Randomized clinical trials dating back to the GISSI Prevenzione study have cemented a role for omega-3s in cardiovascular disease. But further studies have also pointed to populations in whom fish or supplements seem to have no added benefits.
UPDATED WITH COMMENTARY // During a conference call announcing the results, Amarin reported that the 2-g and 4-g dose of AMR101, as the ethyl-EPA is currently known, reduced triglyceride levels 20% and 33%, respectively, all without a significant increase in LDL-cholesterol levels. Experts heartwire spoke with were mixed on the new drug, with some believing the drug represents a new advance, while others adopted a more wait-and-see approach.
UPDATED WITH COMMENTARY // In a randomized trial, taking the Lovaza prescription form of fish-oil supplement at 4 g/day for six months didn't protect against symptomatic recurrences of paroxysmal atrial fibrillation.
The findings could help explain the "quite modest" but significant clinical benefits of omega-3 polyunsaturated fatty acids, typically given as fish-oil capsules, that have been observed in heart failure.
UPDATED WITH COMMENTARY // The investigators say the negative findings are likely the result of the optimal medical therapy that patients in the trial were receiving following their index MI. All patients were treated with "state-of-the-art" therapy and this might explain the discrepancy with previous studies that suggested n-3 fatty acids, particularly EPA, might be cardioprotective following MI.
A new study linking high adherence to a Mediterranean-like diet to better heart-rate variability may get researchers one step closer to understanding just how this diet works to reduce cardiovascular events.
Omega-3 PUFAs from fish oil, started a day or two before surgery, didn't protect against the common post-CABG complication in a >200-patient placebo-controlled trial; on the other hand, researchers reported elsewhere at the HRS sessions that a much longer daily intake of fish-oil caps by patients with symptomatic SVT seemed to help stabilize the atria at electrophysiologic testing.
The researchers suggest further study is still needed, as it is unclear whether higher doses of omega-3 fatty acids or setraline, longer treatment, or a different ratio of EPA to DHA would produce favorable results.
Are the data not shouting loud enough, or is cardiology hard of herring? Omega-3 fatty acids may have only a modest treatment effect in heart failure, but they've performed swimmingly in randomized and observational studies considering how few new HF drugs have been reeled in lately.
An association seen between mercury levels and blood pressure, even after considering omega-3s and selenium, has researchers warning about the need to weigh the risks and benefits of fish consumption and to steer clear of bigger predators.
Study participants will be randomized to one of four groups: daily vitamin D (2000 IU) and fish oil (1 g); daily vitamin D and fish-oil placebo; daily vitamin-D placebo and fish oil; or daily vitamin-D placebo and fish-oil placebo and followed for five years.
A new observational study in Sweden has found that eating oily fish once a week seems to protect middle-aged and older men against developing heart failure, but eating it more often than that did not give a greater benefit.
Evidence for health benefits from fish is inconsistent, and fish stocks are projected to be depleted in 40 years, so urging increased consumption is not warranted, a review concludes; however, the AHA still advocates two servings of fish per week. (Jenkins JA et al. CMAJ2009; 180:633-637.)
A new AHA new scientific advisory is recommending omega-6 PUFAs make up 5% to 10% of daily calorie intake and discounts the health benefits of reduced omega-6:3 ratios promulgated by diet and nutrition books. (Harris WS et al. Circulation; published online before print January 26, 2009.)
The analysis, driven primarily by the results of two large clinical trials, showed that fish oil was associated with a significant 20% reduction in the risk of cardiac death but did not reduce the incidence of appropriate ICD interventions or sudden cardiac death. (León H et al. BMJ 2009; published online before print December 23, 2008.)
Omega-3 fatty-acid supplementation is an "effective, safe, simple, and cheap" option for patients with chronic heart failure, say investigators. Statin therapy, on the other hand, should not be prescribed in heart-failure patients. (European Society of Cardiology Congress 2008. Lancet; published online before print August 31, 2008.)
Study authors say that the public-health message about smoking risks is likely not reaching Alaska Eskimos, who are also becoming more sedentary and eating fewer omega-3-rich traditional foods. Subclinical atherosclerosis is much higher in this group than in age-matched populations elsewhere in the US. (Cutchins A et al. Stroke; published online before print July 10, 2008.)
UPDATED WITH INTERVIEW // A new study has shown that fish and omega-3 fatty-acid consumption are associated with "more optimal" values of various HRV indices, thus shedding some light on the specific mechanisms by which fish and fish oil lower the risk of arrhythmic events. (Mozaffarian D et al. Circulation 2008; 117:1130-1137.)
A meta-analysis finds significant heterogeneity between trials, suggesting fish oil might benefit some cardiac patients but not others. Currently, say investigators, the use of fish oils in patients with implantable cardioverter defibrillators appears to warrant caution. (Jenkins DJ et al. CMAJ 2008; 178:157-164.)