Are canned sardines a good source of protein?

From sardines to mackerel, fish has a multitude of benefits ranging from omega-3 acids to protein. However, there are a few varieties that are healthier for you than others. Registered dietitian Julia Zumpano, RD, LD, breaks down the three fish that deserve more attention and three that you should avoid.

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The Best

1. Sardines

Sardines provide a variety of benefits.

“You can’t go wrong with sardines,” says Zumpano. “They’re a wonderful source of omega-3 fatty acids, they’re caught in the wild and they’re cheap.”

Sardines provide 2 grams of heart-healthy omega-3s per 3 ounce serving, which is one of the highest levels of omega-3 and the lowest levels of mercury of any fish. They contain a great source of calcium and Vitamin D, so they support bone health, too. Other than fortified products, there are few other food sources of Vitamin D. They may be packed in water, tomato juice or olive oil. Read the label to make sure you don’t exceed your daily limits for sodium and fat.

“Since sardines are more likely to be sustainably caught, they’re a safe choice for pregnant and nursing women,” notes Zumpano.

Worried about encountering the entire fish, head intact? Today, only the edible portions are included. Try serving sardines sprinkled with lemon juice and 1 teaspoon of olive oil or with chopped tomatoes and basil, oregano or another Italian seasoning. For a quick snack, serve sardines on whole grain crackers.

2. Herring

Fatty fish like herring provide around 1.5 grams of omega-3s per 3 ounce serving. Herring also boasts more omega-3 fatty acids than either salmon or tuna, which are essential to human health since our bodies can’t make these fats. 

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Herring contains less mercury than other omega-3-rich fish you may be eating, like tuna, king mackerel, swordfish and halibut.

“Try it chilled, with a light marinade of white wine vinegar, red onion and dill,” says Zumpano. “Another popular option is to pair herring with mustard and dill.”

 3. Mackerel

Atlantic and Atka mackerel from Alaska are high in inflammation-fighting omega-3s and low in mercury, but not all mackerel get a thumbs-up. King mackerel, from the Western Atlantic and Gulf of Mexico, has a high mercury content. Zumpano suggests limiting Spanish mackerel as well due to mercury concerns.

“Try grilling or poaching mackerel to throw over a salad, or serve it with a side of grilled veggies,” she notes. 

The Worst

Meanwhile, think twice about ordering these popular fish or adding them to your grocery cart:

1. Tilapia

“Sure, tilapia is a lean source of protein, but it lacks the omega-3 content of fatty fish like salmon, tuna, herring and sardines,” says Zumpano.

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Most people don’t get enough omega-3s in their diet. If you’re going to enjoy fish, it’s best to choose fish that are highest in this essential nutrient.

2. Tuna

“Fresh tuna is a great source of omega-3s,” says Zumpano. “But everyone’s desire for sushi may be putting us at risk for mercury toxicity.”

Exposure to high levels of mercury increases the risk of cognitive defects and other health problems. You’re not necessarily safer with canned tuna, either. Albacore tuna, one of the more popular fish in the United States, is consistently high in methylmercury.

“The same is true for canned light tuna unless you’re purchasing from a company that checks the mercury levels of each can,” continues Zumpano. “But very few companies currently take this extra step.”

3. Imported catfish

Catfish, which is 90% imported, often comes from contaminated waters and may contain dangerous chemicals and antibiotics. If you love your catfish, choose farm-raised varieties from American waters or try Asian carp, which has a similar taste.

The next time you’re weighing dinner options, follow these tips for choosing fish that are high in omega-3, low in mercury, safely sourced and sustainably caught. When purchasing canned fish, be sure that it’s BPA-free. You’ll find yourself enjoying some menu options you haven’t tried before.

Sardines are a small, oily fish that's packed with nutrition. If you're wary of the health benefits of canned foods, you can rest assured that sardines have a lot to offer. In addition to being high in quality protein and healthy fats, sardines are a great source of iron and calcium. Because of their low mercury levels, sardines don't have the same toxicities you might expect with other types of seafood.

Sardine Nutrition Facts

The following nutrition information is provided by the USDA for 5 small sardines with bones (12g) canned in oil (drained).

• Calories: 125
• Fat: 7g
• Sodium: 184mg
• Carbohydrates: 0g
• Fiber: 0g
• Sugars: 0g
• Protein: 14.8g
• Calcium: 45.8mg
• Selenium: 6.3mcg
• Vitamin B12: 1.1mcg
• Vitamin D: 0.6mcg

Carbs

Sardines do not contain any carbohydrates, fiber, or sugar.

