Eating more fish like sardines instead of red meat might prevent up to 750,000 premature deaths by 2050

It has been known for decades that health cannot be separated from the economic and environmental conditions of a given society. A study published on Wednesday in BMJ Global Health estimated the benefits of replacing red meat consumption with forage fish — small fish such as sardines, herring and anchovies that larger fish, and some birds, prey on. The study suggests that by replacing red meat with forage fish in the global diet, up to 750,000 premature deaths from non-communicable diseases such as stroke or colon cancer could be prevented by 2050, especially in in low- and middle-income countries.

In addition to being better for one’s health than red meat, these types of fish are the animals with the lowest environmental impact in relation to their nutritional value. Their affordable price is key in countries with lower incomes, which are experiencing a rise in diseases caused by poor diet, particularly cardiovascular diseases. Unlike red meat, forage fish are rich in polyunsaturated fatty acids that can help reduce the risk of suffering from heart problems.

The study, led by Shujuan Xia of the National Institute of Environmental Studies of Japan, estimated that forage fish “may replace only a fraction (approximately 8%) of the world’s red meat due to its limited supply, but it may increase global daily per capita fish consumption close to the recommended level.” The authors estimated that this substitution would prevent between half a million and 750,000 premature deaths and between 8 and 15 million disability-adjusted life years, especially in countries with lower incomes. “Forage fish as an alternative to red meat could double (or more) the number of deaths that could be avoided by simply reducing red meat consumption.”

This type of fish accounts for 30% of the world’s catches; however, only a quarter is used for human consumption. The rest, including a good part of the fish caught in countries that struggle to feed their own population, are used in fish farms to fatten other fish such as salmon or trout, which are then sold to consumers with more purchasing power. The article by Xia and his colleagues warns that this use of forage fish “is inefficient because fewer nutrients are retained.” For example, they say, less than 50% [of the fatty acids in eaten fish] are maintained in farmed Scottish salmon. According to another study published in Nature Food, a small fraction of the fish that reaches sub-Saharan African countries, less than 20% of the total, would serve to cover the nutritional needs of children under five years of age.

The authors of the study reached their conclusions by proposing four different scenarios for the global distribution of fish in 137 countries. One prioritized the use of fish caught in each country for national consumption and focused on replacing the consumption of red meat. The second proposed that access to forage fish be prioritized in countries with a consumption level below 40 kilocalories per day. A third scenario proposed that the same amount of red meat be replaced in all countries, and a fourth was determined by the availability of forage fish. Of all these options, the first was the one that would prevent the fewest deaths and the third the most, although it is likely that this distribution of fish would be simpler in a model than in reality.

Adrián Carballo, a researcher at the Karolinska Institute in Stockholm (Sweden), said that the main limitation of the study is that it does not allow scientists “to determine whether the theoretical benefits of replacing red meat with small fish in a given country could be applied to a specific person from that same country,” in an opinion collected by the Science Media Center España.

As this is a 30-year prediction, there are many uncertainties. One of them is the impact of climate change on the size of fish catches. Although the authors acknowledge that they have not considered this factor, previous analyses estimate that the quantities of forage fish will vary by less than 3%. To support sustainable production of this type of fishery, the authors propose adopting strategies such as moving fishing sites to more favorable areas if circumstances change with global warming.

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