Scientific review published in Advances in Nutrition finds a link between fish consumption and a lower risk of several chronic diseases

With the meat supply chain threatened due to the COVID-19 pandemic, you might consider fish as an alternative protein.  The good news is that it is a healthy alternative.

According to a scientific review published in Advances in Nutrition, Fish Consumption and the Risk of Chronic Disease: An Umbrella Review of Meta-Analyses of Prospective Cohort Studies, “evidence of moderate quality suggests that fish consumption is associated with a lower risk of cardiovascular disease, depression, and mortality and therefore can be considered as a healthy animal-based dietary source of protein.”  The authors of this review also found a link between fish consumption and a lower risk of certain cancers, including liver and prostate cancer.

These conclusions were drawn following a comprehensive review of 34 meta-analyses of prospective cohort studies that explored the association of fish consumption and the risk of chronic disease.  Together, these 34 meta-analyses comprised 298 individual prospective cohort studies.

Not all fish appear to confer the same benefits.  For example, in this review, the authors did not find an association between total fish consumption and the risk of type 2 diabetes.  However, an additional analysis indicated that a higher intake of fatty fish, but not lean fish, was associated with a lower risk of type 2 diabetes.  Oily fish such as salmon, herring, mackerel, and tuna are rich in vitamin D and have a higher EPA and DHA content than lean fish.  One 120 gram serving of fatty fish per week provides the recommended daily intake of omega-3 fatty acids, whereas several additional servings of lean fish such as cod would be needed to achieve the same recommended intake.

Different methods of fish preparation also have different effects on health outcomes.  Although a higher intake of fish in general was associated with a lower risk of heart failure, a higher intake of fried fish was associated with a higher risk of heart failure.

Some consumers may be concerned about the mercury content in fish, which may induce neurotoxicity and have adverse effects on brain development and cognition.  In particular, large predatory fish such as shark, swordfish, and tilefish are high in mercury.  However, a 2018 American Heart Association scientific statement recommends that “the benefits of 1–2 servings per week, especially when a variety of seafood is consumed, outweigh the potential risks associated with mercury content of fish.”

Interestingly, some data suggests that higher fish consumption may be associated with a higher risk of type 2 diabetes in the United States, but not in Europe and Asia.  This may be due to different types of fish consumed in each region as well as different preparation methods.

In summary, this review supports the 2015–2020 Dietary Guidelines for Americans, which recommends eating 240 grams per week of a variety of seafood.  The authors do, however, call for more research, underscoring the need for “repeated dietary assessments to obtain more reliable data and consider potential differences across geographical locations, as well as confounders such as family history of the disease.”

References Ahmad Jayedi, Sakineh Shab-Bidar, Fish Consumption and the Risk of Chronic Disease: An Umbrella Review of Meta-Analyses of Prospective Cohort Studies, Advances in Nutrition, DOI: https://doi.org/10.1093/advances/nmaa029.

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