Shellfish: Nutrient-Rich Sea Life for Heart and Joint Health

Overview

Is shellfish like lobster, crab, shrimp, or mussels part of your regular diet? You’ll be happy to learn that these sea creatures are packed with nutrients and antioxidants, low in calories, and offer multiple potential health benefits.

Consuming shellfish regularly can boost your heart health, supercharge brain function, ease joint pain, help you lose weight, and much more. In addition to including it in your meals, shellfish like glucosamine, green-lipped mussel, krill, and others are available in supplement form and often included in natural products for their health advantages.

In this review, we discuss the properties and shellfish benefits and explore the ways that you can incorporate them into your life.

What is Shellfish?

Shellfish are sea creatures divided into two categories based on their characteristics and appearance. Crustaceans have hard shells, segmented bodies, and jointed legs, and they include lobster, shrimp, crab, and crayfish. Mollusks are shellfish types with hard, hinged, two-part shells, such as oysters, mussels, clams, and scallops.

Most of these edible sea creatures live in saltwater environments like the ocean and are popular food sources due to their rich nutrient profile. An ideal addition to a healthy diet, shellfish are low in calories and saturated fat, high in protein, and rich in antioxidants and omega-3 fatty acids.

Researcher Latife Ceyda Irkin notes, “They also contain high amounts of many micronutrients, including iron, zinc, magnesium, and B12. Consuming shellfish regularly can boost immunity, aid weight loss, and support brain and heart health ⁽¹⁾.”

Shellfish may also enhance the health of the bones and eyes, and they have anti-inflammatory properties that help ease pain and swelling in joints. High in hunger-curbing protein and low in calories, shellfish also supports weight management.

Thinking of adding more shellfish to your diet, or taking a health supplement that includes one of these sea creatures as an ingredient? Let’s examine the health benefits in detail.

Health Benefits of Shellfish

High in protein, antioxidants, anti-inflammatory agents, and nutrients, there are many advantages to adding shellfish to your diet or taking a supplement. These are the top shellfish benefits:

Helps Strengthen the Immune System

Shellfish has antioxidants that help destroy free radicals to lower oxidative stress and decrease inflammation, and other key support immune-support nutrients like selenium and zinc ⁽²⁾. This promotes repair and healing body-wide, helping to prevent infection and illness and strengthen overall immunity.

Supports Heart Health

Is shellfish heart healthy? Shellfish are considered very good for the heart when eaten in moderation, largely due to their omega-3 fatty acids which help lower cardiovascular inflammation and balance blood pressure levels. While they have some cholesterol and fat, they are primarily rich in healthy fats like polyunsaturated acids.

These sea creatures also contain magnesium, which boosts circulation, and vitamin B12 which may prevent the metabolism of the amino acid homocysteine to help lower the risk of heart disease. A research review of studies on Korean middle-aged adults published in Nutrients concluded that regular shellfish consumption decreased CVD risk (3).

Supports Heart Health

Is shellfish heart healthy? Shellfish are considered very good for the heart when eaten in moderation, largely due to their omega-3 fatty acids which help lower cardiovascular inflammation and balance blood pressure levels. While they have some cholesterol and fat, they are primarily rich in healthy fats like polyunsaturated acids.

These sea creatures also contain magnesium, which boosts circulation, and vitamin B12 which may prevent the metabolism of the amino acid homocysteine to help lower the risk of heart disease. A research review of studies on Korean middle-aged adults published in Nutrients concluded that regular shellfish consumption decreased CVD risk ⁽³⁾.

Supports Brain and Cognitive Health

The omega-3 fatty acids EPAs and DHAs in shellfish help boost cognitive function by supporting brain cell development and repairing neural damage. According to some research, this could boost functions like memory, learning, and mental focus.

In addition, shellfish is high in other nutrients like selenium, copper, and vitamin B12 which support brain development. Regular consumption of these sea creatures may reduce the risk of dementia, according to a review in the Journal of Prevention of Alzheimer’s Disease ⁽⁴⁾.

Supports Weight Management and Metabolic Health

Shellfish is low in calories and unhealthy fats, and it contains nutrients like omega-3 fatty acids which support metabolic health and may speed up fat burning. In addition, shellfish are high in protein, which keeps you feeling full for longer so you take in fewer overall calories.

