How much do we know about omega-3 fatty acids (omega-3)?
Extensive research has been done on omega-3s, especially the types found in seafood (fish and shellfish) and fish oil supplements.
What Are Omega-3?
Omega-3s (short for omega-3 fatty acids) are a kind of fat found in foods and in the human body. They are also sold as dietary supplements.
Types of Omega-3 and Foods That Contain Them
Supplements That Contain Omega-3
Seafood vs. Supplements
The Federal Government’s Dietary Guidelines for Americans 2015–2020 recommends that adults eat 8 or more ounces of a variety of seafood (fish or shellfish) per week for the total package of nutrients seafood provides, and that some seafood choices with higher amounts of EPA and DHA be included. Smaller amounts of seafood are recommended for young children.
Use of Omega-3 Supplements in the United States
According to the 2012 National Health Interview Survey, which included a comprehensive survey on the use of complementary health approaches in the United States, fish oil supplements are the nonvitamin/nonmineral natural product most commonly taken by both adults and children. The survey findings indicated that about 7.8 percent of adults (18.8 million) and 1.1 percent of children age 4 to 17 (664,000) had taken a fish oil supplement in the previous 30 days.
What Do We Know About the Effectiveness of Omega-3?
Conditions Affecting the Circulatory System
Conditions Affecting the Brain, Nervous System, or Mental Health
Attention-Deficit Hyperactivity Disorder (ADHD)
Alzheimer’s Disease/Cognitive Impairment
Other Conditions Affecting the Brain, Nervous System, or Mental Health
Age-Related Macular Degeneration
Dry Eye Disease
What Do We Know About the Safety of Omega-3?
- Side effects of omega-3 supplements are usually mild. They include unpleasant taste, bad breath, bad-smelling sweat, headache, and gastrointestinal symptoms such as heartburn, nausea, and diarrhea.
- Several large studies have linked higher blood levels of long-chain omega-3s with higher risks of prostate cancer. However, other research has shown that men who frequently eat seafood have lower prostate cancer death rates and that dietary intakes of long-chain omega-3s aren’t associated with prostate cancer risk. The reason for these apparently conflicting findings is unclear.
- Omega-3 supplements may interact with drugs that affect blood clotting.
- It’s uncertain whether people with seafood allergies can safely take fish oil supplements.