A pescatarian diet is one that includes fish and seafood, but doesn’t include certain other animal products, especially meat. While there are literally dozens of different styles of meat-less diets, some pescatarians also eat eggs and dairy products, so each person’s pescatarian preferences can be different.
Pescatarian-based diets have been around for thousands of years. Populations living in Japan, other parts of Asia and Mediterranean countries like Greece have relied heavily on fish for protein and nutrient intake for generations.
Fish and seafood are some of the healthiest sources of dietary protein and fatty acids in the world. Benefit-packed salmon and nutritious sardines, for example, are two particularly nutrient-dense foods packed with high levels of omega-3 fatty acids, amino acids (protein), vitamin D as well as vitamin A. Other types of fish and seafood provide similar benefits along with B vitamins and minerals like potassium, phosphorus, calcium, magnesium and selenium.
How healthy are pescatarian diets? Although meat-less, vegetarian and vegan-type diets can vary widely, many people who base the bulk of their food intake around plant foods are very healthy. While some plant-based eaters might exclude all animal products (vegans), others might choose to include fish. There are a lot of benefits of keeping fish and seafood in your diet, since this can help with several common problems seen in vegetarians:
- nutrient deficiencies (vitamin B12 deficiency, for example)
- protein deficiency or lack of certain amino acids in the diet
- imbalanced ratio of essential fatty acids (omega-6s to omega-3s)
- the tendency to eat more refined carbohydrates
- iron deficiency (anemia)
The Importance of Protein in a Pescatarian Diet
Protein is a macronutrient that is vital to life, since it helps build every single part of the body, including muscles, tissue and cells. While carbohydrates are the body’s main source of energy (or in some cases fat, depending on the specific diet plan), high protein foods can also be converted into glucose that’s used for bodily “fuel.” Not every type of food that contains protein offers the same benefits, however — animal products (fish, beef, poultry, dairy, etc.) are “complete sources of protein,” while plants are not.
Protein molecules are made up of individual chains of amino acids. Amino acids are usually categorized as essential and nonessential. Essential amino acids cannot be produced by the body, so we must get them from the foods we eat. On the other hand, nonessential amino acids can be synthesized from essential amino acids, so they’re less of a concern. When a food has the complete set of essential amino acids we must obtain, it’s called “complete.” Fish and other animal products (eggs, dairy, poultry, beef, etc.) are complete proteins and in most cases are needed to prevent symptoms of protein deficiency.
Because of the way amino acids work in the body, there are essentially two important things to consider when it comes to protein foods in your diet: how much you should aim to eat daily and what types you eat. Because complete proteins (usually animal products) supply all of the necessary essential amino acids you need, but incomplete proteins (most plants) are lacking in one or more essential amino acids, it can be risky to cut animal foods from your diet.
Many vegetarians feel that they eat enough protein because they include foods like whole grains, beans, legumes, nuts and seeds. But these are incomplete sources, and their amino acids also aren’t fully digestible once eaten (a concept known as protein bioavailability). Most of these plant proteins also contain antinutrients and types of difficult-to-digest proteins (like gluten, for example) that can cause nutrients to be blocked, immune responses or gut damage.
Many beans and legumes, for example, have been shown to decrease protein absorption in the small intestines because of built-in nutrient-blocking enzymes that they hold. Antinutrients are present in basically all legumes/beans and cereal grains (including wheat, quinoa, corn, oats), which is where most plant-based eaters tend to get their protein from. Eating these foods has been shown to decrease assimilation of amino acids in these foods by as much as 50 percent! Think of it this way: No matter how much protein a food might have, if you can’t digest and absorb the amino acids properly, it won’t really benefit you.
Fish are an excellent source of protein because not only do they supply all essential amino acids, but they also have a low potential for immune responses and toxicity (assuming you choose the right kinds of seafood, but more on this later on). Fish don’t contain antinutrients, so the nutrient-blocking effects that happen with plants doesn’t happen with animal proteins. You can see why including fish and other seafood in a mostly plant-based diet is key for getting enough protein. Considering animal products are naturally a superior and more absorbable source of essential proteins, but some people might not want to meat, adding in fish is a great option for those wishing to boost their protein intake.
