Climate-friendly diet: Eat more seafood instead of meat

Enlarge image

Fish and seafood at a market in Rome

Photo: Jens Ickler / PantherMedia / Jens Ickler

The consumption of fish and seafood is not only more climate-friendly, but also healthier than a meat-based diet.

This is what an international research team reports after a comprehensive comparative study.

For this purpose, not only dozens of marine animal species were evaluated, but the data from breeding animals such as pigs, cattle and chickens were also compared.

In the work, published in the journal "Nature Communications Earth and Environment", the team led by Friederike Ziegler from the state Research Institutes of Sweden (RISE) advises specifically promoting the consumption of fish and seafood - especially with a view to those species with a particularly favorable climate and nutrient balance.

Seafood consumption accounted for about 17 percent of human consumption of animal protein in 2017.

But food from the sea has become increasingly important globally.

In addition, the team notes that there is clear evidence that the health benefits outweigh the potential risks, for example from contamination.

Sea animals not only contain a lot of protein, but also omega-3 fatty acids as well as vitamin D, vitamin B12, selenium, iodine, iron, zinc and phosphorus.

While the environmental impact of eating meat has been compared repeatedly to that of sea creatures, such analyzes are tricky, the researchers say.

On the one hand, environmental consequences are complex and range from land use to greenhouse gas emissions.

In addition, marine animals are extremely diverse and, in addition to various groups of fish, also include crustaceans and mussels, which are either wild-caught or kept in aquaculture.

Better nutrient density than pork, beef and chicken

In their analyses, Ziegler's group did not relate the climate-damaging greenhouse gas emissions to the mass of a food in kilograms, but to the nutrient density.

But even this is not easy: Because the emissions are strongly related to the production conditions, and the nutrient density also depends on which ingredients are referred to.

On average, Ziegler and colleagues write, marine animals have a better nutrient density than pork, beef and chicken and a better climate balance than at least pork and beef.

However, the differences between different groups of marine animals varied by a factor of more than ten, especially in terms of emissions.

The emissions from wild-caught fish therefore depend primarily on fuel consumption, which in turn varies with the type of fishing and the size of the stocks.

For example, line fishing for

, such as bigeye and albacore, is much more energy-intensive than net-catching species such as yellowfin and skipjack.

(Salmonidae) – such as pink salmon and sockeye salmon –

have the best ratio between nutrient units and emissions, as do smaller fatty fish such as

, and cultivated

.

However, these are not the most consumed sea creatures, the team writes, pointing out, for example, that the catch of salmon fish depends on stocks and smaller fish often have to be used as fodder for aquaculture and livestock farming.

In contrast, crustaceans such as

or cephalopods such as

had a lower nutrient density and were associated with high emissions.

Nutrient density of many edible fish not known

The team emphasizes that while the nutrient density of individual species can hardly be changed, the emission balance can be strongly influenced.

The researchers refer to technologies or - in the case of aquaculture - to husbandry conditions.

The CO2 balance of the feed used also plays an important role here.

The greatest nutritional benefits of sea food compared to meat are based on the content of niacin, vitamin D and especially vitamin B12.

White fish - i.e. fish with white meat such as

,

or

- has a less favorable nutrient density and emission balance.

In view of the outstanding importance of this group as edible fish, the team emphasizes that white fish kept in culture have a better balance than wild conspecifics.

However, the researchers concede that the nutrient density of many edible fish is not yet known in detail, and the bioavailability – i.e. to what extent the body can utilize the substances – is also unclear.

In view of their results, the researchers advise making fisheries and aquaculture more climate-friendly and promoting the consumption of marine animals.

To do this, you also have to get the food industry and retail on board.

Better knowledge of nutrient values ​​and appropriate labeling - as intended by the EU Commission in its Green Deal - could therefore enable the world's population to be supplied with food better and at the same time in a more environmentally friendly way.

"In fact, from a global perspective, it may be wise to promote the most nutrient-dense forms of seafood in underserved populations, even if it results in higher emissions," it says.

"In contrast, consumers in other populations may pay more attention to emissions than to nutrient content when choosing products." How increased consumption of marine animals can affect the populations of the respective species was not part of the study.

joe/dpa