Sardines
Small, cheap and low down the food chain. You eat the bones too, and that is where the calcium is.
How to use it
Out of the tin, on sourdough, through a salad, through pasta. Fresh on the grill when you can get them.
The best version
Tinned in olive oil or in water, with skin and bones. A brand that says where and how it was caught. Sardines in tomato sauce taste good, and you are eating the sugar in that sauce as well.
How to prepare it
Nothing. Open the tin, onto bread, lemon over the top. If the taste is too strong, start with the ones in olive oil rather than the ones in their own juice.
What it does
Marine omega-3 has been studied at scale. Across 13 randomised trials with 127,477 participants between them and a mean of five years of treatment, the risk of myocardial infarction came out at a rate ratio of 0.92, death from coronary heart disease at 0.92, and cardiovascular death at 0.93. The reduction grew with the dose.
Watch out
Those trials handed out capsules, not fish. What was measured is the compound, and the fish is the cheapest and most complete way to get hold of it.
Hu Y, Hu FB, Manson JE. Journal of the American Heart Association, 2019.
Salt. A tin can hold a serious share of your day, and it is on the label. Rinsing them helps, and costs you some of the taste.