Sardines are small fish that can grow up to 10 inches long. They are a nutrient-defense superfood that can be part of a healthy and balanced diet. These soft, oily fish can be eaten canned or fresh by grilling or baking.
Sardines have various health benefits, most of which are attributable to their high omega-3 fatty acid and nutrient content and are backed by science. These include reducing heart disease, improving brain health, alleviating inflammation, strengthening bones, and more.
They also provide vitamins and are a great source of calcium and protein. However, they are also high in salt, calories, and purines, which makes them unsuitable for people with gout, high blood pressure, and other health conditions.
1. Reduces Chances of Heart Disease
Sardines' high omega-3 content makes them a heart-healthy food. They have been found to reduce cardiovascular mortality (death due to heart conditions) and improve cardiovascular outcomes.
Omega-3s also have been found to lower triglyceride levels. Too many triglycerides in the blood can raise your risk for heart disease and stroke. Omega-3s may also raise high-density lipoprotein (HDL, good) cholesterol and lower blood pressure, which can reduce your risk for heart disease.
2. Improves Brain Health
Like other fish rich in omega-3s, sardines can promote brain health. When eaten as part of a healthy diet, fish can provide essential nutrients during pregnancy, breastfeeding, and early childhood to support a child's brain development.
Research shows that consuming fish can increase gray matter in the brain. Higher gray matter levels may reduce the risk of neurological diseases.
One 2022 systemic review of omega-3 studies found that consuming omega-3 fatty acids could increase memory, learning, cognitive well-being, and brain blood flow. A significant upside is that omega-3s are well-tolerated and safe for most people, whether taken in supplement form or as part of a healthy diet.
3. Supports Healthy Fetal Development
Sardines contain nutrients that are beneficial for fetal development, including omega-3 fatty acids, calcium, and vitamin D.
Studies have found that the omega-3s in sardines and other fish can provide vital support for fetal and infant neurodevelopment. A low intake of omega-3 fatty acids could lead to impaired fetal neurodevelopment.
Sardines are also a good source of calcium and vitamin D, crucial for fetal bone health during pregnancy.
4. Reduces Risk of Eye Diseases
Diets rich in omega-3 fatty acids from cold-water fish like sardines and salmon may help reduce your risk for eye diseases later in life. This includes age-related macular degeneration and glaucoma.
Omega-3 fatty acid intake can also reduce your risk for dry eye syndrome. Studies should show that omega-3s help relieve dry eye symptoms, including dryness, a gritty feeling, sensitivity to light, and blurry vision.
5. Strengthens Bones
Sardines are high in nutrients needed for a healthy musculoskeletal system. These nutrients include protein, magnesium, calcium, and vitamin D. Sardines are a significant source of vitamin D, a nutrient vital for calcium absorption and maintaining healthy bones.
Sardines also protect bone health by supporting bone mineral density. A 2023 study found that fatty acid intake benefits adult bone density. The study's authors recommended that adults consume moderate amounts of fatty acids to ensure sufficient bone mass.
6. Reduces Inflammation and Oxidative Stress
Sardines provide two types of fatty acids—eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The body uses EPA and DHA to reduce inflammation, which could mean improved heart health, better brain function, and reduced risk for chronic inflammatory diseases.
EPA and DHA are found in fatty fish, including sardines and salmon. Both are extremely helpful and easily absorbed by the body.
Sardines contain high levels of selenium, an essential mineral the body needs to create and convert glutathione. Glutathione is an antioxidant that helps your body fight oxidative stress.
What Is Oxidative Stress?
Oxidative stress is the imbalance between free radicals (reactive molecules that can damage cells and genetic material) and antioxidants in the body.
Selenium can prevent oxidative damage in the body, fight off radicals, and improve cell function. Selenium deficiencies have been linked to thyroid problems, decreased immune system function, hormonal imbalance, mood disorders, and heart disease.
7. Aids Muscle Growth and Repair
Because sardines are an excellent source of protein, they can aid in muscle growth and repair. One can of sardines contains about 23 grams of protein.
Proteins help provide the body with amino acids needed to build and maintain muscle mass. When you eat protein, it is digested and broken down into amino acids. These compounds are involved in various body processes, including muscle tissue growth and repair.
8. Improves Nerve Function
Sardines are a valuable source of B12 (cobalamin). This water-soluble vitamin helps manage nerve function, brain health, energy levels, blood cells, and more. A vitamin B12 deficiency can cause nerve damage, impaired mental function, oxygen depletion, and chronic fatigue.
One can of sardines contains 8.22 micrograms of vitamin B12. That is more than the National Institute for Health's daily recommended amount.
9. May Help Prevent Type 2 Diabetes
Eating more sardines might reduce your risk for type 2 diabetes, which is a problem with the way the body regulates and uses glucose (sugar) as fuel. Sardines are loaded with protein, magnesium, and zinc, nutrients that may help support healthy blood sugar levels.
One 2021 study followed 172 people with prediabetes who were told to consume a diet that included 200 grams of sardines weekly or a control diet for 12 months. Both groups were given nutritional education for managing their blood sugar.
At the end of the 12 months, the people in the sardine group were found to be significantly less likely to develop diabetes. Around 30% of this group was no longer considered "very high" risk compared to only 4.9% of the control group. The sardine group also had higher heart health improvements, including improved triglyceride, blood pressure, and HDL cholesterol levels.
