Sardines

Sardines

Sardines are probably the food with the best ratio of nutritional value to price on the entire shelf. In Hebrew they are called “סרדינים”. A single can provides complete protein, omega-3 in amounts close to salmon, calcium in amounts that rival milk, and a surplus of vitamin D and vitamin B12 — for just a few shekels.

The reason for their special status is biological: the sardine is a small fish that feeds on plankton and lives only 3-5 years. It sits at the bottom of the food chain, so it barely accumulates any mercury — unlike the predatory, long-lived tuna.

Nutrition facts per 100 grams (canned in oil, drained)

Calcium — the standout figure

382 mg of calcium per 100 grams is more than a glass of milk (about 300 mg), and that is an unusual figure for an animal food that is not a dairy product.

The source is the small bones, which soften completely during canning and are eaten with the fish without being noticed. This is calcium with good bioavailability, accompanied by vitamin D and vitamin K, which are needed to direct it to bone — a combination that is hard to find in a single food.

The practical takeaway: boneless sardines lose this key advantage almost entirely. It is worth choosing the whole version.

Benefits

• Omega-3 in amounts that rival salmon: 1,400-1,500 mg per 100 grams, about one third to two thirds of salmon — and five times more than canned light tuna. One can covers the weekly recommendation.
• Among the lowest mercury levels measured: about 0.013 ppm, almost ten times less than light tuna. Sardines are considered safe for frequent consumption, including during pregnancy — and thanks to their DHA they are even recommended.
• Complete protein: 24.6 grams per 100 grams.
• A surplus of vitamin B12: 370% of the Daily Value per 100 grams.
• Selenium: almost 100% of the Daily Value. Selenium also plays a role in binding mercury and reducing its availability.
• Sustainability: sardines are among the most sustainable fish. They reproduce quickly, are caught with targeted nets with little bycatch, and their stocks are stable in most regions.
• Price and shelf life: unbeatable. A can costs a few shekels and needs no refrigeration.

Downsides and considerations

• Purines and gout: this is the most significant downside. Sardines are among the most purine-rich foods there are (over 400 mg per 100 grams), and they appear explicitly on the list of foods to avoid with active gout or high uric acid.
• Sodium: 505 mg per 100 grams. Reduced-sodium versions exist, and draining and rinsing removes some of it.
• Oil vs. water — not like tuna. With tuna the rule is simple: water is better. With sardines it is more complicated. Good-quality olive oil does no harm, but soybean or sunflower oil adds omega-6 and worsens the ratio, and also draws away some of the fish’s omega-3 when you drain it. The recommended order: in water or tomato sauce, then in olive oil, and only last in another vegetable oil.
• Strong taste and smell: the main practical obstacle for most people. Lemon, vinegar, red onion or mustard tone it down considerably.
• Histamine: like all mackerel-type and sardine-family fish, they can develop histamine if not chilled properly before canning. Histamine is heat-stable and is not destroyed by cooking.
• Fish allergy and Anisakis sensitivity.
• BPA in the can lining: most manufacturers have switched to BPA-free linings, but not all. Cans marked “BPA-free” are preferable for anyone who cares about the issue.

Practical use

• Frequency: 1-2 cans a week cover the full omega-3 recommendation at negligible cost.
• Choose bone-in — that is where the calcium is.
• On sourdough bread with lemon, olive oil and onion — the simplest and most common way.
• If you find the taste hard: mash them into a tomato sauce for pasta. They melt in completely and add umami depth without being recognizable.
• Fresh sardines on the grill are a classic Mediterranean dish, and very cheap in season.
• Pair with a source of vitamin C to improve iron absorption.

Summary

A can of sardines provides 24.6 grams of protein, about 1,450 mg of omega-3, 382 mg of calcium, 370% of the Daily Value of B12 and almost 100% of selenium — with mercury among the lowest measured in any fish, good sustainability and a price of a few shekels. Two real caveats: people with gout should avoid them because of their high purine content, and it is worth choosing sardines in water, tomato sauce or olive oil — not in cheap vegetable oil. If you had to pick one food that gives the highest nutritional return per shekel, this is probably the candidate.