“Hidden superfood”: Dried small African fish pack more nutrients than fresh

New African dietary research spotlights dried small fish as a nutrient-dense “superfood hidden in plain sight.” In a first large-scale investigation of its kind, researchers quantified the essential nutrients in sun-dried and smoked fish across the continent. 

The researchers found that sun-drying and smoking fish concentrates essential nutrients into smaller, shelf-stable portions. All forms of dried fish had a higher nutrient density than fresh fish, at equivalent portion sizes, especially for key minerals like iron and zinc.

The study also reveals that small portions of dried fish contribute more than 15% of the recommended intakes for essential dietary nutrients including calcium, iodine, iron, selenium, zinc, and vitamins B12 and D.

The researchers from Lancaster University, UK, believe their findings support malnutrition intervention strategies across the tropics, where fish is affordable and readily available.

“Many countries look toward biofortification of staple crops as a means of boosting micronutrient intakes. The results presented in this paper show that these nutrients are concentrated in dried small fish,” says co-author Dr. Shakuntala Thilsted, senior nutrition expert at CGIAR, a global agricultural innovation network.

“Therefore, we must ensure that dried fish are included in food-based dietary guidelines. We must also use dried fish products in complementary feeding of young children, treatment of malnourished children, school feeding, and food assistance programs.”

Dried fish are a staple in diets among poor households that are close to marine coastlines or urban centers. The researchers believe this reinforces the importance of protecting fish catches for local consumption, rather than for international markets.

West Africa to Indian Ocean

The researchers examined the nutrient content of some of the most readily available dried fish in East and West Africa, as well as the Indian Ocean.

In total, they looked at 19 species of fish, including freshwater fish from the Great Lakes (like the Lake Victoria sardine) and marine species from West Africa (including the Madeiran sardinella) and the Indian Ocean (such as rabbitfish).

The team assessed data from the multinational Living Standards Measurements study conducted in Côte d’Ivoire, Ghana, Nigeria, Malawi, Tanzania, and Uganda. They estimate that dried fish are eaten weekly by a third of households in these countries and are even consumed by 54% more people than fresh fish.

“High-quality analytical data on small processed fish is presently lacking in most African food composition tables, which limits our ability to fully understand and utilize their nutritional potential,” says co-author Marian Kjellevold, research professor at the Institute of Marine Research, Bergen, Norway.

“This paper is an important step toward filling that gap, generating robust data that is essential for developing knowledge-based dietary guidelines and ensuring these nutrient-rich foods are used to improve public health.”

Not all fish are equal

The analysis of sun-dried and smoked fish reveals that dried fish are packed with nutrients. Even small amounts contribute significantly to recommended nutrient intakes for young children and women.

The study authors highlight that nutrients are not equal for all fish. Powdered and smoked marine species, for instance, have high iron and omega-3 fatty acid concentrations. Freshwater species from Lake Victoria have relatively higher calcium and zinc concentrations.

Dried fish rich in omega-3 fatty acids, iodine, and selenium can be powdered and mixed with other food products to produce highly nutritious meals for infants that can be used to treat and prevent malnutrition, the researchers suggest.

“Dried fish can fill nutrient gaps in seasonal seas, such as reef fish in the Lakshadweep Islands [union territory of India] that are caught and dried before the southwest monsoon. But here and across the tropics, policies are needed to protect supply for coastal communities against competing international markets,” says co-author Dr. Rucha Karkarey, of Lancaster University.

The study, which was backed by the Royal Society and the European Research Council, was published in PNAS.

In recent product innovations, nutraceutical supplier DolCas Biotech developed a method to infuse fish collagen tripeptides into a chocolate bar. The company says that its Morikol marine collagen tripeptide formula “seamlessly integrates” concentrated collagen into milk, dark, or white chocolate without affecting the flavor, aroma, or texture.