Surprise about Shellfish
...featuring Dr. K and the Keto Cowboy
The Surprising Carbohydrates in Shellfish
In "The Keto Minute," Dr. Korman and the Keto Cowboy discussed their surprise in finding out that, while meat products such as chicken, steak, and fish don't have virtually any carbs, the oysters they ate did have carbs!
In researching this, the Korman’s found out that, "oysters have carbs in them due to the glycogen in the muscles. Animals, upon death, go through some rigor mortis at which time sugar is depleted from the muscles. Glycogen is actually stored in muscles for future glucose needs. When animals die, the glycogen is depleted from the muscles, leaving them carb free. In the oysters, however, the glycogen remained in their muscle tissue, so carbs remained present."
"It could be that in the earlier days of the hunter-gatherers, the meat was eaten so quickly after the animal died, that there may have been some carbs still in the meat, due to glycogen left in the muscle tissue, albeit very small amounts. So, the fresher the meat, perhaps the more carbs that are in it," according to Dr. Korman and her husband, Brian.
Still we’re talking about very negligible amounts of carbs. Most all meats are absent of carbohydrates EXCEPT shellfish! Very few foods from animals contain carbohydrates, after death.
The fuel that supplies rigor mortis is stored muscle glycogen, and, once this fuel is expended, rigor mortis resides and muscle meats contain virtually zero glycogen and hence zero carbohydrate. Only a very few animal foods contain carbohydrate after death. Liver in mammals escapes rigor mortis and typically contains about 5% carbohydrate. Fish flesh contains virtually no carbohydrate.
Not so for shellfish. A number of shellfish contain a significant percentage of calories (10 – 25%) as carbohydrate, including oysters, mussels, abalone, whelk, clams, octopus and scallops. Does this mean that you should restrict shellfish consumption on a Keto Diet? Absolutely not! Overall, their carbohydrate content is minimal and occurs with a high protein and omega 3 fatty acid intake – both factors which improve your carbohydrate metabolism.
Shellfish are one of the most healthful, high protein foods you can consume to improve your glucose and insulin metabolism in addition to reducing your risk for chronic disease. Shellfish are actually nutrient dense foods rich in zinc, B vitamins and omega 3 fatty acids which improve immune function and resistance to the diseases of western civilization.