New Study: Lower Your Risk of Cognitive Decline Today

If you ask people what they fear most about aging, the answer is often the same.

It’s not wrinkles. It’s not aches and pains. 

What do people really fear?

Losing their mind.

Cognitive decline; forgetting names, faces, memories, and eventually yourself, is one of the most devastating outcomes we can imagine. And for a long time, it’s been framed as something that’s mostly out of our control. 

Genetic. Inevitable. A problem for “later.”

But what if there were meaningful steps you could take today to reduce your risk?

A new large-scale study suggests there may be.

A Groundbreaking Study on Omega-3s and Early Cognitive Decline

Researchers analyzed data from over 217,000 adults in the UK Biobank and followed them for more than eight years.

Instead of relying on food questionnaires or memory tests, researchers measured actual blood levels of omega-3 fatty acids.

What did they find?

People with higher blood omega-3 levels had a 35–40% lower risk of developing early-onset dementia, defined as dementia before age 65.

That association held even after accounting for age, lifestyle factors, cardiometabolic health, and genetic risk, including APOE-ε4.

But here’s the detail most headlines missed: the strongest protective effect wasn’t driven by DHA alone.

Non-DHA omega-3s (such as EPA and DPA) showed even stronger associations with reduced dementia risk. These fats influence inflammation, blood flow, and cellular signaling, all of which play a role in long-term brain health.

The lowest risk was observed in people with an Omega-3 Index around 8%, which is considered really good!

But the truth is, most people fall well below this range, and it’s not something you can reliably estimate without testing.

This also shifts the question from “Do you eat fish?” to “Do you have enough omega-3s in your blood to matter?”

Now, as noted above, this was an observational study. So it does not prove causation, guarantee protection, or suggest omega-3s are a cure.

But when data at this scale align with biological plausibility and carry low downside, they highlight a meaningful opportunity for prevention.

Try This

Aim to eat fatty fish (sardines, anchovies, salmon) two to three times per week.

Consider supplementing with 2-4 grams of high-quality fish oil daily.

Test your Omega-3 Index at least once to understand where you stand. The test I use is OmegaQuant (no affiliation), which you can read about here.

Start early. Brain protection begins decades before symptoms appear.

You may not control every risk factor for cognitive decline, but omega-3 status is one lever you can pull today.

Much love, 

Dhru Purohit

The information in this newsletter is for educational purposes only and should not be construed as medical advice; please consult a qualified healthcare professional before making any health-related decisions.