Sardines are one of the greatest gifts provided by Mother Nature. These small, silvery, elongated fish are abundantly found on coasts and are affordable, nutritious and delicious. Many people all over the world enjoy eating this fish, which is easily available in small tins in any nearby grocery store.1
What are sardines?
Sardines, also known as pilchards, are small, oily schooling fish belonging to the herring family, Clupeidae. They are members of the genera Sardina, Sardinops, and Sardinella. They are generally available in the form of canned fish. 21 types of fish fall under the category of sardine. The most popular species are Sardina, Sardinops, sardinella, and dussumieria. These fish are found in the Mediterranean Sea and off the Atlantic coasts of Spain, Portugal, France, and Britain.1
Sardines of any species are commercially used for drying, salting or smoking; and for reduction into fish meal or oil. These fish are mainly caught at night when they swim to consume plankton. The fish are transported to shore whilst being submerged in brine. Sardines are canned in different ways. The fish are washed and then cooked, either by deep-frying or by steam-cooking, after which they are dried. In some countries, the fish are packed in either olive or soybean oil, while in other countries they are smoked. They can also be packed in a tomato or mustard sauce.
The main use of sardines is for human intake, but meals prepared from fish can be used as animal feed too. Sardine oil is used in manufacturing paint, varnish, linoleum and margarine.2
Nutritional values
Although these fish are small and make a great ingredient for a balanced meal due to their low saturated fat and calorie content. In addition to this, these fish provide high protein, vitamins and minerals.
A 100 g serving of fresh, cooked sardines:
- 208 kcal energy
- 24.6 g protein
- 7.8g fat
- 397 mg potassium
- 382 mg calcium
- 4.8 μg vitamin D
- 12mg niacin
- 8.9 μg vitamin B12
- 52.7 μg selenium
- 101 ug iodine2, 3
Digestive benefits of sardines
Sardines are an excellent source of diverse nutrients. They play a crucial role in healthy bowel movement. They help maintain smooth digestion flow by acting as a lubricant for the digestive tract. Due to their anti-inflammatory and antioxidant properties, they help reduce inflammation and strengthen the intestinal walls, thus also protecting against gastrointestinal diseases.
The major nutrients and their functions in gut health, thereby, preventing other diseases are mentioned below:
Omega-3 polyunsaturated fatty acids (n-3 PUFA)
In general, oily fish are dietary sources of n-3 PUFA. However, the n-3 PUFA content varies depending on the type of fish. It is said that the oilier the fish, the more n-3 PUFA it tends to contain. Sardines are an inexpensive source of n-3 PUFA, mainly containing essential fatty acids like eicosapentaenoic acid and docosahexaenoic acid. Due to this property, sardines act as a cardioprotective agent and help to improve cardiometabolic function. It is also known that n-3 PUFA enhances gut microbiota as it has anti-inflammatory properties.3, 4, 5, 6
Essential vitamins and minerals
Sardines are a great source of vitamins and minerals (calcium, vitamins B12 and D, potassium, magnesium, zinc, etc.) which improve clinical outcomes in patients affected by cardiometabolic diseases. The gut microbiota, including microbiota richness and the abundance of certain vitamins and minerals, are linked to the concentration of serum zonulin. A study found that the lower the zonulin, the higher the microbiota richness. It was noted that a higher intake of n-3 PUFA is associated with lower zonulin concentrations.6, 7
Protein
Sardines are known to contain easily digestible proteins composed of all essential amino acids required for healthy human diets. The essential amino acids in marine proteins are highly digestible (exceeding 90%). This property further helps in reducing protein-deficiency malnutrition, responsible for improving brain, immune and respiratory functions, which are known to cause death in children and adults.8
Digestive enzymes
Like many other fish, sardines also contain digestive enzymes i.e. proteases and lipases. The general characteristics of the enzymes present in sardines resemble those of other fish. These enzymes enable the gut to break down larger molecules into smaller ones to smoothen the process of digestion.6, 9
Other health benefits
Due to their highly nutritious value, sardines are proven to be advantageous in other health issues which may or may not be directly interlinked with their digestive properties. A few of these functions are listed below:
- They are cardioprotective.
- They help with insulin resistance.
- They help support good mental health.
- Their consumption is known to reduce the risk of developing age-related macular degeneration.
- They are known to prevent breast cancer.
- They are known to prevent bone-related diseases.
- They help in boosting the immune system.
- They are hepatoprotective and help with managing weight.5, 10, 11, 12
Food versus supplementation
The use of food supplements versus the use of sardines in diet is debatable. However, we do have a few studies that can help us to decide which to choose. It is noted that food supplements are intended to correct nutritional deficiencies and, in general, society currently uses supplements with the intent of reducing the risk of health issues. It has been reported that 59% of the population in the United Kingdom consumes food supplements. Almost half of them (45%) are reported to consume them five times or more per week.
