What is known:  Herbal medicines have been used in the treatment of behavioural and psychological symptoms of dementia but with variable response. Crocus sativus (saffron) may inhibit the aggregation and deposition of amyloid β in the human brain and may therefore be useful in Alzheimer’s disease (AD).

Objective:  The goal of this study was to assess the efficacy of saffron in the treatment of mild to moderate AD.

Methods:  Forty‐six patients with probable AD were screened for a 16‐week, double‐blind study of parallel groups of patients with mild to moderate AD. The psychometric measures, which included AD assessment scale‐cognitive subscale (ADAS‐cog), and clinical dementia rating scale‐sums of boxes, were performed to monitor the global cognitive and clinical profiles of the patients. Patients were randomly assigned to receive capsule saffron 30 mg/day (15 mg twice per day) (Group A) or capsule placebo (two capsules per day) for a 16‐week study.

Results:  After 16 weeks, saffron produced a significantly better outcome on cognitive function than placebo (ADAS‐cog: F = 4·12, d.f. = 1, P = 0·04; CDR: F = 4·12, d.f. = 1, P = 0·04). There were no significant differences in the two groups in terms of observed adverse events.

What is new and conclusion:  This double‐blind, placebo‐controlled study suggests that at least in the short‐term, saffron is both safe and effective in mild to moderate AD. Larger confirmatory randomized controlled trials are called for.