But Aren’t Vegetarian or Vegan Diets Healthy?
Overall, plant-based diets are promoted as very heart-healthy and a great idea for weight control. Many people claim that studies comparing meat eaters to vegetarians/vegans show that animal protein consumption is associated with poor blood cholesterol levels, weight gain and increased cancer risk. But it’s important to remember that you can’t take every headline you see at face value.
For example, many studies compare “meat eaters” who get most of their protein from processed meats, farm-raised fish and animal products or low-quality cheeses and compare them to plant-based eaters who avoid these processed foods. It’s not exactly a fair comparison and doesn’t take into account all of the other things besides protein sources that these people are, or are not, eating.
That’s not to say that meat-free diets can’t be healthy — they definitely can, but they often require a lot of planning and food combining. Vegetarian diets have been associated with lower levels of obesity (body mass index); reduced risk of cardiovascular disease and lower total mortality; better cholesterol levels; lower blood pressure; and lower rates of hypertension, type 2 diabetes and some forms of cancer.
That being said, in my opinion including at least some animal products in your diet is crucial for health. They’re the only foods that contain beneficial vitamin B12, a critical nutrient that people would die without (the exact reason that vegans need to supplement with B12).
Vegetarians can, of course, avoid fish and choose to eat a lot of eggs or dairy products, but this means they miss out on many important nutrients like omega-3 fatty acids, found almost exclusively in seafood. Other crucial minerals and vitamins that are abundant in animal products but not found in very high quantities in plant foods include vitamin A, heme iron (the more adorable kind), choline, zinc, copper and most B vitamins.
In vegetarian and vegan diets, there’s essentially an absence of EPA and DHA omega-3s but a very high level of omega-6 plant foods. Some plant-based eaters make a point to eat ALA omega-3-containing foods like nuts or seeds, but this isn’t as beneficial as seafood.
As you’ll learn more about, an imbalance in essential fatty acids is one of the primary reasons I believe vegetarian and vegan diets are not optimal for health, since too many omega-6 fats relative to omega-3s causes many problems. Some research suggests that the ideal human intake of omega-6 and omega-3 fats should be a ratio between 1:1 and 2:1, yet some people are eating 10–20 times more omega-6s than this amount!
What can you do if you truly have ethical concerns with eating animal products? It’s understandable that many people become vegetarians for the environment or for animal welfare, but consider the fact that it’s possible to eat fish and seafood as part of a pescatarian diet while still supporting local, organic, sustainable agriculture or fishing practices. It all comes down to sourcing the right kinds of seafood, which is discussed more below.
7 Benefits of a Pescatarian Diet
1. Provides Omega-3 Fatty Acids
One of the primary reasons that fish is so good for us is because of its high levels of omega-3 fats. In a world where most people consume far too many omega-6s — from seed/vegetable oils, plant foods and farm-raised animal products, for example — an increase in omega-3 foods is much needed.
Omega-3s act as a counterbalance against omega-6 fats, helping to keep the body free from heightened levels of inflammation due to an imbalanced ratio (higher omega-6 levels than is healthy). Omega-3 fatty acids are considered anti-inflammatory, while omega-6s are pro-inflammatory. We need both types, but many people are lacking in omega-3s.
Omega-3s truly have enormous health benefits that have been demonstrated in many controlled studies, as well as from observing populations like those living in the Mediterranean region that eat a mostly pescatarian-style, Mediterranean diet. Consuming higher levels of omega-3s has been associated with better mental health, improved cardiovascular health, lower triglyceride levels, increased reproductive health and fertility, better hormone control, and lower risk for diabetes.
What exactly are omega-3 fish oils, and why do we absolutely need them? Essential fatty acids are the shortest-chain polyunsaturated fats that are required for the body’s proper functioning, yet we can’t make them on our own and must get them from our diets. The most important long-chain omega-3 fats are EPA and DHA, which are primarily responsible for the health benefits we get from polyunsaturated fats.
