Medically reviewed by Suzanne Fisher, RD
Fish is one of the most nutrient-dense foods available, providing an array of essential vitamins, minerals, and healthy fats. Whether you're aiming for heart health, brain function, or improved metabolic and hormonal balance, including fish in your diet can offer numerous benefits. However, not all fish are created equal. Some are packed with nutrients, while others may be high in mercury or other contaminants.
In this article, we’ll explore the top five healthiest fish to consume, along with fish you should limit or avoid due to concerns about mercury and sustainability.
The Healthiest Fish to Eat
When selecting fish, it’s essential to consider both nutrient density and contaminant levels. The healthiest fish are rich in omega-3 fatty acids, high in protein, and low in mercury. Here's a closer look at the top five choices.
1. Salmon
Salmon is one of the most popular choices due to its rich nutrient profile and versatility in cooking.
Benefits:
Salmon is an excellent source of omega-3 fatty acids, which are critical for brain, heart, and eye health. Omega-3s support cell membranes, reduce inflammation, and have been linked to decreased risk of heart disease. Additionally, salmon is high in protein, vitamin D (important for bone health), and selenium (necessary for thyroid function and antioxidant defense).
The antioxidant content in salmon, particularly astaxanthin, gives it its vibrant color and supports cardiovascular health by reducing oxidative stress.
Best Sources:
Salmon can be either farmed or wild-caught, and while both types provide similar nutritional benefits, wild-caught salmon is less likely to be treated with antibiotics. However, farmed salmon is often more affordable and easier to find. Be mindful of your source and opt for sustainably sourced fish whenever possible.
2. Mackerel
Mackerel is another oily fish that provides numerous health benefits. However, not all mackerel is created equal.
Benefits:
Atlantic mackerel is an excellent source of omega-3 fatty acids, vitamin D, and B vitamins, all of which support heart and brain health. It is also rich in minerals like selenium and magnesium. A 3-ounce serving of Atlantic mackerel offers almost 100% of your daily vitamin D needs, which is vital for immune function and bone health.
Best Sources:
Be cautious when selecting mackerel. While Atlantic mackerel is a low-mercury option, king mackerel is high in mercury and should be avoided, especially by pregnant women, breastfeeding mothers, and young children. Atlantic mackerel is a sustainable choice and is often recommended for regular consumption.
3. Sardines
Sardines are a small but mighty powerhouse when it comes to nutrition.
Benefits:
As a rich source of omega-3s, sardines are beneficial for heart health, reducing inflammation, and supporting brain function. They also provide significant amounts of calcium, making them an excellent option for bone health, particularly if you eat them whole with the bones. Sardines are also high in iron, zinc, and vitamin D, contributing to a well-rounded nutritional profile.
Best Sources:
Sardines are typically available canned, which makes them affordable and accessible. However, canned sardines can be higher in sodium, so if you're watching your salt intake, choose fresh sardines when possible. Even with their small size, sardines tend to be low in contaminants like mercury.
4. Rainbow Trout
Rainbow trout is a mild-tasting fish that's rich in essential nutrients and low in contaminants.
Benefits:
Like other fatty fish, rainbow trout is a great source of omega-3 fatty acids, which promote heart health. It is also packed with high-quality protein and essential vitamins like B12, niacin, and vitamin D, which are critical for energy production and overall health. Rainbow trout also contains a variety of minerals, including phosphorus and potassium, which support bone and heart health.
Best Sources:
Rainbow trout is often farmed in the United States using sustainable methods, making it an environmentally friendly choice. The low contaminant levels, particularly mercury, make rainbow trout a safe and nutritious option for regular consumption.
5. Anchovies
Anchovies are often overlooked due to their strong, salty flavor, but they pack a serious nutritional punch.
Benefits:
Despite their small size, anchovies are rich in omega-3 fatty acids, protein, calcium, and other vitamins and minerals, including iron and magnesium. These nutrients contribute to heart health, bone strength, and overall well-being. Anchovies also contain a good amount of B vitamins, which support energy metabolism.
