Brown Adipose Tissue – and Modern Ambient Conditions

By Victor 

Recent scientific research suggests that modern ambient living conditions may be an important factor in the worldwide obesity epidemic. One reason for this is related to brown adipose tissue (BAT). Brown fat tissue or BAT has the opposite function of white fat tissue; instead of storing fat, it burns it. BAT makes up 25% of the body mass of new-born infants, who need this fat type to maintain their body temperature. Hibernating animals also use BAT to maintain body temperature during long periods of exposure to cold. Only recently have researchers discovered the importance of BAT in adult humans. BAT uses a specialized protein called “UPC1” to generate heat by “uncoupling” thermogenesis (heat generation) from cellular respiration which results in the production of ATP. The body uses ATP for most of its energy needs. However, uncoupling causes cells to “lose” energy; the “lost” energy (meaning it doesn’t produce ATP) results in the cellular production of heat. This process of uncoupling burns up fat more rapidly than does using fat to produce ATP.

What does all of this have to do with modern ambient living conditions?

The first person to blame for the current obesity epidemic may well be Thomas Edison. The circadian hormone, melatonin regulates both the amount and activity of BAT; and melatonin production is regulated by exposure to light. During the winter season, when there is less daylight, the body increases melatonin production, increasing the amount and activity of BAT, burning greater amounts of fat, presumably to help stay warm during the cold winter months. With exposure to modern lighting humans produce less melatonin, and burn less fat, leading obesity. Why not just take supplemental melatonin? This may not be a bad idea; but it is unlikely to be an adequate substitute for darkness.

See: (2011) Significance and application of melatonin in the regulation of brown adipose tissue metabolism: relation to human obesity.

What about ambient temperature?

BAT activity is very responsive to changes in ambient temperature.


(2009)  Cold-Activated Brown Adipose Tissue in Healthy Men

(2009) Brown Adipose Tissue and Seasonal Variation in Humans

(2010) Identification and Importance of Brown Adipose Tissue in Adult Humans

This fact has led researchers to suspect that another important factor in the current obesity epidemic is modern indoor heating. Very few people are presently subjected to seasonal cold conditions, since virtually all modern dwellings and workplaces have climate control which provides year-round, comfortable, warm temperatures.


(2010) Is thermogenesis a significant causal factor in preventing the “globesity” epidemic?

(2011) Rising indoor winter temperatures linked to obesity?

So, to lose those extra pounds, turn down the thermostat, and turn off the lights.

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3 Responses to Brown Adipose Tissue – and Modern Ambient Conditions

  1. Peter says:

    Good reminder Victor of the value of melatonin. Wasn’t aware of the BAT connection, but knew that maintaining melatonin levels was of value just to assure a good night’s sleep which can dramatically affect health over the long run.

    Melatonin production can be significantly affected by ambient lighting conditions. Best to have a dark bedroom with no nightlights, zero…If nightlights (and clocks and fire alarms) must be used then use very low intensity long wavelength lighting – i.e. red…don’t use green or blue or white..

    also avoid bright lighting as bedtime approaches, again due to the suppression of melatonin production by the pineal gland

  2. electhor says:

    Your point on melatonin may have good currency –
    The articel also concurs with the opinion of BAT being less active due to constant ambient temperatures modern people live in – air conditioning in Summer, heating in Winter.
    Strangely enough, BAT as a general rule, is more prevalent in lean persons than obese persons. There seems to be an inverse relationship where the leaner one is, the more BAT they have.
    Clinical trials have seen lean and obese persons administered ephidrine and found that in the lean person, BAT became active, whilst in the obese, it made no difference to their BAT activity. Maybe that is why cold thermosgenisis seems to work better on leaner individuals than obese individuals.
    BAT in obese individuals seems resistant to stimulation/activation.

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