[FoRK] Hot Trend: Tapping the Power of Cold to Lose Weight, Brown Fat and Thermal Dieting

Gordon Mohr gojomo-forkxent at xavvy.com
Sat Mar 2 12:09:34 PST 2013

Perhaps compare also the Nordic habit of letting babies nap in subzero 


(I love the saying mentioned in that article, "there is no bad weather, 
only bad clothing".)

I wonder if body-worn cooling pads, used by athletes (for either 
post-exertion recovery or mid-competition overheating-protection), could 
find application as a weight-loss/metabolism-accelerating tool.

- Gordon

On 3/2/13 11:24 AM, Stephen Williams wrote:
> As I think I have mentioned on FoRK long ago, I'd read back in the early
> 80's about brown fat: Fat, usually on the back, that was said to grow in
> adults that were frequently exposed to the cold when growing up.  I was
> reading it, I think, in Runner's World, and they were talking about
> running outside, which I did a lot of in NW Ohio.  It was suspected by
> the writer and scientists involved that brown fat was something that had
> to be activated & grown in youth as it didn't seem to able to be
> acquired later.  Specifically, it seemed that people who grew up in warm
> climates who were seldom even chilly seemed unable to acquire brown fat,
> while many of those in persistently cold climates (and probably those
> that didn't always stay warm) seemed to gain strong thermogensis
> ability.  As the articles below point out, babies are born with a lot of
> brown fat to keep them warm, but generally lose it as they grow into
> children and adults.
> Additionally, over the years, when people essentially complained about
> me not having a jacket or wearing shorts when they were cold, I would
> quip that I was on my "thermal diet".  I'm pretty sure that I coined it
> first, probably over 15 years ago, and it occurred to me that it would
> be a good diet fad, but, as with many things, I didn't pursue it.  I'm
> not the type to do that anyway, so no big loss, but still, I claim
> priority.  Having been out in the cold a lot, I can distinctly feel when
> my thermogenesis kicks in, and when it isn't when I'm too depleted.  On
> one occasion, after snorkeling in the Pacific in Monterey with nothing
> but a swimsuit in about 50F water for 20 minutes (when my head and other
> leading edges were prickly numb), I had my thermogenesis locked on
> maximum for at least 4 hours, overheated and sweating profusely even
> with the air conditioning blasting me.  Not much fun in meetings that
> day, but an interesting effect.
> Fast forward to the last several years when brown fat was essentially
> rediscovered in adults, where it was believed not to exist except in
> rare reported instances that were suspected of being wrong. People have
> finally noticed the, obvious to me, fact that your body has to burn a
> lot of calories to stay warm in the cold.
> The following articles show what is being rediscovered and learned about
> this and the near term (thermal dieting) and long term (drugs to induce
> & activate) attempts to make this widespread and monetize this.  There
> are still a couple observations they don't seem to have reached that
> seem verging on obvious:
>   * Many of the differences they find are probably related to whether
> people have spent a lot of time in the cold or not. They
>     seem to treat incidence of brown fat as a random occurrence, as if
> it were purely genetic or some other accident.  There's
>     no mention in the Wired article, for instance, of asking about
> childhood and adult persistent exposure to cold.
>   * An obvious conclusion is that we make our children fat by
> overdressing them.  If they are comfortable running around outside
>     in the "cold" with what seems to be too little on, it is fine as
> long as they don't get frostbite.  Everyone has known that
>     cold doesn't cause infections on its own, even though this is still
> repeated endlessly.  And pneumonia isn't going to occur,
>     with or without infection, because of cold exposure in a healthy
> person used to exercise and cold.
>   * Warm areas tend to have skinnier people probably because they can
> more easily and comfortably be outside and exercise more.
>     Cold areas could actually have the advantage though if the cold were
> used right.  It is relatively easy to exercise to warm
>     up while there's little you can do except air conditioning to cool
> off.  Although running at night helps.  Luckily, the SF
>     Bay Area has just the right climate to support a lot of chilly
> running, easily moderated by where, when, how high, and how
>     much you wear.  And there's always the chilly bay to kayak in.
