by Carole Jackson, Bottom Line Health
Tell someone with Alzheimerâs disease about your day and heâs likely to forget what you said hours — if not minutes — later. This is the sad and frustrating state of affairs that is affecting many families now, since more than five million Americans have Alzheimerâs. Though there are some treatment options out there, there is no known cure and there are no effective ways to prevent it or delay its progression. So I was intrigued to read a new study that found promise in a simple intervention — a few squirts of insulin up the nose appeared to stop memory loss in its tracks.
I called the studyâs lead researcher Suzanne Craft, PhD, a psychiatry professor at the University of Washington and director of the Memory Disorders Clinic at the VA Puget Sound Health Care System — both in Seattle — to learn more. The study was published in the September 12, 2011 issue of Archives of Neurology.
Dr. Craft and her colleagues studied 104 men and women ages 55 to 85 with mild-to-moderate-stage Alzheimerâs or amnestic mild cognitive impairment (often a precursor to the disease) and split them into three groups — one group was given a moderate dose of aerosolized intranasal insulin (20 IU)… another group was given a double dose of insulin (40 IU)… and the third group was given a placebo (a saline nasal spray). The doses were administered twice a day (after breakfast and dinner) using 90-second inhalations for four months. Participants used a special device that shoots the spray deep into the nose, delivering it directly to the nerves that lead to the brain. It may sound unpleasant, but Dr. Craft says that the treatment didnât bother any patients.
Both before beginning treatment and after four months of the treatment, participants had a story read out loud to them that contained 44 bits of information. Twenty minutes after hearing the story, patients were given a recall test. On the second recall test, after four months of the treatment, those who had been given the moderate insulin dose of 20 IU performed 25% better than the placebo group, while the group that got the double dose of insulin didnât show any increase in recall memory.
So how come sniffing a moderate amount of insulin seemed to help? The brains of people with Alzheimerâs either lack normal levels of insulin or are unable to metabolize the amounts of insulin that are present, said Dr. Craft. This is important because the brain needs glucose to function, and effective insulin metabolism is necessary for the brain to use glucose. (This is why past studies have shown an associative link between insulin-related health conditions, such as diabetes, and Alzheimerâs.) So Dr. Craft thought that administering the right amount of insulin directly to the brain — not too much, not too little and not to the entire body, which could be dangerous — might improve memory. And it looks like she and her colleagues are on to something.
THE SILVER BULLET?
This isnât the first study to suggest that insulin might be a helpful therapy for Alzheimerâs patients — I first wrote about this in 2007 (see Daily Health News, May 17, 2007). And Dr. Craft told me that many other researchers are exploring this connection, too. Could this be the treatment for Alzheimerâs that everyone has been waiting for, something that could help stave off its worst effects while scientists continue to seek a cure? Maybe in a few years, but Dr. Craft said that long-term studies that confirm the results and ensure safety will have to be done first. Sheâs cautiously optimistic.
Suzanne Craft, PhD, director, Memory Disorders Clinic, Veterans Affairs Puget Sound Health Care System, professor of psychiatry and behavioral sciences, University of Washington, Seattle.