Intranasal insulin, the nasal spray treatment used for the management of Type 1 diabetes, might be beneficial for boosting cognition in people with mild cognitive impairment or Alzheimer's, a recent study has found.

The researchers conducted a meta-analysis of 29 studies involving 1,726 participants to examine the effect of intranasal insulin on cognitive function. There were participants with different disorders--including mental health conditions like schizophrenia, bipolar disorders, and major depressive disorders--Alzheimer's disease, mild cognitive impairment, and metabolic disorders, such as diabetes.

The study did not find any significant difference in the cognitive function of people with mental health disorders, metabolic disorders, and other disorders, after they used intranasal insulin. However, Alzheimer's patients and people with mild cognitive impairment showed significant improvement with the nasal spray treatment.

How is insulin connected to cognitive ability?

Researchers believe that certain memory centers in the brain when faulty cannot process sugar, leading to insulin resistance and cognitive deficits. When insulin therapy is used, they help recover the faulty memory centers in the brain that are also involved in learning and memory.

"Patients with Alzheimer's could have impaired glucose processing in the hippocampus (an area of the brain involved in human learning and memory). Intranasal insulin may help with this and improve cognition," Dr. Gayatri Devi, a neurologist at Northwell Lenox Hill Hospital in New York who was not involved in the study, told Medical News Today.

Possible side effects of the nasal spray

  • Hypoglycemia, which could lead to serious conditions such as heart attacks and stroke
  • Nasal irritation or rhinitis
  • Dizziness and nausea
  • Nose bleeds

Although the repurposing of intranasal spray has been appreciated, some experts raised their concerns about the safety of using the medication in people without diabetes.

"I find it scary to give insulin to someone without an indication of diabetes. There is a risk of hypoglycemia when you give insulin to someone who does not have diabetes. This can increase their risk of heart attack or stroke," Dr. Clifford Segil, a neurologist at Providence Saint John's Health Center in California who was not involved in the study, told Medical News Today.