> Many in cold climates, or those snow skiiing, are seldom really cold:
> Wearing high-tech parkas, boots, and scurrying between warm buildings
> and warm vehicles, never exercising outside, they never have much of a
> dip in core body temperature or any stress on their bodies.
> I stayed thin until I moved to Virginia in the DC area; been holding
> ever since.
> http://www.livestrong.com/article/336483-thermal-diet/
> http://www.ourvanity.com/health/diet-nutrition/revolutionary-weight-loss-secret-thermo-diet/
> Beware, brown fat can look like a tumor if it isn't noticed that it is
> symmetric.  Wonder how many misdiagnosis and surgeries have been done
> because of former ignorance of this?
> http://forums.runnersworld.com/forums/runner-communities/beginners/brown-fat
> http://sweatscience.com/two-ways-to-trigger-brown-fat/
> http://www.vancouversun.com/health/Ottawa+scientists+turn+muscle+cells+into+calorie+burning+brown/7921443/story.html
> http://articles.cnn.com/2009-04-10/health/brown.fat.obesity_1_calories-adipose-tissue-nejm?_s=PM:HEALTH
> Twitter: @StevenLeckart <https://twitter.com/StevenLeckart> @wired
> <https://twitter.com/wired> http://is.gd/aeL7zA
> http://www.wired.com/video/wired-magazine/wired-magazine/1127106135001/hot-trend-tapping-the-power-of-cold-to-lose-weight/2157918892001
> http://www.wired.com/playbook/2013/02/ff-cold-weight-loss/
> Hot Trend: Tapping the Power of Cold to Lose Weight
>      By Steven Leckart    02.12.13    6:30 AM
> Photo: Adam Voorhes; Illustration: Christoph Neimann
> I’m in the fetal position at the bottom of a swimming pool. Water
> temperature: 60 degrees Fahrenheit. In my lap there’s a 20-pound weight
> anchoring me in place. All I’m wearing is a Speedo, a nose plug,
> goggles, and a snorkel resembling an oversize asthma inhaler. The
> mouthpiece connects to two 4-foot hoses feeding out of the water and
> into a PC-sized box next to a laptop.
> After 20 minutes in the water, I’m shivering intensely. But that doesn’t
> bother me so much as the headache. It feels like a set of pliers is
> clamping the back of my neck while someone pricks my temples with
> icy-hot needles.
> My suffering is natural, I tell myself. It could even be good for me.
> Now a hand from above reaches into the water and slaps the side of the
> pool. It’s my torturer, Ray Cronise, signaling that time is up. A former
> NASA material scientist who spent 15 years overseeing experiments aboard
> shuttles at Marshall Space Flight Center, Cronise is putting me through
> a battery of tests at his home in Huntsville, Alabama. That snorkel
> contraption—a $30,000 piece of lab equipment—is analyzing my breathing
> to chart how the cold water affects my metabolism. (It tracks inhaled
> and exhaled carbon dioxide and oxygen, a proxy for the amount of fuel
> I’m burning.) Cronise believes exposing the body to cold can be a
> radically effective spur for losing weight. He’s doing this home-brewed
> research in hopes of formulating a Weight Watchers-style algorithm, app,
> or wearable device that can help people safely harness what he’s
> convinced is the transformative power of cold.
> Cronise got the idea back in 2008 while watching a TV program about
> Michael Phelps. The coverage claimed that, while training, the Olympic
> swimmer ate 12,000 calories a day. At the time, Cronise was on a diet of
> 12,000 calories per week. (He was carrying 209 pounds on his 5’9″ frame
> and wanted to get back down to 180.) Something didn’t add up. Even if
> Phelps had an exceptionally high metabolism and swam three hours a day,
> he still should have turned into a blob. Then it hit Cronise: Phelps was
> spending hours every day in water, which was sucking heat from his body.
> He was burning extra calories just to maintain his core temperature of
> 98.6.
> That fall, Cronise grew obsessed. He avoided warmth altogether: He took
> cool showers, wore light clothing, slept without sheets, and took 3-mile
> “shiver walks” in 30-degree weather wearing a T-shirt, shorts, gloves,
> and earmuffs. In six weeks he shed 27 pounds, nearly tripling his
> weight-loss rate without changing his calorie-restricted diet.
