Omega-3 Fatty Acids and Brain Function: A Systematic Review

The scientific paper Effects of Omega-3 Polyunsaturated Fatty Acids on Brain Functions: A Systematic Review by Dighriri et al. explores the role of omega-3 fatty acids—particularly DHA, EPA, and ALA—in maintaining and enhancing brain health. Given that omega-3s are crucial components of brain structure and function, the authors aimed to assess how supplementation impacts memory, cognition, and overall mental well-being across different populations. Building on previous research showing the brain’s high lipid content and the importance of DHA in neuronal communication, this systematic review carefully examined randomized controlled trials to present updated, evidence-based insights into the cognitive benefits of omega-3 intake.

Omega-3 fatty acids are a special type of healthy fat that our bodies can't make on their own. We must get them through food or supplements. This study looked closely at three types of omega-3s:

• Docosahexaenoic acid (DHA)
• Eicosapentaenoic acid (EPA)
• Alpha-linolenic acid (ALA)

DHA is especially important for the brain. According to the scientific paper, "DHA comprises approximately 40% of total fatty acids in the brain, while EPA comprises less than 1%."

Omega-3s are critical because about  50-60% of the brain’s weight is made of fat  , and 35% of that fat is made up of omega-3 PUFAs.

DHA helps brain cells send messages to each other by making the cell membranes more flexible. It also protects brain cells from dying early by fighting off harmful molecules called reactive oxygen species. The researchers noted that omega-3s "promote cognition, neuronal preservation, and protection against neurodegeneration."

In this systematic review, the researchers set out to answer one crucial question: Does taking omega-3 supplements really help brain function? They hoped to gather enough evidence to show whether omega-3s can improve memory, thinking, and mental well-being.

The researchers followed strict scientific steps to gather and review the best studies available. They searched through major databases like PubMed, Cochrane, and EBSCO for randomized controlled trials (RCTs) published between 2010 and 2022.

The search included keywords like "omega-3," "DHA," "EPA," "cognition," and "mental health" to make sure no vital study was missed. Only high-quality RCTs that compared omega-3 supplements with a placebo in adults were selected.

The final review included 9 studies with a total of 1,319 participants. The researchers used a special tool called the Cochrane Collaboration bias assessment tool to make sure each study was trustworthy. As they explained, "All trials used appropriate randomization protocols; six experiments used the allocation concealment approach; all trials were double-blind."

Importantly, no studies were excluded because of bias concerns, meaning the overall quality of the evidence was strong.

Many reviewed studies found that omega-3s helped participants remember things better and learn faster.

For example:

• One study involving older adults found that "a 24-week period of a 900 mg/day dose of DHA enhanced learning and memory performance in patients and is a valuable supplement that improves cognitive health as people age."
• In another study, participants who took DHA supplements had their blood DHA levels nearly quadruple, and this increase was directly linked to better scores on memory tests.

These results suggest that boosting DHA levels in the body can make a real difference for memory, especially as we get older.

Taking omega-3s also helped improve how blood flows through the brain during mental tasks.

In one study, participants who took fish oil supplements showed "considerably higher levels of oxyhemoglobin and overall hemoglobin levels," which signals stronger blood circulation while thinking or solving problems.

Good blood flow is crucial because it helps deliver more oxygen and nutrients to brain cells, keeping them healthy and energized during challenging mental activities.

The review found that older adults and lonelier individuals seemed to benefit the most from omega-3 supplementation.

• Older participants who took fish oil supplements had "a 26% improvement in executive functions" compared to those who took a placebo.
• Another study found that lonely individuals—who often experience faster memory loss—showed better memory performance after taking omega-3s. Specifically, "loneliness-related episodic memory impairments were reduced by omega-3 supplementation, especially at a high dose (2.5 g/day)."

This shows that omega-3 supplements may be beneficial for people who are more vulnerable to memory decline.

While the benefits were clear in older and at-risk groups, the results were mixed for healthy adults with no memory problems.

One study concluded, "A moderate dose of omega-3 for a moderate period did not impact neuropsychological function or brain morphology" in middle-aged healthy participants.

This means that if your brain is already functioning well, omega-3 supplements might not make a big difference — at least in the short term. However, the improvements could be more noticeable for people with lower omega-3 levels or early signs of memory loss.

This scientific paper strongly supports the idea that omega-3s can help protect and improve brain function, especially as we age or face mental challenges like loneliness.

The researchers pointed out that omega-3s are not only effective but also very safe. They explained, "Omega-3 treatments are advantageous, well-tolerated, and risk-free."

One of their key recommendations is to encourage people to get omega-3s naturally through food. As the study states, "We suggest that natural omega-3 consumption through the diet should be promoted."

Here are some foods rich in omega-3s:

• Fatty fish (like salmon, mackerel, and sardines)
• Chia seeds
• Flaxseeds
• Walnuts

The U.S. Food and Drug Administration (FDA) also recommends that adults consume up to 3 grams of omega-3s daily, with no more than 2 grams of supplements.

Eating more omega-3-rich foods or using high-quality supplements could help keep the brain healthier, sharper, and more resilient over time.

This scientific paper provides strong evidence that omega-3 fatty acids, especially DHA and EPA, are powerful allies for brain health. Omega-3s can help improve memory, learning, and thinking skills while also boosting blood flow to the brain.

Older adults, lonely individuals, and people with lower omega-3 intake seem to benefit the most, showing better mental sharpness and memory after supplementation.

Although healthy young adults might not see dramatic changes, maintaining good omega-3 levels early in life could still help protect the brain from aging-related decline later on.

Adding more fish and omega-3-rich foods to your diet — or choosing the right supplement — can be a simple, safe, and effective way to care for your brain health in the long term.