Sardines may not enjoy the popularity of other fish, but they're one of the most nutrient-dense foods on the planet.
This article takes a look at their nutrition profile, eight of their health benefits, and some tasty recipes.
We'll also examine the differences between fresh and canned sardines, and whether the type you choose matters.
What Are Sardines?
Sardines are a small, nutrient-rich fish that belong to the herring family.
Similar to other members of the herring family, sardines are an oily-fish that provide a wealth of omega-3 fatty acids.
Unlike salmon, cod, mackerel and other fish, people eat sardines whole including the bones, flesh and organs.
They are available either fresh or in canned form, in which they are usually packed in oil or tomato sauce.
It is likely that the name 'sardine' originates from the island of Sardinia, Italy, with historical records of the fish being caught there as early as the 15th century (1).
Sardines are one of the most nutritious fish on the planet.
The tables below show the nutritional value of sardines per 100 g, including both macronutrient and micronutrient profiles (2).
Macronutrients and Vitamins
As these nutrition facts show, sardines are rich in protein, healthy fat, and virtually every essential vitamin and mineral.
Among these, they are particularly high in vitamins B12, B3, D, selenium, phosphorus, and iron.
Key Point: Sardines are extremely nutritious and contain almost every major nutrient.
Health Benefits of Sardines
Eating sardines can benefit our health in so many ways, from their high calcium content to their provision of omega-3.
Here is a look at nine great advantages sardines bring to our diet;
1. Rich Source of Bio-available Calcium
Calcium is an essential mineral that is important for skeletal and dental health.
Depending on the dietary system, some people may be more prone to a deficiency in this mineral. For instance, vegan dieters and people who follow strict paleo (no dairy) diets.
For the latter group at least, sardines are a great option.
We eat sardines whole, including all the tiny bones that they contain. As a result, sardines provide a substantial amount of calcium; per 100 grams, they contain approximately 38% of calcium's RDA (2).
Furthermore, not all food sources of calcium are equal.
For example, many plant-based sources of calcium (e.g. spinach) contain a compound called oxalic acid (oxalate).
Unfortunately, oxalates bind calcium in the body, so the higher proportion of oxalate food has, the lower the calcium absorption (3).
However, since sardines contain no oxalic acid at all, they are one of the highest bio-available sources of calcium.
Key Point: Sardines offer a significant amount of highly digestible calcium.
2. High in Omega-3 Fatty Acids
One of the best health benefits of sardines comes from their omega-3 content.
Sardines provide a substantial amount of the omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).
Per 100 gram portion, there are approximately 1.5 to 2.0 grams of omega-3 in sardines. However, make sure to choose either fresh sardines or sardines packed in brine, olive oil, or tomato sauce.
Eating sardines packed in omega-6 vegetable oil defeats the purpose of aiming for more omega-3.
Why Is Omega-3 Important?
However, omega-6 fatty acids have an essential pro-inflammatory effect. Our body requires these inflammatory processes from time to time, but the modern diet has skewed the delicate balance between omega-3 and 6.
In evolutionary terms, something along the lines of a 1:1 ratio between omega-6 and omega-3 was the norm. On the contrary, the modern Western diet often exceeds 15:1 in favor of omega-6 (7).
Consuming oily fish like sardines helps to increase our body's omega-3 stores, but we should ideally avoid omega-6 vegetable oils too.
Key Point: Sardines contain a large concentration of omega-3 fatty acids.
3. Excellent Source of Vitamin D
The single best source of vitamin D is sunlight, but not everyone is fortunate enough to have sufficient exposure.
Particularly for those who live in the Northern hemisphere, alternate sources of vitamin D are important during the long, dark winters.
Among food sources of vitamin D, sardines are one of the best, and a 100-gram portion provides 68% of the RDA (2).
Importance of the Sunshine Vitamin
Vitamin D is a hormone rather than a true vitamin, and it is critical for our health.
The 'sunshine vitamin' plays a vital role in immunity and the skeletal system. This fact makes it critical as we age, as it can help to prevent conditions like osteoporosis and cognitive decline (10).
In fact, vitamin D is associated with a reduced risk of almost every chronic disease. Therefore, it makes sense that deficiency leads to an increase in all-cause mortality (11).
Unfortunately, much of the world is deficient in the vitamin. Approximately 1 billion people have inadequate blood levels of vitamin D, likely a result of our modern indoor lifestyle and excessive sunscreen use (12).
Key Point: Sardines are incredibly rich in vitamin D.
4. Sardines Are Rich in Protein
There are many reasons why getting sufficient dietary protein is important.
First of all, protein is essential for the synthesis of hormones and the growth and repair of cells and muscles (13).
Furthermore, diets with sufficiently high protein intake are associated with better body composition and greater satiety (14).
On this note, having more lean mass and a greater feeling of satiation can positively influence our diet and overall health.
If we are looking to increase our protein intake, then sardines are an excellent way to do so.
