BACKGROUND AND PURPOSE:

• Manson et al. (NEJM, 2018) sought to determine whether marine n-3 (omega-3) fatty acids reduce risk for cardiovascular disease and cancer in the general population

METHODS:

• Randomized, double-blind placebo-controlled trial (RCT)
• VITAL trial (VITamin D and OmegA-3 TriaL)
• Two-by-two factorial design
• Vitamin D₃: 2000 IU per day
• Marine n-3 fatty acids: 1 g per day as a fish-oil capsule containing 840 mg of n−3 fatty acids, including 460 mg of eicosapentaenoic acid [EPA] and 380 mg of docosahexaenoic acid [DHA])
• Participants
• Men: ≥50 years
• Women: ≥55 years
• Primary outcomes
• Major cardiovascular events (composite of myocardial infarction, stroke, or death from cardiovascular causes)
• Invasive cancer (any)
• Secondary outcomes
• Site-specific cancers | Death from cancer | Additional cardiovascular events

RESULTS:

• 25,871 participants underwent randomization, including 5106 participants
  • There was a median follow-up of 5.3 years

There were no differences for primary outcomes

• Major cardiovascular event
  • 386 participants in the n−3 group
  • 419 in the placebo group
  • hazard ratio (HR) 0.92 (95% CI, 0.80 to 1.06; P=0.24)
• Invasive cancer
  • 820 participants in the n−3 group
  • 797 in the placebo group
  • HR 1.03 (95% CI, 0.93 to 1.13; P=0.56)

There were no significant differences for secondary outcomes

• In the analyses of key secondary end points, HRs were as follows
  • Expanded composite end point of cardiovascular events: 0.93 (95% CI, 0.82 to 1.04)
  • Total myocardial infarction: 0.72 (95% CI, 0.59 to 0.90)
  • Total stroke: 1.04 (95% CI, 0.83 to 1.31)
  • Death from cardiovascular causes: 0.96 (95% CI, 0.76 to 1.21)
  • Death from cancer: 0.97 (341 deaths from cancer; 95% CI, 0.79 to 1.20)
• Death from any cause: HR 1.02 (95% CI, 0.90 to 1.15)
• No excess risks of bleeding or other serious adverse events were observed

CONCLUSION:

• Supplementation with n-3 fatty acids did not reduce risk of major cardiovascular events or cancer, compared to placebo

Learn More – Primary Sources:

Marine n−3 Fatty Acids and Prevention of Cardiovascular Disease and Cancer

Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease

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