> Cronise set off a full-blown weight-loss fad. In 2010, he talked about
> his self-experimentation in a presentation, and then the Pied Piper of
> body-hacking, Tim Ferriss, name-checked Cronise and prescribed 20-minute
> ice baths in The 4-Hour Body. When the book came out, ABC’s Nightline
> aired a segment on Ferriss and “thermal dieting.” Right on cue, bloggers
> began documenting their own cold-exposure experiences. On websites and
> forums like Fatburningman.com, diehards started sharing tips on making
> DIY ice packs. “My body,” one guy confessed after sleeping with
> ice-filled Ziplocs on his abs, “felt like it had been beaten with heavy
> sticks.” Today the trend has gone truly mass: Best-selling diet books
> like Six Weeks to OMG: Get Skinnier Than All Your Friends urge readers
> to take cold baths. On Today, Kathie Lee Gifford praised a company
> called FreezeAwayFat, which sells Lycra bike shorts with pockets for
> frozen gel packs. Her personal review: “My belt is now one notch smaller.”
> Just one problem: There’s not much rigorous science behind any of this.
> It’s exceedingly difficult to quantify how environmental temperature
> affects an individual’s metabolism. Studies have shown cold exposure can
> boost the metabolism anywhere from 8 to 80 percent, depending on a slew
> of variables including the degree and duration of the exposure, whether
> you’re shivering, your diet, and physiological factors like age, gender,
> and fat mass.
> Scientists are racing to separate the real science from the pseudo.
> They’re investigating the precise mechanisms by which the body adjusts
> to cold temperatures and reaching new insights into the ways our bodies
> burn fat. They’re even trying to come up with a new kind of weight-loss
> pill—a longtime ambition of the pharmaceutical industry—that can mimic
> those processes and make us thinner faster, with less effort.
> But Cronise doesn’t have plans for a pill or institutional backing or VC
> funding. He’s not waiting around for peer review. He wants to see
> results—now. That’s why he’s got me submerged in his cold plunge pool.
> He’s conducting his own experiments, trying to figure out how much cold
> affects metabolism, how best to administer the cold, and for how long.
> After 20 minutes in the pool, I emerge from the water, but I’m still
> breathing through the snorkel. Cronise wants to monitor me for any
> sustained acceleration of my metabolism for at least 30 minutes. I’m
> watching a firefly flicker through a lush maple tree as I sit on the
> deck in sticky 87-degree Southern air. I can’t stop shivering.
> Seven hundred miles away, at the National Institute of Diabetes and
> Digestive and Kidney Diseases, Kong Chen is conducting his own (it must
> be said, more rigorous) experiments to understand the effect of cold on
> human metabolism. Chen, director of a team of researchers at the
> institute, studies something called thermal neutral zone. It’s a range
> where the body requires very little energy to maintain its core
> temperature. It’s a state of biological equilibrium with the environment.
> Researchers want to understand the physiological mechanisms at work when
> mammals live in a thermal neutral zone and what changes in colder
> conditions. Surprisingly little is known about the zone in humans.
> “We’re only in the infancy of getting to know the body better,” Chen
> says. To fix that problem, he’s charting metabolic variability among
> lean and obese people exposed for up to five hours a day to air
> temperatures between 60.8 and 87.8 degrees. That way he can map the
> variables that lead to different thermal neutral zones and learn why
> some people burn more calories at lower temperatures.
> One of the crucial variables Chen has been studying is brown adipose
> tissue, known as BAT. Unlike white fat, which merely stores calories,
> brown adipose cells burn them to produce heat. When your body gets cold,
> this metabolically active tissue kicks into gear to warm you up. BAT
> tends to be scattered in little deposits throughout the upper back and
> neck. Rodents and hibernating mammals have a lot of brown fat. Human
> infants are born with a healthy supply to warm them once they’re outside
> the womb. But for decades it was widely believed that the tissue
> vanished before adulthood.
