Do Not Fade Away

A maverick new germ theory could help keep your ageing mind intact.

- Jeff Bercovici

IN JULY 2000, as the World Alzheimer Congress convened in Washington, DC, there was a moment – a “dawning sense that scientists could be on the verge of stemming the epidemic,” Time magazine put it – when a treatment for the disease seemed imminent. Science was pouring minds and money into solving this devastating problem that creates total neurological meltdown and can break apart and bankrupt families.

Spoiler alert: nope. Almost two decades later, the heartbreaking and costly illness first identified by Alois Alzheimer in 1906 is more prevalent than ever. According to Alzheimer's South Africa, approximately 750 000 South Africans have the disease. While Alzheimer’s often doesn’t show up in a tangible way until your 70s or later, the brain changes associated with it begin decades earlier. The surge of money that inspired that optimism has failed to produce a drug that brings anything more than a modest, temporary improvement in symptoms once they show up – if that.

The dearth of progress has some researchers rethinking everything they’ve been taught about what Alzheimer’s disease is and how it works. Although the ranks of these scientists are small, the idea uniting them is a big one: that Alzheimer’s is caused by germs. And not some exotic new germs, but the same microscopic organisms that cause things such as gum disease and cold sores. Most brains accumulate pathogens as they age – blood vessels become leakier, making the blood-brain barrier more porous. These scientists think some of the germs that infiltrate the brain may be the instigators of the changes that become Alzheimer’s.