Is Omega-3 fish oil consumption beneficial for brain health as we age?

Fish oil is an over-the-counter supplement extracted from fatty fish like anchovies, mackerel, salmon and sardines.

What is fish oil omega-3?

Fish oil is mainly composed of omega-3 fatty acids – docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). It is well known that these are beneficial for the heart and the skin. However, it also incredibly impacts the brain, especially regarding mild memory loss and depression.

In the body, these two fatty acids play a powerful anti-inflammatory role. Additionally, they play a crucial role in heart health and human development [1].

Fish oil and fatty fish are the only sources of DHA and EPA in the human diet. Because most individuals consume the recommended amounts of fish, many likely need more DHA and EPA in their diets [2].

The body can make EPA and DHA from another omega-3 called alpha-linolenic acid (ALA). ALA is found in several food sources, like chia seeds, canola oil, flaxseeds, soybeans, soybean oil and walnuts. It has been reported that humans cannot convert ALA to EPA or DHA very efficiently, with estimates indicating that less than ten percent of ALA consumed is transformed to EPA or DHA [3]. In this case, omega-3 fatty acids might be a good option, particularly for those who don’t consume much fish [4].

What are the effects of omega-3s on the brain?

All stages of life require omega-3 fatty acids EPA and DHA for normal brain function and development. There is no doubt that EPA and DHA have a crucial role in the brain development of a baby. According to several studies, pregnant women who consume fish or use fish oil during pregnancy have children who score higher on intelligence and brain function tests [56].

Maintaining normal brain function throughout life is also dependent on these fatty acids. Brain cells contain abundant amounts of these proteins in their cell membranes, which facilitates communication between them and preserves their health.

Animals fed diets without omega-3 fatty acids have lower levels of DHA in their brains, thus suffering from memory and learning deficits [7]. Meanwhile, studies have shown that older adults with lower DHA levels in their blood are more likely to have smaller brains, which is a sign of accelerated brain aging. A diet high in omega-3 fatty acids prevents some of these negative effects on brain development and function.

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Fish oil may benefit mild memory loss

Omega-3 fatty acids in fish oil play an important role in brain function and development. Also, fish oil is said to enhance brain function in individuals with memory problems such as Alzheimer’s disease.

Millions of elderly adults suffer from Alzheimer’s disease, which affects their brain function and quality of life. The discovery of a supplement that could optimise brain function in this population is likely to be a significant, life-changing event.

Unfortunately, a review of the research didn’t find convincing evidence that omega-3 supplements improve brain function in those suffering from Alzheimer’s [8]. In contrast, a number of studies have suggested that fish oil supplements may improve brain function in people with mild cognitive impairment (MCI) or age-related cognitive decline [9].

Although these conditions aren’t as severe as Alzheimer’s disease, they still cause memory loss and other difficulties with the brain. In one study, 485 older adults with cognitive decline were given 900 mg of DHA or a placebo daily for one year. Tests of memory and learning showed that people who took DHA after 24 weeks performed better [10].

Another study investigated the effects of taking 24 weeks of 1.8 grams of omega-3s from fish oil supplements. Researchers found positive effects in brain function in individuals with MCI, but not in those with Alzheimer’s [11].

This study suggests taking fish oil supplements at the beginning of brain function decline is most beneficial. The brain may not benefit from it if you wait too long.

Depression may be improved by fish oil

In the future, non-medicinal interventions will likely become more popular as treatments for depression and other mental health disorders are sought. Research has long linked fish oil to better mental health, but does it stand up to scrutiny?

The results of a review of clinical studies found that taking fish oil supplements improved depressive symptoms similar to antidepressant medication [12]. Depressive symptoms seem to improve most dramatically in people taking antidepressants as well. 

In addition, higher doses of EPA resulted in more significant effects. The mechanism by which EPA and omega-3s improve depression symptoms is still unclear.

There has been speculation that it has something to do with their effects on brain serotonin receptors and serotonin. Omega-3s from fish oil may also improve depression symptoms through anti-inflammatory properties [13].

There is also evidence that fish oil may be beneficial for other mental health conditions like bipolar disorder and borderline personality disorder. There is, however, a need for more high-quality research before the medical community can make definitive recommendations [14].

Brain function in healthy people is not improved by fish oil

Fish oil benefits people with Alzheimer’s disease and mild declines in brain function, but many people with normal brain function are curious about its effects. Observational studies report that eating more omega-3 fatty acids from fish significantly correlates with better brain function. Nevertheless, these studies evaluated fish consumption rather than fish oil supplements. Additionally, correlational studies like these can’t prove causality [15].

Fish oil supplements do not appear to improve brain function in healthy individuals without memory problems, according to the majority of higher-quality controlled studies. The results of a study that included 159 young adults showed that taking supplements containing 1 gram of fish oil per day did not boost brain function [16].

Likewise, several studies have shown that taking fish oil supplements does not improve brain function in people with no memory problems [1718]. 

Does fish oil benefit your brain as you age?

In the case of mild brain decline or depression, you may want to consider taking fish oil. While fish oil supplements may have other health benefits, these two groups are likely to benefit the most from them.

In order to see benefits in brain function and mental health, you don’t need to take a certain amount of omega-3s from fish oil. There was a wide variation in the amounts used in each study.

Omega-3 fatty acid supplements should not exceed 3,000 mg per day as set by the US Food and Drug Administration. A higher recommendation has been set by the EFSA (European Food Safety Authority), at a maximum of 5,000 mg per day [1920].

In terms of omega-3 fatty acids, 1,000–2,000 mg of fish oil is a good starting point that is well below the upper limit recommended by experts. A fish oil supplement with a higher amount of EPA is recommended for people with depression.

When evaluating fish oil supplements, it is imperative to read labels carefully [21]. Some brands may contain less than 500 mg of essential omega-3 fatty acids in a 1,000-mg fish oil capsule.

It is generally considered safe to take fish oil supplements at dosages below the ones mentioned earlier. Nonetheless, fish oil supplements should always be discussed with a doctor before taking them. Taking blood-thinning medications or undergoing surgery may make this especially important because of their potential effects on blood clotting.

[1] https://www.ncbi.nlm.nih.gov/pubmed/22332096
[2] https://www.ncbi.nlm.nih.gov/pubmed/24694001
[3] https://www.ncbi.nlm.nih.gov/pubmed/9637947
[4] https://www.healthline.com/nutrition/17-health-benefits-of-omega-3
[5] https://www.ncbi.nlm.nih.gov/pubmed/12509593
[6] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1281283/
[7] https://www.ncbi.nlm.nih.gov/pubmed/17392137
[8] https://www.ncbi.nlm.nih.gov/pubmed/27063583
[9] https://www.ncbi.nlm.nih.gov/pubmed/22305186
[10] https://www.ncbi.nlm.nih.gov/pubmed/20434961
[11] https://www.ncbi.nlm.nih.gov/pubmed/18573585
[12] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4872453/
[13] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3976923/
[14] https://www.ncbi.nlm.nih.gov/pubmed/12505817
[15] https://www.ncbi.nlm.nih.gov/pubmed/14745067
[16] https://www.ncbi.nlm.nih.gov/pubmed/21864417
[17] https://www.ncbi.nlm.nih.gov/pubmed/18678826
[18] https://www.ncbi.nlm.nih.gov/pubmed/20410089
[19] https://www.ncbi.nlm.nih.gov/pubmed/12438303
[20] http://onlinelibrary.wiley.com/doi/10.2903/j.efsa.2012.2815/epdf
[21] https://www.healthline.com/nutrition/omega-3-supplement-guide

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