One food, three jobs no pill copies. EPA, one of the two marine omega-3s, shifts your inflammatory chemistry toward calm ¹. DHA, the other, gets built into brain-cell membranes and stays there for life. Vitamin D is the third: almost no other food carries it, and a salmon portion delivers most of a day's supply ².

The fish-eaters die later. Chicago men eating fish daily had 38% fewer fatal heart attacks over thirty years ³. Nurses eating fish two to four times a week had 31% lower heart-attack death ⁴. Measure the omega-3 in blood instead of asking, and the top fifth had 13% lower death from anything ⁵. The brain signal is just as steady: highest plasma DHA meant 47% lower dementia risk ⁶, and lowest omega-3 meant a brain aged two extra years by midlife ⁷.

Food beats the pill here. Fish-oil capsule trials in healthy people are shakier than the food data ⁸. Probably because fish displaces red meat, the whole nutrient stack does part of the work, and a real diet runs for decades where a pill test runs for years.

The rule is two servings a week. Roughly 250 g cooked total. Every major guideline body converges on it ^{9 10}.

What you get, and when. The first month: fasting triglycerides drop 5–10% within four to eight weeks, and if you were low on vitamin D over winter, your next blood draw reads higher ¹². The first year: inflammation markers trend down and a low mood baseline lifts a notch ¹³. The decades are where it lives — a fifteen-to-thirty-five percent lower coronary death rate ⁴, and a brain at seventy still finishing the crossword ⁶. None of it takes willpower. The whole intervention is a Tuesday and a Friday.