APOE4 germane section:
In March, Dr. Dubal and her colleagues published a study suggesting that Klotho may also provide some protection from Alzheimer’s disease to people as well.
One of the biggest risk factors for Alzheimer’s disease is a genetic variant called APOE e4. Inheriting two copies of the gene can increase the risk more than eightfold.
Dr. Dubal and her colleagues found that many people with APOE e4 appeared to be on their way to Alzheimer’s disease even if they had no sign of dementia yet. They had markers indicating a buildup of clumps in their brains.
Then Dr. Dubal and her colleagues looked at the people with both APOE e4 and extra Klotho. They had no extra clumps.
It’s possible that in these people Klotho is slowing the effects of carrying APOE e4, Dr. Dubal speculated. “Maybe their brains are biologically younger,” she said.
A few other research groups have also found promising results in people, but all of the studies — Dr. Dubal’s included — are small.
Dr. King doesn’t dispute the remarkable results of the Klotho experiments. It’s just that researchers can’t account for them.
When Dr. Dubal injects Klotho into mice, for example, the hormone doesn’t actually get into the brain. It must trigger some series of reactions in the body — but no one can say what they are.