> In the 1970s, autopsies occasionally turned up unusual tissue samples
> suggesting some adults might maintain reserves of BAT. But the instances
> were rare enough to be discounted. Then in 2004, Jan Nedergaard and his
> wife, Barbara Cannon, both physiologists at Stockholm University, noted
> an anomaly that would change BAT research forever. While conducting PET
> scans in search of tumors, some radiologists had noticed mysterious dark
> spots in cancer patients’ necks. Typically, such findings—which indicate
> areas of elevated glucose uptake—were signs of tumor presence. But
> tumors are irregularly shaped, and these spots were symmetrical. They
> realized it must be BAT. Nedergaard and Cannon published a review of the
> PET scans in 2007 in the American Journal of Physiology—Endocrinology
> and Metabolism.
> In the spring of 2009, three papers published in the same issue of The
> New England Journal of Medicine established that BAT exists and is
> functionally relevant in at least some adults. One of the studies was
> coauthored by Aaron Cypess, an endocrinologist at Beth Israel Deaconess
> Medical Center in Boston. He and his colleagues had dug through his
> hospital’s records and examined 3,640 full-body PET-CT scans. Sure
> enough, there were plenty of symmetrical spots. He acquired a biopsy
> specimen from the pathology library to corroborate the scans. Under a
> microscope the tissue sample was confirmed—they were brown fat cells.
> This discovery has set off a flurry of research into the prevalence of
> BAT and the ways it might be tapped to accelerate weight loss. In
> adults, BAT activates within minutes when the body loses heat;
> experimenters often trigger it by exposing subjects to temperatures
> between 61 and 66 degrees. So BAT researchers now routinely chill
> subjects before placing them in PET-CT scanners. The hope is that by
> stimulating more of the tissue to “turn on”—and light up in the
> scans—scientists can better determine who has more brown fat and why.
> At Beth Israel last July, Cypess stood over a trim 23-year-old male
> volunteer. “I have no idea if he’s gonna have BAT or not,” Cypess says.
> The volunteer is one of 19 paid lab rats that Cypess is examining for
> his follow-up study. “We’re just on the verge of statistical
> significance,” he says.
> The medical center has a designated cold room for BAT studies. It’s a
> windowless vault with a gurney and 21-inch television. To administer the
> cold, Cypess puts the volunteer in a khaki vest lined with blue plastic
> tubing that circulates 58-degree water around his torso. We watch The
> Wedding Singer on VHS while his blood is drawn, his vitals are taken,
> and he receives a 12-millicurie intravenous injection of
> 18F-fluorodeoxyglucose, an isotope tracer that is taken up by tissue
> just like glucose. He shivers only slightly toward the end of our
> experiment, which suggests he could have a lot of BAT keeping him warm.
> Sure enough, when Cypess looks at the resulting scan he sees four
> symmetrical black splotches within the gray-and-white outline of the
> volunteer’s body. According to Cypess’ preliminary analysis, the subject
> has from 70 to 100 grams of BAT—enough to fill one, maybe two shot
> glasses. That’s an above-average store of BAT, at least based on the
> data that exists. For a more precise measurement, Cypess will scrutinize
> the 50 axial slices of the subject’s PET-CT scan. It can take many hours
> to quantify the BAT in one person.
> Cypess will spend months tabulating his results. Then he will comb
> through the blood work—the levels of glucose, pyruvate, fatty acids,
> lactate, and norepinephrine—to look for patterns. He hopes to uncover
> correlations between a subject’s quantity of BAT and the chemicals that
> are most active when that person’s metabolism is stimulated by cold.
> Cypess warns that until more studies are completed, dieters should be
> wary of freezing themselves to get skinny.
> A Cold Case Study
> Ray Cronise didn’t set out to investigate the effects of cold on weight
> loss—he just wanted to find a way to drop pounds, fast. Caloric
> restriction and cardio had worked for him in the past, but Cronise was
> getting impatient with his usual methods. Here’s how he added cold to
> his diet regimen and lost 27 pounds in six weeks, tripling his previous
> rate of weight loss. —Katie M. Palmer
> If cold speeds up weight loss, and if the effects of cold are the result
> of an underlying physiological process, then it follows that
> theoretically you could synthesize a drug to induce that physiological
> process without ever having to bother with cold exposure. In other
> words: a magic diet pill. That possibility is exceedingly enticing to
> drugmakers.
