A study found that a nasal spray containing an artificial form of insulin may improve memory and cognitive abilities in people with mild cognitive impairment or Alzheimer's disease. The study of 60 participants found that those receiving 40 international unit doses of the insulin detemir nasal spray for 21 days showed significantly better short-term memory and processing abilities than those receiving lower doses or a placebo. Specifically, those with the APOE-e4 gene who are at higher risk of Alzheimer's saw greater benefits from the higher dosage, while lower-risk participants saw fewer effects overall. This suggests nasally administered insulin may help treat cognitive decline, building on previous promising trials.