Shellfish Showdown – Which Shellfish is Best for you?

Written By: Owennie Lee, RD

Title: Registered Dietitian

Alumni: University of British Columbia

Last Updated on:

The “r” months are here again and shellfish season is back. They are all delicious and nutritious in different ways, but some of you may limit shellfish because of concerns about mercury, cholesterol, etc. Care to find out the real scoop on shellfish nutrition?


The Ultimate Seafood Showdown (per 3 oz. edible portion, cooked with moist heat)

Highest in Iron

1st Place: Clams (23.8 mg)

Runner-Up: Oysters (7.8 mg)

Red meat comes to mind for most people when asked about iron sources. Surprisingly, clams are an amazing source of heme iron. Three ounces of clams contain almost 8 times as much iron as in 3 ounces of roast beef tenderloin (3 mg iron), and twice as much as 3.5 ounces of chicken liver (12.8 mg). If you are not a fan of red meat or livers, try some clams and oysters to boost your iron intake next time!

Best in Class for Zinc

1st Place: Oysters, Eastern, Wild (66.8 mg)

Runner-Up: Oysters, Pacific, Wild (28.3 mg)

Zinc is essential to our immune function and aids in DNA synthesis, amongst its many other functions in our bodies. Oysters are incredibly rich in zinc, which is also known to boost testosterone and sperm production. No wonder why oysters top the chart as one of the all-time favorite aphrodisiac food!

Lowest in Mercury

Clams and Shrimps (Non-detectable levels of mercury)

Contaminants such as mercury always loom in our minds when it comes to eating seafood. Fortunately, both clams and shrimps have no detectable levels of mercury, and other shellfish surveyed contain very low levels of mercury.

King of Selenium

1st Place: Oysters, Pacific, Wild (130.9 mg)

Runner-Up: Clams (54.4 mg)

Selenium is a trace mineral that doubles as a potent antioxidant. In some recent studies, men with high blood selenium levels were about half as likely to develop advanced prostate cancer as the men with lower blood selenium. Find tons of selenium in Pacific oysters and clams.

Top Omega-3 Shellfish

1st Place: Oysters, Pacific, Wild (1.259 mg)

Runner-Up: Oysters, Eastern, Wild (0.838 mg)

In addition to fatty fishes such as salmon, shellfish such as oysters offer decent levels of omega-3 fats. Three ounces of oysters contain nearly as much omega-3 fats as 3 ounces of Chinook salmon (1.57 mg). Switch your omega-3 fatty acid sources up once in a while to add taste and variety.

Lowest in Cholesterol

1st Place: Scallops (35 mg)

Runner-Up: Alaskan King Crab (45 mg)

Shellfish in general contains a high level of cholesterol but is low in saturated fats. This combination means that most people’s blood cholesterol will not be affected by consuming shellfish. However, if you have high cholesterol and have been instructed to limit your dietary cholesterol (e.g. follow a TLC diet), then you might want to watch your intake of high cholesterol shellfish, such as shrimp (179 mg), lobster (124 mg) and crayfish (113 mg).

The Bottom Line

Not only are shellfish delectable, they are moderate in calories, low in fat, high in protein and rich in many micronutrients. This makes these yummy mollusks and crustaceans a great alternative to meat and poultry. Enjoy a variety of shellfish that are prepared in a healthy way (i.e. stay away from breaded and deep fried choices) to maximize nutrition!

Health, Lifestyle, Nutrition 101

cholesterol, fish, heart smart, men's nutrition, mercury, oysters, seafood


What type of ground sugar do you use in cooking most often?

Turkey: Health Benefits and How-To

Olive Oil 101 – Podcast

Leave a Comment