Ruth Itzhaki, a research scientist at the University of Oxford, stirred curiosity in the 1990s when she shared evidence tying Alzheimer’s to herpesvirus — a scourge spread by oral or genital contact and often resulting in painful infections. For years, powerful promoters of the amyloid hypothesis ignored or dismissed the infection hypothesis for Alzheimer’s, effectively rendering it invisible, Dr. Itzhaki said with exasperation. Research suggests that viruses may hide undetected in organs, including the brain, for years, causing symptoms divergent from the original infection.
But her ideas might finally be catching on. Nearly 5,000 papers have been written about infections and Alzheimer’s since Dr. Itzhaki began her work. National Institutes of Health funding intended in part to examine such links jumped from a few million dollars to nearly $250 million annually in 2023. A clinical trial treating latent herpes among Alzheimer’s patients with an antiviral drug is underway, and results are expected as soon as next year.
None of us can stop growing older or change our genes. But risk factors like diabetes, high blood pressure and cholesterol, obesity, depression, hearing loss, sedentary lifestyles, poor diets and racial discrimination can be targeted. Miguel Arce Rentería, a neuropsychologist at Columbia University, argues that more accessible treatment that also addresses social issues may stave off the worst of Alzheimer’s for years. Although a vast majority of research seeks an elusive remedy, the mood is shifting. Federal funding for studying care and prevention, like some of Dr. Arce Rentería’s research, has recently risen.
Sometimes a disease stems from a single clear-cut origin, such as genetic mutations that cause deadly sickle cell disease. “But very few diseases of aging have just one cause. It’s just not logical,” said Dr. Matthew Schrag, a neurologist at Vanderbilt University Medical Center. Working independently of his university, he discovered the 2006 research image manipulations.
Like most amyloid skeptics, Dr. Schrag agrees that amyloid-beta proteins play a role in the complex mystery of Alzheimer’s, but they’re not the singular key to a cure that so many scientists imagine. If there was a universal source for Alzheimer’s it would show up earlier in life, and be more evident in everyone who suffers from the disease.