Along with their potential anti-obesity properties ⁽⁵⁾, evidence indicates that consuming shellfish regularly could help reduce insulin resistance and balance blood sugar levels.

Supports Joint Health

Shellfish are high in anti-inflammatory agents due to their high levels of omega-3 fatty acids, which could help lessen pain and swelling in joints. In addition, it has antioxidants that lower oxidative stress to repair damage to connective tissue.

Supplements for joint pain in particular include glucosamine, which is a shellfish extract that is similar to the glucosamine that exists naturally in our connective tissue. This ingredient helps repair tissue damage and supports the cartilage to ease joint pain and inflammation.

Research indicates that glucosamine helps manage the symptoms of mild to moderate osteoarthritis ⁽⁶⁾. Read about some of the best natural solutions with this ingredient in our article on the 14 Best Glucosamine Supplements of 2025.

Supports Bone Health

Shellfish is packed with nutrients that support bone health, including calcium, vitamin D, potassium, zinc, and omega-3 fatty acids. Some evidence indicates that eating shellfish regularly could help strengthen the bones, boost mineral density, and lower the risk of developing osteoporosis⁽⁷⁾.

Supports Eye Health

Shellfish contains nutrients that help enhance ocular health, notably zinc, which supports vision and protects the eyes from UV rays, and vitamin A, which is essential for healthy eyesight and night vision. It is also rich in omega-3 fatty acids which help decrease ocular inflammation.

Some evidence indicates that consuming shellfish regularly could help lower the risk of age-related eye conditions. A cross-sectional study published in Ophthalmology found support for the protective effects of fish and seafood against age-related macular degeneration⁽⁸⁾.

Shellfish Sources

While it is not recommended generally to eat shellfish raw, some types like oysters, shrimps, and clams can be consumed that way if you follow proper safety precautions and buy from a reputable manufacturer. Generally, it’s best to not prepare raw seafood on your own.

When it comes to cooking shellfish, there are several methods of preparation, including steaming, poaching, pan-searing, and grilling. Before cooking, it’s important to soak the shellfish in salt water to remove dirt and possible contaminants.

Several forms of shellfish are included in health products, and you can purchase shellfish supplements in capsule, liquid, oil, or powder form. Some of the top ingredients include glucosamine, chitosan, green-lipped mussel, oyster extract, and krill. For some great options, read our article outlining the Best Krill Oil Supplements of 2025.

Safety and Side Effects

Shellfish are healthy, rich in nutrients, and an important part of a healthy diet. However, as it may accumulate metals like mercury or cadmium from the ocean, it’s best not to consume it daily. According to the U.S. Department of Agriculture ⁽⁹⁾ , adults should eat about 8 ounces per week of all seafood types, which is about 2-3 servings.

In addition, shellfish is a fairly common allergen, so it is important to ensure that you do not have a sensitivity before consuming it. An allergic reaction to shellfish could lead to symptoms like nausea, vomiting, digestive upset, hives, or throat swelling.

Raw shellfish are also prone to contamination if not handled, cooked, and refrigerated correctly, as they can acquire bacteria from the environment. Ensure that you purchase shellfish from a safe, reputable source, put it in the fridge within 2 hours of purchasing it, and cook it fully to an internal temperature of 90°C.

If you plan to take a shellfish supplement, consult with a healthcare practitioner for approval and advice regarding usage and dosage.

FAQs About Shellfish

Q: What is the healthiest shellfish to eat?

A: Shellfish are rich in protein and nutrients, and healthy to eat in moderation. Some of the best sources to incorporate into your diet include crab, lobster, mussels, shrimp, and clams.

Q: Can you eat shellfish every day?

A: The experts recommend eating shellfish in moderation, up to 12 ounces a week. It’s best to avoid consuming it daily as shellfish can absorb mercury and other chemicals from the ocean, which can be unhealthy at high levels.

Q: What type of fish is not shellfish?

A: Shellfish includes mollusks like oysters, mussels, and clams, and crustaceans like lobster, crayfish, and shrimp, all of which are invertebrates with hard shells. Fish that are vertebrates like salmon, tuna, haddock, and cod are not classed as shellfish.

