Great article from Outside Magazine reframing how we should now view fat and muscle. Fat shouldn’t just be viewed as a form of energy storage, it should also be considered as a hormone secreting organ that sends out signals to the rest of the body. This also applies to muscle tissue. It’s much more than just a way to help us move around because it too secretes hormones that can affect the rest of the body.
I’d known that fat cells actually can produce estrogen (which is why obese men develop gynecomastia, or as described in Fight Club with the more politically incorrect term). So the fact that fat can produce other hormones and chemical factors makes sense. Some snippets from the article about fat:
On a strictly mechanical level, more fat means less muscle, which means fewer mitochondria, the cellular power plants that are most plentiful in muscle tissue. The majority of fat contains almost no mitochondria. This explains one of the nagging problems with obesity: the more fat you accumulate, the harder it becomes for your body to burn off that stored energy….
…FAT IS STUBBORN, DEMANDING stuff. Much of the time it’s telling you to eat more, which is one reason why most attempts at dieting are doomed to fail. Our fat wants to keep us fat…
…The reason was a hormone called leptin, which is produced by fat tissue. Ordinarily, leptin tells the brain, “Dude, we’re fat. It’s time to stop eating.” But the brains of obese people often become deaf to leptin, so they don’t get the message….
The part that really surprised me, and that I had never heard before was about muscle having the similar ability to secrete chemical factors. I always thought that muscle was there to help us run, jump, and armbar AND to help us increase our basal metabolic rate and look good at the beach. To actually view it as an endocrine organ, and a very potent one at that, totally blew my mind. Some snippets about muscle:
In 2003, biologists Mark Febbraio, from Australia, and Bente Pedersen, of Denmark, figured out that muscle is an endocrine organ, just like fat, and that exercising muscle produces chemical secretions—which they called myokines—that communicate with the rest of the body. As Pedersen puts it: “Skeletal muscle is the organ that counteracts fat…”
Febbraio and Pedersen identified the most common myokine as none other than IL-6, the inflammatory cytokine that’s also produced by excess fat. But when released during exercise, they found, IL-6 actually had beneficial effects, telling the liver to increase the rate of fat oxidation…
“There’s a growing body of evidence suggesting that healthy muscle may lead to a healthier liver, a healthier gut, a healthier pancreas, and a healthier brain,” says Nathan LeBrasseur, a Mayo Clinic scientist who specializes in muscle tissue…
Another reason to go out and lift heavy things… which I’ve been doing more than my share of with my recent Crossfit workouts. If you have the time, I highly recommend checking the entire article out.