Irisin has been getting increasingly good research results the past few years.
This one in mice suggests that irisin, an exercise-induced myokine, may help alleviate ageing-associated chronic diseases.
Recombinant irisin protein administered intraperitoneally in ageing mice alleviated ageing-associated sarcopenia and metabolic disorders, including adiposity, hyperlipidaemia, insulin resistance and fatty liver.
FNDC5/irisin deficiency in aged mice showed exacerbated muscle wasting.
Irisin ameliorates age-associated sarcopenia and metabolic dysfunction
I am cautiously optimistic that this is a safer approach than steroids or sarms which bind to the androgen receptor. Cautious because what happens to endogenous myokine production when we introduce exogenous myokines? People thought sarms were safe at first, but only 1 mg per day of lgd 4033 will tank a man’s natural testosterone production.
As reported in the journal Neuron, the Massachusetts General Hospital (MGH)–led team has uncovered promising results suggesting that irisin-based therapies might help combat AD.
Physical exercise has been shown to reduce amyloid beta deposits in various mouse models of AD, but the mechanisms involved have remained a mystery.
Exercise increases circulating levels of the muscle-derived hormone irisin, which regulates glucose and lipid metabolism in fat tissue and increases energy expenditure by accelerating the browning of white fat tissue.
Eunhee Kim, Hyeonwoo Kim, Mark P. Jedrychowski, Grisilda Bakiasi, Joseph Park, Jane Kruskop, Younjung Choi, Sang Su Kwak, Luisa Quinti, Doo Yeon Kim, Christiane D. Wrann, Bruce M. Spiegelman, Rudolph E. Tanzi, Se Hoon Choi. Irisin reduces amyloid-β by inducing the release of neprilysin from astrocytes following downregulation of ERK-STAT3 signaling. Neuron, 2023; DOI: 10.1016/j.neuron.2023.08.012
From the Alzheimer’s Forum: (and of course, you could just buy the irisin).
Sit Less, Move More to Induce Irisin and Stave Off Dementia
Physical activity staves off dementia, but does that mean being sedentary makes cognitive decline more likely? Yes, according to David Raichlen, University of Southern California, Los Angeles, and colleagues. In the September 12 JAMA, the scientists reported that, among almost 50,000 people, being inactive for 15 hours per day tripled dementia risk over seven years compared to the group’s average of nine hours of sitting a day.
“Sitting all day long deteriorates pretty much all biological systems in the body, including the brain,” wrote Borja del Pozo Cruz, University of Southern Denmark in Odense, to Alzforum (comment below).
The study implies that exercise benefits the brain. “Moving and engaging in physical activities as much as possible is very important for physical and cognitive health in old age,” wrote Kumar Rajan, Rush University, Chicago.
Read the full, in-depth story on the Alzforum Website:
“A striking feature of these investigations was the vast variation of reported irisin levels, differing by orders of magnitude even in healthy subjects. This was the case for results obtained with tests from different manufacturers but also with the same test from a single supplier used in different laboratories. More than 80 studies have been published with irisin levels ranging between 0.01 and more than 2,000 ng/mL in human serum or plasma.”