Can Omega-3 Supplements Trigger Diabetes?
What is your opinion about taking a liquid omega-3 fish oil supplement? My husband started taking one and loves it, but last year his blood tests showed that he might be on the verge of developing diabetes. I was wondering if he should stop taking fish oil, and if it could have caused the problem? Name Withheld
Christy L. Parkin, MSN, RN, CDE, responds: There is no evidence that taking fish oil supplements leads to diabetes; in fact, numerous studies demonstrate the valuable benefits of omega-3 fatty acids, which are substances that the body needs but cannot produce on its own.
A great source of omega-3s is fish oil, which is extracted from cold-water fish such as salmon, mackerel, herring, and cod. One benefit of fish oil is improved cardiovascular health. Omega-3s reduce the risk for developing coronary heart disease. Their potent anti-inflammatory properties may not only help the heart but also ease symptoms of rheumatoid arthritis, Crohn's disease, and inflammatory bowel disease. In addition, fish oil is used to treat depression, bipolar disorder, postpartum depression, anxiety, and schizophrenia. The Alzheimer's Association recommends eating fish to protect against dementia.
So far, scientific evidence suggests that there are no significant long-term negative effects of fish oil in people with diabetes, including no changes in A1C levels, according to a Mayo Clinic report. However, some precautions should be taken when it comes to fish oil supplements. You should buy a pharmaceutical-grade, purified supplement to help guard against potentially harmful contaminants found in some species of fish. Problems with contaminants tend to arise when eating fish, not when taking supplements.
Other risks apply to specific groups of people. Young children and pregnant or nursing women should avoid the heavy metals that are found in some fish. High doses of omega-3 fatty acids may also increase the risk for bleeding.
Fish oil supplements often cause gastrointestinal upset, and diarrhea may occur, especially with very high doses. The supplements can also have a fishy aftertaste and increase burping, acid reflux, heartburn, and indigestion. You can minimize these side effects by taking the supplement with meals and starting with smaller doses.
According to the Food and Drug Administration, most people can safely take up to 3 grams (3,000 mg) per day of omega-3 fatty acids. Young children, pregnant and nursing women, people who are at risk for bleeding, and those who have high levels of LDL ("bad") cholesterol may need to limit their intake of omega-3s in consultation with their doctor or dietitian.