Everything You Should Know About the Pescatarian Diet

In recent years, there has been an increasing interest in reducing meat consumption. People choose to consume less or no meat for various reasons, including environmental, ethical, or health concerns. 
One dietary pattern—the pescatarian diet— may be a healthy and sustainable alternative because it allows for dairy, eggs, fish, and seafood to be consumed. (40) It may also be a manageable stepping stone to a more strict vegetarian or vegan diet.

What is a pescatarian diet?

The term pescatarian is a combination of the italian word for “pesce” meaning fish and the word  “vegetarian.” As the name implies, a pescatarian diet is a type of vegetarian diet that includes plant-based foods as well as fish, seafood, and sometimes dairy and eggs. (40) 

What pescatarians eat 

• Eggs 
• Dairy products
• Fish 
• Fruits 
• Grains 
• Legumes 
• Nuts and seeds 
• Shellfish and other seafood 
• Vegetables (40)

What pescatarians do not eat 

• Beef 
• Goat 
• Lamb
• Poultry 
• Wild game (40)

Did you know? Seafood, particularly, herring, mackerel and oysters are one of the most nutritionally dense foods. They contain high amounts of vitamin B12, calcium, copper, iron, selenium, and zinc. (11)

Pescatarian diet benefits 

There are many benefits associated with a pescatarian diet, such as improved blood sugar control, reduced environmental impact and improved heart health. (19)

Blood sugar regulation 

Due to the rise of sedentary lifestyles and obesity, type 2 diabetes mellitus  is becoming increasingly common. (32) There are approximately 422 million people globally who have diabetes, and 1.6 million deaths occur each year from diabetes related complications. (39) 

Following a pescatarian diet may help with blood sugar regulation due to its emphasis on fish and fiber-rich plant-based foods. (15)(26) A study conducted in 2017 found that individuals who had high intakes of fatty fish had better blood sugar regulation than those who did not consume fatty fish. (15) Additionally, the pescatarian diet is rich in a variety of plant-based foods such as grains, legumes, fruits, and vegetables, which are rich in fiber. (35) Fiber slows the release of sugar into the bloodstream and can therefore prevent blood sugar spikes. (26) Fiber also increases satiety and can reduce the intake of excess calories and sugar cravings. (16)(19)  

Environment  

Compared to meat products, seafood and plant-based foods have a lower environmental impact. (29) Animal agriculture contributes to greenhouse gas emissions in several ways, including: 

• Deforestation for land use for feed production and grazing
• Fossil fuel use during feed and farmed animal production,
• Fossil fuel use during the production and transport of processed and refrigerated animal products
• Methane emissions, primarily associated with the digestive process of farmed animals 
• Nitrous oxide and methane emissions, primarily associated with farmed animal manure (9)(33)  

The expansion of animal agriculture has contributed to deforestation in many countries. For example, in Australia, beef production was responsible for 94% of all forest clearing in the Great Barrier Reef catchment areas between 2013 and 2018. (33) 

Did you know? Animal agriculture accounts for at least 16.5% of total greenhouse gas emissions, a percentage that continues to increase as the amount of livestock increases. (33)

A study that analyzed the possible effects of a global switch to plant-based diets concluded that eliminating animal agriculture could reduce CO2 emissions by 8.1 billion metric tons per year over 100 years. (25) Furthermore, a report published by the EAT-Lancet commission stated that reducing meat consumption would reduce carbon emissions and improve biodiversity and water conservation. (38) The commission also stated that switching to more sustainable diets would help to successfully meet the mitigation targets of the Paris Agreement and the United Nations’ Sustainable Development Goals (SDGs). (33)(38)  

Heart health 

Heart disease is the leading cause of death in the United States and is also a major cause of disability. (34) Cardiovascular risk factors such as elevated body mass index (BMI), hypertension, and high cholesterol are less common in those who follow vegetarian diets, including the pescatarian diet, than those who follow omnivorous diets. (6)(40) Research also suggests that following a plant-based diet can have a protective effect on ischemic heart disease. (6) The pescatarian diet, in particular, has been found to reduce the risk of ischaemic heart disease by 13%. (31)

The cardiovascular benefits from plant-based diets are a result of various factors. Plant foods are usually lower on the glycemic index and in saturated fat. They are also higher in unsaturated fat, plant protein, and phytochemicals, which have been shown to have a beneficial effect on many cardiovascular risk factors. (19) Pescatarians refrain from animal meats and processed foods, which are higher in saturated fats, trans fat, and salt, components known to increase the risk of cardiovascular disease. (3)

In addition to the heart health benefits of reduced meat consumption and increased consumption of plant-based foods, the pescatarian diet may protect against heart disease because of its richness in fish. A meta-analysis of 11 studies and 13 cohorts found that as fish consumption increased incidence of cardiovascular disease decreased. Additionally, the study also concluded that chances of death from cardiovascular disease may be reduced by consuming fish at least once a week. (12)

Inflammation

Although inflammation is essential for survival during physical injury and infection, recent research has demonstrated that certain environmental factors such as diet,  lifestyle, and stress can promote chronic inflammation. Chronic Inflammation, in turn, can lead to several diseases, such as autoimmune conditions, cardiovascular disease, cancer, diabetes, kidney disease, non-alcoholic fatty liver disease, and neurodegenerative disorders. (10) 

Diets high in saturated fat from animal meats and processed meat have been found to increase many inflammatory markers, such as  C-reactive protein (CRP), interleukin-6 (IL-6), and homocysteine, while diets high in whole grains and fruit have been shown to decrease these biomarkers. (23)

Fish, particularly oily fish, is high in the omega-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA). (5) Evidence suggests that a high intake of PUFAs can help to reduce inflammation. (20)(21)(30) Fish and shellfish that contain higher levels of these fatty acids include:

• Anchovy 
• ​​Blue crab
• Capelin 
• Char 
• Clam
• Hake 
• Herring
• Lake whitefish
• Mackerel (Atlantic)
• Mullet
• Mussel 
• Oyster
• Pollock (Boston bluefish)
• Rainbow trout
• Salmon
• Smelt
• Shrimp (14) 

Pescatarian diet concerns: mercury 

Mercury is a naturally occurring element found in air, water, and soil. It is also released into the environment as a form of pollution from human activities, such as coal-fired power generation, metal mining, and waste incineration. (13) Exposure to high levels of mercury can be harmful to human health as it can damage the brain and kidneys. (22)

The mercury found in water can pass through the food chain and build up in fish, shellfish, and animals, such as humans, that eat fish. (22) Larger fish and predatory fish that eat other fish have higher levels of mercury as they absorb and accumulate the mercury from the fish they eat. (14) For this reason, it is important to choose seafood options that lower down on the food chain (i.e., smaller fish) and therefore typically lower in mercury. 

The table below outlines the fish and seafood that can be enjoyed freely and that should be minimized. (4)

The bottom line

The pescaterain diet is a type of vegetarian diet that includes fish, seafood, and sometimes dairy products and eggs. Following a pescaterian style diet may reduce a person’s carbon footprint and help prevent and manage certain health conditions, such as diabetes and heart disease. It is important to be mindful of mercury content when choosing seafood. Always speak to your integrative healthcare provider before making any changes to your diet or wellness plan.