Cardiovascular diseases are the leading cause of death globally, making heart health a priority. A healthy heart enhances overall quality of life, enabling individuals to stay active and energetic for longer periods of time.⁸ Some potential ways to support heart health are as follows:

• Eating a healthy, well-balanced diet
• Exercising regularly, at least three times a week
• Undertaking stress-reducing activities such as yoga, meditation, and deep breathing exercises
• Getting seven to eight hours of sleep every night
• Eliminating tobacco use
• Limiting alcohol consumption
• Regularly monitoring pre-existing health conditions, such as blood pressure and cholesterol levels
• Having regular check-ups with your GP to monitor heart health and catch potential issues early

Carrying out these tasks consistently can significantly improve and support your heart health. Specifically, when focusing on dietary modifications, sardines are an excellent source of protein that can promote heart health.

An introduction to sardines

Sardines are small, oily fish known for their strong flavour and soft texture.¹ These are a type of forage fish, which survive on smaller organisms and plankton and are commonly preyed upon by larger fish. Sardines are part of the Clupeidae family and possess distinct, identifiable features, such as shiny scales, a single dorsal fin, and a spindle-shaped body. Sardines can be further sub-grouped into different species like the European pilchard, the South American pilchard, and the Pacific sardine. While all three species are considered sardines, they vary morphologically in aspects like scale colour, length, and mass. As indicated by their names, the differences between each of the sub-groups can be attributed to their native geographical locations.

Sardines as a global delicacy

Sardines are eaten all over the world and are especially common in the staple dishes of coastal towns and cities in countries such as India, Italy, Spain, and the Philippines. In India, fresh sardines are very popular due to their low cost in comparison with larger fish; they are prepared in various ways, including curries, stews, and fried delicacies. In Italy, sardines are used in pasta dishes, such as the traditional Sicilian meal pasta con le sarde. These are just a few examples of how sardines serve as a versatile ingredient in meals.

While fresh sardines are popular in coastal towns, they are more readily delivered and consumed by the rest of the population in canned form. Sardines are pre-cooked and packed in cans, often with added liquids such as oil, brine, or water. The cans are then sealed and sterilised using steam or hot water. These canned sardines are then exported to be enjoyed by those living in non-coastal areas and are estimated to have a shelf life ranging from one to five years.

The nutritional value of sardines

Sardines are known to offer a range of health benefits, particularly for heart health. This is due to the abundance of nutrients found in sardines, including omega-3 fatty acids, vitamins, and minerals. This article will explore the effects of these individual nutrients and how they specifically support heart health.²

Omega-3 fatty acids

Omega-3 fatty acids are natural fats found in sardines that can improve heart health. Since these are essential fats that cannot be produced by the body on its own, they must be obtained through the diet. The fatty acids most commonly found in sardines are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These help reduce inflammation, which plays a significant role in preventing and managing chronic heart diseases. As a result, omega-3s can reduce triglyceride levels, reduce blood pressure, and prevent blood clot formation. Several studies have shown that omega-3s decrease the risk of coronary heart disease and arrhythmias. Additionally, they interfere with key mechanisms involved in atherosclerosis, reducing the risk of this condition as well.³

Vitamin D

Sardines are a natural food source of vitamin D. While the mechanistic actions of vitamin D in cardiovascular health are yet to be established, several clinical studies have shown a strong association between vitamin D deficiency and degenerative cardiovascular diseases.⁴

Vitamin B12

Sardines are also rich in vitamin B12, which is essential for maintaining healthy blood cells and preventing anaemia. Anaemia can increase the amount of work that the heart must do in order to pump blood around the body. Additionally, vitamin B12 helps reduce levels of a molecule named homocysteine, which is associated with an increased risk of heart disease and atherosclerosis when present in high amounts.⁵

Selenium

Selenium is a mineral found readily in sardines. It has distinct antioxidant properties that protect cells from damage and reduce inflammation. Additionally, selenium plays a role in preventing the oxidation of a key factor in the development of atherosclerosis, a major contributor to heart disease.⁶

