Combining 21 trials evaluating lipid outcomes , fish oil consumption result ed in a summary net change in triglycerides of -27 ( 95 % CI -33 , -20)mg/dL , in HDL cholesterol of + 1.6 ( 95 % CI + 0.8 , + 2.3)mg/dL , and in LDL cholesterol of + 6 ( 95 % CI + 3 , + 8)mg/dL. There was no effect of fish oil on total cholesterol .
Across studies , higher fish oil dose and higher baseline levels were associated with greater reductions in serum triglycerides .
The evidence supports a dose-dependent beneficial effect of fish oil on serum triglycerides , particularly among people with more elevated levels .
Fish oil consumption also modestly improves HDL cholesterol , increases LDL cholesterol levels , but does not appear to adversely affect glucose homeostasis .
The evidence regarding the effects of omega-3 fatty acids on hs-CRP is inconclusive , as are data on ALA
Greater fish oil consumption has been associated with reduced CVD risk , although the mechanisms are unclear .
Plant- source oil omega-3 fatty acids ( ALA ) have also been studied regarding their cardiovascular effect .
Effect of Fish Oil Concentrate on Lipoprotein Composition in NIDDM
Non-insulin-dependent diabetes mellitus ( NIDDM ) is associated with elevated very-low-density lipoprotein ( VLDL ) triglyceride concentrations and abnormalities of low-density lipoprotein ( LDL ) composition . Because fish oil supplementation may favorably affect lipid and lipoprotein concentrations in nondiabetic subjects , we determined the effect of fish oil concentrate on plasma lipids and lipoprotein composition in patients with NIDDM .  Dietary-supplementation 1-mo periods of 4.0 and 7.5 g of omega-3 fatty acids in fish oil were compared with a placebo of 12 g safflower oil by use of a single-blind crossover design . Medications , including antidiabetic therapy , were continued through the study . Compared with safflower oil treatment , fish oil supplementation result ed in a significant reduction of total plasma triglycerides of 24 % at the 4-g dose and a larger reduction of 39 % at the 7.5-g dose . These decreases were due to similar reductions in VLDL triglycerides . LDL cholesterol levels were mildly elevated , but a larger 20 % increase in LDL apolipoprotein B ( apoB ) concentration was observed . During supplementation with the fish oil concentrate , the LDL cholesterol-to-apoB ratio was significantly reduced when compared with pretreatment values , but not when compared with safflower oil treatment .  Highdensity lipoprotein ( HDL ) cholesterol and plasma apoA1 levels were not significantly changed during fish oil treatment . At the 7.5-g dose , fasting glucose and glycohemoglobin levels increased by 20 and 12 % , respectively , but were unchanged at the lower level of supplementation . Thus , in NIDDM patients , dietary supplementation with omega-3 fatty acids induces a reduction in total plasma and VLDL triglyceride levels . However , the observed increase in LDL apoB levels , and the deterioration in glycemic control , indicate thatfurther study will be required to establish whether fish oil has a role in the treatment of NIDDM
Combining 21 trials evaluating lipid outcomes , fish oil consumption result ed in a summary net change in triglycerides of -27 ( 95 % CI -33 , -20)mg/dL , in HDL cholesterol of + 1.6 ( 95 % CI + 0.8 , + 2.3)mg/dL , and in LDL cholesterol of + 6 ( 95 % CI + 3 , + 8)mg/dL. There was no effect of fish oil on total cholesterol .
Across studies , higher fish oil dose and higher baseline levels were associated with greater reductions in serum triglycerides .
The evidence supports a dose-dependent beneficial effect of fish oil on serum triglycerides , particularly among people with more elevated levels .
Fish oil consumption also modestly improves HDL cholesterol , increases LDL cholesterol levels , but does not appear to adversely affect glucose homeostasis .
The evidence regarding the effects of omega-3 fatty acids on hs-CRP is inconclusive , as are data on ALA
Greater fish oil consumption has been associated with reduced CVD risk , although the mechanisms are unclear .
Plant- source oil omega-3 fatty acids ( ALA ) have also been studied regarding their cardiovascular effect .