Exercise produces irisin — irisin might prevent Alzheimer’s, researchers say

Some hope for those who are struggling with the disease.

  • Irisin, a hormone in the human body that is generated by muscle tissue and is carried throughout the body in the bloodstream, can play a part in Alzheimer's onset and effects.
  • In tests on mice, it has become clear that irisin plays a key part in memory and learning; the removal and subsequent adding back of the hormone showed dramatic changes in memory and learning.
  • Researchers think a supplement including the hormone is not far off for those who have Alzheimer's, to slow it down or even stop it.


Irisin is a hormone that is generate by muscle tissue, specifically from physical exercise; its effects on memory were studied recently, and scientists have seen a strong connection between irisin levels and what they call "synapse and memory fails." People with Alzheimer's have lower amounts of the hormone versus healthy individuals.

"We know that physical activity is linked to better brain health as we age, and this research highlights a biological mechanism that may contribute to this beneficial effect," said Rosa Sancho of the charity Alzheimer's Research UK.

Data from study. Image source: Nature Medicine

In mice where irisin was blocked, memory and learning deficits appeared; when it was restored later, this effect reversed itself. What that means for humans is this: Physical exercise will very likely help stave off Alzheimer's. And going without it can cause its acceleration.

There already were dozens of reasons to leave that couch and get active, including research that suggests a larger belly means a shrinking brain, but this one could be a game-changer.

And for those of us who can't exercise as much because of physical limitations, there might be hope as well, in the form of irisin injections or even oral supplements.

Dementia patients visit alpaca farm as therapy. Photo credit: Morris MacMatzen / Getty Images

From the study, which was published in the January installment of Nature Medicine:

Bolstering brain FNDC5/irisin levels, either pharmacologically or through exercise, may thus constitute a novel therapeutic strategy to protect and/or repair synapse function and prevent cognitive decline in Alzheimer's disease.

Further studies and peer reviews will attempt to verify the findings.

Stand up against religious discrimination – even if it’s not your religion

As religious diversity increases in the United States, we must learn to channel religious identity into interfaith cooperation.

Sponsored by Charles Koch Foundation
  • Religious diversity is the norm in American life, and that diversity is only increasing, says Eboo Patel.
  • Using the most painful moment of his life as a lesson, Eboo Patel explains why it's crucial to be positive and proactive about engaging religious identity towards interfaith cooperation.
  • The opinions expressed in this video do not necessarily reflect the views of the Charles Koch Foundation, which encourages the expression of diverse viewpoints within a culture of civil discourse and mutual respect.
Keep reading Show less

How expectation influences perception

These prior beliefs help us make sense of what we are perceiving in the present.

Mind & Brain

For decades, research has shown that our perception of the world is influenced by our expectations. These expectations, also called "prior beliefs," help us make sense of what we are perceiving in the present, based on similar past experiences.

Keep reading Show less

NASA's idea for making food from thin air just became a reality — it could feed billions

Here's why you might eat greenhouse gases in the future.

Jordane Mathieu on Unsplash
Technology & Innovation
  • The company's protein powder, "Solein," is similar in form and taste to wheat flour.
  • Based on a concept developed by NASA, the product has wide potential as a carbon-neutral source of protein.
  • The man-made "meat" industry just got even more interesting.
Keep reading Show less

Where the evidence of fake news is really hiding

When it comes to sniffing out whether a source is credible or not, even journalists can sometimes take the wrong approach.

Sponsored by Charles Koch Foundation
  • We all think that we're competent consumers of news media, but the research shows that even journalists struggle with identifying fact from fiction.
  • When judging whether a piece of media is true or not, most of us focus too much on the source itself. Knowledge has a context, and it's important to look at that context when trying to validate a source.
  • The opinions expressed in this video do not necessarily reflect the views of the Charles Koch Foundation, which encourages the expression of diverse viewpoints within a culture of civil discourse and mutual respect.
Keep reading Show less