Full Article
Evidence Summary
What is an Evidence Summary?
Key messages from scientific research that's ready to be acted on
Got It, Hide thisIn people with, or at risk of, heart disease, fatty acid supplements do not prevent heart attacks or death
Chowdhury R, Warnakula S, Kunutsor S, et al. Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis. Ann Intern Med. 2014;160:398-406.
Review question
Do fatty acid supplements reduce risk of events related to heart disease, such as heart attacks or death?
Background
Fatty acids help our bodies grow and develop. They are also thought to improve our health, including reducing blood fats and risk of heart disease (e.g., coronary artery disease, angina, heart rhythm problems).
We get fatty acids, which include omega-3 and omega-6 polyunsaturated fatty acids and alpha-linolenic acid, from foods or supplements that contain fish, nut, flax seed or plant oils, such as sunflower oil, walnut oil and evening primrose oil.
How the review was done
The researchers did a systematic review, searching for studies that were published up to June 2013.
They found 27 randomized controlled trials with 105,085 people.
Most people had heart disease (e.g., coronary artery disease, angina, heart rhythm problems) or risk factors for heart disease (e.g., high blood pressure, diabetes, current smoker).
Treatments were omega-3 fatty acid supplements, including alpha-linolenic acid, and omega-6 fatty acid supplements.
Most treatments were compared with a placebo or other nut or plant oils, although some were compared with specific diets or dietary advice, or another treatment.
What the researchers found
Compared with placebo or other treatments, none of the fatty acid supplements reduced events related to heart disease, such as heart attack or death.
Conclusion
In people with, or at risk of, heart disease, use of fatty acid supplements does not reduce events related to heart disease, such as heart attacks or death.
Fatty acid supplements vs control* to reduce events related to heart disease (e.g., heart attack or death)
| Type of fatty acid supplement | Number of trials (people) | Rate of events with supplement | Rate of events with control | Absolute effect of fatty acid supplements† |
| Omega-3 (alpha-linolenic acid) | 4 trials (18,866 people) | 2.2% | 2.3% | No difference in effect |
| Omega-3 (other than alpha-linolenic acid) | 17 trials (76,580 people) | 6.3% | 6.7% | No difference in effect |
| Omega-6 | 8 trials (14,476 people) | 6.1% | 7.1% | No difference in effect |
*Control included placebo, other nut or plant oils, specific diets or dietary advice, or other treatments.
†Although the rates for the 2 groups look a little different, the differences were not statistically significant. This means that the differences could simply be due to chance rather than due to the different treatments.
Glossary
Chest pain due to reduced blood flow to the heart.
A harmless, inactive, and simulated treatment.
Studies where people are assigned to one of the treatments purely by chance.
Aspects making a condition more likely.
A comprehensive evaluation of the available research evidence on a particular topic.
Related Evidence Summaries
-
Self-monitoring reduces blood-sugar levels in patients with non-insulin-treated Type 2 diabetes
Journal of Diabetes Science and Technology (2018)
-
Culturally appropriate health education for people in ethnic minority groups with type 2 diabetes mellitus
Cochrane Database of Systematic Reviews (2014)
-
Self-monitoring of blood glucose in patients with type 2 diabetes mellitus who are not using insulin
Cochrane Database of Systematic Reviews (2012)
