Brazil has an extensive coastline and rich aquatic biodiversity, yet seafood makes up a relatively small share of the average diet.
A new study suggests that increasing the role of seafood could help address shortages of nutrients such as vitamin A, calcium and magnesium, even though Brazilians already meet protein recommendations on average. The findings also show why improving nutrition is not as simple as telling people to eat more fish.
Researchers analyzed food intake data from about 30,700 people along with fisheries statistics and information on the nutrient content of different seafood species. Their goal was to examine how much seafood Brazilians currently eat and whether the existing seafood supply could help improve nutrient intake.
The study, published in Nature Food, found that average seafood consumption in Brazil was less than half the recommended level.
“What’s very surprising is that in Brazil, people don’t consume a lot of seafood” despite the country’s extensive coastline, said Juan Pablo Quimbayo, an assistant professor of biology at the University of Miami.
The researchers modeled what could happen if seafood increased from about 6% to 25% of total protein intake. Their analysis suggested that a larger and more varied share of seafood could reduce some common nutrient gaps.
That does not mean 25% is a new dietary recommendation for Brazilians. It was a modeled scenario used to estimate how much seafood could potentially contribute to the diet.
The findings also highlight an important point about protein. Getting enough protein overall does not guarantee that a diet provides enough vitamins and minerals.
“One of the important findings is that this is not simply a question of getting enough protein,” Quimbayo said. “Brazilians already meet protein recommendations on average, yet their diets still fall short for several essential micronutrients. What people eat, and the nutritional quality of those foods, matters as much as how much protein they consume.”
Seafood can vary widely in its nutrient content. Different fish and shellfish provide different combinations of vitamins, minerals and other nutrients, which means dietary variety may matter as much as the total amount eaten.
“Seafood is highly diverse, both taxonomically and nutritionally, which means that different species can provide different combinations of nutrients,” said Luiza Waechter, a postdoctoral researcher and co-author of the study.
But increasing seafood consumption also comes with a practical problem: supply.
The researchers found that demand already exceeds seafood supply in several Brazilian states. Many wild fisheries are also under pressure, making a simple increase in fishing an unrealistic solution.
“Increasing seafood consumption cannot simply mean catching more fish,” Quimbayo said. “Many fisheries are already under pressure, so improving nutrition has to go hand in hand with sustainable fisheries management.”
The researchers suggest that aquaculture, or seafood farming, could help expand supply without putting additional pressure on wild fish populations. They also argue that decisions about which species to catch or farm could take nutritional value into account alongside factors such as availability and environmental impact.
Cultural preferences may present another challenge. In some parts of Brazil, people strongly favor chicken, beef and pork, so increasing seafood intake would require more than simply making it available.
The study does not show that eating more seafood will automatically correct nutrient deficiencies. It combined national dietary and fisheries data to estimate what seafood could contribute under different scenarios rather than testing a dietary intervention in people.
Still, the findings offer a broader lesson about how diets are evaluated. Protein quantity is only one part of the picture. The foods providing that protein can differ substantially in the vitamins and minerals they bring with them.
The research also shows how nutrition and food supply are connected. Encouraging people to eat more of a nutrient-rich food only works if enough of that food can be produced and distributed without undermining the resources needed to provide it in the future.
The research was conducted by the Reef Synthesis Working Group and supported by Brazil’s Synthesis Center on Biodiversity and Ecosystem Services through the National Council for Scientific and Technological Development, or CNPq. Several researchers also received support through CNPq scholarships and grants, as well as funding from Brazil’s Coordination for the Improvement of Higher Education Personnel, or CAPES.