Overview

Athletics encompasses a range of sports that primarily use the arms, chest, and legs. While the demand for each type of muscle depends on the exercise, diet can greatly improve all types of athletic performance. Mackerel is an oily fish that contains a wide array of vitamins, amino acids, and high unsaturated fat. This nutritional profile provides multiple health benefits from muscle growth to improved oxygen delivery, aspects that assist athletes with maximising their performance when training or competing.

Preparation methods can influence the nutrients you can obtain from mackerel, making its nutrient profile as varied as that of its flavour.

Nutritional benefits of Mackerel

Amino acids

You may be aware that proteins are made up of amino acids, and they are responsible for muscle synthesis and repair (being popular for bodybuilders or gym-goers). However, there is much variation in the nutritional value of protein which is in turn based on their amino acid composition.

There are 20 different amino acids that code for human proteins, with 9 that the human body is not capable of producing, These are considered essential amino acids, as they can only be obtained through food. They include: 

• Histidine
• Isoleucine
• Leucine
• Lysine
• Methionine
• Phenylalanine
• Threonine
• Tryptophan
• Valine

The other 11 are non-essential amino acids since they are synthesised by the human body, therefore consuming foods with these would not provide any benefit to you.

Mackerel is a highly reliable amino acid source, containing all of the essential amino acids except for tryptophan, which is at a considerably lower level than the rest.¹

While all amino acids are involved in the structure of proteins in general, certain ones have importance regarding specific functions, most notably:

• Histidine is a component of haemoglobin found in red blood cells to aid in oxygen transport to muscles. Muscles have a higher oxygen demand when exercising, so higher levels of haemoglobin mean muscles can work for longer before being exhausted

Phenylalanine can be used to create phenylethylamine, a neurotransmitter that suppresses the inhibition of dopamine and serotonin, also neurotransmitters, that are responsible for promoting pleasure and positive moods. While these are not physical benefits, providing motivation for athletes is important, and contributes to the runner’s high phenomenon – a rush of endorphins you may feel as you exercise.

• Leucine, isoleucine, and valine are classified as branched-chain amino acids (BCAAs) based on their chemical structure and are associated with muscle repair and growth. The muscles that athletes use the most are in the legs (running), chest (pole vault, javelin throw), and arms (shot put), but all muscles within the body are required for stability and posture. In excess, BCAAs can reduce the availability, of that is the amount of a substance that the body can use. Therefore, the overall balance of amino acids in mackerel makes it a reliable source of most of the proteins that we need²

Omega-3 fatty acids

There are three types of omega-3 fatty acids: eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA). Oily fish such as mackerel, salmon, and trout are rich in EPA, which has significant implications for heart health

Research has shown that EPA reduces the risk of sudden death from arrhythmia (irregular heartbeat) as well as hypertension (high blood pressure).³ Eicosapentaenoic acid, alongside all omega-3 fatty acids, is not known to interact with any drugs and cause complications.

There is also evidence that omega-3 fatty acids can stabilise atherosclerotic plaques, which are formations on the interior walls of arteries. These plaques can be vulnerable to breaking away and causing blockages that could potentially lead to heart attacks or strokes.⁴ Ensuring that arteries remain clear from atherosclerotic plaques means these vessels can reliably transport oxygenated blood to all parts of the body, optimising athletic performance.

While the role of exercise on heart and vascular health has been well-established, incorporating mackerel into the diet can enhance these benefits, making related illnesses or setbacks less likely to occur, thus optimising an athlete's performance.

