Have scientists found the cause of Alzheimer's?

Researchers in California may have found the molecular-level cause for Alzheimer’s disease after exploring the DNA tangles in the brains of dementia patients.

A recently published study from the University of California – Riverside (UCR) studied the different forms taken by tau proteins and identified key differences between individuals suffering from dementia and those unaffected by the disease, The Hill reported.

Typically, patients are diagnosed with Alzheimer’s or dementia if doctors find both brain plaques and tangles inside the brain’s grey matter cells. However, after researchers at UCR discovered that one-fifth of individuals with brain plaques do not suffer from dementia, they decided to take a closer look at what role tau proteins play in the development of the disease.

The study analyzed donated brain samples and ultimately found that brains with plaques or tangles – but no dementia – had a normal form of the tau protein. However, those with a “different-handed” form of tau that developed plaques or tangles did ultimately have dementia.

“Roughly 20% of people have the plaques, but no signs of dementia. This makes it seem as though the plaques themselves are not the cause,” said Ryan Julian, a chemistry professor at UCR in a press release.

According to Julian, the amino acids that make up the tau protein can either be right or left handed isomers, but the proteins in living things are normally made up from left-handed amino acids. However, if proteins remain in the body for too long, certain amino acids can convert into the “other-handed” isomer, leading to serious health issues for humans.

“If you try to put a right-handed glove on your left hand, it doesn’t work too well. It’s a similar problem in biology; molecules don’t work the way they’re supposed to after a while because a left-handed glove can actually convert into a right-handed glove that doesn’t fit,” said Julian.

Although the human body usually mitigates this mutation through a process called autophagy, which clears spent or defective proteins from cells, autophagy slows down as people age.

Drugs currently are being tested to improve the body’s process of autophagy, but UCR researchers report that the process can also be induced naturally by fasting or exercise.

But Julian offered some optimistic news regarding the connection between autophagy and the development of Alzheimer's. "If a slowdown in autophagy is the underlying cause, things that increase it should have the beneficial, opposite effect.”