A new review shows that fish can help bridge nutrition and sustainability goals, but only when consumers choose lower-impact species and use seafood to replace more environmentally intensive meats.
Review: Environmental burden of fish in healthy and sustainable diets. Image source: Sergey Zaykov / Shutterstock
In a recent narrative review published in International Journal of Food Sciences and Nutritiona team of authors examined how fish contribute to healthy, environmentally sustainable diets and assessed their environmental footprint relative to other animal-based foods.
Background
Did you know that food systems are responsible for nearly a third of global greenhouse gas emissions while consuming vast amounts of land and fresh water?
As global concern has grown about climate change, biodiversity loss and food security, there has been an increasing emphasis on producing food that is good for both people and the environment.
Fish consumption has been associated with benefits for cardiovascular health, neurocognitive outcomes, and overall mortality. However, there is still uncertainty about whether increasing fish consumption is an environmentally sustainable practice.
To develop better dietary guidance, further research is needed to understand and quantify the relationships between the nutritional benefits and ecological impacts of different species and fishing methods. Because this was a narrative, non-systematic review, the findings provide a broad synthesis rather than pooled estimates from a formal systematic review or meta-analysis.
This infographic titled “Environmental burden of fish in healthy and sustainable diets” includes three main panels: Observational studies assess the environmental impact of fish intake, generally finding low impacts. Environmental footprint analyzes show that most fish have lower emissions than land-based meats, while there is variability across species. Dietary Optimization Models focus on how fish intake can vary with dietary goals and constraints. The following section summarizes the general conclusions and future research needs, emphasizing the balance of health, environmental and sustainability factors in fish consumption.
Fish and sustainability: A complex relationship
Fish occupy a unique place in discussions of sustainable diets. Unlike many foods of animal origin, particularly red and processed meats, fish often provide significant nutritional benefits while producing a comparatively smaller environmental footprint. However, the level of environmental impact depends on the type of fish, fishing methods, aquaculture practices, transport requirements and supply chains.
The environmental impact of fish in current diets
Evidence from many countries shows that fish generally contributes a relatively small proportion of the total dietary environmental impact compared to meat.
Studies have found that, in typical diets of people from the UK, the Netherlands, France, Spain, Italy, Canada, Japan, Portugal, Lebanon and the United States, fish generally contributes a relatively small share of dietary greenhouse gas emissions compared to meat, although this varies by country, type of seafood and dietary pattern.
Research involving more than 65,000 adults in the UK showed that adults who ate fish instead of meat had significantly lower greenhouse gas emissions than those who ate meat. People who follow healthier and more sustainable dietary patterns generally consume more fish while maintaining a lower overall environmental impact.
Studies have also shown that increased fish consumption can lead to greater greenhouse gas emissions, particularly when certain species are consumed in large quantities.
Fish and seafood can have different environmental impacts, with small pelagic fish and molluscs generally having a lower environmental burden. In contrast, crustaceans and some aquaculture systems can be more carbon intensive.
Fish in optimized, healthy and sustainable diets
Many researchers have used dietary modeling techniques to identify dietary patterns that meet nutritional requirements while minimizing environmental impact.
Several studies show that increased fish consumption occurs when diets are optimized for adequate nutrition.
The reason for increasing fish compared to other commonly consumed foods is that it can be difficult to obtain certain nutrients, particularly long-chain omega-3 fatty acids such as EPA and DHAfrom these other foods.
In many European countries, replacing some meat with fish has led to measurable reductions in greenhouse gas emissions and land use, with potential health benefits.
The researchers found that fish often replaced environmentally intensive meats (such as beef and processed meats) rather than adding to the growing number of animal-based foods. Therefore, fish are allowed to maintain the same level of nutritional quality while meeting environmental targets.
As part of some optimally designed diets, consumers have been encouraged to eat more oily fish for their higher nutrient density and potential health benefits.
When more fish is not always better
While fish is commonly included in many sustainable diet options, simply increasing fish consumption does not automatically guarantee environmental benefits. Some dietary models with strict greenhouse gas reduction targets called for lower fish intake or a shift to lower-impact seafood, alongside reductions in meat and other high-impact foods.
When we were working toward more aggressive targets (33% to 50%) for reducing emissions in dietary models, fish consumption was sometimes reduced because some types of seafood still produce high carbon emissions.
Fish consumption levels often need to increase more for women than for men to meet their nutritional needs. However, some models found that men could meet their environmental goals without significantly changing their seafood intake. These disparities are due to differences in basic dietary habits and the amounts of nutrients required.
The results show that no one-size-fits-all approach to creating a sustainable diet is appropriate. To develop successful strategies for a sustainable food planning program, it is necessary to consider the local food culture, nutritional needs, environmental goals, and availability of seafood in the region.
Implications for public health and food policy
The review highlights important implications for policy makers, health professionals and consumers. For consumers, the findings reinforce the value of replacing portions of red and processed meat with carefully selected fish species. Such substitutions can improve the quality of nutrition while reducing the environmental impact. However, informed choices remain essential as environmental performance varies significantly among seafood products.
Food systems can also expand access to sustainably caught seafood and improve aquaculture practices that support healthy diet transitions. Investments in responsible fisheries management and practices that reduce environmental impacts will help strengthen the place of fish in sustainable food systems.
Conclusion
Evidence shows that fish can make a meaningful contribution to healthy and sustainable diets when consumed as part of wider dietary shifts away from environmentally intensive animal products.
Compared to meat, fish generally produce lower greenhouse gas emissions and require fewer natural resources, although environmental impacts vary significantly between species and production systems.
Modeling studies often show increased fish consumption in nutritionally optimized diets, particularly when fish replaces red and processed meat.
Overall, fish appear incompatible with achieving both nutritional sufficiency and sustainability goals when responsibly sourced and consumed, but sustainability depends on which species are chosen, how they are produced and what foods they replace.
Revelation
The authors reported that the study was supported by Bolton Food SPA. one author was an employee of the company, and the authors declared that the funder had no role in the design, analysis, interpretation, or writing of the study.
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