No CVD Benefit With Omega-3 Fatty Acids
According to the Age-Related Eye Disease Study 2 (AREDS2: Published March 17, 2014
in JAMA Internal Medicine
A moderate
dose of long-chain omega-3 fatty acids supplementing
the diets of elderly patients failed to
reduce CVD risk.
Taking omega-3
fatty-acid supplements for nearly five years failed to reduce the incidence of CVD
mortality, MI, stroke, unstable angina, revascularization, CHF
hospitalizations, and resuscitated cardiac arrest.
The trial is an ancillary
study which includes 4203 men and women treated at US ophthalmology clinics.
As part of the
factorial-design randomized trial, individuals were treated with 350-mg
docosahexaenoic acid and 650-mg eicosapentaenoic acid (EPA) for 4.8
years. Approximately 20% of randomized participants had a history of CVD.
Participants
were also treated with the macular xanthophylls lutein and zeaxanthin to
determine impact on CV outcomes.
Regarding the
primary end point, a composite of CV mortality and morbidity, supplementation
with omega-3 fatty acids failed to provide any reduction in clinical events.
In terms of
secondary end points, which included multiple combinations of components of the
primary end point, there was also no reduction in events.
In an
exploratory analysis, the researchers did not observe any significant
difference in clinical-event rates among those with high or normal
triglycerides.
Supplementation with
lutein and zeaxanthin also failed to reduce CV morbidity and mortality.
In an editorial[2], Drs Evangelos Rizos (University Hospital of Ioannina,
Greece) and Evangelia Ntzani (University of Ioannina School of
Medicine, Greece) point out that sales of omega-3 fatty acids were over $25
billion in 2011 and continue to
grow.
The US Food and Drug Administration (FDA) has approved omega-3 fatty acids for hypertriglyceridemia,
and the European Medicines
Agency has approved them as
adjuvant treatment in post-MI patients. However, their use for CV-risk
modification remains controversial.
"What is evident so
far is that omega-3 supplementation with daily doses close to 1 g in patients
with or without established CVD shows no clear, considerable benefit,"
write Rizos and Ntzani. "Continuing to conduct more randomized, controlled
trials seems unjustified." The field, they add, would be better served by
conducting a large meta-analysis or focusing on higher-risk populations, such
as those with triglycerides greater than 200 mg/dL.
To heartwire , Bonds said her recommendations for patients would be to focus
on consuming a heart-healthy diet that includes fish, which the editorialists
agree with, given the epidemiologic evidence supporting whole-fish consumption.
Last October, an FDA advisory panel voted against approval of an expanded indication for a highly
purified ethyl ester of EPA for use in combination with a statin in patients
with mixed dyslipidemia and CHD or a CHD risk equivalent. Despite reducing
lipid parameters, the panel was concerned about the lack of benefit on hard CV
outcomes.
