Is farmed fish from aquaculture a healthy source of protein?
In this edition of our Aquaculture Series we explore the nutritional value of farmed fish. You will discover:
- The nutritional benefits of eating fish as a provider of protein, micronutrients and omega-3 and omega-6.
- The nutritional similarities and differences between farmed fish and wild-caught fish.
- How farmed seafood compares to sources of alternative proteins such as insects and lab-grown meat.
Seafood, and especially fish is an important component of our diets that is in increasing demand. In fact, fish provides 17% of the world’s meat consumption (1,2). In particular, seafood plays an important role in the diets of billions of consumers in low-and middle-income countries (3). In these countries, nutrient-rich foods such as meat can be expensive, whereas fish provides a more affordable alternative (4).
The fish that we eat are either wild-caught or farm-raised. Wild-caught fish are harvested from their natural environment such as oceans or freshwater lakes and rivers. Farm-raised fish are bred and grown commercially in controlled pens that exist within lakes, oceans or rivers, as well as large tanks.
However, due to overfishing and bycatch, wild-caught fish stocks are declining, thereby affecting food and nutrition security (5,6). In comparison, aquaculture could offer a promising sustainable solution to producing affordable seafood in an efficient way, while helping to feed a rising global population. This is especially the case for those living in coastal and rural communities, as aquaculture also provides jobs and economic development opportunities (7).
How nutritious is fish?
In general, fish has many nutritional benefits (3,8,9) for example:
- Protein: The protein from fish is readily digestible and of high biological value. It consists of all of the essential amino acids required to support body functions such as muscular health.
- Micronutrients/Vitamins and minerals: Fish also provides other important vitamins, such as vitamin D for calcium fixation in bones and minerals such as phosphorus and iodine.
- Omega-3 and Omega-6: Fatty fish is also rich in polyunsaturated fatty acids including omega-3 and Omega-6 which are indirectly involved in regulating inflammatory responses and blood pressure.
Fish – “they are what they eat!”
Fish are one of the most efficient converters of feed into high quality food. Their nutritional composition depends largely on what they eat (10, 11). Wild-caught fish eat a varied diet of invertebrates and other fish, and they are exposed to environmental uncertainties and seasonal variabilities. This means that the consistent nutritional value of the final product cannot be guaranteed.
By contrast, an advantage of farmed fish is that their diets can be managed. For example, feed constituents such as the percentage of fishmeal and the quality of its oils can be tailored. Farmed fish can therefore yield excellent quality when farmed correctly and responsibly, resulting in product consistency, size, and flavour.
Nutritional value of farmed fish versus wild-caught fish
The type of fish and where it comes from also impacts its nutritional value. With 50% of the fish we eat coming from wild-caught fisheries and 50% coming from fish farms (12), the nutritional values of fish from both sources is often compared. There is often contradictory information about the differences between wild-caught fish and farmed fish. Let’s take a look at these differences using salmon as an example.
While the protein composition of wild-caught fish and farmed fish is virtually identical, wild salmon is higher in minerals, including potassium, zinc and iron. Farmed salmon contains slightly more omega-3s, much more omega-6 and is higher in vitamin C. However, farmed salmon does contain more calories and saturated fat. This could be for the reason that wild fish typically get more exercise, and because farmed fish are typically given feed high in saturated and unsaturated fat (13).
Since farmed fish generally provide a higher amount of polyunsaturated fatty acids such as omega-3 compared to wild fish, vegetable food is increasingly replacing fishmeal in fish feeds to reduce these lipid levels in the fish (14). Since humans need some polyunsaturated fats such as omega-3 and omega-6 in their diets, we rely on foods like fish for these essential fatty acids, because our body does not produce them (15).
In summary, overall nutritional differences between farmed and wild-caught fish, are minimal. Many people have come to realize the importance of seafood in their diet and several health organisations recommend that at least two portions of seafood (150g -200g) are consumed per week to support optimal health (16).
How healthy is fish protein versus meat or alternative protein sources such as algae?
Proteins are made of up of building blocks known as amino acids. While our bodies can produce some amino acids, there are nine of them which we cannot produce and need to obtain through our food. Known as ‘essential amino acids”, our diets must include enough of each of them to maintain optimum health (17).
Traditional meat such as beef and pork, is an excellent source of protein with high biological value, however it carries sustainable and ethical disadvantages (18,19). Over the past decade, alternative sources of protein which can be produced in sustainably, are actively being developed and considered to be vital for the future of food (20,21). Let’s explore some examples of alternative proteins.
Algae is a product of aquaculture. While seaweed is becoming more renowned as a future food, microalgae or microplankton, its microscopic relatives, are looking even more promising (22). As an alternative to traditional sources of protein, over half of their dry matter consists of protein. As a way of comparison, the Spirulina algae can contain up to 63% protein, while soy (an important plant-based protein source) contains 40% protein.
- For example, EIT Food RisingFoodStar Vaxa is producing microalgae that is rich in protein and omega-3 for human consumption. The microalgae has a minimal environmental footprint and is carbon negative. Learn more about how Vaxa are converting clean energy to sustainable food by farming omega-3 rich microalgae in their ‘Food Fight’ podcast episode here.
Lab-grown meat is predicted to become one of the largest alternative protein markets globally. Companies are developing lab-grown chicken, beef and salmon. One of the main benefit is that the nutritional profile of lab-grown meat can be tailored and personalised (21).
