The Truth About Eating Fish With Their Scales Still On Them

Unless you grew up on the water, it's very possible you've never given much thought to the anatomy of a fish. Especially if you're used to picking up a cleaned, scaled, and deboned filet from the grocery store or fish market, being confronted with a freshly caught, whole fish for the first time can seem intimidating. Which parts are edible, and which do you need to discard? Where do the scales end and where does the skin begin — and is either safe to eat?

In fact, fish skin is not only edible (for the most part), but it can also be one of the most flavorful and nutritious parts of fish such as salmon. As for the pesky scales that coat the skin, however, the answer depends. In most cases, the fish scales you are likely to encounter are technically safe to eat, as long as they have been properly cleaned and cooked. However, most people prefer not to eat them due to their unpleasant texture.

The potential benefits of eating fish scales are minimal. They are primarily composed of collagen, which is an important structural protein for your body, but there are more effective and delicious ways to eat a collagen-rich diet. Compared to fish flesh, scales are not a significant source of ingestible nutrients. That's why we usually recommend asking your fishmonger to descale your fish when you buy it, or to use a spoon for a DIY descaling at home in a pinch.

To better understand when it's safe to eat fish scales and why you might want to, it's important to understand what exactly they are. Broadly, they are a protective external layer meant to guard fish against predators and irritants, but their composition, size, shape, and function differ depending on the species of fish. There are five different categories of scales — placoid, cosmoid, ganoid, cycloid, and ctenoid — but most commonly eaten fish have cycloid or ctenoid scales.

Cycloid and ctenoid scales are found on bony fishes, like salmon, bass, trout, or carp. They are similar in structure and both made from collagen and bone, but are differentiated by the smoothness of their outer edges (cycloid scales are smooth-edged while ctenoid edges have spiny projections). These scales are generally safe to consume, although they can present a choking hazard, and should be thoroughly cleaned and properly sourced to prevent contamination.

Whether you'd actually want to eat them is debatable, however. Some people theorize that the collagen in fish scales can boost your skin health, but they're not considered the most efficient source of collagen – you can try bone broth or supplements instead. Others enjoy the crunchy textural element that scales can bring to a whole cooked fish, especially if you're pan-frying or grilling your fish. In some cultures, chefs even elect to remove fish scales and fry them separately as a garnish. Keep in mind, though, that scales can have an unfortunate tough or chewy texture, which many consumers find off-putting.