Your Brain Is Probably Running Low on This One Fat

Here’s something nobody really talks about in health class: your brain is mostly fat. And one specific type of fat — called DHA, short for docosahexaenoic acid — is so critical to how your brain develops and runs that being low on it can actually change how you think, feel, and behave.

And most of us are low on it.

Research published in PubMed Central points out that most of the global population is deficient in long-chain marine omega-3s like DHA — and this matters especially during the years when your brain is still actively developing, which, if you’re a teenager or young adult, is literally right now.

So what does low omega-3 actually look like? It’s not like a broken arm where you know something’s wrong. It’s subtler. Studies have found associations between low omega-3 levels in kids and young people and things like hyperactive or impulsive behavior, anxiety, temper issues, and learning difficulties. That doesn’t mean omega-3s are a magic fix for every hard day — but it does mean your brain chemistry is genuinely affected by whether you’re getting enough of this stuff.

On the mood side, a systematic review on omega-3s and brain function found that EPA and DHA — two of the key omega-3 fatty acids — are essential for cognitive performance at every stage of life. Not just when you’re old. Every stage. That includes right now, while you’re trying to get through school, manage stress, and figure out who you are.

And then there’s your heart. The NIH Office of Dietary Supplements notes that higher omega-3 levels are associated with a reduced risk of coronary heart disease. Heart disease feels like an old person problem, but the habits and deficiencies you build now are the ones your body carries forward. Getting enough omega-3s in your teens and twenties is investing in a healthier heart in your forties and beyond.

The main food sources are fatty fish — things like salmon, sardines, mackerel, and tuna. If fish isn’t really your thing, that’s honestly pretty common, especially among younger people. There are also algae-based DHA supplements, which is actually the original source of omega-3s in the marine food chain — fish accumulate DHA largely by eating algae or smaller fish that ate algae. So you can skip the fish and still get what your brain needs.

This isn’t about becoming obsessive over every meal. It’s just worth knowing that if you’re constantly feeling foggy, anxious, or just off — and you rarely eat fish — your omega-3 levels might genuinely be part of that picture.