Best Sources:
Anchovies are commonly consumed in a cured, salted form, which may be higher in sodium. Fresh anchovies are available in some regions and may offer a more subtle flavor while still providing the same health benefits. Importantly, anchovies are low in mercury, making them a safe option for most people.
Fish to Limit or Avoid
While fish is generally considered a healthy part of a balanced diet, there are certain types that should be limited due to high mercury levels or environmental concerns.
1. High-Mercury Fish
Larger, longer-lived fish tend to accumulate more mercury in their tissues. Mercury is a neurotoxin that can impact brain function, particularly in fetuses and young children. For this reason, the FDA advises limiting or avoiding fish that are high in mercury.
Fish to Avoid:
King mackerelMarlinOrange roughySharkSwordfishTilefish (from the Gulf of Mexico)Bigeye tuna
These fish contain the highest levels of mercury and should be avoided, especially by pregnant women, nursing mothers, and young children.
2. Fish High in Contaminants
Some fish are more likely to contain environmental pollutants, including polychlorinated biphenyls (PCBs) and dioxins. These contaminants can accumulate in fat tissue and may be carcinogenic or have other harmful health effects.
Fish to Limit:
While not all fish are heavily contaminated, species that are high in fat or have been exposed to polluted waters may carry higher levels of these harmful chemicals. Fish like Atlantic cod and certain types of tuna may contain higher contaminant levels, so it's best to consume them in moderation and ensure they are sourced from clean waters.
3. Overfished Species
Overfishing depletes fish populations, disrupts ecosystems, and may lead to the extinction of certain species. To support sustainable practices, limit your intake of overfished species.
Fish to Limit:
Atlantic codSome types of tuna (albacore, bluefin)
These species are vulnerable to overfishing, so choosing sustainably sourced options, or alternative species, can help preserve the environment.
Is Tuna Good for You?
Tuna is a common choice due to its availability and versatility, but its health benefits depend on the type and amount consumed. Canned light tuna, made from smaller species like skipjack, is low in mercury and a healthy option in moderation. However, bigeye tuna and other large species are high in mercury and should be avoided.
How Much Tuna Can You Eat?
According to the FDA, it’s safe to consume two to three servings (4 ounces each) of canned light tuna per week. However, limit albacore or yellowfin tuna to one serving per week due to higher mercury levels.
Health Benefits of Regular Fish Consumption
Including fish in your diet can offer numerous health benefits. Some of the most significant include:
1. Heart Health
The omega-3 fatty acids found in fish like salmon, mackerel, and sardines have been shown to reduce inflammation, lower blood pressure, and decrease the risk of heart disease. Omega-3s can help prevent abnormal heart rhythms and reduce triglyceride levels.
2. Brain Function
Omega-3s are crucial for brain development and function. Regular consumption of omega-3-rich fish has been linked to improved mental performance, reduced cognitive decline, and better memory in older adults.
3. Bone Health
Fish is a natural source of vitamin D, which helps the body absorb calcium, leading to stronger bones. Eating fish regularly may help reduce the risk of osteoporosis and fractures, particularly in older adults.
How Much Fish Should You Eat?
The Dietary Guidelines for Americans recommend consuming at least 8 ounces of fish per week for adults. Pregnant and breastfeeding women should aim for 8 to 12 ounces of low-mercury fish per week to support fetal and infant development. Children should also be encouraged to eat fish, but in smaller amounts—around 8 ounces or less per week, depending on their age.
Fish is a nutritious and delicious addition to any diet, offering a rich source of essential nutrients, including omega-3 fatty acids, vitamins, and minerals. The top five healthiest fish—salmon, mackerel, sardines, rainbow trout, and anchovies—are not only nutrient-dense but also relatively low in mercury, making them safe and beneficial for regular consumption. However, it's important to be mindful of fish that may be high in mercury or environmental contaminants, and to opt for sustainably sourced fish whenever possible.
By including a variety of these healthy fish in your diet, you can reap the many health benefits they offer, from improved heart health to enhanced brain function, while also making a positive impact on the environment by choosing sustainable options.
Source: Verywell Health.