The pescatarian diet is a modified version of the vegetarian and Mediterranean diets with the allowance of fish. Learn more about the diet, health benefits and potential drawbacks.
This article is based on reporting that features expert sources.
When it comes to diets, there’s plenty of fish in the sea. But if you’re looking for an eating pattern that touts all the benefits of a vegetarian diet, without swearing off sushi, look no further than the pescatarian diet.
A portmanteau of the Italian word for fish, “pesce,” and the term “vegetarian,” the pescatarian diet is a healthy, delicious marriage of both worlds. It’s a plant-based diet that incorporates animal protein solely from fish and seafood.
In fact, the pescatarian diet was shown to have the highest diet quality compared to other popular eating patterns, such as vegetarian, low-grain, restricted carbohydrate, time-restricted and high-protein preferences, in a September 2022 study published in Current Developments in Nutrition.
“It’s more flexible than a vegetarian or vegan diet in that it allows some more variety in being able to get protein in your diet,” says Rebecca Purcell, a registered dietitian nutritionist at Yale University in New Haven, Connecticut, adding that eating should be pleasurable. “You should enjoy eating the foods that you’re nourishing your body with and have the flexibility to.”
Pescatarian vs. Mediterranean Diet
While the pescatarian diet’s etymology stems in part from a vegetarian diet, health experts liken it more to the Mediterranean diet without the meat. The Mediterranean diet is a plant-based approach inspired by the eating habits of people in countries near the Mediterranean Sea – including Greece, Italy, Spain and France. It emphasizes whole grains, fruits, vegetables, beans, herbs, spices, nuts and healthy fats from extra-virgin olive oil, as well as fish, seafood and dairy. Eggs and poultry are consumed in moderation, while red meats and sweets are rarely part of a meal.
The Mediterranean diet ranks as the top diet, and there’s good reason for that: Researchers have repeatedly shown that this eating plan offers a plethora of health benefits, from lowering blood pressure, improving “good” cholesterol levels, reducing Type 2 diabetes risk and boosting cognitive function to protecting against age-related disease – to name a few.
Given the strong evidence behind the Mediterranean diet, it’s no wonder health experts highly recommend a fish-forward diet.
“The focus on fish and seafood as the only animal product utilized in the pescatarian diet helps to greatly reduce the saturated fat consumption but also adds the benefits of healthy,” explains Mary Ellen DiPaola, a registered dietitian and certified diabetes educator at the University of California, San Francisco. “A diet based on plant foods and fish and seafood is beneficial to all as it is nutrient-dense, can reduce disease risk, reduces the carbon footprint and is delicious.”
Food Is Medicine
An abundance of research over the past several decades has conclusively shown that following a plant-based eating plan offers significant health benefits. It corroborates the emerging idea of food as medicine that many in health care are promoting to combat the global epidemic of diet-related chronic diseases, such as heart disease, diabetes and certain cancers.
At its crux, the “food is medicine” movement focuses on food and nutrition as effective, nonpharmacological interventions for disease prevention, management and treatment. In some cases, eating the right foods could even lead to reversing – or, in other words, curing – a disease, according to the American Society for Nutrition.
“Food could be medicine,” Purcell says. “You could avoid long-term complications, prescription medications and medical costs. If you’re fueling yourself with good, healthy, nutrient-dense foods, it could help you feel better on a daily basis, lower stress, increase energy levels and improve your immune system.”
Thanks to omega-3 polyunsaturated fatty acids, the “good fat” known for its heart health benefits, regularly eating fish has been shown to be good for heart health. Several studies, including a June 2021 study on fish and cardiovascular health, have demonstrated that a pescatarian approach can protect the heart from cardiovascular disease and related events.
In a prospective analysis of 472,377 participants, a team of researchers followed a group of regular meat eaters, low meat eaters, pescatarians and vegetarians over the course of 11 years to evaluate the association between diet and cancer. The findings, published in a February 2022 paper in BMC Medicine, found that those who adhered to a pescatarian diet, as well as low meat and vegetarian diets, had lower incidence rates of colorectal cancer, breast cancer and prostate cancer compared to those who consumed processed, red meat (including beef, pork and lamb) or poultry more than five times a week.
Eating fish is also good for the eyes. In a September 2022 study published in Nutrition Reviews, a meta-analysis of 21 studies evaluating the relationship between plant-based diets and eye health showed that a pescatarian diet reduced the risk of age-related eye disease among adults, whereas a red meat diet was associated with poor ocular health.