- For example, EIT Food RisingFoodStar Mosa Meat produces beef by growing it directly from animal cells for human consumption. They are able to produce 80,000 burgers from one sample of cells. Learn more about Mosa Meat here.
Plant-based protein consumption is increasing at an annual rate of 7% globally (23). The most common protein-rich plants are soybean, legumes and oilseeds. Typically, plant-based proteins are not ‘complete’ as they do not provide all the essential amino acids. However, if two or more plant-based protein sources are consumed throughout the day this problem can be easily solved.
- For example, EIT Food RisingFoodStar ENOUGH is producing a high-quality food grade protein (ABUNDA®) from alternative sources like fungi, that are environmentally & economically sustainable, yet rich in protein and fibre. Learn more about how ENOUGH are helping to meet the growing demand for sustainable protein here.
Edible insects are already consumed by 2 billion people around the globe (24). They are an abundant, sustainable protein source and contain all of the essential amino acids that are needed for human health (21).
- For example, EIT Food RisingFoodStar Essento is creating protein-rich and eco-friendly insect food products, such as insect protein bars and insect burgers. Learn more about how they are developing tasty and sustainable food products made from farmed insects in this Food Fight podcast episode here.
Aquaculture is the most efficient protein generator
Though fish compose a small amount of global protein intake (6.7%), they are an important source of animal protein, providing 17% of the world’s meat consumption. Also, fish play a vital nutritional role for many people. 3.1 billion people rely on fish for 20% of their daily protein intake, with some coastal communities reliant on fish for upwards of 70%. (25).
Aquaculture is one of the most important long-term growth areas for food production. With the catches from wild fisheries remaining largely flat and some stocks already overexploited, it is important to increase the amount of seafood available using aquaculture to provide enough protein for the growing population. It’s predicted that protein production will need to double by 2050, so our reliance on aquaculture is likely to increase. In fact, the FAO forecasts that aquaculture’s share of production will increase to 59% (109 million tonnes) by 2030. (26).
How EIT Food is accelerating innovation in sustainable aquaculture and nutrition
The following EIT Food projects are transforming aquaculture into a highly sustainable and nutritious sector.
- Ground-breaking Circular Economy Feed Ingredient for Farmed Salmon project– is developing a fish feed for salmon that contains protein from recycled wastewater in the starch industry. The fish feed will be made from a sustainable fungi-based protein to replace the use of fishmeal and soybean meal. Project Consortium: Cewatech (Sweden), Technical University of Denmark (Denmark) and Matis (Iceland)
- Fermented seaweed based novel feed additives (SEAFEED) project – is supplying feed formulations that promote bioactive ingredients in feed and overall gut health in fish, enhancing productivity and animal welfare and reducing utilization of antibiotic agents. Project Consortium: Matis (Iceland), Quadram Institute (UK) and the University of Helsinki (Finland).
- Energy-to-Feed (E2F) project – is developing a sustainable source of protein & lipid from omega-3 rich microalgae cultivated using clean power sources (Geothermal/Hydro) & natural CO₂. Project Consortium: Matis (Iceland), Waitrose (UK), Siemens (Germany) and Vaxa (Israel)
So, do you think aquaculture is able to provide nutritious food for us to eat?
Up next in our EIT Food Aquaculture Series: Why alternative and sustainable fish feeds are needed. Read here
Do you want to learn more about the latest sustainable innovations within the aquaculture sector? Download EIT Food North West's Aquaculture Showcase report here.
- Sustainable Fisheries: What does the world eat?
- FAO: The State of World Fisheries and Aquaculture 2020
- Béné, C., Barange, M., Subasinghe, R. et al. Feeding 9 billion by 2050 – Putting fish back on the menu.
- PHYS: Fish farms are helping to fight hunger
- WWF: Threats - Overfishing
- Reuters: World's fish consumption unsustainable, U.N. warns.
- European Commission: Strategic guidelines for a more sustainable and competitive EU aquaculture for the period 2021 to 2030.
- British Nutrition Foundation: Nutrients, Food and Ingredients - Fish in the diet: A review
- FAO: The nutritional benefits of fish are unique.
- Skretting: How much feed is needed to grow a farmed fish?
- EcoCaters: Wild Caught vs. Farm-Raised Fish: Which is Better?
- FAO: Aquaculture
- Healthline: Wild vs Farmed Salmon: Which Type of Salmon Is Healthier?
- Cahu C, Salen P, de Lorgeril M: Farmed and wild fish in the prevention of cardiovascular diseases: assessing possible differences in lipid nutritional values.
- Medline Plus: Facts about polyunsaturated fats.
- NHS: Fish and shellfish: Eat well.
- Healthline. Essential Amino Acids: Definition, Benefits and Food Sources.
- Forum for the Future: The Future of Protein Report.
- FOODDIVE: The meat industry is unsustainable, report finds.
- Good Food Institute: Record $3.1 billion invested in alt proteins in 2020, 3x the capital invested in 2019.
- Future Learn: EIT Food: The pros and cons of alternative proteins.
- Food Unfolded: Microalgae: Health and Environmental Benefits.
- European Commission: Development of plant proteins in the EU
- Future Learn: EIT Food: Insects as Food
- Sustainable Fisheries: What does the world eat?
- Reuters: Can sustainable aquaculture feed the world?