What clinical trials have tested honey or cinnamon for cognitive decline in adults?

1. Cinnamon: a mountain of lab work but only a few human blips

Lab and animal studies of cinnamon and cinnamon components (cinnamaldehyde, cinnamic acid, eugenol) dominate the literature and commonly report beneficial effects on learning, memory, oxidative stress and amyloid/tau pathology, but human data are sparse and inconsistent: a 2023 systematic review counted 40 studies meeting inclusion criteria — 33 in vivo, five in vitro and just two clinical studies — and concluded that most non‑human work showed positive effects while the two clinical trials gave mixed results (one positive, one null) ^{[1] [6] [7]}.

2. The two human cinnamon trials: one adolescent gum study, one oral dose in adults — very different designs, very different outcomes

The systematic review and coverage in mainstream outlets make clear the two clinical studies were heterogeneous: one trial examined cinnamon chewing gum used for 40 consecutive days in adolescents and reported improvements in memory and reduced anxiety, while the other administered cinnamon orally as a single dose (2 g) in a cohort described as pre‑diabetic adults up to age 60 and found no significant memory changes — neither trial was designed to test dementia, MCI, or progressive cognitive decline in older adults ^{[2] [3] [1]}.

3. Major Alzheimer’s research resource flags “no clinical trials” for cognition — an apparent discrepancy

The Alzheimer’s Drug Discovery Foundation’s Cognitive Vitality resource reports that their search found zero clinical trials in humans investigating cinnamon’s effects on cognitive function or cognitive decline, highlighting the gap between abundant preclinical work and clinical evidence for dementia or MCI; this appears at odds with systematic‑review counts that included two small clinical studies, reflecting differences in inclusion criteria (age groups, endpoints, or publication coverage) and underscoring uncertainty about whether any human trials targeted cognitive decline in older adults or clinical dementia ^{[5] [1]}.

4. Honey: promising in animals, absent in human trials

A recent review of honey and Alzheimer’s disease summarized 27 preclinical studies showing that honey’s phytochemicals can counter oxidative stress, inflammation and amyloid aggregation in lab and animal models, but the authors explicitly report that no human clinical trials exist testing honey for cognitive protection or treatment of Alzheimer’s or MCI, leaving a complete human‑evidence gap for honey ^[4].

5. Safety, dosing and why small human studies don’t translate to dementia care

Even where cinnamon has been tested clinically for metabolic outcomes, doses and cinnamon species vary (cassia versus Ceylon), and cassia contains coumarin that can cause liver toxicity with prolonged high intake; short trials have tested up to 6 g/day without serious events, but experts caution against long‑term high doses and stress that metabolic benefits do not equal evidence of dementia prevention or treatment ^{[5] [8]}.

6. Bottom line and the research agenda

There are no well‑powered randomized controlled trials testing honey for cognitive decline in adults and only two small, methodologically heterogeneous human cinnamon studies (one adolescent gum study, one single‑dose adult study) with mixed results; no clinical trial to date demonstrates benefit for dementia or MCI in older adults, and major reviewers call explicitly for larger, targeted RCTs to establish efficacy, dose, safety and mechanisms before clinical recommendations can be made ^{[1] [2] [4] [5]}.