> More than 30 percent of adults in the US are obese. It’s easy to fathom
> the broad appeal and potential payoff of a weight-loss pill that can
> activate BAT—or spur its formation in the body. “Every major
> pharmaceutical company is interested in brown fat right now,” says Lou
> Tartaglia, CEO of Ember Therapeutics, a Massachusetts startup that in
> 2011 raised $34 million to develop BAT pharmaceuticals. In January 2012,
> Ember cofounder Bruce Spiegelman, a Harvard professor and Dana-Farber
> Cancer Institute researcher, published the identification of a hormone
> he named irisin, which transforms white fat into brown fat—a process
> called browning. Spiegelman dropped another bomb in July: His team
> isolated a third type of fat cell, one that’s neither white nor brown.
> Dubbed beige fat, this third distinct tissue can be found within white
> fat cells and functions much like BAT.
> Ember just has to distill all these developments into a pharmaceutical
> cocktail: a bit of irisin and maybe a dash of the growth factor BMP7 to
> brown your white fat, then a few other proteins to jump-start the
> metabolic process that causes energy-burning.
> Tartaglia isn’t wasting time. In September Ember opened a
> 15,000-square-foot office with a wet lab in Watertown, Massachusetts,
> and went on a hiring spree. One of the biggest challenges: finding a way
> to keep BAT turned on—and burning energy—perpetually. For now, the only
> method for stimulating BAT in humans for a meaningful amount of time is
> cold exposure. “We don’t have any simple methods to increase the
> activity,” says Nedergaard, a member of Ember’s scientific advisory
> board. “You can build 10 furnaces, but if you don’t actually ignite
> them—and keep them lit—it won’t do much.”
> Tartaglia says he expects Ember to begin testing its first BAT drugs on
> primates by the end of 2013. But even if all goes according to plan, BAT
> drugs for humans won’t hit the market until at least 2020.
> Critics say the whole effort misses the point. “Obesity is not a disease
> of insufficient BAT, but rather one of overconsumption and reduced
> calorie expenditure: couch potato-itis,” says Shaun Morrison, a
> neurobiologist studying BAT at Oregon Health & Science University.
> “Obese individuals will simply eat their way through the therapy and
> remain obese.”
> Nevertheless, the race to understand BAT is accelerating. Since 2010,
> the NIH has awarded $4.5 million in grants to improve technology that
> measures BAT. (PET scanning exposes patients to radiation. It’s also
> expensive and prone to false negatives.) More than a dozen researchers
> in the US and abroad are exploring techniques using MRI and infrared
> cameras.
> Cronise, the man who kicked off the freeze-yourself-thin fad, doesn’t
> have any NIH funding. He also doesn’t care much whether BAT is
> responsible for his weight loss. His obsession is figuring out how
> people can most effectively lose weight, not why. And he’s concerned
> that some of his more overzealous acolytes have adopted “stupid crazy”
> tactics—cold showers, frigid ice baths—that can be uncomfortable,
> dangerous, and unnecessary.
> Cronise thinks there’s a way to lose weight without subjecting your body
> to such extreme temperatures. Studies have shown that the same
> thermogenic mechanism used by BAT also occurs in skeletal muscles during
> cold exposure. Before you shiver, your muscles produce heat—just as BAT
> does. The findings suggest that exposing yourself to less extreme cold
> could still be metabolically beneficial—even if you have very little BAT.
> Since 2008, Cronise has tried to invent a more user-friendly way for
> people to tap into the power of cold exposure. By 2010 he settled on his
> ultimate goal: a wearable device that would make it simple for anybody
> to shed pounds. It would have a temperature sensor and could connect
> wirelessly to an app on your laptop. You’d type in what clothes you were
> wearing and the software would then factor in the ambient temperature
> and ultimately estimate the net effect on your metabolism.
