The effects of spirulina intake on clinical and metabolic parameters in Alzheimer's disease: A randomized, double‐blind, controlled trial

The current study aimed to determine the effects of spirulina intake on cognitive function and metabolic status among patients with Alzheimer's disease (AD). This randomized, double-blind, controlled clinical trial was done among 60 subjects with AD. Patients were randomly assigned to receive either 500 mg/day spirulina or a placebo (each n = 30) twice a day for 12 weeks. Mini-mental state examination score (MMSE) was recorded in all patients before and after intervention. Blood samples were obtained at baseline and after 12 weeks' intervention to determine metabolic markers. Compared with placebo, spirulina intake resulted in a significant improvement in MMSE score (spirulina group: +0.30 ± 0.99 vs. Placebo group: -0.38 ± 1.06, respectively, p = 0.01). In addition, spirulina intake decreased high-sensitivity C-reactive protein (hs-CRP) (spirulina group: -0.17 ± 0.29 vs. Placebo group: +0.05 ± 0.27 mg/L, p = 0.006), fasting glucose (spirulina group: -4.56 ± 7.93 vs. Placebo group: +0.80 ± 2.95 mg/dL, p = 0.002), insulin (spirulina group: -0.37 ± 0.62 vs. Placebo group: +0.12 ± 0.40 μIU/mL, p = 0.001) and insulin resistance (spirulina group: -0.08 ± 0.13 vs. Placebo group: 0.03 ± 0.08, p = 0.001), and increased insulin sensitivity (spirulina group: +0.003 ± 0.005 vs. Placebo group: -0.001 ± 0.003, p = 0.003) compared with the placebo. Overall, our study showed that spirulina intake for 12 weeks in patients with AD improved cognitive function, glucose homeostasis parameters, and hs-CRP levels.