Omega-3 PUFA supplementation provides beneficial effects on cardiometabolic markers and glycaemic control in diabetes mellitus type 2
Cardiovascular disease is the main cause of morbidity and mortality in people with diabetes mellitus type 2 (DMT2) and glycaemic control, the key objective in antidiabetic control, only has a marginal effect on cardiovascular risk. However, correcting cardiometabolic parameters (e.g. lipid parameters, inflammation markers and blood pressure) has been shown to provide significant reductions in cardiovascular risk and mortality in DMT2. These factors are susceptible to modification through diet and controlled randomised trials indicate that supplementation with omega-3 polyunsaturated fatty acids (PUFAs) can favourably modify cardiometabolic markers in DMT2.
With the aim of assessing the effect of omega-3 PUFA on cardiometabolic markers and glycaemic control rates in people with DMT2 and identifying how dose and duration of treatment (or the interaction between them) modify these effects, a meta-analysis was conducted that included controlled, randomised trials investigating these aspects, published in PubMed and MEDLINE up to 13 July 2017. A total of 45 studies were selected, with a total of 2,674 participants with DMT2.
The joint meta-analysis showed that supplementation with omega-3 PUFA was significantly related to reductions in low-density lipoproteins (p = 0.007), very-low-density lipoproteins (p = 0.044), triglycerides (p ≤ 0.001) and glycosylated haemoglobin(p = 0.010). Furthermore, supplementation with omega-3 PUFA was associated with a reduction in plasma levels of tumour necrosis factor-α (P = 0.045) and interleukin-6 (p = 0.026). No changes were observed in other lipid markers, glycaemic control rates, inflammation markers or blood pressure.
The authors of the meta-analysis concluded that supplementation with omega-3 PUFA produces favourable hypolipidaemic effects, reduces levels of proinflammatory cytokines and improves glycaemia. Neither the duration of treatment nor the dose seem to explain the heterogeneity of the response to supplementation.