Q: What shellfish supplement is best for joint pain?

A: Many shellfish are rich in omega-3 fatty acids with potent anti-inflammatory agents that can help ease joint pain and discomfort. The green-lipped mussel has support for its joint health and pain-relieving properties. In addition, glucosamine derived from shellfish helps repair cartilage damage and prevent breakdown to ease joint pain.

Q: Does shellfish make you gain weight?

A: Generally no, shellfish is low in calories and rich in protein and healthy fats, and does not contribute to weight gain unless you eat it fried. The protein in shellfish helps curb hunger and the omega-3 fatty acids stimulate the metabolism, supporting weight management.

The Bottom Line

Shellfish includes a variety of invertebrates like shrimps, mussels, lobster, and crabs, which can be delicious additions to your diet and pack a wealth of protein, antioxidants, and nutrients like omega-3 fatty acids, vitamins, and minerals.

Including shellfish in your diet twice a week is highly recommended by experts and offers multiple benefits, including helping to boost heart and brain health, ease joint pain, strengthen the immune system, and support weight management.

If you prefer your shellfish in supplement form, there are many brands available that incorporate ingredients like green-lipped mussel, glucosamine, and krill for multiple benefits to health and well-being. Before taking a supplement, consult with a healthcare practitioner regarding suitability and optimal dosage.

14 Sources

We review published medical research in respected scientific journals to arrive at our conclusions about a product or health topic. This ensures the highest standard of scientific accuracy.

[1] The Effects of Shellfish Consumption Frequency for Human Health: https://www.intechopen.com/chapters/79077
[2] Zinc as a Gatekeeper of Immune Function: https://pmc.ncbi.nlm.nih.gov/articles/PMC5748737/
[3] Association between Seafood Intake and Cardiovascular Disease in South Korean Adults: A Community-Based Prospective Cohort Studyhttps://pmc.ncbi.nlm.nih.gov/articles/PMC9695428/
[4] Fish and Shellfish Consumption, Cognitive Health and Mortality from Alzheimer's Disease among US Adults Aged 60 and Older: https://pubmed.ncbi.nlm.nih.gov/38706279/
[5] Seafood Intake and the Development of Obesity, Insulin Resistance and Type 2 Diabetes:https://pmc.ncbi.nlm.nih.gov/articles/PMC6536831/
[6] Role of Glucosamine in the Treatment For Osteoarthritis: https://pmc.ncbi.nlm.nih.gov/articles/PMC3456914/
[7] https://www.researchgate.net/publication/6977460_Impact_of_seafood_and_fruit_consumption_on_bone_mineral_density
[8] The Impact of Fish and Shellfish Consumption on Age-Related Macular Degeneration: https://pmc.ncbi.nlm.nih.gov/articles/PMC3894610/
[9] Why is it Important to Eat Seafood and How Often Should I Eat It? https://ask.usda.gov/s/article/How-often-should-I-eat-seafood#:~:text=Seafood%2C%20which%20includes%20fish%20and,healthy%20diet%2C%20can%20support%20health
[10] https://www.researchgate.net/publication/320664039_Shellfish_Nutritive_Value_Health_Benefits_and_Consumer_Safety
[11] Fish and Shellfish Consumption in Relation to Death From Myocardial Infarction Among Men in Shanghai, China: https://pubmed.ncbi.nlm.nih.gov/11682363/
[12] Seafood Consumption and Components for Health: https://pmc.ncbi.nlm.nih.gov/articles/PMC4776937/
[13] Seafood Intake and the Development of Obesity, Insulin Resistance and Type 2 Diabetes:https://pmc.ncbi.nlm.nih.gov/articles/PMC6536831/
[14] Effectiveness and Safety of Glucosamine in Osteoarthritis: A Systematic Review:https://pmc.ncbi.nlm.nih.gov/articles/PMC10366893/

Sara Barsky-Weiss, RDN

Sara Barsky-Weiss, RDN, is a registered dietitian nutritionist in the NYC area. Sara is a newly certified RDN and is excited to begin h Read Full Bio