Oysters are very nutritious, providing you with more than your daily requirements for zinc and vitamin B-12 as well as significant amounts of riboflavin, calcium, iron and phosphorus in each serving. Oysters do contain some saturated fat and cholesterol. However, this cholesterol might not be efficiently absorbed by your body.
Each 3-ounce serving of oysters contains 67 milligrams of cholesterol. This is about 22 percent of the recommended daily limit of 300 milligrams for healthy people and about 34 percent of the recommended daily limit of 200 milligrams for people at high risk for heart disease. While saturated fat affects cholesterol levels more than dietary cholesterol, oysters contain only 0.8 gram of saturated fat per serving, which is 4 to 5 percent of the recommended daily limit for saturated fat for people who consume 2,000 calories per day.
Oysters and Cholesterol Absorption
Components in oysters may prevent some dietary cholesterol from being absorbed, according to a study using rats published in "Bioscience, Biotechnology and Biochemistry" in 2010. Rats fed oyster extract had 34 percent lower blood cholesterol levels than rats fed the control diet. One component in oysters that may help decrease cholesterol absorption is phospholipids, according to an article published in February 2010 in "Nutrients," although the evidence for this is still preliminary and based mainly on animal studies. Consuming nuts, olive oil, foods that contain omega-3 fatty acids, including other types of seafood, and those that contain soluble fiber like oatmeal can help lower your cholesterol as well, according to the Mayo Clinic.
High Cholesterol Risks
Cholesterol levels over 240 milligrams per deciliter are considered high and those greater than 200 milligrams per deciliter are considered borderline. Having high cholesterol increases your risk for stroke and heart disease. Cholesterol can accumulate in your arteries, causing them to be narrow and making your heart work harder, and it can also cause clots that block your arteries, leading to heart attack or stroke.
It is much safer to eat cooked oysters than raw oysters. Raw oysters can contain Vibrio vulnificus and cause food poisoning that may be life-threatening for some people. There isn't any way to tell which raw oysters might be contaminated, and nothing but cooking oysters will kill these bacteria. Even a few raw oysters could cause you to become sick if they are contaminated.
- USDA Nutrient Data Laboratory: Mollusks, Oyster, Eastern, Wild, Cooked, Moist Heat
- MayoClinic.com: Healthy Diet: End the Guesswork With These Nutrition Guidelines
- Bioscience, Biotechnology, and Biochemistry: Effects of Dietary Oyster Extract on Lipid Metabolism, Blood Pressure, and Blood Glucose in SD Rats, Hypertensive Rats, and Diabetic Rats
- Nutrients: Dietary Phospholipids and Intestinal Cholesterol Absorption
- U.S. Food and Drug Administration: Raw Oyster Myths
- Centers for Disease Control and Prevention: Cholesterol
- MayoClinic.com: Cholesterol: Top Five Foods to Lower Your Numbers
Based in Massachusetts, Jessica Bruso has been writing since 2008. She holds a master of science degree in food policy and applied nutrition and a bachelor of arts degree in international relations, both from Tufts University.