Per 100 grams they provide around 25 grams of protein (2).
Depending on how much protein you require, they could also be a great high-protein snack between meals.
Key Point: Sardines are a rich source of dietary protein - approximately 25% by weight.
5. Sardines Contain Large Amounts of Selenium
Selenium is a mineral that plays a role in many critical biological processes.
Among these, the mineral has an antioxidant role in the body and helps to attenuate oxidative stress. Selenium also plays an essential role in DNA repair and the proper functioning of the endocrine and immune systems (15).
Also, adequate selenium intake is necessary to maintain optimal thyroid health. The thyroid gland contains the most concentrated amounts of selenium in the body, and a deficiency can lead to autoimmune conditions (16).
Our intake of selenium can vary greatly depending on the composition of the local soil.
If the soil is depleted in selenium, then the food grown from it will contain inadequate amounts too. Worldwide, approximately 1 billion people are believed to have insufficient intakes of selenium (17).
Fortunately, many foods still offer high concentrations of this important mineral. In this context, sardines are one of the very best, and they provide a substantial 75% of the RDA for selenium per 100 grams (2).
Key Point: Sardines offer a significant amount of selenium, providing three quarters of the daily RDA per 100 g.
6. Sardines Are Very Low in Mercury
Thus far, we have only looked at the benefits of sardines.
However, most people know that seafood has a pretty substantial downside; methylmercury contamination.
Some oily fish, such as bigeye tuna, contain large enough concentrations of mercury for the FDA to advise completely avoiding them (18).
So, how do sardines fit in?
Fortunately, as a very small fish, sardines are near the bottom of the food chain, and so they only consume tiny amounts of mercury.
Notably, sardines are among the five seafood choices with the very lowest amount of mercury contamination. The mean mercury concentration that this fish provides is only 0.013 PPM (19).
Rest assured, you can enjoy the health benefits of sardines without having to worry about their mercury content.
Key Point: Sardines contain an insignificant amount of mercury, and they are among the cleanest fish in the ocean.
7. Impressive Nutrient-Density
As we have seen throughout this article, sardines are incredibly nutrient-dense, and they supply the majority of essential nutrients.
However, when we take a total view of everything these fish provide, it is even more impressive;
When you add all these benefits together, it is very impressive considering that a single can of sardines contains less than 200 calories.
This just shows how healthy and nutritious sardines are; they are one of the most nutrient-packed foods around.
Key Point: In terms of nutrient-density, sardines are one of the best things we can eat.
8. Sardines Are Cheap
Another great benefit of sardines is their affordable price.
I know everyone loves salmon, but it can be costly depending on where you live.
On the other hand, everyone has access to either fresh or canned sardines, and the cost is quite economical.
You can buy wild sardines for little over $2 per can.
On a gram per gram basis, this is much cheaper than most other species of wild fish. For instance, you will have a difficult time finding wild salmon for an equivalent price.
Although the price isn't a health benefit as such, it does mean that a wider variety of people can benefit from these oily fish.
Key Point: As well we being rich in protein, high in omega-3's, and full of essential nutrients, sardines are affordable too.
Fresh vs. Canned Sardines
Many people wonder whether canned sardines are just as healthy as the fresh variety.
Before I looked into it, this is something I often thought about too, so let's have a quick rundown of the considerations.
You can source canned sardines virtually everywhere you go in the world, but it is not always possible to find fresh ones.
Raw vs. Cooked
Fresh sardines are found in their raw state, and you can control how you cook them at home.
On the other hand, canned sardines are usually steam cooked in their cans - the temperature will vary depending on brand/company.
Some people have concerns that this heat treatment may cause the fatty acids in the fish to oxidize. Unfortunately, there is not a tremendous amount of research available on sardines and oxidation.
However, one study showed that the omega-3 content of the sardines decreased slightly following heating and canning. Despite this, the fish remained a good source of omega-3 (21).
There is little substantial data on the generation of oxidized products, so I wouldn't worry too much.
The nutritional content of fresh and canned sardines is the same; it is only the freshness that is in question.
Fresh foods are usually preferable to processed ones, and this is the case here too. Overall, fresh sardines are the better choice if they are available.
However, canned sardines are just as good for you nutritionally, and either choice is better than no sardines!
Key Point: Both fresh and canned sardines are very nutritious, convenient, and good for health.
5 Tasty Ways To Eat Sardines
Some people dislike the taste of 'plain' sardines, so here are a few quick and simple ways to eat them.
Each idea requires minimal preparation and very few ingredients.
Key Point: If you dislike the taste of plain sardines, try flavoring them with one of these healthy dressings.
Sardines are one of the most nutritious foods in the world.
Due to the wide range of beneficial nutrients they provide, these fish can play a great role in a healthy diet.
While some people don't enjoy sardines alone, there are many delicious ways to eat them, and their health benefits are certainly worth it.