Fresh vs. Canned Sardines
Fresh sardines are better quality than canned sardines because they are often caught and sold locally. They tend to have a better, milder, and sweeter taste. Fresh sardines are healthier than canned sardines because they are lower in sodium and contain nutrients that may be lost in processing.
However, fresh sardines are harder to find than canned sardines, especially if you do not live near a coastal area. They also have a short life and must be cooked or frozen soon after being caught. Fresh sardines require more preparation time than canned sardines because they need to be cleaned and cooked.
Canned sardines have the heads removed, and what you eat includes the skin and bone. These components are sources of calcium and vitamin D.
Canned sardines are packed in various liquids—oils, water, tomato sauce, and mustard. Sardines packed in oil tend to be higher in fat and calories than those packed in water.
Canned sardines are a more convenient option because they are easy to use and store. They are an alternative for people who don't have the time to prepare fresh fish. They also have a long shelf life and can last in the pantry for many years.
While canned sardines are highly nutritious, they do contain high sodium. They are also processed and may contain lower-quality sardine varieties.
Some canned sardine varieties may contain bisphenol A (BPA), a chemical believed to be linked to cancer and fertility problems. Although levels tend to be low, it is always a good idea to read the product's labeling and balance your diet between fresh and canned foods.
Potential Downsides
Sardines are generally considered generally safe for most people to consume. The main concerns about sardines are mercury poisoning, heavy metal contamination, environmental impacts, and BPA.
Mercury poisoning: Mercury is a damaging pollutant found in fish, including sardines. High amounts of mercury can lead to nerve damage in adults and affect childhood development. However, research has found that the low levels of mercury in sardines pose little risk to human health.
Pregnant people were previously advised to avoid fish due to mercury and heavy metal containment. However, the guidance on this has since changed, and eating any fully cooked fish, including sardines, is safe during pregnancy. Sardines are steamed, fried, or smoked before they are canned, which means they are fully cooked.
Heavy metal contamination: In addition to mercury, sardines may be contaminated by other heavy metals, such as cadmium and lead. Fortunately, research shows that present levels of these heavy metals in fish are low and pose low health risks.
Even so, sardines from various parts of the world can contain higher levels of toxic metals. It is always a good idea to check where your sardines are coming from to ensure they are not harmful to your health.
BPA concerns: BPA is a chemical used to manufacture vinyl, aluminum, and tin can liners. This includes some cans used to pack sardines and other canned fish. If you have concerns about BPA, it is best to try to find can-free seafood brands.
Environmental impact/sustainability: Sustainability creates conditions in which people and nature coexist in harmony to support present and future generations. To practice
sustainability, look for wild sardines caught in the Pacific. It is best to avoid sardines that are becoming depleted, such as those that are Mediterranean-caught.
Who Should Avoid Eating Sardines?
Sardines may not be suitable for everyone, including people with certain health conditions and those taking certain medications.
High sodium intake: One can of sardines has around 282 milligrams of sodium. That is a little over 12% of the daily recommended intake. If you have high blood pressure, you should limit your sodium intake. Having high blood pressure does not mean you cannot eat canned sardines. It just means you should decrease your serving sizes or opt for fresh sardines over canned ones.
High-purine food: Sardines are high-purine foods, which means they cause uric acid buildup and increase the risk of diabetes, kidney stones, and gout flares. A low-purine diet is best for someone with any of these conditions.
Anticoagulant medications: Omega-3s may have an anticoagulant effect, which means they can decrease blood clotting. If you take anticoagulant medications, like warfarin and Eliquis (apixaban), check with your healthcare provider whether eating oily fish like sardines is safe.
Allergies: Some people are allergic to seafood, including sardines. A fish or seafood allergy can cause skin reactions, digestive troubles, swelling, redness, or anaphylaxis.
Anaphylaxis
Anaphylaxis is a severe allergic reaction that can be life-threatening. Symptoms include swelling, hives, and breathing troubles. Immediate treatment for anaphylaxis is often necessary and typically requires an epinephrine injection.
Can You Eat Sardines Every Day?
While sardines are healthy, eating canned sardines every day is probably not a good idea. This is because they contain low levels of mercury and high amounts of sodium.
You can eat canned sardines in moderation, such as two or three times a week, as part of a healthy, balanced diet. However, eating fresh sardines and other fresh fish more than three times a week without any adverse effects is possible.
Sardines vs. Salmon: Which Is Better?
While canned sardines are still rich in nutrients, they are not as healthy as other fish that are available fresh. Fresh sardines are much healthier than canned, but still not as healthy as other fatty fish.
Fresh salmon is healthier than sardines because it contains higher amounts of omega-3 fatty acids. It also has less cholesterol, calories, fat, and sodium.
Summary
Sardines are small, nutrient-dense fish that are available fresh and canned. These oily fish contain omega-3 fatty acids and are good sources of protein, vitamins, selenium, and calcium.
Sardines are an excellent source of omega-3 fatty acids, which have anti-inflammatory properties. Additional health benefits include supporting heart and bone health, promoting fetal development, improving nerve function, and preventing type 2 diabetes.
Most people can safely eat sardines as part of a regular, healthy diet. Because canned sardines are high in sodium and are a high-purine food, they should only be eaten in moderation for people with high blood pressure, diabetes, gout, and kidney disease. People who take anticoagulant medications may need to control their intake of omega-3 fatty acids. You should also avoid sardines if you are allergic to seafood.
While sardines are a highly nutritious food, eating them every day is probably not a good idea. Fresh sardines and other fresh fish can be eaten more frequently.