Deciding whether to eat a greasy burger, chicken chow mein, or fish and chips is a conundrum that sparks family debates every Friday.
But a new study from Dalhousie University could help you decide, as researchers have found that seafood is more nutritious and climate-friendly than meat.
Environmental economists from Canada and Sweden calculated the nutrient density and climate impact of different fish sources.
They found that half of the fish species they studied had higher nutrient densities and emitted fewer greenhouse gases than beef, pork and chicken.
Of the more commonly consumed fish species in the UK, wild-caught salmon, herring and mackerel are the species with the lowest climate impact relative to their diet.
The results suggest that strategies to promote seafood in the diet as a substitute for other animal proteins could improve future food security and help combat climate change.
The researchers found that half of the fish species they studied had higher nutrient densities and emitted fewer greenhouse gases than beef, pork and chicken (stock image)
Speaking to MailOnline, Peter Tyedmers, a professor at Dalhousie University’s School for Resource and Environmental Studies, said: “This work makes it clear that many of us are making a real reduction in climate impact through the choices we make about animal-based foods can cause in our diet.
“Switching from beef, pork and often even chicken to fish dishes will almost always result in lower production-related emissions, which will ultimately be necessary if we are to meaningfully address the climate crisis.”
With the world population expected to reach 8 billion this year, scientists have predicted that we will face major food shortages in the future.
This will coincide with an increase in the impacts of climate change, which could pose challenges in meeting food needs while reducing emissions.
Although meat is high in protein, eating it in large amounts has been linked to heart disease and other health problems.
Its production has devastating effects on the planet as factory farming destroys habitats and creates greenhouse gases.
However, seafood is known to be a good source of protein, fatty acids, vitamins and minerals.
Professor Tyedmers investigated whether these nutritional benefits weighed alongside the greenhouse gases released by its production.
His team analyzed the nutrient density and climate impacts of globally important seafood sources from a wide range of fisheries and aquaculture operations.
For each seafood product, including farmed mussels (left) and wild-caught salmon (right), the researchers calculated a nutrient density value and the greenhouse gases emitted in relation to catch weight (stock images).
For each seafood product, they calculated a nutrient density value using data from the uFishJ Food Composition Database, the Canada Nutrient File, the Japan Standard Tables of Food Composition, or the Swedish Food Composition Database.
They created a composition profile of 19 desirable nutrients, including protein and vitamins A, D and B12, and two undesirable nutrients from saturated fat and sodium.
To assess the climate impact of aquaculture seafood, they determined carbon dioxide emissions in kilograms per kilogram live weight from nine appropriate LCA studies.
For species obtained through wild capture fisheries, data from studies on fishing vessel fuel consumption were used to calculate greenhouse gas emissions per tonne of catch landed.
Greenhouse gas emissions for terrestrial-based meats from beef, pork, and poultry were based on published LCA data, while nutrient data was from the Canada Nutrient File database.
The study, published today in Communications Earth & Environment, shows that seafood can feed humans better than meat with lower greenhouse gas emissions.
Wild-caught salmon, herring, mackerel and anchovies, and farmed mussels and oysters had the lowest climate impacts relative to their nutritional value.
The fish species with the highest food density was pink salmon with a score of 6.3, however capelin has the lowest climate impact, emitting 498 kg of carbon dioxide per tonne caught.
In comparison, 56 kg of carbon dioxide emissions per kg of edible product were determined for beef and almost 7 kg of greenhouse gas emissions for pork.
| seafood | Nutritional Density Score | Greenhouse gas emissions (kg CO2 per tonne of food) |
|---|---|---|
| Alaska Pollock | 2.1 | 1120 |
| American lobster | 3.7 | 11137 |
| atlantic cod | 2.3 | 2905 |
| Atlantic herring | 4.3 | 623 |
| Atlantic mackerel | 5.1 | 811 |
| Atlantic Salmon | 5.4 | 6978 |
| mussel | 3.5 | 1354 |
| Cape hake | 1.8 | 4500 |
| carp | 4.8 | 3235 |
| European sprat | 5.4 | 836 |
| giant tiger shrimp | 3.6 | 3977 |
| Green Shell | 3.7 | 1354 |
| haddock | 2.5 | 3998 |
| Japanese anchovy | 5 | 3998 |
| Northern Shrimp | 2.8 | 20619 |
| Pacific shell oyster | 3.8 | 682 |
| pink salmon | 6.3 | 932 |
| yellowfin tuna | 4.5 | 4843 |
| meat | Nutritional Density Score | Greenhouse gas emissions (kg CO2 per kg retail weight) |
|---|---|---|
| beef | 3.56 | 56.24 |
| pork meat | 3.74 | 6.96 |
| Chicken | 2.38 | 3.5 |
The researchers conclude that seafood can provide a sustainable source of nutritious food that also benefits the climate.
Professor Tyedmers added: “In many ways, this study confirms insights that many of us have had for a long time: that seafood, in general, is a source of highly nutritious food whose production leads to a relatively low climate impact, particularly compared to the climate impacts of.” Beef, pork and often even chicken.
“But to confirm this, we did so using the best available data for the broadest group of globally important seafood species that are important to various diets around the world.”
“However, we go further and highlight the wide variety of nutritional attributes of different seafood species that may be of concern to individuals or subpopulations whose diets are restricted in some key nutrients.”
