Grey Matters: 90% of us aren't getting enough of this brain nutrient

FEATURED BIOMARKER

Omega-3 Index: What Your Blood Reveals About Your Brain

What it is: The Omega-3 Index measures the percentage of EPA and DHA in your red blood cell membranes. It reflects your omega-3 status over the past 2-3 months (similar to how HbA1c reflects blood sugar over time). An Omega-3 Index of 8% or higher is considered desirable for heart and brain health; most Americans fall between 4-5%.

Why it matters for your brain: DHA is one of the primary structural components of your brain's cell membranes, and EPA plays a powerful anti-inflammatory role. Together, they support everything from neurotransmission to neuroplasticity.

The research is compelling and continues to grow. A large meta-analysis of 48 longitudinal studies involving over 103,000 participants found that dietary omega-3 intake was associated with an approximately 20% lower risk of dementia and cognitive decline. In the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort, long-term omega-3 supplement users showed a 64% reduced risk of Alzheimer's disease. And a dose-response meta-analysis of 58 randomized controlled trials published in Scientific Reports found significant improvements in attention and processing speed with omega-3 supplementation.

The APOE4 connection: If you carry the APOE4 gene variant, omega-3s may be especially relevant for you. Research suggests that APOE4 carriers may have more difficulty transporting DHA into the brain, which means they may benefit from higher intake, ideally started before cognitive symptoms appear. 

How to improve it:

• Eat SMASH fish regularly. Salmon, Mackerel, Anchovies, Sardines, and Herring are the richest food sources of EPA and DHA. Aim for at least two servings per week. (Tilapia, shrimp, and clams are good protein sources but are not meaningful sources of omega-3s.)
• Supplement strategically. BetterBrain recommends fish oil with 1-2g of DHA daily, taken with food, from a reputable third-party tested brand. If you're vegetarian or vegan, algal oil supplements provide EPA and DHA directly from the original marine source.
• Monitor your levels. Your optimal dose depends on your starting point, your genetics, and your diet. Tracking your Omega-3 Index through blood testing takes the guesswork out of supplementation.

BetterBrain Tip: Low omega-3 levels are one of the most common findings among our members, and one of the most actionable. In fact, fish oil supplementation is one of the first techniques our coaches recommend. Many members see meaningful improvement in their omega-3 ratio within 90 days of starting a targeted protocol.

Check your omega-3 levels with BetterBrain →

BETTERBRAIN HACK

The SMASH Strategy: Making Omega-3 Rich Foods Easy

Getting enough omega-3s from food alone is absolutely possible, but it takes some intention. The acronym SMASH makes it simple to remember the best sources: Salmon, Mackerel, Anchovies, Sardines, and Herring.

The science: Not all fish are created equal when it comes to omega-3 content. A 3-ounce serving of wild salmon delivers roughly 1,500-2,000 mg of EPA and DHA combined. Sardines pack around 1,600 mg along with impressive amounts of protein (22g), vitamin D, B12, calcium, and selenium. Meanwhile, popular choices like tilapia or shrimp contain only a fraction of those levels.

Quick wins to try this week:

• Sardine lunch hack: Grab a tin of sardines packed in extra virgin olive oil. Pair with whole grain crackers and your favorite hot sauce. It's one of the easiest, most nutrient-dense lunches you can assemble in under two minutes.
• Salmon prep day: Bake a couple of salmon fillets on Sunday. Use them throughout the week in salads, grain bowls, or alongside roasted vegetables. If you're looking for a new recipe, here's an awesome from coach Erika that we featured in a previous newsletter. 
• Anchovy upgrade: Melt anchovies into pasta sauces, salad dressings, or olive oil for a savory umami boost. They dissolve completely, so even anchovy skeptics tend to enjoy them this way.
• Frozen is fine: Don't overlook frozen fish. Flash-frozen fish is often fresher than what's sold at the counter, and wild-caught frozen salmon is widely available and more affordable.

A note on mercury: You may wonder about heavy metals in fish. The SMASH fish are all smaller, shorter-lived species that accumulate far less mercury than large predatory fish like tuna and swordfish. Eating SMASH fish multiple times per week is both effective and safe.

BetterBrain Insight: Combining omega-3 intake with B vitamin supplementation may enhance the benefits. Research suggests that DHA supplementation works best when paired with adequate B vitamin levels, particularly for slowing brain atrophy. This is why BetterBrain looks at the full picture of your nutritional biomarkers, not just one nutrient in isolation.

If eating SMASH fish multiple times a week isn't realistic for your lifestyle, or if your Omega-3 Index is still below target after dietary changes, supplementation is a simple and effective next step. Our go-to pick is Carlson's The Very Finest Fish Oil, which delivers 1,600 mg of omega-3s per serving, is third-party tested for purity and potency, and comes in a natural lemon flavor that makes it easy to take daily.

Content Corner

The Form of Omega-3 May Matter for Your Brain

A clinical trial underway at the University of Cincinnati is investigating something fascinating: not just whether omega-3s help the brain, but which form of DHA is most effective at actually reaching it.

Bottom line: Standard fish oil supplements deliver DHA in a form called TAG-DHA (triglyceride-bound). But emerging evidence suggests that LPC-DHA (lysophosphatidylcholine-bound DHA), the form naturally found in fish, may be significantly more effective at crossing into the central nervous system. The trial is comparing the two head-to-head in 153 older adults with mild cognitive decline, measuring DHA levels directly in cerebrospinal fluid for the first time.

This research is still in progress, and we want to be clear that standard fish oil supplements remain well-supported by the existing evidence base. But it's an exciting example of how the field is moving beyond "do omega-3s help?" toward "how do we optimize their delivery to the brain?" We'll be watching this one closely and will share results when they're published.

Also worth noting: a December 2025 narrative review highlighted the particular importance of omega-3s for postmenopausal women, given the loss of estrogen's neuroprotective effects. The authors recommended monitoring omega-3 levels and integrating supplementation into public health strategies for women after menopause.

BetterBrain Takeaway

Omega-3 fatty acids are among the most studied nutrients in the world, with over 50,000 published research papers. The evidence consistently points in one direction: adequate EPA and DHA intake is associated with better cognitive outcomes and lower dementia risk. Yet the vast majority of us aren't getting enough. Testing your levels, eating SMASH fish regularly, and supplementing strategically are three concrete steps you can take today.