Scientists have known for years that exercise not only keeps seniors in good physical shape, but it helps them stay mentally sharp. Study after study show that people who work out regularly perform better on cognitive tests as they get older.[i]
But researchers did not know exactly how physical activity improved memory and staved off dementia.
What is the mechanism?
Researchers may finally have an answer.
The Hormone That Stops Alzheimer’s
Athletes know that a vigorous workout can lead to “runner’s high.” This is a feeling of euphoria you get when exercise-activated hormones called endorphins boost your mood.
In recent years, researchers have discovered that exercise produces another hormone. It may have more profound brain effects than endorphins. Studies show it improves memory and may protect against Alzheimer’s disease.
It’s called irisin.
Our bodies release irisin into the bloodstream when we’re active. It seems to play a role in energy metabolism. But researchers have found it also promotes the growth of neurons in the hippocampus. That’s a region of the brain responsible for memory and learning.
Dr. Ottavio Arancio is a researcher at Columbia University’s Vagelos College of Physicians and Surgeons and the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain. He co-led a major study of irisin’s brain effects.[ii]
Dr. Arancio said that irisin helps “explain why physical activity improves memory.”
It may also point to why exercise “seems to play a protective role in brain disorders such as Alzheimer’s disease.”[iii]
Dr. Arancio’s study was done in three parts:
Part 1: Scientists examined tissue samples from brain banks. They found that irisin levels in the hippocampus are lower in people with Alzheimer’s.
Part 2: The team determined what irisin does to the brain. Experiments with mice showed that the hormone protects nerve connections and memory. When the scientists disabled irisin, brain synapses and memory suffered. When they boosted irisin levels, brain health markers improved.
Part 3: The researchers analyzed how exercise affects irisin and the brain. They injected beta-amyloid into mice. Beta-amyloid is a protein that interferes with neurons and is linked to Alzheimer’s. They had the mice exercise by swimming almost every day for five weeks. Despite having the brain-damaging protein, the mice did not develop memory impairment.
When they gave the mice a drug that blocked irisin, the rodents no longer gained any brain benefit from exercise.
After seeing the benefits of irisin in his lab, Dr. Arancio said: “I would certainly encourage everyone to exercise, to promote brain function and overall health.”
A new animal study at Massachusetts General Hospital confirmed the findings. It showed that irisin improved cognitive function while preventing Alzheimer’s disease.
Dr. Christiane Wrann led the study. She said that irisin seems to go beyond Alzheimer’s protection to improve the overall health of the brain. “We’re optimistic it could have beneficial effects on neurodegenerative diseases beyond just Alzheimer’s,” she said.[iv]
3 Ways to Boost Your Irisin Levels
There is not yet an irisin supplement on the market, although scientists are working on it. But there are other ways to increase your levels of this crucial hormone…[v] [vi]
- Do high-intensity interval training (HIIT). Research shows that this type of exercise does the best job of boosting irisin.
The basic formula for HIIT is simple. Warm up for three to five minutes, doing whatever form of cardio you like best…jogging, swimming, biking, etc. Then go hard at an all-out pace for the next 30 to 60 seconds. Then slow down for a minute or two to catch your breath. Repeat this process five to seven times. Then cool down for at least two minutes. A beneficial workout takes only about 15 minutes total.
- Eat a diet high in healthy fats. A 2016 study published in the journal Scientific Reports found that a high-fat diet increases irisin levels. Healthy fats include those from olive oil, avocado oil, and organic eggs, dairy, and meats.
- Don’t avoid the cold. Research has found that shivering due to being cold raises irisin almost as much as exercise does. You don’t have freeze yourself. But simply spending a few minutes under a cold shower or swimming in cool water can increase your levels.
Irisin is the little-known hormone that could help keep you mentally sharp as you get older.
Editor’s Note: Discover how to strengthen your natural defense against memory decline and Alzheimer’s. One woman who tried it said: “I could actually feel my brain healing.” Get all the details in our monthly journal Independent Healing HERE.