The General Rule: 2-3 Servings per Week
For most healthy adults, federal health agencies like the FDA and EPA recommend eating 2 to 3 servings (8 to 12 ounces) of seafood per week. A typical adult serving is considered to be 4 ounces, measured before cooking. This recommendation balances the intake of beneficial nutrients, such as protein and omega-3 fatty acids, with potential exposure to environmental contaminants like methylmercury. It is important to choose a variety of seafood from different sources to ensure a balanced intake of nutrients and minimize exposure to contaminants from a single source. The American Heart Association specifically highlights fatty fish rich in omega-3s, like salmon and sardines, for their cardiovascular benefits.
What are omega-3 fatty acids and why are they important?
Omega-3 fatty acids, particularly EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), are essential nutrients that the body cannot produce on its own. They are crucial for a variety of bodily functions, including brain and eye development, and play a significant role in reducing inflammation and promoting heart health. Fatty fish are one of the richest dietary sources of these nutrients.
Navigating Mercury Levels: Best, Good, and Avoid
Not all fish are created equal when it comes to mercury levels. Mercury naturally occurs in the environment and can accumulate in fish, particularly in larger, longer-lived predatory species. This is why the FDA and EPA have categorized fish based on their mercury content to help consumers make informed choices.
Best Choices: Eat 2–3 servings a week
This category includes a wide variety of fish and shellfish that are low in mercury and excellent sources of nutrients. By prioritizing these options, most people can safely reach their weekly consumption goals.
- Salmon
- Shrimp
- Canned light tuna (canned light tuna is often a mix of smaller species, most often skipjack)
- Tilapia
- Cod
- Catfish
- Sardines
- Scallops
- Flounder
- Trout (freshwater)
Good Choices: Eat 1 serving a week
This list consists of fish with higher mercury concentrations than the "Best Choices" but that still offer health benefits. For these options, it is recommended to limit intake to one serving (4 ounces) per week and to avoid eating any other fish that week to control total mercury exposure.
- Albacore (white) tuna (limit to 6 ounces per week for most adults)
- Halibut
- Mahi-mahi
- Grouper
- Bluefish
Choices to Avoid
This category includes fish with the highest mercury levels. For the safety of all consumers, and especially vulnerable populations, these fish should be avoided altogether.
- Shark
- Swordfish
- King mackerel
- Tilefish from the Gulf of Mexico
- Bigeye tuna
- Marlin
- Orange roughy
Special Considerations for Vulnerable Populations
Certain groups of people need to be especially mindful of their fish consumption to prevent harm from mercury exposure, which can affect the developing nervous system.
- Pregnant and Breastfeeding Women: The FDA advises this group to consume 8 to 12 ounces per week of a variety of fish from the "Best Choices" list. They should limit albacore tuna to 6 ounces per week and completely avoid all "Choices to Avoid." It is also critical for this group to avoid raw or undercooked fish to prevent foodborne illness.
- Children: Parents should provide children with 2 servings of fish per week, with portion sizes adjusted for age and weight. The selections should come exclusively from the "Best Choices" list, with an even stricter limit on mercury than for adults.
Local Fish and Sourcing Tips
If you catch fish locally from rivers, lakes, or coastal waters, it is essential to check local advisories for those specific bodies of water. Where no information is available, consumption should be limited. State and tribal health departments often provide this information. When buying commercially, choosing seafood from responsible and sustainable sources can also be a consideration for environmental health. An authoritative resource for guidelines can be found on the FDA/EPA Advice on Eating Fish website.
Comparison Table: Mercury Levels and Intake Recommendations for Adults
| Fish Species | Mercury Level | Intake Recommendation (Adults) |
|---|---|---|
| Salmon | Low | 2–3 servings per week |
| Shrimp | Low | 2–3 servings per week |
| Canned Light Tuna | Low | 2–3 servings per week |
| Tilapia | Low | 2–3 servings per week |
| Cod | Low | 2–3 servings per week |
| Albacore (White) Tuna | Moderate | 1 serving (6 oz max) per week |
| Halibut | Moderate | 1 serving per week |
| Mahi-mahi | Moderate | 1 serving per week |
| King Mackerel | High | Avoid |
| Shark | High | Avoid |
| Swordfish | High | Avoid |
Conclusion: Making Informed Choices for a Healthy Diet
Eating fish offers significant health benefits, particularly from heart-healthy omega-3 fatty acids. By following the clear guidelines provided by the FDA and EPA, consumers can confidently enjoy a variety of seafood without excessive mercury exposure. The key is to prioritize low-mercury "Best Choices," especially for pregnant women and children, while limiting or avoiding high-mercury species. Checking local advisories for wild-caught fish and opting for healthier cooking methods like baking or grilling over frying further enhances the nutritional value of your meals. Making informed decisions about seafood is a simple yet powerful step towards a healthier lifestyle.
Cooking Methods and Other Safety Tips
Choosing healthier cooking methods is another way to ensure you are getting the most from your seafood. Steaming, baking, and grilling are excellent options that keep fat content low, especially compared to frying. For all consumers, but especially for pregnant women and children, it is important to ensure all fish and shellfish are cooked to a safe internal temperature to reduce the risk of foodborne illnesses from bacteria or viruses. Avoid raw or undercooked seafood if you are in a high-risk group. Selecting fresh, firm fish with a mild, not strong, odor is another sign of quality. For canned products, check labels for details on the type of fish and its mercury content, as it can vary.