> Cronise started by modeling some basic assumptions about the body and
> creating a unit of measurement he called thermal load. The idea was to
> boil all the variables down to one simple number that helps people
> understand the amount of cold exposure they’re getting and then
> approximate its impact on metabolism. Cronise has filled 10 binders with
> notes, peer-reviewed journal articles, and data about his own energy-use
> patterns.
> But to build his dream device he needed more data, so in 2011 he spent
> $1,500 building his own calorimeter out of sensors from LabQuest, a CPAP
> mask normally used for treating sleep apnea, and a lunchbox-sized
> plastic tub. He designed a custom air valve in CAD and had it
> 3-D-printed at the local community college. But it didn’t work well
> enough, so early in 2012 he got a $3,000 BodyGem, a version of the
> handheld device used to assess metabolic changes in contestants on The
> Biggest Loser.
> In March 2012, Cronise turned off his home thermostat, opened his
> windows, and spent one month letting in the cool outdoor air. He
> measured his resting metabolic rate every morning. His body burned 22.5
> percent more calories in the cooler air, without any change in diet or
> exercise. He was, in theory, losing weight while he was sleeping. But
> Cronise wanted better, less anecdotal data.
> The BAT Effect
> Scientists are beginning to understand how cold affects metabolism, but
> they’re still not sure which mechanisms really kick your calorie-burning
> engine into overdrive. One variable is brown adipose tissue, which
> converts energy from food directly into heat. After a chilly dip in a
> pool, two people with different levels of active BAT will both get a
> metabolic boost—but the person with higher levels typically burns even
> more calories, as shown here. —K.M.P.
> When exposed to cold for two hours, a man with relatively little active
> BAT burned 35 more calories per hour than usual. (If you keep up that
> rate all day, staying cool could net you an extra burger or a skipped
> workout.) In people with little or no BAT, this extra burn likely comes
> from skeletal muscle, which produces heat both before and after you
> start to shiver.
> But a man with a lot of active BAT increased his energy expenditure even
> more after cold exposure, burning an extra 68 calories per hour (two
> burgers!). The more BAT you have, generally the more calories you’ll
> burn when exposed to cold, as the tissue’s mitochondria convert caloric
> energy into heat instead of energy that can be stored as fat.
> Illustration: Christoph Neimann
> Which brings us to that $30,000 snorkel-inhaler we’re using in the pool.
> Cronise bought the Cosmed Quark CPET last August, because it’s the gold
> standard for measuring metabolism. The setup can be calibrated to the
> environment and quantify the percentage of fat versus carbohydrate that
> a subject metabolizes. Cronise wants to pinpoint how various types of
> cold exposure burn fat. And he has expanded his selection of test
> subjects: I’m the fifth person he has analyzed but the first he has
> subjected to water torture.
> It’s the final day of our experiments in Huntsville. I’m luxuriating in
> the sun in my Speedo. I finished an 80-degree soak—it was certainly more
> pleasant than my first 60-degree submersion. I shivered, just nowhere
> near as long or as violently.
> Cronise is eager to deconstruct my data. We’re looking at my total
> energy expenditure and respiratory quotient, or RQ, which reflects what
> kind of fuel I was burning. Ideally my RQ should stay as close to 0.7
> for as long as possible, because that indicates 100 percent of the
> energy being generated by my body is coming from fat (RQ = CO₂
> eliminated/O₂ consumed). When RQ shoots up to 1.0, the body is fueling
> itself on carbohydrates only. But sustained fat burning is the goal of
> cold exposure.
> Cronise walks me through the graphs. During and after running, cycling,
> or swinging kettle bells and while I swam, my RQ hovered around 0.9,
> often spiking closer to 1.0. Not good. I was burning carbs instead of
> just fat.
> But Cronise assures me that “slobbering in a tube underwater, looking
> like a bondage slave” was worth it. He points out that my RQ dropped
> noticeably; I was burning fat steadily every time I exited the pool.
> After the 20-minute swim in 70-degree water, my RQ averaged 0.73 for 15
> minutes. Following a 20-minute swim in 60 degrees, I hit 0.695 for 12
> minutes. After that first miserable soak in 60-degree water? 0.73 for 15
> minutes.
