Introduction

Respiratory health refers to the overall wellness and function of the respiratory system which allows us to breathe. This system includes the nose, mouth, throat, voice box, windpipe, and lungs. Maintaining good respiratory health is important as any conditions that affect these structures can have a profound effect on other systems in the body, not just those involved in breathing. 

Sardines are small healthy fish that contain nutrients such as omega-3 fatty acids, vitamin D, proteins, and antioxidants. All of these can improve your respiratory health and overall well-being. This article will discuss how this nutrient-dense food can improve your respiratory health and how it can easily be incorporated into your diet.¹

Poor respiratory health can affect the cardiovascular system because the lungs oxygenate the blood. If this is disrupted, it can cause strain on the cardiovascular system leading to high blood pressure and strokes.² The immune system is also closely intertwined with respiratory health.

A healthy respiratory system is important, serving as a physical barrier against pathogens, housing immune cells, coordinating inflammatory responses against pathogens and promoting tissue repair. Chronic respiratory infections such as cystic fibrosis can cause systemic inflammation, which is widespread inflammation that can affect and damage various organs in the body. It is therefore important to maintain good respiratory health to reduce the risk of serious complications and diseases throughout the body. Sardines in multiple studies have been reported to improve respiratory health and decrease lung function decline, which will be discussed in more detail.³

Nutrient breakdown

Sardines are rich in essential nutrients and low in calories making them a very healthy option. In one serving of 92 grams they typically contain:

• 190 Calories
• 22 grams of protein
• 11 grams of fat
• 1,5000 milligrams of omega-3 fatty acids
• 40% of the daily recommended intake of vitamin D
• 160% of the recommended intake of B12
• 15% of the daily recommended intake of Calcium
• 45% of the recommended intake of Selenium¹

Some of the key nutrients include omega-3 fatty acids which are important in reducing inflammation in the airways of the lungs. Vitamin D is essential for the immune system and vitamin b12 which has been shown to reduce respiratory infections, as well as antioxidants such as selenium that protect the body and more specifically the lungs against oxidative stress. 

Omega-3

Omega three fatty acids play a very important role in health as they can’t be made by the body and therefore must be obtained from your diet. There are three important types of ALA (alpha-linolenic acid), DHA (docosahexaenoic acid), and EPA (eicosapentaenoic acid). Sardines contain around 1500 mg of EPA and DHA. EPA combats inflammation by producing eicosanoids, a type of lipid that interacts with the immune system, it has also been shown to have antioxidant and bronchodilatory effects which improve respiratory function.

Furthermore, EPA has also been shown to play an important role in brain, cardiovascular and bone health. Some parts of EPA can be converted into DHA which is generally considered the most important omega-3 fatty acid. Similarly, some research has shown that DHA can improve lung function and help individuals with chronic lung diseases such as asthma, through its antioxidant and anti-inflammatory effects which can reduce airway inflammation, bronchoconstriction (tightening of the windpipe), and mucus production, leading to improvements in symptoms.

Just two portions of sardines a week would be sufficient to meet the recommended omega-3 intake.⁴ 

Selenium

One portion of sardines contain nearly half the recommended intake of selenium: an important trace mineral due to its antioxidant effects.  Selenium forms part of several antioxidant enzymes including glutathione peroxidases. These antioxidant enzymes protect the body from oxidative damage, where molecules in the body known as free radicals react and damage other molecules in the body such as proteins and DNA. These enzymes protect the respiratory tract and help neutralise free radicals which are common in the tract as it is often exposed to environmental pollutants and pathogens which generate free radicals.

A certain level of selenium is also needed for the proper functioning of immune cells for the recognition and elimination of foreign molecules and pathogens. This is essential to reduce infection of the respiratory tracts and lungs. Similar to omega-3 fatty acids, selenium also has been shown to modulate and reduce inflammation reducing the effect of chronic lung diseases.⁵

Vitamin D

Vitamin D - similarly to omega 3 fatty acids and antioxidant enzymes - can reduce inflammatory effects, interact, support the immune system, and reduce the risk of inflammatory infections. It is difficult for people to get enough vitamin D through diet alone. Not many foods are naturally rich in vitamin D, but sardines are one of them.

Many people suffer from what is known as vitamin D deficiency, and if this is severe or there is a chronic lack of vitamin D it can cause a serious decline in phosphorus and calcium levels which can cause cramps, muscle weakness, fatigue, and significant increased risk of developing respiratory infections.⁶

Protein

Sardines also contain a significant amount of protein, approximately 22 grams per serving. Having adequate protein levels is essential in maintaining respiratory health. Protein is needed to maintain the strength of the respiratory muscles such as the intercostal muscles and diaphragm involved in breathing. Sufficient levels of protein are also needed in the repair of damaged lung tissue.

Protein is made up of building blocks known as amino acids needed for cellular repair after lung damage to pathogens and environmental pollutants. Once again, adequate protein levels also support the function of the immune system and therefore reduces the risk of developing lung infections. Sardines are considered a high-quality source of protein because they contain all 9 essential amino acids which the body can’t make on its own.¹

Incorporating sardines into a diet

Sardines are a cheap healthy addition that can be added to a variety of meals and even eaten as a snack on their own, some meals include:

• Sardine pizza
• Sardines added to your favourite salad
• Sardine fish cake - a very popular meal where mashed sardines are combined with breadcrumbs and herbs to produce a fishcake
• Grilled sardines topped with an onion sauce with potatoes and vegetables - this is one of the most popular summer meals in Portugal. In Portugal, canned sardines are a delicacy after the two world wars where sardines were distributed to soldiers due to their nutritious benefit
• Sardine crackers

FAQs

Are canned sardines as healthy as fresh sardines?

Both canned and fresh sardines have huge nutritional benefits and are very healthy, but fresh sardines tend to be higher quality with more nutrients and less sodium. Canned sardines are much more versatile, easier and cheaper to use.

How often should I include sardines in my diet?

A few times a week as little as two portions will reach the many daily recommended vitamin amount.

Are there specific recipes or ways to prepare sardines for respiratory health?

Sardines can be enjoyed in various ways, such as grilled, baked, or added to salads, sandwiches, or pasta dishes. Avoid deep-frying sardines, as this can add unnecessary unhealthy fats.

What other foods are high in omega-3?

Other fish such as salmon and anchovies, seaweed, algae, nuts and seeds.

Do sardines contain a high amount of fat?

Sardines contain relatively high levels of fat, however, this is largely unsaturated fat and with low levels of saturated fats.

What do sardines taste like?

They have a rich oily taste with a hint of saltiness. Many people describe sardines as being overly and intensely fishy.

Summary

Sardines are a very cheap nutritious food that supports your respiratory and overall health. This fish contains many important vitamins, omega-3 fatty acids, antioxidants, and protein which play an important role in interacting with the immune system, reducing inflammation, repairing damaged lung tissue and protecting against lung infections. Maintaining lung health is important for all organs in the body and sardines provide a variety of vitamins that can support this.