"Brown Fat: Losing Weight Through Thermogenesis"
During World War I, it was discovered that many of the chemicals
for the new explosives they were working on had toxic or even lethal effects on the
workers in the munitions factories, chemicals such as di-nitro-phenol or DNP.
It boosts metabolism so much, workers were found somewhere
along the road after work, covered in sweat, with a temperature
of 106 degrees Fahrenheit, or even 109 before they die,
and then even after death their temperatures
keep going up like a total body meltdown.
But at subacute doses, workers claimed to have grown thin to a notable extent
after several months working with the chemical.
That got some Stanford pharmacologists excited
about the "promising metabolic applications" of DNP.
One dose and our resting metabolic rate jumps up 30%, an actual fat burning drug.
People started losing weight with no apparent side effects
as a result of their weight-reducing treatment.
On the contrary, they felt great — until thousands of people
started going blind and users started dropping dead
from hyperpyrexia, fatal fever from the heat created by the burning fat.
Of course it continued to be sold.
"Here, at last, is a weight reducing remedy that will bring you a figure men admire
and women envy, without danger to your health
or change in your regular mode of living. No diet, no exercise!"
It did work, but the therapeutic index was razor thin,
a razor thin difference between the effective dose and the deadly dose.
It was not until thousands suffered irreversible harm
that it got pulled from the market.
Until, of course, it was brought back by the Internet for those dying to be thin.
There is a way our body naturally burns fat to create heat though.
When we're born we go from a nice tropical 98.6 in our mother's womb
straight to room temperature, and we're all wet and slimy.
This represents a challenge for thermoregulation,
for maintaining our warm body temperature.
As an adaptive mechanism, the appearance of a unique organ
around 150 million years ago allowed mammals to maintain
our high body temperatures.
That unique organ is called brown adipose tissue or BAT, whose role
is to consume fat calories by generating heat in response to cold exposure.
The white fat in our bellies stores fat, but the brown fat located up between
our shoulder blades burns fat.
It's essential for the thermogenesis, the creation of heat in newborns,
but is considered unnecessary in adults, has been considered unnecessary,
who have higher metabolic rates and increased muscle mass
for shivering to warm us up if we ever get cold.
So we used to think it just kind of shrank away when we grew up,
but if it was there, then it could potentially make a big difference
for how many calories we burn every day, but supposedly we outgrew it.
But when PET scans were invented to detect metabolically active tissues
like cancer, oncologists kept finding hot spots in the neck and shoulder regions
that on CT scan turned out to be not cancer, just fat.
Then some observant radiologists noticed they appeared in patients
mostly during the cold winter months.
And when we looked closer at tissue samples taken from people
who had undergone neck surgery we found it: brown fat in adults.
The common message from these studies is that BAT is present and active in adults,
and the more we have and the more active it is, the thinner we are.
And we can rapidly activate our fat-burning
brown fat by exposure to cold temperatures.
For example, if you hang out in a cold room for two hours in your undies
and put your legs on a block of ice for four minutes every five minutes,
and you can elicit a marked increase in energy expenditure
thanks to brown fat activation.
So, hey, these studies point to a potential "natural" intervention to stimulate energy
expenditure: turn down the heat and burn calories
(and reduce your carbon footprint in the process!).
But thankfully for those of us who would rather not lay our bare legs on blocks
of ice, our brown fat can also be activated by some food ingredients —
such as those that we'll cover in the next video.