^{Caffeine and Growth Hormone Increases UCP-3 Activity}

Resting metabolic rate can be increased by 30% by the sympathetic nervous system agents²⁷ and by about 15% by growth hormone²⁸.  Growth hormone has also been shown to increase UCP-3 in muscle which may be a part of GH's powerful effect on fat loss^{39, 40}.    Any supplement that increases adrenaline should increase UCP-3 activity.  UCP-3 activity varies between people; research has demonstrated that of all of these possible regulators of the expression of the UCP3 between people, only norepinephrine (a sympathetic catecholamine) could explain part of the variability between UCP-3 expression in subjects. Interestingly, norepinephrine urinary excretion also correlated with resting energy expenditure³⁴.  It should be of no surprise that many of the fat loss supplements target fat loss by increasing norepinephrine levels.  Basically, the higher your norepinephrine levels are, the higher your resting energy expenditure and UCP-3 activity will be.  Caffeine is a potent stimulator of norepinephrine and increases fatty acid mobilization has also been shown to increase UCP-3 activity³⁸.  I suspect the combination of caffeine with ephedrine and yohimbine would further increase UCP-3 activity as all increase norepinephrine levels but no research is available. 

Olive Oil, Palm Oil, and Fish Oils: Potent Stimulators of UCP-3

UCP-3 is upregulated in situations where fatty acid availability is higher than its oxidation rates, as for example fasting, treatment with thyroid, high-fat/high protein diets, and intense exercise⁸.  UCP's are activated much more effectively by palm oil, olive oil, and fish oils than by saturated fats. Instead of consuming saturated fats before a competition, you may be get leaner by consuming more fish oils and olive oils.  Researchers conducted a study to determine what fats led to the greatest increase in UCP.  The results were as follow: 1. Palmitic acid (palm oil) 2. Oleic acid (olive oil) 3. Eicosatrienoic acid (omega 3 fatty acid) 4. Linoleic acid (safflower and sunflower oils) 5. Arachidonic acids (meat, eggs, dairy fats).  Palm oil might be another consideration as palm oil can increase UCP-3 activity as well.  It has been shown that palmitic acid or palm oil led to a 10% increase in oxygen consumption.  Consistent with previous studies showing that palm oil not only increases resting oxygen consumption but the expression of the UCP3 gene is approximately doubled by palmitic acid concentrations²⁴.  Another potent stimulator of UCP-3 is olive oil.  After the various types of fat, there was an up-regulating effect of olive oil on UCP-3 expression in muscle. The expression of the UCP3 mRNA in muscle was significantly higher after olive oil feeding than beef fats. Total-body oxygen consumption, an index of resting metabolic rate, was significantly higher in rats fed olive oil than other fats tested ³³.  The results of the data suggest that palm oil, olive oil, and fish oils are better stimulators of UCP-3 production than saturated fats¹⁷. Thus, not all fats are equal and certain types of fats can enhance diet-induced UCP-3 production in muscle.

Blocking Fats Reduce UCP-3 Expression

Clinical data also demonstrate a strong correlation between the amount of circulating fatty acid concentrations and skeletal muscle UCP-3, suggesting fat intake stimulates UCP-3 expression²⁵.   Mingrone and colleagues found a 35% reduction in UCP-3 protein levels in subjects having undergone gastric bypass surgery ²². But since gastric bypass surgery minimizes stomach capacity and reduces dietary fat absorption, the drop in fat absorption likely lowered UCP-3 expression in muscle.  Additionally, Dr. Civaterese at Pennington Biomedical Research center has shown that glucose ingestion during exercise lowered UCP-3 expression and other genes involved in fatty acid metabolism²⁶.  The reduced expression of lipid metabolism genes during glucose ingestion during exercise may have been due in part to suppressed lipolysis and a lowering of circulating fatty acids.  The new over the counter "fat blocker" drug "Alli" will probably lead to a reduced expression of UCP-3 I suspect, but no research is available at this time.

Leucine: The Ultimate Diet Amino Acid?

Leucine is an essential, branched chain amino acid that not only as a building block for protein synthesis, but is also a potent activator of the mammalian target of rapamycin (mTOR), a potent activator of may functions including protein synthesis, cell growth, and metabolism. Branched chain Amino Acids, especially leucine, have been speculated to play a key role in regulating metabolism. For example, Donato et al reported that leucine supplementation during caloric restriction results in more fat loss and improves protein synthesis in muscle³¹.  Get ready for more exciting news on leucine and fat loss.  It was recently shown that doubling leucine intake while on a high calories diet substantially reduced diet-induced weight gain and improved glucose and cholesterol metabolism in mice. The use of L-leucine supplementation also resulted from increased resting energy expenditure associated with increased UCP-3 protein expression in skeletal muscle and in brown and white adipose tissues³².  So leucine not only increases protein synthesis but also reduces bodyfat by increasing UCP-3....can't get much better than that!! Leucine is the one supplement you can't do without before a competition.

Key Points:

• UCP-3 is increased by growth hormone, thyroid, catecholamines, and caffeine.
• UCP-3 is stimulated more by olive oil, palm oil, and fish oil than saturated fats.
• UCP-3 is reduced by high carbohydrates and Fat Blockers.
• New research suggests that Leucine stimulates UCP-3 expression in muscle.