But beyond physical health benefits, eating fish has also been tied to improved mental health. Numerous studies have demonstrated the relationship between fish consumption and depression. For example, a randomized control trial published in December 2018 in Nutrients showed that moderate intake of fish and omega-3 polyunsaturated fatty acid found in fish was associated with significantly lower odds of depression in the 6,587 participants who were involved in the study. It adds to a growing body of evidence that fish consumption reduces the risk of depression and depressive symptoms.
What Can and Can’t Pescatarians Eat?
The pescatarian diet follows the same approach as the vegetarian diet, with the addition of fish, and the Mediterranean diet, without the meat.
What to eat:
- Whole grains.
- Legumes and beans.
- Herbs and spices.
- Fish and seafood.
- Eggs and dairy, including cheese and yogurt.
What not to eat:
- Red meat, including beef, lamb and pork.
- Poultry, including chicken and turkey.
What Are the Health Benefits of Fish?
In addition to all the nutrients in the fruits, vegetable, whole grains, beans, nuts and seeds of the Mediterranean and vegetarian diets, the inclusion of fish in the pescatarian diet provides a boost of protein and boasts a wide range of added health benefits:
- Omega-3 fatty acids: Reduces the risk of heart disease and stroke, lowers triglyceride levels, relieves rheumatoid arthritis symptoms, promotes fetal growth and development and may protect against certain cancers and other conditions.
- Vitamin D: Essential for promoting healthy bones, reduces cancer cell growth, controls infections and reduces inflammation.
- Calcium: Helps build strong bones and teeth, in addition to helping muscles contract and regulating normal heart and nerve functions.
- Phosphorus: Promotes the formation of healthy bones and teeth.
- Choline: Supports the brain and nervous system’s ability to regulate memory, mood and muscle control, as well as other functions.
- Iron: Essential in the production of hemoglobin in red blood cells, which transports oxygen from the lungs to the rest of the body.
- Zinc: Helps the immune system and metabolism function properly and plays a role in cell growth, protein building and the repair of damaged tissue.
- Magnesium: Supports muscle and nerve function, energy production and heart and bone health.
- Potassium: Regulates fluid levels within cells, helps muscles to contract and maintains normal blood pressure.
What Are the Disadvantages?
Nothing is perfect, of course, and a pescatarian diet comes with some warnings, including concerns over sustainability.
“As with meat, not all fish is sourced sustainably, and commercial fishing can decimate oceans,” DiPaola says. However, “sustainable fish-buying resources are available, and purchasing such fish also benefits the environment.”
Another potential downside of eating seafood is mercury, a naturally occurring chemical element found in the earth. It is a known neurotoxin that can damage the brain and nervous system.
The types of fish that contain high levels of mercury tend to be larger, predatory fish, including:
- King mackerel.
- Tuna (bigeye).
“If someone is eating too much high-mercury fish … they will have higher mercury levels, which can have negative health consequences,” says Aileen Birkitt, a registered dietician and owner of Nutrition 4 You in North Kingston, Rhode Island. “Nursing and pregnant women, women of childbearing age and young children need to be most careful when choosing seafood options.”
To be safe, experts recommend selecting fish and seafood that contain lower mercury levels. The U.S. Food and Drug Administration and U.S. Environmental Protection Agency’s joint Dietary Guidelines for Americans outlines the best choices for low-mercury fish, including:
- Atlantic mackerel.
Ultimately, not all fish are created equal. But as long as you choose your fish wisely and consume in healthy quantities, you can reap the benefits of a pescatarian diet without worrying about mercury poisoning.
According to the 2020-2025 Dietary Guidelines for Americans, adults should eat at least 8 ounces of seafood per week based on a 2,000-calorie diet, and people who are pregnant or breastfeeding should consume 8 to 12 ounces per week of a variety of low-mercury fish and seafood.
“The benefits of eating the fish, if they’re eating it in moderation, really outweigh the risk of the mercury it contains,” Purcell says.
Best Flexitarian Diet Recipes to Try
The U.S. News Health team delivers accurate information about health, nutrition and fitness, as well as in-depth medical condition guides. All of our stories rely on multiple, independent sources and experts in the field, such as medical doctors and licensed nutritionists. To learn more about how we keep our content accurate and trustworthy, read our editorial guidelines.
Aileen Birkitt, RD
Birkitt is a registered dietician and owner of Nutrition 4 You in North Kingston, Rhode Island.
DiPaola is a registered dietitian and certified diabetes educator at the University of California, San Francisco.
Purcell is a registered dietitian nutritionist at Yale University in New Haven, Connecticut.