A few studies have demonstrated that intake of food supplements will not always significantly reduce the risk of diseases. It is recommended to consume at least 1 to 2 servings of sardines per week to benefit health. Several studies have shown that despite supplements being a convenient method of achieving nutrients, they are unlikely to achieve satiety similar to a portion of sardines or any other fish.3
Summary
Sardines are small, oily fish that are home to various nutrients. They have an excellent nutritive value and are delicious, normally eaten as a part of traditional dishes in different parts of the world. Due to their smooth digestive properties, they not only help protect against gastrointestinal diseases but also help other diseases like cardiovascular disorders, where their function of good metabolism is utilized. The selection of consuming sardines as a food item or as a supplement is solely based on an individual’s choice, convenience, doctor’s recommendation and the ability to adhere to the treatment.
References
- What Are Sardines? The Spruce Eats [Internet]. [cited 2024 Apr 5]. Available from: https://www.thespruceeats.com/all-about-cooking-with-fresh-sardines-1300644.
- Sardine | Health Benefits, Types & Recipes | Britannica [Internet]. [cited 2024 Apr 5]. Available from: https://www.britannica.com/animal/sardine.
- Santos HO, May TL, Bueno AA. Eating more sardines instead of fish oil supplementation: Beyond omega-3 polyunsaturated fatty acids, a matrix of nutrients with cardiovascular benefits. Front Nutr [Internet]. 2023 [cited 2024 Apr 5]; 10:1107475. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10153001/.
- Siriwardhana N, Kalupahana NS, Moustaid-Moussa N. Chapter 13 - Health Benefits of n-3 Polyunsaturated Fatty Acids: Eicosapentaenoic Acid and Docosahexaenoic Acid. In: Kim S-K, editor. Advances in Food and Nutrition Research [Internet]. Academic Press; 2012 [cited 2024 Apr 5]; bk. 65, p. 211–22. Available from: https://www.sciencedirect.com/science/article/pii/B9780124160033000135.
- Harris WS. Fish oil supplementation: Evidence for health benefits. CCJM [Internet]. 2004 [cited 2024 Apr 5]; 71(3):208–21. Available from: https://www.ccjm.org/content/71/3/208.
- Costantini L, Molinari R, Farinon B, Merendino N. Impact of Omega-3 Fatty Acids on the Gut Microbiota. Int J Mol Sci [Internet]. 2017 [cited 2024 Apr 5]; 18(12):2645. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5751248/
- Mokkala K, Röytiö H, Munukka E, Pietilä S, Ekblad U, Rönnemaa T, et al. Gut Microbiota Richness and Composition and Dietary Intake of Overweight Pregnant Women Are Related to Serum Zonulin Concentration, a Marker for Intestinal Permeability123. The Journal of Nutrition [Internet]. 2016 [cited 2024 Apr 5]; 146(9):1694–700. Available from: https://www.sciencedirect.com/science/article/pii/S0022316623006958.
- Šimat V, Hamed I, Petričević S, Bogdanović T. Seasonal Changes in Free Amino Acid and Fatty Acid Compositions of Sardines, Sardina pilchardus (Walbaum, 1792): Implications for Nutrition. Foods [Internet]. 2020 [cited 2024 Apr 5]; 9(7):867. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7404705/.
- Castillo-Yañez FJ, Pacheco-Aguilar R, Garcia-Carreño FL, Toro M de los AN-D. Characterization of acidic proteolytic enzymes from Monterey sardine (Sardinops sagax caerulea) viscera. Food Chemistry [Internet]. 2004 [cited 2024 Apr 5]; 85(3):343–50. Available from: https://www.sciencedirect.com/science/article/pii/S0308814603003583.
- Are sardines healthy? Good Food [Internet]. [cited 2024 Apr 5]. Available from: https://www.bbcgoodfood.com/howto/guide/are-sardines-healthy.
- Daidj NBB, Lamri-Senhadji M. Hepatoprotective and Anti-Obesity Properties of Sardine By-Product Oil in Rats Fed a High-Fat Diet. Prev Nutr Food Sci [Internet]. 2021 [cited 2024 Apr 5]; 26(3):285–95. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8531423/.
- Febriyanti VN. The Benefits of Consuming Sardines to Prevent Hypertension and Type 2 Diabetes Mellitus for Senior Citizens. Muhammadiyah International Public Health and Medicine Proceeding [Internet]. 2021 [cited 2024 Apr 5]; 1(1):893–906. Available from: https://e-journal.fkmumj.ac.id/index.php/miphmp/article/view/149.