Choosing the Best: Why Choose Salmon Fish Oil

Salmon oil is pressed from the fatty tissue of salmon and is one of the few dietary sources that supplies all three long-chain marine omega-3 fatty acids: EPA, DHA and DPA. The body cannot produce these in meaningful quantities on its own, so they have to come from the diet. For people who rarely eat oily fish, a fish oil supplement is a straightforward way to obtain them.

Nutrition at a glance

Salmon oil is essentially pure fat: a teaspoon is roughly 4.5 g of fat and about 40 kilocalories, with no protein, carbohydrate, fibre or sugar. That is why serving sizes are small, and why the meaningful figure on a label is not the total oil weight but the amount of EPA and DHA per serving. Two products with the same 1,000 mg capsule size can differ substantially in their omega-3 content.

The three marine omega-3s

EPA (eicosapentaenoic acid) is a 20-carbon omega-3 fatty acid found in fish, shellfish and algae. EPA and DHA together have a role in the maintenance of normal heart function.

DHA (docosahexaenoic acid) is the longest of the three and is a major structural fatty acid in the brain's gray matter and in the retina. DHA contributes to the maintenance of normal brain function and normal vision. Salmon oil is among the richer natural sources.

DPA (docosapentaenoic acid) is the least discussed of the three. Structurally it sits between EPA and DHA, and it functions as an intermediate in the pathway that converts one to the other, meaning the body can use it to make either as needed. It is found almost exclusively in marine sources, with salmon among the better ones. Research on DPA specifically is far younger and thinner than research on EPA and DHA, and it is best described as an active and unfinished area of study.

Why many people fall short

Omega-3 intake depends almost entirely on how much oily fish someone eats. Populations that eat salmon, mackerel, sardines or anchovies once or twice a week generally reach reasonable intakes; people who eat mostly lean protein, or who avoid fish for taste, cost, sustainability or dietary reasons, typically do not. Plant sources such as flax and chia supply ALA, a shorter omega-3, but conversion of ALA to EPA and especially to DHA in the human body is limited.

How to read a fish oil label

• Check EPA and DHA in milligrams per serving, not the capsule size
• Note the serving count: some products list values for two or three capsules
• Look for the chemical form, usually triglyceride or ethyl ester
• Look for evidence of purity testing for heavy metals and contaminants
• Check freshness indicators such as peroxide value, since fish oils oxidize; a strongly rancid smell means the oil has degraded

How to take it

Fish oil is fat-soluble, so it is commonly taken with a meal containing fat, which also reduces the aftertaste some people notice. Splitting the daily amount across two meals is another common approach. Store the container closed and away from heat and light, and refrigerate liquid oils once opened. If you take anticoagulant medication, are pregnant, or are scheduled for surgery, check with a qualified healthcare provider before starting.

Salmon oil is a food-derived source of nutrients that most diets in urban settings supply inconsistently. Choosing a product from a manufacturer that discloses its omega-3 content and its testing is the practical part of the decision; the rest is taking it regularly enough to matter and keeping fish on the menu when you can.