> The cold had a prolonged effect on my metabolism. The data confirms what
> Cronise has been saying: Water is an efficient way to force the body to
> produce a lot more heat for a sustained period of time. If my goal is to
> burn fat, I’m better off swimming—or even sitting—in San Francisco Bay
> than jogging or cycling, provided I let my body warm itself naturally
> afterward (no hot showers or sauna allowed).
> “Do we know it was BAT?” Cronise asks. “We don’t know. Not for sure. You
> were definitely burning more calories after cold exposure.” Conceivably,
> I’m walking around with a generous supply of brown fat that makes the
> cold worth my while. But it could also be my muscles burning the
> calories. For now there’s no way to know. None of the researchers I
> interviewed would give me a PET-CT scan. Unless it can be included in a
> study, one scan is pointless to them, not to mention costly: It can cost
> up to $4,000.
> One thing is certain: Cronise’s data has only whetted my appetite. Could
> less-extreme measures help me maintain my weight without changing my
> diet? How long in a cold shower would equal my results from the pool? Do
> I need to measure the water temperature?
> Before I leave Cronise’s house, I head for the shower. Our last test was
> a 20-minute treadmill jog. So I’m sweaty and tired and about to catch a
> plane, where I’ll wrap myself in a fleece blanket and sit still in a
> climate-controlled cabin for hours. I reach for the faucet, turn on the
> water, and feel the first cold drops splash my hand.
> Correspondent Steven Leckart (@stevenleckart) wrote about Stanford
> professors teaching free online courses in issue 20.04.
> http://www.biosciencetechnology.com/News/2012/06/Natural--Exercise--Hormone-Transforms-Fat-Cells
>> Natural 'Exercise' Hormone Transforms Fat Cells
>> Featured In: Academia News | Health
>> Wednesday, June 6, 2012
>> Exercise makes cells burn extra energy—that’s one way it helps control
>> weight. It also generates a newly discovered hormone, called irisin,
>> that transforms energy-storing white fat cells into energy-burning
>> brown fat cells. Irisin also appears to help prevent or overcome
>> cellular changes that lead to type 2 diabetes.
>> “Irisin travels throughout the body in the blood and alters fat
>> cells,” explains Dr. Anthony Komaroff, editor in chief of the Harvard
>> Health Letter, in the June 2012 issue. “If your goal is to lose
>> weight, you want to increase the number of brown fat cells and
>> decrease white fat cells.”
>> Fat “color” makes a difference
>> White adipose tissue, more commonly known as body fat, is the tissue
>> that dimples thighs, enlarges waists and derrieres, and pads internal
>> organs. Each white fat cell stores a large droplet of fat. Brown fat,
>> in comparison, is chock full of energy-burning mitochondria. Its main
>> function is to generate body heat by burning fat.
>> Babies are born with brown fat, but it was thought to gradually
>> disappear. In 2009, several studies showed that adults still have
>> brown fat cells lurking in their bodies. Earlier this year, a team led
>> by Dr. Bruce Spiegelman, professor of cell biology and medicine at
>> Harvard Medical School, identified irisin in mice and humans. His team
>> also showed how irisin transforms white fat cells into brown ones, at
>> least in mice. The same thing is likely to happen in humans, too, but
>> that remains to be worked out.
>> This transformation helps the body burn more energy during exercise.
>> The effect lingers, since brown fat cells keep burning fat even after
>> you’ve stopped exercising. In addition, Spiegelman’s work showed that
>> irisin also helps prevent or overcome insulin resistance, which leads
>> to type 2 diabetes.
>> No need to wait
>> The possibility of creating a new medication based on irisin for
>> weight loss or type 2 diabetes may have pharmaceutical companies
>> already mapping out the long, expensive process for bringing a new
>> drug to market. But you can make your own irisin today, for free, by
>> exercising. And even if irisin’s effects aren’t quite as potent in
>> humans as they are in mice, you are still getting all the other
>> benefits that exercise has to offer.
>> Source: Harvard Medical School
> sdw
> _______________________________________________
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