Fats

The oils in sardines are high in omega-3 fatty acids, which are commonly referred to as “healthy fats.” A serving of 5 small sardines canned in oil has 7 grams of total fat. It is important to note that when sardines are canned in oil (as opposed to water), they are higher in fat even when drained.

Protein

A serving of canned sardines has nearly 15 grams of complete protein, including all of the essential amino acids. Sardines are a healthy way to boost your protein intake.

Vitamins and Minerals

Sardines are high in iron and calcium, with just 5 sardines with bones (the bones are edible) providing 1.75mg iron and 229mg calcium. Sardines are also a good source of vitamin B12, vitamin D, vitamin E, magnesium, potassium, and zinc.

Health Benefits

If you enjoy eating sardines, you'll reap several health benefits. Along with protein and "good" fats, sardines are rich in several vitamins and minerals associated with disease prevention.

Protects Cognitive Function

Sardines and other types of seafood have been associated with lower cognitive decline. Seafood is protective against some types of Alzheimer's disease, strokes, and dementia. DHA, a type of omega-3, is especially helpful for maintaining a sharp memory. For optimal memory function, include sardines in your meal plan twice a week.

Strengthens Muscles

Sardines supply complete protein and essential fatty acids for muscle building and fuel. Instead of loading up on processed protein powders and bars, sardines provide all the amino acids your body needs to build strength without unnecessary additives.

When you're doing a tough strength-training workout, the fats in sardines will give your muscles a steady stream of calories to finish all of your reps, and the protein profile of sardines gives your muscles the building blocks required for recovery.

Promotes Heart Health

The omega-3 fatty acids in sardines protect the heart in several ways. Omega-3s reduce LDL ("bad") cholesterol and increase HDL ("good") cholesterol. They lower blood pressure, prevent abnormal heart rhythms, and decrease hardening of the arteries and blockages. Increased sardine intake in people with diabetes has been shown to reduce inflammation and cardiovascular risks.

Supports Healthy Pregnancy

Omega-3s are essential for a healthy pregnancy, especially when it comes to the baby's brain and vision development. For this reason, women of childbearing age are advised to consume two or three servings of fish per week. Sardines are on the "best choices" list due to their low levels of mercury. They provide the benefits of fish with minimal risk of mercury toxicity.

Builds Strong Bones

Sardines are a good source of both calcium and vitamin D (which enhances calcium absorption). Most adults should aim for 1000mg of calcium per day, the recommended dietary allowance (RDA), to get enough to maintain strong bones. A 3-ounce serving of canned sardines with the bones provides over 32% of your daily value of calcium. Regular intake of sardines, along with some muscle-building exercise, can help protect your bones from weakening with age.

Allergies

Fish allergies are common and may not appear until adulthood. Allergies to fish like sardines are usually separate from shellfish allergies to shrimp and crab. Symptoms may include asthma, hives, headache, or stuffy nose. See an allergist for a professional diagnosis if you suspect an allergy to sardines.

Varieties

Sardines are usually sold fresh or canned. Canned varieties are packed in liquid such as water, oil, mustard sauce, or tomato sauce. If you prefer, you can find canned sardines that are boneless and skinless. However, since the bones are such a good source of calcium and the skin is such a good source of omega-3s, sardines are most nutritious when eaten with them.

There are several varieties of sardines found around the world. Pacific sardines are from the United States and Canada. Imported sardines include European pilchard sardines, Japanese sardinellas, orangespot sardines, and Spanish sardines.

Storage and Food Safety

Food safety rules for sardines are the same as for any other type of fish. If you buy fresh sardines, you want to make sure they've been stored at properly cold temperatures (below 40 degrees Fahrenheit) and packed on ice. Fresh sardines should smell fresh and not overly fishy. The eyes should be clear and shiny.

Keep fresh sardines refrigerated and cook or freeze within 2 days of purchase. Wash your hands well along with any utensils or cutting boards used for raw sardines. Cook fish to an internal temperature of 145 degrees Fahrenheit. When serving, avoid keeping fish out at room temperature for more than an hour at a time.

Canned sardines should be eaten once opened. If you don't eat the whole can, place in a covered plastic or glass container and store in the refrigerator for consumption within a couple of days.

How to Prepare

The fact that sardines are most often purchased canned means that you don't have to do much in the way of cooking or preparation. Canned sardines are usually pretty flavorful on their own, as they are usually preserved in salt. They can be eaten cold in salads, on top of crackers, warmed in pasta dishes, or even grilled as a main course.

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