Fish micronutrients can alleviate tropical coast residents’ malnutrition, research suggests

27 Sep 2019 --- Fish micronutrients are “slipping through the hands” of many vulnerable, malnourished groups. According to a recent Lancaster University study, fish-based food strategies have the potential to substantially contribute to ensuring nutrition security and human nutrition should be at the core of fishing policy. Published in Nature, it reveals that millions of people living in tropical coastal areas suffering from malnutrition could see significant health improvements if just a fraction of the fish caught nearby was diverted into their diets.

“Fish contains high concentrations of bio-available micronutrients, such as zinc and iron. It can be particularly hard to ensure children between the ages of six months and four years gain sufficient quantities of these nutrients. Deficiencies in these nutrients in the early years can have long term impacts on physical and cognitive development, ultimately reducing a country’s GDP and contributing to early death,” Christina Hicks, Professor at Lancaster University’s Environment Center and lead author of the study, tells NutritionInsight.

The research team collected data on the concentration of seven nutrients in more than 350 species of marine fish and developed a statistical model for predicting how much nutrition any given species of fish contains, based on their diet, seawater temperature and energy expenditure.

They found that species from tropical thermal regimes contain higher concentrations of calcium, iron and zinc; smaller species contain higher concentrations of calcium, iron and omega 3 fatty acids; and species from cold thermal regimes or those with a pelagic feeding pathway contain higher concentrations of omega 3 fatty acids.

As a rich source of vitamins, minerals and fatty acids, fish is often missing in the diets of poor populations throughout the world, despite their proximity to many tropical areas, where fish are abundant. This is due to a host of challenges, such as international fishing and market demands, as well as cultural practices and norms.

International fishing fleets and trade in seafood are major contributors to fish not being retained.“International fishing fleets and trade in seafood are major contributors to fish not being retained and eaten locally in a number of countries. However, diet preferences that do not include fish, or norms regarding who in the household eats what part of the fish, can all also serve as barriers to fish reaching those most in need,” Hicks says. 

Climate justice
In light of the UN climate summit that was held this week in New York, US, Hicks indicates that eating fish is part of the recommendations to move toward lower carbon diets and has a much smaller carbon footprint than eating many terrestrial animals, especially red meat. However, fish from waters in countries where micronutrient deficiencies are prevalent are being eaten or used as fish food in richer nations.

“We are proposing that a greater proportion of the catch should be retained locally to where it is caught in these countries. This is particularly important in the face of climate change, where declines in fish catches are projected to be largest in the tropics,” Hicks concludes. 

The research also revealed that currently, many global fisheries prioritize revenue growth and have neglected human nutrition at the core of fishing policies. “It’s time that food security policymakers acknowledge the nutrient-rich food swimming right under their noses and think about what can be done to increase access to fish by those populations,” Dr. Andrew Thone-Lyman, Co-Author from John Hopkins Bloomberg School of Public Health and Nutritionist emphasizes.

This study is not the first to highlight the nutritional benefits of an increased fish intake. Recently, a joint study from Queen Mary University and the University of Warwick found that a Mediterranean-style diet, promoting olive oil, fresh fruits and vegetables, and a moderate to high fish intake, can lead to health benefits during pregnancy. 

Another analysis published by Elsevier showed that the low consumption of fish and shellfish among US adults was due to a lack of awareness of its health benefits. The scientific evidence also suggested that the benefits of fish intake exceed the potential risks for most individuals, such as mercury contamination. 

By Anni Schleicher