By Eric Meyer
What starts out as something pretty routine can sometimes lead you down a rabbit hole. We recently circulated an interesting article among the board members for Healthy Adams Bicycle/Pedstrian, Inc. (HABPI) about how bicycling can help fight dementia. It was a well-written article from what seemed to be a reputable cycling news source that included citations for original research material. It touted recent research that showed how a hormone produced by exercising can actually help grow more neurons. The article went on to describe how bicycling was the perfect sport to produce these benefits.
However, there were a few red flags. First, the author provided only a first name and no credentials. Then, with a little more digging, I discovered this online cycling news source is not the reputable one we knew, but one with a very similar name. Lastly, every article on their website seemed to be written by this one-named reporter. So, should we believe any of this? Down the rabbit hole we go.
Our first stop is the Alzheimer’s Society website. Here we learn that “Regular physical activity is one of the best things that you can do to reduce your risk of developing dementia.” They note that the combined analysis of 58 studies has shown that regular exercise can reduce the risk of Alzheimer’s disease by 20%. They also note that one study looked at the daily activity of older people. It showed that the least active people were twice as likely to develop Alzheimer’s disease as the most active people. And by physical activity, they mean an activity that increases the heart rate for 20-30 minutes or more. It can be biking or running, but it can also be brisk walking, gardening, or house-cleaning. So, there’s a pretty solid basis for claiming exercise helps prevent dementia. What about growing neurons?
Our next stop is Harvard Magazine and their article of December 7, 2021, called “Your Brain on Exercise” by Jonathan Shaw. The tagline for the article is “The hormone irisin, promising as a therapeutic against Alzheimer’s and dementia, is responsible for the cognitive benefits of exercise.” Shaw notes that epidemiological studies have shown that people who exercise are at greatly reduced risk of developing Alzheimer’s disease and dementia. He goes on to write “Now, a study published in Nature Metabolism provides powerful evidence that a single hormone produced during endurance exercise is the key link to these improvements in cognitive health.”
The senior author for the study’s paper, Dr. Christiane Wrann, is Assistant professor of Medicine and the leader of Massachusetts General Hospital’s Program in Neuroprotection in Exercise. (Impressive credentials!) According to Shaw, Dr. Wrann and her team found that irisin “improves cognitive function, dampens neuroinflammation, ensures the healthy development of new neurons and has beneficial effects on the brain even after Alzheimer’s disease has begun to develop.” So, there it is. Irisin, which is produced during exercise, helps to ensure development of new neurons. What makes this finding especially promising is that irisin can cross the blood-brain barrier which makes it a good candidate for development as a drug for treatment of Alzheimer’s.
Which takes us back to the original article. The author may have taken some liberties by claiming that the discovery “transforms the bicycle from a simple fitness tool into a precise medical device.” However, it’s clear that bicycling, like other aerobic activities, will help protect against Alzheimer’s and other neurodegenerative diseases. To quote the study’s co-author, Dr. Rudolph Tanzi, “It’s hard to imagine anything better for brain health than daily exercise, and our findings shed new light on the mechanism involved: protecting against neuroinflammation, perhaps the biggest killer of brain neurons as we age.”
To learn more about HABPI and our work, please visit “HABPI.com” on the internet.
Eric Meyer is President of HABPI and a retired engineer who rediscovered his love of biking more than 25 years ago.