Vitamins

Mackerel contains a variety of vitamins, specifically B vitamins, that provide a range of benefits:

• Vitamin B2: metabolises proteins and fats into glucose, to be converted into energy⁵
• Vitamin B6: involved in the formation of haemoglobin⁶
• Vitamin B12: converts homocysteine to methionine, a precursor to non-essential amino acids⁷

Mackerel also contains vitamin B3, which helps athletes maintain muscle strength and coordination. However, vitamin B3 is commonly found in many other foods, such as red meat, seeds, nuts, breads, and cereals.⁸

Mackerel also contains vitamins A and E, both of which have antioxidant properties. This means they are able to remove free radicals from the body that would otherwise cause cellular damage. Free radicals can come from oxygen, and due to a higher demand for O₂ during exercise, athletes are more at risk for damage caused by them.⁹

A common belief is that frying food is an unhealthy way of cooking, but different cooking methods may affect the availability of vitamins A and E. In oven-baked mackerel, vitamin A levels are higher compared to that fried, however, this is the opposite for vitamin E. The healthiness of your mackerel will depend on other factors such as the type and amount of additional oil used, other ingredients, and any charring that occurs during cooking.

Both cooking methods optimise vitamins with antioxidant activity. Vitamin A, which also supports retinal health in the eyes, makes baking mackerel a slightly “healthier option in this regard.

Other benefits of mackerel

Convenience

Aside from its nutritional benefits, there are reasons why mackerel can be a valuable part of a diet.

Mackerel is commonly smoked as a preservation method, making it a convenient food if on the go. Marathon runners who eat before and during their runs could eat mackerel given not only its nutritional value, but its handy nature coming tinned or canned, pre-cooked.

Like all fish, mackerel can be bought fresh, and be prepared according to preferences. Weight management

Despite being high in fat, mackerel is believed to aid in weight loss and management. Obese rats were fed mackerel as part of a high-fat, low-calorie, low-sodium (no added salt) diet, which resulted in higher serum glucose levels than mice that followed a diet without mackerel and higher salt content. Evidence indicated that liver and kidney weights were significantly lower in the mackerel-fed group.¹⁰

This research suggests that mackerel can satisfy hunger to prevent overeating due to its omega-3 fatty acid content. Furthermore, the results also demonstrate the importance of lower dietary sodium levels, as recommended by organisations such as the NHS and NICE.

FAQ’s

Can I get mercury poisoning from eating mackerel?

There is a chance that any fish or seafood you eat contains mercury, which is harmful in large quantities.

Human activities such as waste incineration and coal burning lead to toxic chemicals leaking into water; including mercury, a neurotoxin that damages nerves and affects the central nervous system.¹¹ The resulting symptoms are movement, hearing, and speech impairments. Muscles gradually become weak due to diminished use.¹²

Mercury is mostly present as methylmercury, and can enter the body via the gastrointestinal tract when consuming mackerel). Once absorbed, it can spread to other organs such as the kidneys and the reproductive system.¹³

The effects of mercury poisoning are detrimental to anyone and can cause significant and irreparable damage to the whole body. Not all mackerel contain mercury and those that do vary in amount based on their sourcing location.

What alternatives to mackerel can I eat?

Depending on what nutrients are sought, there are other foods that can be consumed instead of mackerel. Salmon, also an oily fish, is an excellent source of omega-3 fatty acids as well as multiple amino acids, including all three BCAAs.

It is worth noting, however, that other sources of seafood, including oily fish may contain mercury. These levels vary depending on their sourcing location, and checking with local authorities for safety information prior to consumption is advisable.

Summary

Mackerel offers a variety of nutritional benefits for athletes, including a range of non-essential amino acids essential for muscle repair and growth, and vitamins that optimise oxygen transportation to muscles under higher demand. Mackerel is an oily fish, rich in omega-3 fatty acids that is shown to maintain heart and blood vessel health, ensuring the risk of conditions such as heart attack or arterial blockages.

The versatility of mackerel’s nutrients is influenced by its preparation method before consumption, with certain vitamins to be present depending on the cooking method. Smoking is the most popular of these methods, for the purposes of convenience and preservation. Other factors in preparing mackerel such as using additional oil or salt can also impact its nutritional profile. 

It's important to ensure that the mackerel intended for consumption has safe levels of mercury. This food has the potential to bring a number of lifestyle benefits, whether athletes or not.