How Much Sardines Can You Eat in a Week with Mercury Concerns?

December 6, 2025 •

4 min read

According to the FDA, sardines are a 'best choice' for low-mercury fish consumption, meaning they contain significantly lower levels of mercury than many other fish. This makes them a nutrient-dense and safe option for most people. The key lies in understanding how much sardines you can eat in a week while maintaining a balanced diet to benefit from their omega-3 fatty acids, calcium, and protein without worry.

Quick Summary

This guide details the low mercury levels in sardines, providing clear recommendations for safe weekly intake based on expert guidelines. It covers why sardines are a safer choice compared to larger fish, and how to incorporate them into a healthy, balanced diet. The nutritional benefits, risks, and factors influencing mercury content are also explored.

Key Points

Low Mercury Content: Sardines are small, short-lived fish low on the food chain, resulting in very low mercury levels compared to larger predatory fish like tuna or swordfish.
Safe Weekly Intake: Most adults can safely eat 8-12 ounces of sardines (about 2-3 cans) per week, according to FDA guidelines for 'Best Choice' seafood.
Benefits for Sensitive Groups: The low mercury levels and high omega-3 content make sardines a safe and beneficial choice for pregnant and breastfeeding women within recommended weekly limits.
Nutrient-Dense Superfood: Sardines are packed with omega-3s, calcium (from edible bones), vitamin D, and high-quality protein, offering significant health benefits for heart, brain, and bone health.
Considerations for Regular Consumption: While low in mercury, regular intake requires attention to sodium content (choose water-packed) and purine levels, which can affect individuals with gout.
Dietary Variety is Key: To ensure a balanced intake of nutrients and minimize risks, it is best to enjoy a variety of seafood rather than relying solely on a single source.

Understanding Mercury Levels in Sardines

Mercury, specifically methylmercury, is a neurotoxin that can build up in fish through a process called biomagnification. This means that larger, longer-lived predatory fish at the top of the food chain tend to have the highest mercury concentrations. Sardines, being small, short-lived, and feeding primarily on plankton, are at the very bottom of this food chain, which is why their mercury levels are extremely low. The FDA has classified sardines as a 'Best Choice' seafood due to their low mercury content, making them one of the safest and most nutritious fish available.

Official Weekly Intake Recommendations

Health authorities generally recommend specific amounts of seafood for weekly consumption to balance nutritional benefits with potential exposure to contaminants like mercury. For the general population, the Dietary Guidelines for Americans suggest consuming at least 8 ounces of seafood per week, with a focus on 'Best Choice' options like sardines. A standard can of sardines is typically around 3.75 ounces, meaning that consuming two to three cans per week is well within safe limits.

For more sensitive populations, such as pregnant or breastfeeding women, the guidelines are slightly more specific. The FDA recommends 8 to 12 ounces per week of a variety of low-mercury fish. Since sardines are an excellent low-mercury option, they are a recommended choice for this group, providing crucial omega-3 fatty acids for fetal and infant brain development.

Sardines vs. Other Fish: A Mercury Comparison

Comparing sardines to other popular seafood options reveals just how safe they are regarding mercury exposure. The FDA has documented mercury concentrations in commercial fish, and the data clearly shows sardines have minimal levels.


Fish Type	Mean Mercury Concentration (PPM)	Typical Food Chain Position	Recommended Intake
Sardines	0.013	Bottom-feeder	2-3 cans (3.75 oz each) per week for most adults
Canned Light Tuna	0.126	Higher-level predator	Limited to 1-2 servings per week, especially for pregnant women
Canned Albacore Tuna	0.350	Higher-level predator	Limited to occasional consumption due to higher mercury
Swordfish	High (not specified in table)	Apex Predator	Avoid for sensitive populations; limited for all adults
Salmon	0.022	Low-to-mid level predator	Several servings per week

As the table illustrates, sardines have a substantially lower mercury concentration than even light tuna, and are a much safer alternative to larger fish like swordfish and albacore tuna.

The Nutritional Upside: More Than Just Low Mercury

Focusing solely on mercury can cause us to overlook the significant nutritional benefits that sardines offer. These small fish are a powerhouse of essential nutrients that support overall health.

Omega-3 Fatty Acids: Sardines are one of the richest sources of EPA and DHA, two types of omega-3s known for their powerful anti-inflammatory properties. These fatty acids are vital for heart health, brain function, and reducing blood pressure.
Calcium and Vitamin D: A major benefit of canned sardines is that the small, edible bones are rich in calcium and vitamin D, both essential for building and maintaining strong bones. This is particularly valuable for those who cannot consume dairy.
Protein: A single can of sardines can contain over 20 grams of high-quality protein, which helps with satiety and muscle repair.
Other Minerals: Sardines also provide a host of other minerals, including phosphorus, iron, and potassium.

Potential Downsides and Considerations

While the mercury risk is low, there are other factors to consider when consuming sardines regularly. The sodium content in canned sardines can be high, particularly if they are packed in sauces or salt-heavy brines. Individuals with high blood pressure or other sodium-sensitive health conditions should opt for low-sodium versions or sardines packed in water. Sardines also contain purines, which can increase uric acid levels in the body, a potential issue for those with gout or kidney problems.

It is also prudent to practice variety in your diet. While safe to eat frequently, eating the same food every day can lead to nutrient imbalances. The FDA's advice to eat a variety of seafood within the recommended weekly intake is a sensible approach to maximizing health benefits while minimizing any potential risks.

Conclusion

Ultimately, sardines are a highly nutritious and safe food choice with minimal mercury risk, even when eaten regularly. The FDA classifies them as a 'Best Choice' for consumption, and most adults can safely consume two to three cans (8 to 12 ounces) per week without concern over mercury accumulation. This intake level is particularly beneficial for high-risk groups like pregnant women due to the omega-3 content essential for development. While larger, predatory fish like swordfish and certain types of tuna pose a higher mercury risk, sardines remain an affordable, accessible, and low-mercury alternative. To balance your diet and manage other concerns like sodium, opt for water-packed or low-sodium options and enjoy a variety of seafood throughout the week. For personalized advice, particularly concerning pre-existing conditions like gout, it is always wise to consult a healthcare professional.

Frequently Asked Questions

While mercury levels in sardines are very low, most dietitians recommend eating them a few times a week rather than every day to ensure dietary variety. The general recommendation for overall seafood intake is 8 to 12 ounces per week for most adults.

Sardines have significantly lower mercury than canned tuna. For example, FDA data shows sardines average 0.013 ppm, while canned light tuna is 0.126 ppm, and albacore tuna is even higher at 0.350 ppm.

A standard serving is typically one can, which is about 3.75 ounces or 85 grams. Based on FDA recommendations, two to three cans a week is considered safe and healthy.

Sardines packed in water generally have fewer calories, less fat, and less sodium. While still a healthy option, those packed in extra virgin olive oil may offer additional heart-healthy fats. For those watching their sodium intake, water-packed is the better choice.

Yes, sardines are on the FDA's 'Best Choice' list for low-mercury fish and are safe for pregnant and breastfeeding women. They provide vital omega-3 fatty acids for a baby's brain and nervous system development.

Yes, sardines are a safe and nutritious option for children due to their low mercury levels. They are rich in omega-3s, calcium, and vitamin D, all beneficial for a child's growth. As with adults, moderation is key.

Canned sardines can be high in sodium, which is a concern for individuals with high blood pressure. Choosing low-sodium or water-packed varieties and draining the fish can help reduce sodium intake.