Fish oil is one of the most widely used nutritional supplements in the United States. A survey by the National Institutes of Health (NIH) found that nearly 19 million adults swallowed a fish oil pill in the past month – that’s roughly one in 17; There are good reasons for this: Many supplements are plagued by inconclusive research, but fish oil does not belong to. Solid evidence suggests that fish oil supplements have health benefits and can even slow the aging process.
But before you jump on this trend, here are 8 facts you need to know in order to decide if fish oil is right for you.
What is fish oil?
As the name suggests, fish oil is essentially fat that is extracted from fish. The specific components of fish oil researchers are most interested in omega-3 fatty acids.
The number “3” stands for the position of an important carbon double bond in the molecular structure of the compound. The position of the bond differentiates the behavior of omega-3 fatty acids in the body from other omega-3 fatty acids such as omega-6 fatty acids, which come from plant sources, according to Harvard Medical School.
Omega-3 fatty acids come in three main varieties: alpha-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Again, these three types of omega-3s come from different sources – EPA and DHA come from fish oil, while ALA is found in plant sources like flaxseed.
Which foods contain fish oil?
If you’re following a Mediterranean diet or pescatarianism, your diet is likely already high in omega-3s. But there are other natural sources of this essential nutrient that are not related to fish.
These are the best foods to consume to make sure you are getting enough omega-3 fatty acids:
- seafood: Fatty cold water fish is ideal. The best include tuna, mackerel, salmon, sardines, and herring.
- Nuts and seeds: Walnuts, flax seeds, and chia seeds are all excellent sources.
- Vegetable oils: Soybean oil, flaxseed oil, and rapeseed oil all contain omega-3 fatty acids.
- Fortified foods: This can include yogurt, juice, milk, soy drinks, and eggs.
Salmon is high in omega-3 fatty acids and relatively low in mercury. Enn Li Photography Getty Images
If you don’t eat fish, have a nut allergy, or otherwise think you are not getting enough omega-3 fatty acids in your daily diet, consider taking omega-3 supplements – usually fish oil capsules.
What are fish oil supplements?
Food supplements to increase omega-3 consumption are usually made from fish oil and most commonly from cod liver oil, krill oil or even from algae oil. Algae oil is a vegetable source of omega-3s that contains both EPA and DHA.
While scientists aren’t sure whether a certain type of omega-3 is better for you than another, there is evidence that omega-3 fatty acids are – at least in part – the reason why regular consumption of fish, like in the Mediterranean diet, it is so good for your physical and mental health.
How do omega-3s affect mental health?
Your body uses omega-3s to build cell membranes, the basic receptacle for all of your body’s cellular processes, but some of your cells use more omega-3s than others. DHA levels are particularly high in brain cells, suggesting that they play an important role in brain health.
Here are four key ways omega-3 fatty acids can affect your brain:
- Neurogenesis and brain structure:
A 2014 review found that omega-3 fatty acids play a role in neurogenesis, or the formation of brain cells. People who consumed more fish oil tended to have higher amounts of gray matter in their brain. Evidence has also been found to suggest that both gray and white matter may be less prone to the effects of aging in people who consume more fish oil.
According to the National Institutes of Health, research shows that consuming more omega-3 fatty acids from food sources like fish can lower your risk of Alzheimer’s, dementia, and other cognitive health problems. But as the NIH researchers point out, the evidence for omega-3 fatty acids and the defense against cognitive decline is mixed.
A 2015 study showed that two to four years of omega-3 supplementation did not prevent cognitive decline in 4,000 older participants. However, the study did not test the effects of dietary omega-3 fatty acids – a major limitation.
However, researchers have found stronger evidence that omega-3 supplementation helps with depression. In a review of multiple studies involving more than 10,000 participants, researchers found that taking omega-3 supplements in conjunction with conventional treatments for depression was significantly better at relieving symptoms than conventional therapies alone.
There is also evidence that omega-3 fatty acids can curb aggressive behavior. In Australia, researchers are testing the idea that omega-3 supplementation can reduce violent incidents in Australian prisons. In a pilot study published in 2015 in the journal PLOS ONE, the team found that omega-3 levels varied between individual Australian prisoners, and lower omega-3 levels correlated with increased aggression and signs of attention-deficit hyperactivity disorder, or ADHD . The jury has yet to clarify their overarching hypothesis – a study published earlier this year evaluating the feasibility of a randomized, double-blind, placebo-controlled trial of omega-3 supplements in prisoners suggests that these supplements reduce violent or aggressive behavior in inmates – but The sample size in the feasibility study is far too small to reach a definitive conclusion.
