Houston, Texas, USA : Increasing the intake of omega-3 long-chain polyunsaturated fatty acids (LCPUFA) during pregnancy reduces the risk of premature births according to the findings of a new Cochrane Review published today.
Premature birth is the leading cause of death for children under 5 years old worldwide, accounting for close to one million deaths annually. Premature babies are at higher risk of a range of long-term conditions including visual impairment, developmental delay and learning difficulties.
“We know premature birth is a critical global health issue, with an estimated 15 million babies born too early each year,” explains Associate Professor Philippa Middleton from Cochrane Pregnancy and Childbirth and the South Australian Health and Medical Research Institute (SAHMRI). “While the length of most pregnancies is between 38 and 42 weeks, premature babies are those born before the 37-week mark—and the earlier a baby is born, the greater the risk of death or poor health.”
Associate Professor Middleton and a team of Cochrane researchers have been looking closely at long-chain omega-3 fats and their role in reducing the risk of premature births—particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) found in fatty fish and fish oil supplements. They looked at 70 randomised trials and found that for pregnant women, increasing the daily intake of long-chain omega-3s:
lowers the risk of having a premature baby (less than 37 weeks) by 11% (from 134 per 1000 to 119 per 1000 births)
lowers the risk of having an early premature baby (less than 34 weeks) by 42% (from 46 per 1000 to 27 per 1000 births)
reduces the risk of having a small baby (less than 2500g) by 10%
“There are not many options for preventing premature birth, so these new findings are very important for pregnant women, babies and the health professionals who care for them,” Associate Professor Middleton says. “We don’t yet fully understand the causes of premature labour, so predicting and preventing early birth has always been a challenge. This is one of the reasons omega-3 supplementation in pregnancy is of such great interest to researchers around the world.”
The Cochrane review published today was first undertaken back in 2006, and concluded there wasn’t enough evidence to support the routine use of omega-3 fatty acid supplements during pregnancy. Over a decade on, this updated review concludes that there’s high quality evidence for omega-3 supplementation being an effective strategy for preventing preterm birth.
“Many pregnant women in the UK are already taking omega-3 supplements by personal choice rather than as a result of advice from health professionals,” says Associate Professor Middleton. “It’s worth noting though that many supplements currently on the market don’t contain the optimal dose or type of omega-3 for preventing premature birth. Our review found the optimum dose was a daily supplement containing between 500 and 1000 milligrams (mg) of long-chain omega-3 fats (containing at least 500mg of DHA) starting at 12 weeks of pregnancy.”
“Ultimately, we hope this review will make a real contribution to the evidence base we need to reduce premature births, which continue to be one of the most pressing and intractable maternal and child health problems in every country around the world.”
Citation: Middleton P, Gomersall JC, Gould JF, Shepherd E, Olsen SF, Makrides M. Omega-3 fatty acid addition during pregnancy. Cochrane Database of Systematic Reviews, Issue 11. Art. No.: CD003402. DOI: 10.1002/14651858.CD003402.pub3
Omega-3 fatty acids (omega-3s), the Bottom Line
Extensive research has been done on omega-3s, especially the types found in seafood (fish and shellfish) and fish oil supplements.
What we know about the effectiveness of omega-3 supplements
- Research indicates that omega-3 supplements don’t reduce the risk of heart disease. However, people who eat seafood one to four times a week are less likely to die of heart disease.
- High doses of omega-3s can reduce levels of triglycerides.
- Omega-3 supplements may help relieve symptoms of rheumatoid arthritis.
- Omega-3 supplements have not been convincingly shown to slow the progression of the eye disease age-related macular degeneration.
- For most other conditions for which omega-3 supplements have been studied, the evidence is inconclusive or doesn’t indicate that omega-3s are beneficial.
What do we know about the safety of omega-3 supplements?
- Omega-3s usually produce only mild side effects, if any.
- There’s conflicting evidence on whether omega-3s might influence the risk of prostate cancer.
- If you’re taking medicine that affects blood clotting or if you’re allergic to fish or shellfish, consult your health care provider before taking omega-3 supplements.
What Are Omega-3s?
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-3s and Foods That Contain Them
- Supplements That Contain Omega-3s
- Seafood vs. Supplements
The U.S. 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 a 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 We Know About the Effectiveness of Omega-3s
Omega-3s are effective in the following conditions according to research and the NIH.
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 We Know About the Safety of Omega-3s
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.