The Role of Fish Oil and DASH Diet in Lipid Metabolism and Inflammation In Patients with T2D

Consumption of fish oil plus DASH diet is associated with a partial alteration in lipid metabolism and inflammatory mediators in patients with type 2 diabetes. 

With nearly 400 million adults living with diabetes worldwide, the global disease burden is expected to increase to about 600 million by 2035, with an estimated 260 billion USD cost to diabetes healthcare in North America and the Caribbean. Therefore, investment in effective prevention and management measures has become critical. Nutritional strategies and lifestyle changes have become an integral element of therapy for people with diabetes. Total fat intake has been shown to contribute to diabetes by promoting weight gain and insulin resistance. However, several metabolic studies have shown that the intake of plant-based fats, especially omega-6 polyunsaturated fatty acids (PUFA), was associated with a lower risk of developing diabetes.  

A recent randomized controlled trial investigated the effects of dietary approaches to stop hypertension (DASH) diet and omega-3 fatty acid on lipid metabolism in patients with type 2 diabetes (T2D). DASH diet originated in 1992 based on the funding of several research projects designed for hypertension intervention by the National Institute of Health (NIH). DASH promotes minimally processed and fresh food consumption and includes 2 to 5 servings per day of fruits, vegetables, carbohydrates, low-fat dairy products, lean meat products, nuts, and seeds. For people with T2D, a DASH diet with two 400mg/d sodium restrictions has been shown to have beneficial effects on glycemic control and CVD risk factors.  

Omega-3 PUFAs are essential dietary elements found in fish like sardines and salmon and nut oils. They are fatty with more than one carbon-carbon double bond in their backbone and are essential for everyday health, especially brain development and other cellular functions. They are an integral part of the membrane phospholipids and are involved in many cellular functions. A large body of evidence from experimental, clinical, and epidemiologic research reported on the role of long-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid [DHA] in mitigating the significant risk factors of metabolic syndrome, especially adiposity, dyslipidemia, insulin resistance and diabetes, hypertension, oxidative stress, and inflammation. 

The study included 32 patients with T2D randomized into two parallel groups; placebo (n = 15) and treatment group that consumed six capsules of 1000mg EPA/DHA per day (n = 17). The results showed significant differences in body weight, body mass index, blood pressure, interleukin-6, and tumor necrosis factor-α in both groups. However, triglyceride (TG) levels and VLDL cholesterol showed a significant decrease in the fish oil groups (p < 0.05) only. Fasting glucose, fasting insulin, HOMA of insulin resistance levels, HBA1c, total LD and HDL cholesterol, adiponectin and leptin (5.53% and 6.48% respectively, and the effect on glycemic control and body weight) were not statistically significant across the groups.  

The study concluded that consuming fish oil plus DASH diet is associated with a partial alteration in lipid metabolism and inflammatory mediators in patients with T2D. However, additional studies on various dietary considerations in the development and prevention of diabetes are needed to examine the synergistic effects of individual elements of various dietary patterns and understand the physiological mechanisms underlying the observed associations. 

 Practice Pearls: 

• Long-chain omega-3 fatty acids play an essential role in mitigating the risk factors associated with metabolic syndrome. 
• Consumption of fish oil plus DASH diet is associated with a partial alteration in lipid metabolism and inflammatory mediators in patients with type 2 diabetes.
• Further studies are needed to investigate the role of various dietary considerations in the development of diabetes. 

Ali, F., Saleh, M., & Al-Junaid, A. “Omega-3 Fatty Acids intervention and DASH Diet Ameliorates Metabolic profiling in Patients with Diabetes Mellitus Type 2.” The Metabolic Institute of America (TMIOA) 2021 World Congress Insulin Resistance Diabetes & Cardiovascular Disease. December 6, 2021  

Ley, Sylvia H et al. “Prevention and management of type 2 diabetes: dietary components and nutritional strategies.” Lancet (London, England) vol. 383,9933 (2014): 1999-2007. doi:10.1016/S0140-6736(14)60613-9 

Gammone, Maria Alessandra et al. “Omega-3 Polyunsaturated Fatty Acids: Benefits and Endpoints in Sport.” Nutrients vol. 11,1 46. 27 Dec. 2018, doi:10.3390/nu11010046 

Elmoataz Elmamoun, PharmD Candidate, 2022, South College School of Pharmacy