Background: Functional food ingredients, such as dietary fiber, long-chain polyunsaturated fatty acids, and high-quality protein, have been shown to help control blood glucose concentration and lower high blood pressure (BP), as well as improving other cardiovascular disease risk factors. However, little research has assessed the impacts of consuming chia seeds, which are rich in these nutrients, on metabolic and physiological outcomes, and results are conflicting. Aim: The study aimed to investigate the possible effects of chia seeds on fasting blood glucose, insulin, glycated hemoglobin, BP, lipid profile, body weight, and the inflammatory marker – high-sensitivity C-reactive protein – in people with type 2 diabetes (T2DM). Methods: Adults with T2DM ( n = 42) were randomly assigned equally to the chia seed group, which consumed 40 g/day chia seeds for 12 weeks, or a control group, which did not consume any supplement. Blood samples were collected at baseline and after a 12-week intervention period to assess the study outcomes, such as glycemic control, BP, cardiovascular risk parameters including lipid profile, inflammatory marker, and body weight. Results: Adjusted for gender and baseline values, the chia seed group had systolic BP (SBP) significantly reduced compared to control [ t (1) = 2.867, p = 0.007, η 2 p = 0.174]. No differences were observed in any other parameter tested in the chia seed or control group. Conclusions: People with T2DM and hypertension, maintaining usual dietary consumption, physical activity pattern, and medications, had significantly reduced SBP compared to the control group when having consumed 40 g/d of chia seeds for 12 weeks.
