Long-acting insulin administered via the nose may help some people with memory loss, according to a pilot study.
Researchers randomly assigned 60 people with mild cognitive impairment (MCI) or mild to moderate Alzheimer’s disease to get either a placebo or one of two intranasal doses (20 or 40 IU a day) of a long-acting type of insulin (insulin detemir).
After three weeks, only those who got the higher dose scored better on a composite of several memory tests asking them to recall a list of words or a story immediately or after 20 minutes.
But when the researchers dug deeper into the data, they found that insulin only helped people on the higher dose if they had APOE-4 (a common variation of a gene that boosts the risk of dementia). Those without APOE-4 did worse after taking insulin.
What’s more, people with APOE-4 who got the higher dose of insulin had less insulin resistance—that is, their body’s insulin was more effective—than if they got a placebo. In contrast, people without APOE-4 who took the higher dose of insulin had more insulin resistance.
What to do: It’s too early to know if intranasal insulin can improve memory in people with—or at risk for—Alzheimer’s. In the meantime, protect your brain with exercise and by keeping your blood sugar and blood pressure under control. (See Nutrition Action Healthletter, Jan./Feb. 2014, cover story.)