Fish oil doesn't directly affect blood sugar levels. However, blood sugar, referred to as blood glucose, changes into other substances during the metabolic process, and the essential fatty acids in fish oil alter how these post-glucose products metabolize. Fish oil reduces the level of the potentially harmful glucose metabolite called triglycerides.
Blood Glucose
During digestion, sugars and carbohydrates transform into glucose, which your intestines absorb and release into the blood stream. As your blood glucose levels rise after eating, your pancreas detects the increase and releases insulin, which attaches to cells throughout your body. The insulin activates other receptors on the cells that allow glucose to enter them, where it is broken down for cellular energy.
Energy Transformation and Storage
Insulin transforms excess glucose not needed by the cells into glycogen, a form of fat, for future energy use. The glycogen stores in your liver and muscles. As your glycogen stores fill, remaining excess glucose converts into triglycerides, another form of fat, and stores in fat cells under your skin and in a sheath attached to your stomach called the omentum. So, the calories you consume change to glucose, which then converts directly into energy or into fat in the form of glycogen or triglycerides.
Triglycerides and Health
High levels of triglycerides pose a significant health risk when stored as fat in the omentum and especially when circulating in the bloodstream. High triglycerides occur with various conditions that increase the risk of cardiovascular disease and stroke, including obesity, metabolic syndrome, high blood pressure, abnormal cholesterol levels and high blood sugar. Excessive weight, diet and exercise all influence triglyceride levels.
Fish Oil, Glucose and Triglycerides
Supplementation with fish oil usually does not significantly increase or decrease blood sugar levels in most people. However, it lowers triglyceride levels by almost 30 percent, according to a statistical analysis of 26 different studies, reported in 1998 in "Diabetes Care." The omega-3 fatty acids in fish oil can also increase the good HDL cholesterol, according to MayoClinic.com. Some people with type 2 diabetes do have slight increases in fasting blood sugar when they take fish oil, especially if they also take medications that regulate blood sugar, according to a research review published in 2004 in the "Journal of Applied Nutrition."
Dosage
The Medline Plus website, sponsored by the National Institutes of Health, recommends supplementing with 1 to 4 g of fish oil daily to reduce triglycerides. Fish oil can interact with certain medications and medical conditions, so consult with your doctor before taking it.
References
- American Diabetes Association; Fish Oil and Glycemic Control in Diabetes: A meta-analysis; Cylla Friedberg, et. al.; April 1998
- "Diabetes Care"; Moderate Intake of n-3 Fatty Acids for 2 Months Has no Detrimental Effect on Glucose Metabolism and Could Ameliorate the Lipid Profile in Type 2 Diabetic Men. Results of a Controlled Study; J Luo, et al.; May 1998
- "Journal of Applied Nutrition"; Fish Oil Supplementation in People with Diabetes: A Review of the Research; Gretchen Vannice, et al.; 2004
- MedBio.info: Insulin and Glucagon
- Oregon State University: Glycogen Metabolism Notes; Kevin Ahern
- "Pathophysiology: The Biologic Basis for Disease in Adults and Children," Sixth Edition; Kathryn L McCance, et al.; 2010