Why Are Omega-3 Fatty Acids Good For The Body?
Omega-3 fatty acids are not only a building block of cell membranes, but also play an important role in ensuring the health of the respiratory tract, the cardiovascular system, the immune system and the functioning of the endocrine system.
Here are three of the most important omega-3 benefits for the body:
According to the NIH, both dietary and supplemented omega-3 sources are beneficial for cardiovascular health.
One or two servings of seafood per week is recommended by the American Heart Association (AHA) to help reduce the risk of cardiovascular problems. And both dietary and supplemental omega-3 fatty acids have been shown to reduce triglycerides – a particle in the blood that carries fat around the body.
A large clinical study of 26,000 participants found that omega-3 supplementation reduced heart attacks by 28 percent and deaths from heart attacks by 50 percent – there is also evidence that omega-3 fatty acids reduce the risk of cardiac arrhythmias – a potentially fatal one Disease in which the heart falls into the wrong rhythm.
For patients with heart disease, the AHA recommends 1 gram of EPA and DHA per day. Ideally, these fatty acids are included as part of the diet, but dietary supplements work too. However, the AHA does not recommend nutritional supplements for those who are not at high risk for cardiovascular disease.
Just like brain cells, the retinal cells in the eye have a particularly high level of DHA. People who consume high levels of omega-3 fatty acids from their diet can reduce their chances of developing age-related macular degeneration, a condition that eventually leads to blindness. This condition, in which the retina deteriorates, is a major cause of the decline in eyesight in the elderly. But you have to start the way you want to continue: According to the NIH, there is no evidence that dietary supplements prevent the problem from getting worse once it starts.
Brain and retinal cells are not the only ones in the body with particularly high levels of DHA. The proportion of this fatty acid is also particularly high in the sperm cells. Studies suggest that omega-3 supplementation can support male reproductive health and increase sperm fitness.
Men aren’t the only beneficiaries. Between 8 and 12 ounces of seafood per week during pregnancy and breastfeeding can also be of significant benefit to the unborn baby. Omega-3 supplements can increase birth weight and length of pregnancy, which can be beneficial for infant health, according to the NIH.
You can get omega-3 fatty acids from both foods and supplements. John Lawson, Belhaven / Getty Images
Are Fish Oil Supplements Good For You?
It depends on who you ask. The evidence for omega-3s is strong, but the NIH and other health research institutes say the best way to consume omega-3s is to eat fish instead of taking fish oil supplements.
What is not controversial, however, is whether fish oil supplements increase omega-3 levels – they do.
How long does it take for fish oil supplements to work?
Fish oil supplements seem to work, but it’s not clear how long it takes for them to work, according to Carol Haggans, a nutritionist at the NIH Office of Dietary Supplements. Part of this has to do with the studies we have available to suggest that fish oil supplements are useful in the first place.
“Most studies examining the health effects of fish oil on conditions like cardiovascular disease take many years, about 5 years or more,” she told Inverse. “The idea is to increase your omega-3 fatty acid intake to see if they have long-term health benefits.”
There are some studies that have tested omega-3 supplements over shorter periods of time. For example, a 2011 study found that omega-3 fatty acids reduced inflammation and anxiety in a group of 68 students after just 12 weeks.
Can you take too much fish oil?
According to the NIH, there is no fixed recommended daily allowance for DHA or EPA, the omega-3 fatty acids found primarily in fish oil. However, the US Food and Drug Administration sets an upper limit of 3 grams of DHA and EPA combined per day.
You should speak to your doctor before choosing omega-3 supplements, says the NIH. These supplements can interact with prescription drugs, including warfarin and other anticoagulant drugs, and potentially cause bleeding problems, according to the NIH.
However, at low doses, the side effects of fish oil supplements are usually minimal. But they can be: bad breath, bad taste in the mouth, nausea, stomach discomfort, heartburn, diarrhea, headache and smelly sweat.
The Inverse Analysis – Ultimately, the evidence for fish oil supplements mirrors the evidence for a Mediterranean diet high in oily fish, nuts, and plants. While this diet isn’t for everyone, the evidence is good enough to suggest that sticking to this diet will ultimately benefit your health – from your brain to your gut to your heart.