As a diabetes educator, I’ve found that for a number of my patients, foods from the sea are mysteries. Questions I’ve received include:

- Should I eat seafood and what are the health benefits, if any?
- What type and how much should I eat?
- Will eating foods from the sea help prevent diabetes or help me if I have diabetes?
- I heard something about unusual seafood being used in diabetes research to develop medications. Can you tell me more?
- Is there really a problem with mercury in fish? 
- What are sea vegetables, and are they healthy for me to eat?
- What about sea salt? Does it contain less sodium than table salt and is it healthier for me?

As you can see, there are many good questions about foods from the sea. Let’s get started answering them!

Seafood: The exact definition of seafood differs, depending upon the dictionary or source. The Merriam-Webster dictionary defines seafood as: “Edible aquatic animals excluding mammals, but including both freshwater and ocean creatures. Seafood includes bony and cartilaginous fishes, crustaceans, mollusks, edible jellyfish, sea turtles, frogs, sea urchins and sea cucumbers.” (1)

Some of these foods may be familiar to you and others maybe not.  Let’s define the different kinds of seafood and potential health benefits for people with diabetes:
  1. Fish, Crustaceans and Mollusks
Fish are cold blooded vertebrate that live solely in the water. They have bones or cartilage, sometimes fins, a two-chambered heart and gills. (2)  

Crustaceans are arthropods that have an exoskeleton, a pair of appendages on each segment and two pairs of antennae. Lobsters, shrimp and crabs are examples. (3)

Mollusks are invertebrates with a soft body that is usually enclosed in a calcareous shell. Snails, clams and squids are in this group of animals. (4)
The 2010 Dietary Guidelines for Americans and the American Heart Association (AHA) recommend that adults eat two 3.5-4 oz. servings per week of fish and seafood that is high in the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and low in mercury.  (5,6) The Centre of Excellence for Science, Seafood and Health (CESSH) in Australia recommends consuming 600mg  of omega-3s per day for men, and 500mg for women from seafood. (7)

Omega-3 fatty acids are essential to consume as they cannot be made in the body. Fatty fishes are especially good sources of omega-3’s. The Dietary Guidelines specifically recommend salmon, trout and herring. (5)  Seafood Health Facts has a list of seafood products and the amounts of omega-3’s they contain. For more information, click here

Mercury is a poison to humans. In children it can affect brain development, delay walking and cause learning disabilities. In adults some of the problems it can cause include affecting fertility, blood pressure, as well as causing numbness and vision loss. It may also be a factor in heart disease. (8) The Natural Resource Defense Council (NRDC) has a wallet card that gives guidance to the amount of mercury in common seafood. To find a copy, click here.
These recommendations reflect cardiac research showing that omega-3 fatty acids will decrease triglyceride levels, slow the progression of atherosclerotic plaque, will slightly reduce blood pressure and decrease the risk of abnormal heart beats (5,6).

Why do people with diabetes need to be concerned about heart disease?  Cardiovascular disease is the leading cause of death in people with diabetes. The JDRF (formerly called the Juvenile Diabetes Research Foundation) agrees with this statement for people with type 1 diabetes (9).  In people with type 2 diabetes, 65 percent of people die from cardiovascular disease. (10) These statistics show that all people with diabetes need to take precautions to lower the incidence of heart disease.
  1. Edible Jellyfish
Jellyfish are animal with a soft gelatinous structure and a single cavity for bodily functions. Jellyfish have tentacles and usually an umbrella like body. (11)

Approximately 12 species of jellyfish can be dried and eaten. In parts of the world they are considered a delicacy. (12)  According to the USDA data base of foods, 1 cup of dried salted jellyfish has approximately 3 grams of protein, 1 gram of fat and 5,620mg of sodium, which is very high. (13)

Jellyfish are being studied in diabetes research.  In fact, in the bodies of particular species of jellyfish, green fluorescent protein (GFP) is made. This protein attached to insulin producing cells in the pancreas is helping diabetes researchers understand how insulin is made in the body. This type of research is potentially helpful in the development of new diabetes treatments. For example, attaching GFP to insulin-producing cells in the pancreas has helped researchers study how they're made, which could inform new diabetes treatments. (14)
  1. Sea Turtles
Sea turtles are marine turtles that have the feet modified into paddles and that include the green turtle, leatherback, hawksbill, loggerhead, and ridley. (15)

According to the National Oceanic and Atmospheric Administration, all sea turtles are listed under the Endangered Species Act (ESA). (16) Little or no research into sea turtles and diabetes exists, and certainly no studies have been found linking the consumption of turtles with diabetes health.
  1. Frogs
Frogs are largely aquatic amphibians that have slender bodies with smooth moist skin and strong long hind legs with webbed feet. (17)

Research published in 2013 has shown that skin secretions from several species of frogs are showing insulin-releasing actions that potentially this may be developed into a therapeutic agent for type 2 diabetes. (18)
  1.  Sea Urchins and Sea Cucumbers
These are marine animals that live in the ocean and have exoskeletons. They have five-fold symmetry, which means they have appendages (rays or arms) in multiples of five. (19)  

Sea Urchins are being studied to help find answers to a condition called diabetes insipidus (20). This form of diabetes is not related and should not be confused with type 1 or type 2 diabetes. People with diabetes insipidus usually have an injury to their pituitary gland in the brain and the storage and release of the hormone vasopressin is disrupted. This causes a problem with the function of the kidneys to concentrate urine. People with this condition typically urinate between 2- 2.5 liters of urine per day. (21)

Sea Cucumbers are being studied in connection to wound healing. (22)

According to the American Diabetes Association, a very common complication of both type 1 and type 2 diabetes is delayed wound healing. (23) Perhaps with the help of sea cucumbers, novel ways to heal wounds will be developed.
  1. Sea Vegetables
The definition of sea vegetables is: an edible seaweed. (24)

A very small study published in 2008 looked at 20 participants with type 2 diabetes randomized into a control group or given a total of 48 grams of sea tangle and sea mustard in supplement form per day. Results of the study showed the group that consumed the seaweed had their fasting blood glucose levels and the level 2 hours after a meal decreasing significantly. The researchers suggest confirming these results with further studies before these effects before recommendations can be made to people with type 2 diabetes. (25)
  1. Sea Salt
Sea salt is made from evaporated sea water. The texture is courser and it contains a small amount of trace minerals that is not present in table salt. It may also contain contaminants from the sea. Does sea salt have less sodium than table salt? According to the American Heart Association, there is no difference in sodium content between sea salt and table salt. (26)

Both sea salt and table salt contain 590mg of sodium in ¼ tsp or 1.5g. (27, 28) Iodine is added to “iodized salt” and in many places in the United States, and the world, this has helped to prevent goiter and iodine deficiency. Both table salt and sea salt can be purchased in an iodized version. Please consult with your physician to discuss if what is recommended for you. Remember that the American Heart Association recommends no more than 1,500mg of sodium per day for everyone including those with diabetes.

As you can see there are many mysteries from the sea. If there are no allergies or intolerances, seafood can be a very valuable component to a healthy diet for people with type 1 or type 2 diabetes. Important research is taking place with seafood to develop medications and potential treatments for diabetes. Seafood is an amazing and wonderful resource and no longer so mysterious!

Article Referenced Links by Number:

1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28