EPA (eicosapentaenoic acid; 20:5(n-3)) and DHA (docosahexaenoic acid; 22:6(n-3))—are the main players when we talk about omega-3 fatty acids (FA). They're called “omega-3” from the location of the first double bond (non-saturation) sitting three carbons from the tail of their 20- or 22-carbon backbone. They are polyunsaturated fatty acids (PUFAs) and have been studied for decades for their physical and mental health benefits. They reduce cardiovascular risk–likely by reducing clotting–and have efficacy in mild-to-moderate depression, ADHD, and reduce symptoms of mild cognitive impairment. In the brain they 1) support neuroprotection and resolve inflammation, and 2) enhance membrane fluidity for better neuronal signaling. Unfortunately, 89% of US adults land in the “high-risk” zone for the Omega-3 Index, as measured by RBC values, with only 1% of adults in the “optimal” zone. This means Americans are not consuming nearly enough omega-3s to benefit from all they have to offer.

EPA is often referred to as anti-inflammatory but it would more accurately be called “inflammation-resolving.” It doesn’t block inflammation from starting, but once pro-inflammatory cytokines are raging, it helps dampen them and return your brain to baseline. Inflammation is a normal defense against infection and injury but can get out of control or keep going once the threat has passed. EPA (and eicosanoids/resolvins) stop the inflammatory process once the job is done. Why does this matter for attention? Chronic inflammation is linked to cognitive decline and depression and some theorize that inflammation causes or worsens inattention. Even better: EPA boosts attention with decent effect sizes of 0.3-0.9, varying by dose and subject group. In healthy adults, EPA >420mg/day improves executive function with an effect size of ~0.3. To fully dial down inflammation, target an intake of 1.3g EPA+DHA/day.

DHA plays a different role by improving neuronal membrane fluidity–it represents 90% of brain omega-3s, 30-40% of FA in gray matter, and 10-20% total brain lipids. DHA’s bent shape prevents tight phospholipid packing, boosting flexibility within the cell surface. This enhanced fluidity supports ion channel and receptor function, synaptic vesicle release, and membrane-bound enzyme activity. DHA may also specifically support dopaminergic neurons–critical, since dopamine is the most important molecule for maintaining focus. Omega-3 deficiency decreases pre- and post-synaptic dopamine receptors (D2R) in the frontal cortex–undermining your brain’s attentional circuitry.

Omega-3s are generally safe and well-tolerated; the most common side effects are fishy burps or mild GI upset–these can be reduced by taking with fatty meals, which also improves absorption and makes the form of the omega-3 (FFA, TG, rTG, PL, or EE) virtually irrelevant. Above 3g/day they can increase bleeding time at 3g/d–talk to your doctor if you are on blood thinners. At >4g/day they can increase risk of atrial fibrillation. Intake up to 5g/d is considered safe by the European Food Safety Authority, though most stick to 500mg - 2,000mg of EPA + DHA daily. Don’t rely solely on pills: eat salmon, anchovies, sardines, and trout which are low in methylmercury but high in omega-3s. These fatty fish consumed twice weekly in 6oz servings adds an extra 3g EPA + DHA per meal and in combination with an omega-3 supplement of around 1,000mg per day should shift you from the high-risk to the optimal range of the Omega-3 Index within 3 months.

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