In a new study entitled “Effects of Omega-3 Fatty Acid Supplementation on Glucose Control and Lipid Levels in Type 2 Diabetes: A Meta-Analysis”, researchers performed a systematic analysis of randomized clinical trials to investigate the potential therapeutic benefits of omega-3 fatty acids in patients with type 2 diabetes. The study was published in the open-access journal PLOS One.
Type 2 diabetes prevalence is increasing throughout the world with life-style, particularly diet, pointed to as the key driver for the development of the disorder – a condition characterized by hyperglycemia (high blood glucose) as a result of insulin resistance and beta-cells (unique cells in the pancreas that produce, store and release the hormone insulin) dysfunction.
High fish and seafood consumption was reported to reduce the incidence of type 2 diabetes in the Finnish population, with researchers attributing this effect to omega 3 fatty acids – particularly the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), a group belonging to polyunsaturated fatty acids, PUFAs). Recently, however, other studies have reported opposite results, thus challenging the suggested benefits of omega-3 for type 2 diabetes patients.
Here, the authors performed a systematic analysis of published randomized clinical trials to evaluate the evidences for omega-3 benefits in patients with type 2 diabetes and which dosages might have a therapeutic effect. To this end, the team searched the Medline, Pubmed, Cochrane Library, Embase, the National Research Register, and SIGLE databases for trials reporting on omega-3 and type 2 diabetes.
The team included 20 randomized clinical trials in their analysis. They observed that patients in an omega-3 supplementation diet exhibited significantly decreased levels of triglycerides (a type of fat found in the blood). No alterations, however, were registered for a series of parameters including, blood total cholesterol, glycated hemoglobin (HbA1c, a form of hemoglobin that is measured with the objective of identifying the average blood glucose concentration over prolonged periods of time), fasting plasma glucose, postprandial plasma glucose, body mass index and body weight. Thus, while a high ratio of the omega-3 fatty acids EPA/DHA was associated with a decreasing tendency for the aforementioned parameters, the team identified no significant clinical outcome (except for triglycerides). The team postulates that the small sample size, limited study number, and short trial duration may account for the lack of statistical significance.
In sum, the authors highlight that the ratio of EPA/DHA and early intervention with omega-3 fatty acids are potential parameters for clinicians and nutritionists when considering dietary interventions in diabetic patients.