Alpha-linolenic acid (ALA) is the type of omega-3 found in plant foods (like walnuts and flaxseeds), while eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the most important long-chain omega-3 fats found in seafood and some animal products like eggs or beef. ALA, EPA and DHA must come from our diets, yet vegetarians often think that they can cover their bases by eating lots of nuts, taking flax oil or loading up on seeds. This is actually a misconception — it’s true that the body can convert some ALA to EPA and DHA, but this process isn’t very efficient and we are much better off eating EPA and DHA directly to get the most benefits.
2. Helps Lower Inflammation
The reason that omega-3s found in fish are so valuable mostly comes down to their ability to fight inflammation. They help control inflammatory conditions that lead to numerous diseases, including cancer, rheumatoid arthritis and asthma.
Both types of polyunsaturated fats described above play an important role in the body, helping to form our hormones, cell membranes, immune responses and so on. But omega-3 and omega-6 fatty acids have opposite effects when it comes to inflammation. Generally speaking, too much omega-6 and too little omega-3 causes inflammation. Inflammation is the root of most diseases, and therefore, lowering its presence and severity makes us less likely to development diseases like cancer, cognitive decline and cardiovascular disease.
While fats can seem confusing, remember that polyunsaturated fats can be divided into two categories: omega-6 and omega-3. Omega-3 fats are present in foods at the core of a pescatarian diet, including seafood, green leaves and algae, while omega-6 fats are found in seeds, nuts, vegetables, vegetable oils (all foods that a typical vegetarian eats a lot of) and to an extent animals that eat these seeds. Since packaged and processed foods are loaded with omega-6s — and most people eating a modern diet rely on these food for the bulk of their diets — we need to go out of our way to eat fish and other sources of omega-3s to keep the ideal ratio balanced and inflammation down.
3. Improves Heart Health
EPA and DHA are essential to heart health since they control inflammation. Systemic inflammation is a term for the body’s immune response that increases production of white blood cells and other substances in an effort to fight perceived threats or infections. Coronary heart disease is a result of inflammation mostly from fatty material that forms plaque accumulations within the walls of your arteries.
Consumption of EPA and DHA (200 to 500 milligrams/day) has been shown to help reduce heart disease risk and deaths from heart disease, sometimes just as effectively as prescription statin-drug therapies. The combination of nutrients found in seafood also helps regulate heartbeats, reduce blood pressure and cholesterol levels, decrease blood clot formation, lower triglycerides, and prevent a heart attack or stroke.
4. Can Lower the Risk for Cancer
Research shows that consuming more fish and seafood high in omega-3s benefits our immune system and helps fight cancer by suppressing inflammation. Wondering if people who avoid fish and all animal products experience even less inflammation and lowered cancer risk than pescatarians do? One meta-analysis found no significant differences in mortality rates caused by colorectal, stomach, lung, prostate or breast cancers and stroke between vegetarians and “health-conscious” nonvegetarians.
That means anyone who focuses first and foremost on eating plenty of fruits and vegetables (not just limiting or reducing animal products) is likely to naturally lower the risk of cancer. In fact, while vegetarian diets are associated with an overall lower incidence of certain cancers (like colon cancer), pescatarians are even more protected from cancer compared with vegetarians and non-vegetarians, according to some studies.
Inflammation dictates the rate of tumor progression, so including anti-inflammatory foods in your diet is key for cancer prevention. Omega-3s can even help people who have already been diagnosed with cancer by stalling tumor growth. A pescaterian diet high in omega-3s can also help people undergoing chemotherapy or other cancer treatments since they help preserve muscle mass and regulate inflammatory responses, which are already compromised in cancer.
5. Helps Fight Cognitive Decline
Omega-3s like DHA are essential for the proper development of the brain and preservation of cognitive function as we age. Many studies have found that low omega-3 levels in the elderly are associated with multiple markers of impaired brain function like dementia or Alzheimer’s disease. Lower levels of omega-3s during pregnancy are even associated with children having lower memory test scores and trouble with learning.
