Halibut is a species of flatfish.

In fact, the Pacific halibut is the largest flatfish in the world.

When it comes to eating fish, there is much debate on whether the health benefits, like omega-3 fatty acids and essential nutrient content, outweigh the potential risks, such as mercury contamination and sustainability.

The variety of nutrients in halibut might sway you.

This article evaluates the nutritional benefits and potential risks of eating halibut.

Halibut Fish

Halibut is an excellent source of selenium, a trace mineral with many health benefits that your body needs in small amounts.

A cooked half-filet (160 grams) of halibut, which is the recommended serving size, provides over 100% of your daily dietary needs (1).

Selenium is a powerful antioxidant that helps your body repair damaged cells and can decrease inflammation. It also plays an important role in thyroid health (2, 3, 4, 5).

In addition, halibut is a good source of a variety of other micronutrients that contribute to good health, including (1):

  • Niacin: Niacin plays a positive role in heart health and even helps prevent heart disease. It can also protect your skin from sun damage. A half-filet (160 grams) of halibut provides 57% of your dietary needs (6, 7, 8).
  • Phosphorus: The second most abundant mineral in your body, phosphorus helps build bones, regulates metabolism, maintains a regular heartbeat and more. A serving of halibut provides 45% of your dietary needs (9, 10, 11, 12).
  • Magnesium: Magnesium is required for more than 600 reactions in your body, including protein formation, muscle movements and energy creation. A serving of halibut provides 42% of your dietary needs (13).
  • Vitamin B12: Vitamin B12 plays an essential role in red blood cell formation and proper nervous system function. It’s found naturally in animal foods. A half-filet (160 grams) of halibut provides 36% of your dietary needs (14, 15).
  • Vitamin B6: Also known as pyridoxine, vitamin B6 is involved in over 100 reactions in your body. It’s beneficial to the central nervous system and may boost brain function. Halibut provides 32% of your dietary needs (16, 17, 18).
Summary One half-filet (160 grams) of halibut can provide more than a third of your dietary needs for multiple vitamins and minerals, including selenium, niacin, phosphorus, magnesium and vitamins B12 and B6.

One serving of cooked halibut packs 42 grams of high-quality protein and thus can help meet your dietary protein needs (1).

The Dietary Reference Intake (DRI) for protein is 0.36 grams per pound or 0.8 gram per kilogram of body weight. This is sufficient to meet the needs for 97–98% of healthy, sedentary people (19).

It’s important to note that this amount is required to prevent deficiency. Your activity level, muscle mass and current state of health can increase your protein needs.

Protein is made up of amino acids, which are involved in almost every metabolic process in your body.

Therefore, getting enough protein is important for various reasons. It can help build and repair muscle, suppress appetite, aid weight loss and more (20, 21, 22, 23).

Fish and other animal proteins are considered high-quality, complete proteins. This means they provide all of the essential amino acids that your body cannot make on its own.

Summary Protein plays a variety of important roles in your body, including building and repairing muscle or suppressing appetite. Halibut is a high-quality source of protein that can contribute to your total protein needs.

Heart disease is the leading cause of death in men and women worldwide (24).

Halibut contains a variety of nutrients that are good for your heart, such as omega-3 fatty acids, niacin, selenium and magnesium.

While there is no DRI for omega-3 fatty acids, the adult Adequate Intake (AI) recommendation is 1.1 and 1.6 grams for women and men respectively. A half-filet of halibut provides about 1.1 grams of omega-3 fatty acids (1, 25, 26).

Omega-3 fatty acids have numerous heart health benefits (27, 28, 29).

They can help lower triglycerides, increase “good” HDL cholesterol, help prevent blood clots and lower blood pressure in those with high levels (28, 30, 31, 32).

Niacin, also known as vitamin B3, can help improve cholesterol and triglyceride levels as well. (33, 34, 35).

In addition, the high selenium content in halibut helps decrease your risk of heart disease by reducing oxidative stress, inflammation and the buildup of “bad” LDL cholesterol in your arteries (2, 36).

Finally, studies show that adding magnesium to your diet may help lower blood pressure (37, 38, 39).

Summary Halibut provides a variety of nutrients that may improve your heart health and help fight heart disease.

While inflammation can sometimes be helpful for your body, chronic low-grade inflammation can harm your health.

Halibut’s selenium, niacin and omega-3 contents can help reduce the negative effects of chronic inflammation.

One serving of halibut contains 106% of your daily selenium needs. This powerful antioxidant helps lower oxidative stress in your body (1, 2, 36).

