Glucose and omega-3s become dangerously associated in the context of Type 2 diabetes. If you have diabetes and are considering omega-3 supplementation, it's important to talk to your doctor. Some studies show that high omega-3 intake can aggravate impaired glucose metabolism while others indicate a diabetes benefit. Uncertainties aside, the American Diabetes Association recommends eating omega-3-rich seafood as part of a balanced diet.
The Relationship
After eating a meal, dietary sugar is digested into glucose and transported into the blood for delivery to muscle, liver and fat cells for energy use and storage. As described by physicians reporting in the January 2007 issue of "Diabetes Care," diabetes is defined by abnormally high blood glucose levels while fasting and after a meal. Rather than be transported for energy storage, glucose remains in the bloodstream, creating a cascade of health problems. Studies have shown that both dietary and supplemental omega-3 intake can raise blood glucose in people with Type 2 diabetes.
Supplement Dangers
A group of researchers reporting in the September 2006 issue of the "American Journal of Clinical Nutrition" randomly assigned 26 Norwegian diabetic patients to receive either 5.9 g omega-3 supplements or placebo for one week. The subjects were aged 40 to 75 years, and the study was brief because of the relatively high dose of omega-3s used. The dose reflected the chemical composition of Norwegian cod liver oil and was not typical of most commercial supplements. In just one week, the fish oil group experienced significantly elevated blood glucose levels while no change was detected in the placebo group.
Dietary Dangers
The Women's Health Study followed 36,268 women with an average age of 55 for 16 years with the aim of determining associations between diet and disease. Researchers reporting in the January 2011 issue of the "Journal of Clinical Nutrition" gleaned Health Study data looking for relationships between diabetes and omega-3 intake. Participants answered a food frequency questionnaire that asked about average consumption of canned tuna, dark-meat fish, other fish, as well as shrimp, lobster and scallops. The researchers found that high dietary omega-3 consumption significantly increased the risk of developing Type 2 diabetes.
Epidemiological Versus Clinical
An epidemiological study involves investigations of entire populations in relation to a health issue. One of the reasons omega-3s came under scientific investigation in relation to blood glucose was because populations with high dietary omega-3 intakes such as Eskimos have low diabetes prevalence. Researchers reporting in the April 2007 issue of "Diabetes Care" noted that these studies are in contrast with clinical trials showing elevated glucose levels in response to omega-3 intake. The researchers reviewed 22 clinical studies and concluded that omega-3 supplements are generally safe but can adversely affect glucose control in a minority of diabetes patients.
References
- American Diabetes Association; The Balanced Diet; May 2011
- "Diabetes Care"; Primary Prevention of Cardiovascular Diseases in People With Diabetes Mellitus; John Buse, et al.; January 2007
- "The American Journal of Clinical Nutrition"; Effects of N-3 Fatty Acids in Subjects With Type 2 Diabetes: Reduction of Insulin Sensitivity and Time-Dependent Alteration From Carbohydrate to Fat Oxidation; Ingrid Mostad, et al.; September 2006
- "Journal of Clinical Nutrition"; Dietary Omega-3 Fatty Acids and Fish Consumption and Risk of Type 2 Diabetes; Luc Djoussi, et al.; January 2011
- "Diabetes Care"; N-3 Fatty Acids in the Treatment of Diabetic Patients Biological Rationale and Clinical Data; Raffaele De Caterina, et al.; April 2007
Member Comments