to HDL cholesterol and lower ratios of LDL to HDL cholesterol than the egg diet as well as lower triacylglycerol concentrations. We conclude that moderate shrimp consumption in normolipidemic subjects will not adversely affect the overall lipoprotein profile and can be included in 'heart healthy' nutritional guidelines. (c) 1996 American Society for Clinical Nutrition [ABSTRACT FROM AUTHOR]

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. Copyright © 2006 American Society for Nutrition [ABSTRACT FROM AUTHOR]