Studies have shown that increased selenium blood levels improve your immune response, whereas a deficiency may negatively affect immune cells and their function (40).

Omega-3 fatty acids and niacin also play a role in reducing inflammation. Niacin is involved in producing histamine, which helps dilate your blood vessels and improves blood flow (41, 42, 43).

What’s more, studies have shown a consistent link between omega-3 fatty acid intake and decreased levels of inflammation. The fatty acids can reduce molecules and substances that contribute to inflammation, such as cytokines and eicosanoids (44, 45, 46, 47).

Summary The selenium, niacin and omega-3 contents in halibut can help fight chronic inflammation that contributes to poor health.

From nutrition to sustainability to contamination, there are a lot of things to consider when comparing wild-caught and farm-raised fish — each have their pros and cons (48).

More than 50% of seafood produced for human consumption is farm-raised, and the World Bank estimates that this number will increase to 62% by 2030 (49).

In an effort to keep wild fish populations from being overfished, Atlantic halibut is farmed in Canada, Iceland, Norway and the UK. This means the fish are commercially raised in controlled pens in lakes, rivers, oceans or tanks.

One benefit of farm-raised fish is that they’re typically less expensive and more readily available to consumers than wild-caught fish (50, 51, 52, 53).

A downside is that they’re often raised in crowded conditions and thus may be exposed to more bacteria, pesticides and parasites. However, more farms now grow fish in ways that are better for the environment and result in a product that’s safer for people to eat.

On the other hand, Pacific halibut comes from a well-managed fishery in the Pacific Ocean and is wild-caught. This means the fish are caught in their natural habitats in nets and traps or with fishing lines.

Wild-caught fish are often thought to be healthier with less contamination due to their natural diet of smaller fish and algae and since they come into less contact with parasites and bacteria. However, some can be contaminated by the natural food they eat.

The minor nutritional differences between wild-caught and farm-raised halibut are not enough to proclaim one healthier than the other.

Summary There are pros and cons to both wild-caught and farm-raised halibut. Environmental reasons and sustainability, as well as price and personal preference influence consumer choice. Nutritionally speaking, differences are minimal.

As with any food, there are potential concerns to consider before eating halibut.

Mercury Levels

Mercury is a toxic heavy metal found naturally in water, air and soil.

Fish can be exposed to low concentrations of mercury due to water pollution. Over time, the metal can build up in the fish’s bodies.

Larger fish and those with longer life spans often contain more mercury (54).

King mackerel, orange roughy, shark, swordfish, tilefish and ahi tuna seem to carry the highest risk of mercury contamination.

For most people, the mercury levels consumed by eating recommended amounts of fish and shellfish is not a major concern.

What’s more, the benefits of fish rich in omega-3 fatty acids, like halibut, may outweigh the risk.

Pregnant and nursing mothers should avoid high-mercury fish but not fish altogether. Omega-3 fatty acids aid the brain development of fetuses and babies (55, 56, 57).

Halibut fish tends to be low to moderate in mercury content and is considered safe to eat (58).

Purine Content

Purines are naturally produced in your body and found in certain foods.

They break down to form uric acid, which can contribute to gout and the development of kidney stones for some people. Those at risk of these conditions should limit their purine intake from certain foods (59, 60).

Though halibut contains purines, its levels are low to moderate. Therefore, it’s considered safe for those who are healthy and not at risk of certain kidney diseases (61).

Sustainability

Sustainability is a concern with the increased demand for wild-caught fish (62).

One way to sustain wild fish populations is to increase the availability of farmed fish. This has made aquaculture, or fish farming, more popular. It’s the fastest growing food production in the world (63, 64, 65).

According to Seafood Watch, wild Atlantic halibut is on the “avoid” list due to its low population. It has been overfished and is not expected to repopulate until 2056 (66).

Pacific halibut is thought to be safe to consume due to sustainable fishing practices enforced in the Pacific Ocean.

Summary There are some low to moderate concerns of consuming halibut, such as mercury and purine levels or sustainability. However, the benefits may outweigh the risks. It’s best to compare the facts, before making a personal decision.

Though it's low to moderate in mercury and purines, halibut's nutrition benefits outweigh potential safety concerns.

It’s rich in protein, omega-3 fatty acids, selenium and other nutrients that offer various health benefits.

Choosing farm-raised or Pacific halibut instead of overfished Atlantic halibut may even help the environment.

Eating halibut or not is obviously a personal choice, but the evidence suggests it’s a safe fish to eat.