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 .
Mediterranean alpha-linolenic acid-rich diet in secondary prevention of coronary heart disease
In a prospect i ve , r and omised single-blinded secondary prevention trial we compared the effect of a Mediterranean alpha-linolenic acid-rich diet to the usual post-infa rct prudent diet .  After a first myocardial infa rct ion , patients were r and omly assigned to the experimental ( n = 302 ) or control group ( n = 303 ) . Patients were seen again 8 weeks after r and omisation , and each year for 5 years . The experimental group consumed significantly less lipids , saturated fat , cholesterol  , and  linoleic acid  but more  oleic  and  alpha-linolenic acids  confirmed by measurements in plasma . Serum lipids , blood pressure , and body mass index remained similar in the 2 groups . In the experimental group , plasma levels of albumin , vitamin E , and vitamin C were increased , and granulocyte count decreased . After a mean follow up of 27 months , there were 16 cardiac deaths in the control and 3 in the experimental group ; 17 non-fatal myocardial infa rct ion in the control and 5 in the experimental groups : a risk ratio for these two main endpoints combined of 0.27 ( 95 % CI 0.12 - 0.59 , p = 0.001 ) after adjustment for prognostic variables . Overall mortality was 20 in the control , 8 in the experimental group , an adjusted risk ratio of 0.30 ( 95 % CI 0.11 - 0.82 , p = 0.02 ) . An alpha-linolenic acid-rich Mediterranean diet seems to be more efficient than presently used diets in the secondary prevention of coronary events and death
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 .