MALAYSIAN parents have been deploying the same argument at dinner tables for generations: eat your fish, it is good for your brain.
It did not matter whether it was steamed siakap, fried ikan kembung or a bowl of asam laksa, the message was always the same, delivered with the same absolute conviction as "don't sit too close to the TV."
For a nation that puts away an average of 44.7kg of fish per person every year, more than double the global average, Malaysians have a lot riding on this claim being true.
Does eating fish regularly actually make you smarter?
Verdict:
TRUE
The good news for every Malaysian parent who has ever forcefully placed a piece of ikan kembung on a child's plate is that science is broadly on their side.
The bad news is that it is a little more complicated than simply eating fish and waking up smarter the next morning.
The secret ingredient is something called DHA, short for docosahexaenoic acid, which sounds like something from a chemistry exam but is essentially one of the main building blocks of the human brain.
Around 10% to 20% of the brain's total fat content is DHA, and it plays a critical role in keeping brain cells communicating properly with each other, releasing the right chemicals at the right times and processing information efficiently.
The catch, so to speak, is that the brain cannot produce meaningful amounts of DHA on its own.
It has to come from food, and fish is by far the richest and most practical source available.
The most compelling evidence came from a study that actually measured the effect on children's IQ scores.
A cohort study published in Scientific Reports followed 541 schoolchildren from the ages of nine to twelve and found that kids who regularly ate fish scored 4.8 IQ points higher on average than those who rarely touched it.
Even children who only ate fish sometimes scored 3.31 IQ points higher than the fish-avoiders.
The study also found that regular fish eaters slept better, and that better sleep partially explained the IQ boost, since the brain consolidates memories and processes information during sleep.
So fish appeared to be making children smarter in two ways at once: by feeding the brain directly and by improving the quality of the sleep that the brain needed to do its job properly.
The benefits did not stop at childhood either.
A systematic review of 25 studies published in GeroScience found that older adults who ate more fish consistently showed slower rates of cognitive decline and lower rates of dementia than those who did not.
Researchers pointed to the omega-3 fatty acids in fish improving blood flow to the brain and reducing the kind of low-level inflammation that quietly damaged brain cells over decades.
A separate large-scale meta-analysis confirmed that regular fish consumption was associated with a meaningfully lower risk of developing dementia later in life.
One study even found visible differences in brain structure between frequent fish eaters and non-fish eaters, with fish consumers showing healthier white matter fibres, the connective tissue that links different parts of the brain together and keeps everything running smoothly.
The important caveat was that none of this happened overnight.
The research consistently pointed to regular, long-term fish consumption as the key factor, not the occasional plate of fish at the weekend.
Fish oil supplements showed far more mixed results in clinical trials, with researchers generally agreeing that getting DHA from actual fish produced better outcomes than getting it from a capsule.
The type of fish also mattered.
Fatty fish such as mackerel, sardines and anchovies were far richer in DHA than leaner white fish, which was either very convenient or deeply inconvenient depending on personal feelings about sardines.
Fortunately for Malaysians, ikan kembung, the humble Indian mackerel that costs next to nothing and appears at virtually every wet market and mamak stall in the country, happens to be one of the most DHA-rich fish available anywhere in the world.
So the parents were right all along, even if none of them could have told anyone what DHA stood for.
Just do not expect one bowl of asam laksa to make up for years of quietly sliding the fish to the side of the plate.
Sources:
1. https://www.nature.com/
2. https://pmc.ncbi.nlm.nih.gov/
3. https://pmc.ncbi.nlm.nih.gov/
4. https://pmc.ncbi.nlm.nih.gov/
5. https://pmc.ncbi.nlm.nih.gov/
6. https://link.springer.com/
7. https://www.frontiersin.org/
