19/10/2025
Rose oil costs a small fortune, but the rest of the oils on this list are quite reasonable.
Did you know that research suggests that deterioration of olfaction (sense of smell) precedes a decline in cognitive abilities? Indeed, olfactory loss is associated with significant losses of brain matter (gray and white) in humans. Loss of olfaction can even predict the progression of mild cognitive impairment to Alzheimer's disease.
Knowing the correlation between olfaction and cognition, researchers set out to investigate whether olfactory enrichment (exposure to fragrances) can improve memory in older adults (aged 60-85). Participants in the study were provided a diffuser and seven essential oils (rose, orange, eucalyptus, lemon, peppermint, rosemary, and lavender). They diffused each oil in a rotation--changing the oil they diffused daily--for two hours as they slept. This process was continued for six months.
The researchers found that aromatic molecules have privileged access to areas of the brain and pathways relevant to olfaction and memory, which may help normalize brain circuitry linked to memory. Remarkably, nightly diffusion improved cognition, memory, and neural functioning by 226%!
https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2023.1200448/full