Iron

Sardines contain a high amount of iron compared to other commonly consumed fish, meaning they can be consumed readily in order to meet daily iron requirements. Cardiovascular diseases and iron-deficiency anaemia are linked; thus, iron intake should be taken seriously for patients with cardiovascular conditions. Inadequate management of iron-deficiency anaemia can lead to negative outcomes in these patients. Therefore, iron supplementation is sometimes necessary, and in such cases, iron-rich sardines can be beneficial for achieving the recommended daily iron intake.⁹

High protein, low caloric content of sardines

Sardines are an excellent source of protein, which is essential for tissue repair and the maintenance of muscle mass, including the heart muscle. Despite their rich nutritional content, sardines, like many fish, have a low caloric content, making them a suitable choice for those looking to achieve or maintain a healthy weight. Obesity is a risk factor for many chronic conditions, especially cardiovascular diseases. By incorporating low-calorie, nutrient-dense foods like sardines, individuals can effectively manage their weight , thereby promoting cardiovascular health.⁷

Environmental sustainability of sardines compared to other fish species

According to the Marine Stewardship Council, sardines are certified as sustainable. They are considered environmentally friendly due to their low carbon footprint. Sardines are also found in greater abundance and have a lower impact on marine ecosystems, making them a responsible choice with regards to the planet, especially during a time period in which overfishing is a significant environmental concern.

Economic affordability of sardines

Compared to other fish and meat options, sardines are relatively inexpensive, making them appealing to a wide range of consumers, especially those who are budget-conscious. Overfishing has resulted in fish being caught at a faster rate than they can breed, which is particularly problematic for larger, slower-growing species such as salmon. However, this is not the case with sardines, due to their abundance and fast reproductive cycle. This increased availability leads to a reduced demand for sardines, driving their cost down.

In addition, sardines are often consumed in canned form, as mentioned earlier. This typically means they have a long shelf life, which adds to their cost-effectiveness by reducing food waste. As a result, sardines offer a cheap and nutritious option for people across various socioeconomic backgrounds, contributing to food security and nutritional health globally.

FAQ’s

What is the difference between sardines and pilchards?

Sardines and pilchards belong to the same family of fish, and the two terms are often used interchangeably. However, sardines are generally thought to be smaller, younger fish within the Clupeidae family, while pilchards are considered larger, older members of the same family. The term ‘sardines’ is more commonly used in the United States, whereas ‘pilchards’ is more commonly used in the United Kingdom to refer to the larger fish.

What is inflammation?

Inflammation is a mechanism used by the immune system in response to injury and infection. However, prolonged chronic inflammation occurs when the immune system remains activated despite the absence of injury or infection, leading to damage and dysregulation of healthy cells and tissues. Conditions aggravated by chronic inflammation include atherosclerosis, type 2 diabetes, and inflammatory bowel disease.

What are triglycerides?

Triglycerides are a type of fat found in your blood, and they can aid in maintaining good health. However, high levels of triglycerides can be detrimental to your health, specifically the health of your heart and blood vessels. These levels are typically measured and monitored through a simple blood test. 

What is atherosclerosis?

Atherosclerosis is a condition characterised by plaque formation on artery walls. Plaques consist of a build-up of fats, cholesterol, and other substances, leading to the thickening or hardening of the arteries. This can result in blocked arteries and inefficient blood flow to tissues, increasing the risk of strokes and heart attacks. 

Summary

Sardines are a nutritious and budget-friendly food option that offer numerous health benefits, including the promotion of heart health. These small forage fish are packed with vital nutrients such as omega-3 fatty acids, vitamin B12, vitamin D, and selenium, which help prevent heart disease by reducing inflammation and lowering blood pressure. Sardines are high in protein and low in calories, making them an excellent option for maintaining a healthy weight and supporting heart health. Additionally, sardines are not only environmentally friendly but also affordable and accessible. By incorporating sardines into meals, individuals can enjoy a sustainable and affordable food that supports both personal health and environmental conservation.