Can you outrun DEMENTIA? Exercise-induced hormone reduces Alzheimer’s plaque in lab

Australia
By William
  • A hormone called irisin released during exercise reduces plaques in the brain
  • It causes higher levels of the neprilysin enzyme, which removes amyloid beta
  • READ MORE: Scientists launch studies into whether Ozempic can treat dementia

By Caitlin Tilley, health reporter for Dailymail.Com

Published: | Updated:

The reason why exercise can prevent Alzheimer’s disease has been discovered and could lead to new treatments for the incurable condition.

Experts have shown that a hormone called irisin, released during exercise, removes plaques in the brain linked to memory-robbing disorder.

In a laboratory study, amyloid beta proteins exposed to irisin showed a “remarkable reduction.”

Exercise has been shown to reduce amyloid beta deposits in several mouse models, but the mechanisms involved have remained a mystery.

Now the study, published in the journal neuronsolves the puzzle and promises new ways to prevent or cure the condition.

Experts have found that a hormone called irisin released during exercise reduces the plaques and tangles in the brain that are thought to cause Alzheimer’s disease.

For example, the researchers said it could boost new potential treatments, such as irisin injected into the bloodstream.

Lead author of the study Dr. Se Hoon Choi, assistant professor of neurology at Massachusetts General Hospital (MGH), said: ‘First, we found that treatment with irisin led to a remarkable reduction in amyloid beta pathology.

‘Second, we have shown that this effect of irisin can be attributed to increased neprilysin activity due to increased levels of neprilysin secreted by cells in the brain called astrocytes.’

The team had previously developed the first 3D model of Alzheimer’s disease: a system of cells built in a laboratory to represent a human brain with the condition.

It had the two main hallmarks of the condition: amyloid beta deposits and tau tangles in the brain.

It was already known that exercise causes the muscles to release irisin, increasing its concentrations in the body.

It improves muscle activity, increasing the amount of energy the muscles can use.

The team applied the hormone to their 3D model of an Alzheimer’s disease human brain.

Neprilysin is an amyloid beta-degrading enzyme found in the brains of mice designed for exercise.

Previous studies have shown that irisin, injected into the bloodstream, can reach the brain in mice, making it potentially useful as a therapeutic agent.

Dr. Rudolph Tanzi, senior author of the study and director of the Genetics and Aging Research Unit at MGH, said: ‘Our findings indicate that irisin is an important mediator of exercise-induced increases in neprilysin levels, leading to reduced amyloid beta burden, indicating a new target route for therapies aimed at the prevention and treatment of Alzheimer’s disease.’

What is Alzheimer’s disease and how is it treated?

Alzheimer’s disease is a progressive, degenerative disease of the brain in which the buildup of abnormal proteins causes nerve cells to die.

This disrupts the transmitters that transmit messages and causes the brain to shrink.

More than 5 million people suffer from the disease in the US, where it is the sixth leading cause of death, and more than 1 million Britons have the disease.

WHAT IS HAPPENING?

As brain cells die, the functions they provide are lost.

That includes memory, orientation and the ability to think and reason.

The progression of the disease is slow and gradual.

On average, patients live five to seven years after diagnosis, but some can live another ten to fifteen years.

EARLY SYMPTOMS:

  • Loss of short-term memory
  • Disorientation
  • Behavioral changes
  • Mood swings
  • Problems handling money or making a phone call

LATER SYMPTOMS:

  • Severe memory loss, forgetting close relatives, familiar objects or places
  • Becoming anxious and frustrated about the inability to understand the world, leading to aggressive behavior
  • Eventually you lose the ability to walk
  • May have problems eating
  • The majority will ultimately require 24-hour care

HOW IS IT TREATED?

There is no known cure for Alzheimer’s disease.

However, there are some treatments available that help relieve some of the symptoms.

One of these is acetylcholinesterase inhibitors, which help brain cells communicate with each other.

Another example is menantine, which works by blocking a chemical called glutamate, which can build up in the brains of people with Alzheimer’s disease and inhibit mental function.

As the disease progresses, Alzheimer’s patients may exhibit aggressive behavior and/or suffer from depression. Medications may be provided to help relieve these symptoms.

Other non-pharmaceutical treatments, such as mental training to improve memory and combat one aspect of Alzheimer’s disease, are also recommended.

Source: Alzheimer’s Association and the NHS

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