A small NIH-funded study of 70 people with mild cognitive impairment found that a home device delivering customized odors for 45 minutes daily improved cognitive test scores and increased gray matter volume in brain regions affected early by Alzheimer's. The results are preliminary and the researchers emphasize the need for larger studies to confirm whether this olfactory training actually slows cognitive decline. This is one potential non-drug approach being explored for early-stage memory problems, though it's still years away from clinical use.