You may have been hearing about the miracles of omega-3 for years, but what does the science really say? Is it as good as they say? Should we take supplements?
Omega-3 fatty acids are essential nutrients. That means we need them to function properly and our bodies can’t make them. Therefore, we completely depend on implementing it in ourselves from food.
But let’s start by defining exactly…
What is? Types?
Omega-3 fatty acids are a type of fat, a group of polyunsaturated fatty acids that are important for a number of functions in the body. The structure of our cells, more specifically in the membrane, contains omega-3 fatty acids. They are mostly found in sperm, retina and brain cells. What you may not have known is that there are several types of omega-3. That’s right, when we talk about “omega-3” we are talking about a group of fatty acids, not a single molecule. Thus, the main 3 are the fatty acids EPA , DHA and ALA . EPA and DHA are found in shellfish, such as fatty fish (such as salmon, tuna, and trout) and shellfish (such as crab, mussels, and oysters). A different type of omega-3, called ALA, is found in other foods, such as flaxseed, walnuts, and chia seeds, as well as some vegetable oils (for example, canola and soy). Omega-3s are also available as dietary supplements; for example, fish oil supplements contain EPA and DHA, and flaxseed oil supplements contain ALA.
Moderate evidence has emerged for the health benefits of consuming shellfish. The health benefits of omega-3 dietary supplements are unclear.
What are Omega-3s for?
These acids provide calories to our body, that is, they are a source of energy. In addition, omega-3s can act on various parts of our body, from the skin to the cardiovascular, nervous, respiratory and endocrine systems.
Studies have shown that people who include fish in their diet (the main choice for omega-3 fatty acids) have a lower risk of various chronic diseases compared to people whose diet is poor in fish. However, it remains unclear whether dietary supplements containing omega-3 fatty acids have the same benefits.
Before we commented that omega-3 are part of the lipids that make up the cell membranes of organisms. This is important for our health, as they have anti-inflammatory functions, having some antioxidant activity.
On the other hand, the effects of omega-3s do not stop there, they are also vasodilators , which help lower blood pressure, and have a moderate anticoagulant effect, which is important for cardiovascular health.
And the list of claims goes on. They also clearly lower triglycerides and slightly increase HDL (“good”) cholesterol. From all this, one of the most commonly cited benefits of these fatty acids is understood, the improvement of cardiovascular health.
Another of the usual claims is about memory and cognition .
With all these benefits, it would be reasonable to point to omega-3 as one of the best supplements to consume, right? […]
What does science say?
[…] No. As we mentioned, people who consume more fish and nuts (rich in omega-3) also tend to have a more balanced diet. In this sense, they have less cardiovascular risk and less chance of dying from a heart attack, stroke or other cardiovascular event. However, omega-3 supplements have not shown this effect . Therefore, it is important to focus our efforts on the diet.
This detail about supplements, moreover, is well established through various studies (some well-designed meta-analyses ). So as of today we can say that there doesn’t seem to be any significant benefit.
A benefit of supplements
At this point, it seems important to reiterate that there is a proven benefit of omega-3 supplementation, and it is the decrease in triglycerides, so in people with cardiovascular risk factors (smoking, obesity, hypertension, diabetes, previous heart attacks, etc. .) in which triglycerides cannot be lowered with lifestyle changes, may be a valid option.
There is another benefit with some evidence behind it that may surprise you: on rheumatoid arthritis. That’s right, it seems that there is evidence that some of the symptoms can improve with omega-3 supplementation.
And for the view? Concentration? Dementia? Prostate? Cancer?
In everything that we have not mentioned prior to this section, the evidence is contradictory and it cannot be said that there are clear established benefits. The benefit in cognitive problems, or lack of concentration, dementia, or in any type of cancer is not clear.
It is true that the retina contains the omega-3 fatty acid DHA. Due to its deficiency, there may be vision and eye health problems. Macular degeneration is the cause of blindness, so the hypothesis is that it may be preventable by regular intake of omega-3 fatty acids. However, science has only scratched the surface of this so far, so we cannot say that this is a proven benefit.
Finally, let’s remember that one of the best established benefits is on cardiovascular health. But in that case, we are talking about diet, not supplementation.
And in pregnancy?
In pregnancy, the intake of vitamins and minerals, as well as omega-3 fatty acids, is certainly important for the mother to provide everything necessary for the normal development of the fetus. However, studies examining taking omega-3 fatty acid supplements during pregnancy have not produced convincing results about their benefits. There is some (weak) evidence that children are born with slightly higher body weights and that pregnancies last slightly longer. At the moment, no harmful effects have been shown either, but in these cases it is better to be cautious and not take things without a clear proven benefit and guaranteed safety.
Risks?
Side effects of omega-3 supplements are usually mild and can include: heartburn, nausea, diarrhea, poor sweating, bad breath, and headache. If a person is taking anticoagulants, drugs that prevent blood from clotting, taking high doses of omega-3 supplements can increase the risk of bleeding.
conclusion
Omega-3 fatty acids are essential in the diet. They are important for the function and maintenance of all cells in the body. Its main source is fish. Consuming omega-3 in a diet on a regular basis can help reduce the risk of cardiovascular disorders significantly. However, science has yet to provide proof of the same efficacy of omega-3 fatty acid supplements.
References:
Aung T, Halsey J, Kromhout D, et al. Associations of Omega-3 Fatty Acid Supplement Use With Cardiovascular Disease Risks: Meta-analysis of 10 Trials Involving 77 917 Individuals. JAMA Cardiol. 2018;3(3):225-234. doi:10.1001/jamacardio.2017.5205
He K, Song Y, Daviglus ML, et al. Accumulated evidence on fish consumption and coronary heart disease mortality: a meta-analysis of cohort studies. Circulation. 2004;109(22):2705-2711. doi:10.1161/01.CIR.0000132503.19410.6B
Bhatt DL, Steg PG, Miller M, et al. Cardiovascular Risk Reduction with Icosapent Ethyl for Hypertriglyceridemia. N Engl J Med. 2019;380(1):11-22. doi:10.1056/NEJMoa1812792
Omega-3 Fatty Acids. NIH: National Institutes of Health. https://ods.od.nih.gov/factsheets/Omega3FattyAcids-Consumer/
Omega-3 Supplements: In Depth. (2018). NCCIH: National Center for Complementary and Integrative Health. https://www.nccih.nih.gov/health/omega3-supplements-in-depth
Xue, Z., Sharpe, P., Hong, SP. et al. Production of omega-3 eicosapentaenoic acid by metabolic engineering of Yarrowia lipolytica. Nat Biotechnol 31, 734–740 (2013). https://doi.org/10.1038/nbt.2622
