Do Sardines Increase Hemoglobin? What the Science Says

January 10, 2026 •

3 min read

Anemia affects a significant portion of the global population, which makes dietary strategies crucial. A common question is: do sardines increase hemoglobin?

Quick Summary

Sardines are nutrient-rich with bioavailable heme iron and vitamin B12, vital for hemoglobin and red blood cell production. A balanced diet including sardines supports blood health, especially when iron deficiency is present.

Key Points

Heme Iron Source: Sardines offer bioavailable heme iron, which is absorbed more efficiently than non-heme iron.
Vitamin B12 Rich: Sardines contain vitamin B12, which is vital for red blood cell and hemoglobin production.
Calcium Content: Eating canned sardines with bones provides calcium, but can inhibit iron absorption if consumed together.
Anti-inflammatory Properties: Omega-3 fatty acids in sardines reduce inflammation, aiding the body's use of iron.
Nutrient Synergy: Sardines offer iron with nutrients like protein, omega-3s, and Vitamin B12, supporting blood health.

The Connection: Sardines, Iron, and Hemoglobin

Iron is central to hemoglobin production. Sardines, being seafood, provide heme iron, which the human body absorbs easily. Plant-based foods contain non-heme iron, which is less efficiently absorbed. Sardines are a strong dietary choice to increase iron intake and, consequently, hemoglobin.

A 100-gram serving of cooked sardines contains a notable amount of iron, along with other essential nutrients for blood health, such as vitamin B12. Vitamin B12 is essential for creating red blood cells, which house hemoglobin, and a deficiency can lead to anemia. Sardines provide high-quality iron and B vitamins, offering a comprehensive approach to supporting healthy blood.

Nutrients in Sardines Supporting Hemoglobin

Beyond iron and B12, sardines contain other nutrients that contribute to overall blood health and the body's efficient use of iron.

Omega-3 Fatty Acids: EPA and DHA in sardines reduce inflammation, which can affect iron absorption and utilization, particularly in inflammatory disorders. These fatty acids help ensure the body effectively uses iron.
Protein: Sardines are a source of high-quality protein, which is essential for building and repairing body tissues, including blood cells.
Vitamin D: Vitamin D aids in the absorption of other minerals, indirectly supporting overall nutritional status.

Inhibitors and Dietary Pairings

Certain factors can influence iron absorption. The high calcium content in sardines (consumed with their bones) can inhibit iron absorption if consumed at the same time. To maximize iron absorption from a sardine-rich meal, consider these strategies:

Separate high-calcium intake: If taking calcium supplements or consuming large amounts of dairy, do so at a different time than your sardine meal.
Pair with Vitamin C: Consume sardines with vitamin C, such as bell peppers, tomatoes, or citrus fruits. Vitamin C enhances iron absorption, particularly non-heme iron.

Comparing Sardines to Other Iron Sources


Food Source	Type of Iron	Bioavailability	Additional Benefits	Consideration
Sardines	Heme (highly absorbed)	High	Omega-3s, Vitamin B12, Protein	Lower mercury than larger fish. High calcium can interfere with iron absorption.
Red Meat	Heme	Very High	Excellent protein source	Higher in saturated fat; limit intake.
Spinach	Non-heme (plant-based)	Low	Good source of fiber, vitamins	Absorption enhanced by Vitamin C; inhibited by oxalates.
Lentils	Non-heme	Low	High in fiber and folate	Pairing with Vitamin C is recommended.
Fortified Cereals	Non-heme	Low	Convenient source of iron and B vitamins	Absorption less efficient; check labels for sugar content.

Incorporating Sardines into the Diet

Sardines can be a versatile addition to your meals. Ways to include them:

Snack: Serve sardines on whole-grain crackers with lemon. The lemon provides vitamin C to boost iron absorption.
Salads: Add flaked sardines to salads with leafy greens and chopped tomatoes for an iron-rich boost.
Pasta: Mix sardines into a tomato-based pasta sauce for a savory, nutrient-dense meal.
Omelets: Incorporate sardines into an omelet with spinach for a powerful combination of heme iron and folate.

Overall Diet and Medical Advice

While including sardines can increase hemoglobin, consider overall diet and health needs. Other iron-rich foods should also be included. A diet rich in a variety of nutrients is key for optimal health and hemoglobin production.

Persistent issues with low hemoglobin may indicate an underlying medical condition. Consulting a healthcare professional for a diagnosis and treatment plan is always the best course of action. Dietary changes should complement, not replace, medical advice.

Conclusion: A Small Fish with Big Benefits

Sardines can increase hemoglobin, mainly due to heme iron and vitamin B12. While the high calcium content can potentially inhibit iron absorption, strategic dietary pairings can mitigate this effect. For those with iron-deficiency anemia or looking to support blood health, incorporating sardines into a balanced diet can be a potent and sustainable nutritional strategy. Combining regular consumption of sardines with other iron-rich foods and medical guidance offers a robust path to maintain or improve hemoglobin levels. To learn more about incorporating sustainable, nutrient-dense seafood into the diet, consider visiting a resource like Sustainable Seafood.

Frequently Asked Questions

Yes, it is safe to eat sardines daily in moderation. Dietitians suggest staying within the recommended seafood intake of 8 to 12 ounces per week. Sardines are low in mercury, making them a healthy option for frequent consumption.

The timeframe for changes in hemoglobin levels from dietary changes varies based on the individual's degree of deficiency and overall diet. Consistently incorporating iron-rich foods like sardines can lead to a gradual increase over weeks or months. For specific medical conditions, always follow a doctor's advice.

Yes, canned sardines are as effective, if not more convenient, for increasing hemoglobin. The canning process preserves key nutrients, including iron and B12. Some canned varieties contain higher levels of certain nutrients like calcium due to the edible bones.

Yes, pairing matters. While high calcium intake from the edible bones can inhibit iron absorption, consuming vitamin C (like lemon, bell peppers, or tomatoes) can significantly enhance non-heme iron absorption from other meal components.

To maximize hemoglobin, pair sardines with vitamin C (citrus fruits, bell peppers), folate (leafy greens, legumes), and other heme iron sources (lean red meat, poultry). This enhances iron utilization.

No, sardines are not high in mercury. As small fish that feed on plankton, they accumulate less mercury than larger fish like tuna or swordfish. This makes them a safe seafood choice, especially for vulnerable populations.

Yes, vegetarians can get enough iron, but it is more challenging. Plant-based non-heme iron is less bioavailable, so vegetarians need to consume a higher volume of iron-rich plant foods like lentils, beans, spinach, and fortified grains, and pair them with vitamin C to enhance absorption.