Consuming lots of omega-3s in a pescatarian diet helps naturally treat Alzheimer’s disease and other cognitive disorders.
6. Improves Your Mood and Fights Depression
Because they fight oxidative stress that impairs proper brain functioning, omega-3s from fish and seafood are associated with better cognitive health and lower risk for dementia, depression, anxiety and ADHD. That means following a pescatarian diet can be a natural remedy for anxiety, treat the symptoms of ADHD and double as a form of the depression diet to deal with signs of depression.
7. Can Help with Weight Loss and Maintenance
Low intakes of omega-3s are now being tied to obesity and weight gain. Studies, of course, also show that people who eat more plant foods (including vegetarians) tend to have lower BMIs and better weight control, likely because they eat lower amounts of saturated fats and calories overall. Whether you choose to eat fish or not, your diet should take into account the need for plenty of whole plant foods.
Some vegetarians can find themselves eating more carbohydrates (especially refined carbs like bread, pasta, pizza, etc.) and a lower proportion of calories from healthy fats and protein. This can lead to blood sugar fluctuations, problems regulating insulin and overeating. Healthy proteins and fats are crucial for feeling full, and nutrients found in fish can help many people reduce cravings. No matter your diet, aim for a high intake of fruits, vegetables, quality proteins, healthy fats, seeds, nuts, fiber and phytochemicals — all of which can help you lose weight fast and keep it off.
The Best Types of Fish and Seafood to Include in a Pescatarian Diet
The best types of fish to regularly eat include naturally fatty fish, like salmon, sardines, mackerel, anchovies and herring. Wild-caught fish are definitely preferable over farm-raised fish since they are lower in toxins and chemicals that are used in most fish-farming facilities. Just like grass-fed animal products are higher in nutrients, the same goes for wild fish. Farmed fish are generally lower in EPA and DHA when compared to freshwater fish and contribute to heavy metal toxicity, so avoid inferior seafood products like commonly sold farmed salmon.
One thing I don’t recommend, however, is eating shellfish (like shrimp, clams, mussels, etc.) or catfish. Many people assume that shellfish are a source of “lean protein” because they are low in calories, but seafood like shrimp is not good for you for a few reasons. Shellfish are known to be “bottom feeders” and are more likely to be contaminated with heavy metals due to ocean pollution. They can carry antibiotics, bacteria, xeno-estrogens, chemical residues and other things you don’t want to ingest. They are also commonly farm-raised and can contribute to overfishing and ecological concerns.
Some of the fish and seafood that I recommend most, especially since they are highest in EPA and DHA, include:
- Caviar (fish eggs)
- Bluefin tuna
How much fish should you eat? Most experts recommend eating fish at least several times a week (two to three times is a great start). Another goal to aim for is to eat three six-ounce servings of fatty fish per week in order to get enough of the anti-inflammatory omega-3 fats EPA and DHA that you need.
Are There Any Drawbacks to a Pescatarian Diet?
Like all types of “diets,” restricting certain food groups can lead to issues. It’s possible to start feeling mentally deprived when following a pescatarian diet because meat and most animal products become “off limits.” It’s also possible to become bored with eating fish (or eggs and dairy) over and over again each day in order to obtain enough protein, potentially leading someone to choose more carbohydrates instead. This poses its own risks for potential weight gain, protein deficiency, fatigue and other health problems.
Another thing to consider when following a pescatarian diet is your intake of mercury. Mercury is, in fact, toxic, but its toxic effects are somewhat mitigated by the mineral selenium, which is present in nearly all wild-caught seafood. However, considering the level of toxins found in today’s oceans, mercury toxicity is a real concern, so it’s best to also focus on eating smaller fish.
Generally speaking, the smaller a fish is, the less mercury it stores in its tissues. That’s because mercury in fish builds up as you move up the food chain, meaning bigger fish (like swordfish or tuna) tend to have more than smaller fish (sardines, anchovies, herring and salmon).