Brown Fat

White Fat, Brown Fat, Beige Fat... This is beginning to sound like jazz.
Many of us would like to hear a simple pop song "An apple a day keeps the fat away" or maybe some hard
rock "Eat what you want 5 days and almost nothing for 2 days and you'll kill that fat".
But when it comes to the chemistry in our body, things are so complicated that can't be compared, not
even with a symphony.

I smile bitterly when I read that "weight gain is caused by a fundamental energy imbalance,
when energy intake from food chronically exceeds energy expended by physical activity and metabolic
processes".
A therapy for weight loss must, of course, involve less food intake and more exercise. But by far is
not enough. Anyone who's been through a diet knows this too well.
Humans have evolved incredible complex biological mechanisms to acquire and defend their energy stores.
Besides some "wheels" in this mechanism can malfunction, as a result of some environment changes, because of age, too much sugar and starch or I don't know what else.

For years now, scientists have been studying the brown fat, a type of heat-generating fat that burns
energy rather than storing it (like the white fat does).
Babies have it, to keep them warm. This explains why babies survived after hours spent in freezing cold.
Initially, researchers thought adults had no brown fat at all. But, surprise, adults have some of it too and it's playing an important role in heat production and energy metabolism.
Another surprise, brown fat provides a natural defense against obesity: people with greater quantities of brown fat have lower body weights

Following a severe diet makes things worse.
In normal weight people, brown fat burns energy while white fat tends to store energy.  But in obese
people following a calorie restricted diet, brown fat can become largely inactive which means both
types of fat become organs of energy storage making weight loss extremely difficult.
It's like you're driving a car, and the harder you press on the accelerator, the harder an invisible
foot presses on the brake.
While this phenomenon is known, scientists at Sydney’s Garvan Institute of Medical Research and the
University of NSW have found a scientific explanation. They used mice in their research but the
mechanism discovered is probably similar in humans.
They have shown that the neurotransmitter Neuropeptide Y (NPY), known for stimulating appetite, also
plays a major role in controlling whether the body burns or conserves energy.
“High levels of NPY signal to the body that it is in ‘starvation mode’ and should try to replenish and
conserve as much energy as possible. As a result, the body reduces processes that are not absolutely
necessary for survival.”
Brown fat, one of the primary tissues where the body generates heat and therefore uses up energy,  is
deactivated as a result.

A lot of hormones are involved in fact in human metabolism and I don't know how many other chemicals.
Not to mention the genome and the mechanisms that activate/ deactivate genes.
But when fighting the stubborn fat, you try to cling to the last straw.
Studies now try to find how to increase and activate the brown fat in obese people.

One year ago, researches at the Harvard University made an exciting discovery on mice models, confirmed
lately on human. It seems that exercise has more benefits that burning calories. A hormone, named
Irisin, is produced. Irisin is an "eco" traveler in our body. Increases the good brown cells and
decreases the "garbage sources", the white fat cells.
Irisin is not the only "by-product" of exercise, hundreds of proteins result which make us healthier.

Another candidate for increasing brown fat is Ursolic Acid, found in apples (especially in skin),
prunes, some Mediterranean herbs like basil, rosemary, lavender, oregano, thyme and several berries like
bilberries and cranberries.
Of course mass-media launched immediately a new top song "Eat apples" but it's not that easy.
Reasearch results are confirmed for the moment in mice only.
Nevertheless, an apple a day is one of the best ideas for your health.

Other researches discovered a protein that activates the brown fat but whether this discovery would be
practical for weight control, is unclear.

Best advice so far, until better methods are identified to increase the brown fat:
- don't follow fad diets, which restrict drastically calories. Don't eat too much either.
- what you eat and when you eat is very important. Don't eat too much in the evening. Eat a variety of
food, mostly vegetable, fruit and beans but also lean meats, eggs, dairy and cheese. Include "good fats".
Make fish, vegetable oils, nuts part of your weekly menu.
- a salad a day and a couple of fruits, apples and prunes included,  won't probably increase your brown fat but will keep the doctor away.
- make daily walking and other physical exercise a part of your life. Even if you won't see immediate
results, on the long term, your health and weight will improve for sure.

So, whatever song is on top, put your shoes on and start moving!




References

Mechanism That Regulates Production of Energy-Burning Brown Fat Discovered
Apple Peel, New Weapon to Fight Obesity
Wikipedia Brown Adipose Tissue
Ursolic Acid
Ursolic Acid Increases Skeletal Muscle and Brown Fat and Decreases Diet-Induced Obesity, Glucose 
Intolerance and Fatty Liver Disease
Understanding Obesity And How Brown Fat Cells Form
Turning White Fat Into Energy-Burning Brown Fat: Hope for New Obesity and Diabetes Treatments
Why obesity is stubborn
Protein that stimulates brown fat could boost weight loss strategies
Joslin Scientists Discover Mechanism That Regulates Production of Energy-Burning Brown Fat
A PGC1α-dependent myokine that drives browning of white fat and thermogenesis