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Caffeine's Fat Reducing Effects: An Update |
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Written by Dan Gwartney, MD
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Saturday, 14 February 2009 |
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Page 3 of 3
One More Round
The researchers performed an additional round of tests, this time using
caffeine in the presence of propanolol. Propanolol is a drug that
blocks the B-receptors, preventing any adrenalin-like responses in the
body. This drug is used to prevent people with heart disease from
becoming excited, but it is also effective as a research tool in
blocking the effect of naturally produced adrenalin-like hormones and
neurotransmitters, taking the sympathetic tone down to an absolute
minimum.15
When propanolol was present, fat release was not increased by caffeine,
meaning there was no additional fat loss. The increase in energy
expenditure that had been previously recorded was also less, meaning
fewer additional calories were burned. Thus, it would appear that the
fat-releasing effect of caffeine is primarily dependent upon
B-adrenergic stimulation. This stimulation may be the result of
exercise, drugs (ephedrine, clenbuterol), cold weather (shivering), or
an excited state. Regardless of the cause, without an increase in
sympathetic tone, caffeine will have little effect on fat loss. Acheson
did note that even under the influence of propanolol, caffeine was able
to increase the energy expenditure slightly, possibly due to the entry
of calcium into the muscle cell.5 However, the degree of increase is
low and would only account for an additional 100 calories burned daily.
Summing Up
Caffeine is a popular, widely used drug with performance-enhancing
benefits to athletes, soldiers and others who battle fatigue.
Additionally, it has been shown to be effective as a fat-burning agent,
particularly when used in conjunction with drugs or supplements that
increase sympathetic tone by acting like the hormone adrenalin.8
Caffeine increases fat loss through a number of pathways. It increases
the fat-releasing effect of ephedrine, clenbuterol and similar drugs by
prolonging the cell signal, causing a greater amount of FFA to be
released into the bloodstream. Caffeine again acts as a chemical
companion to adrenalin-like hormones and drugs by increasing the
activity of muscles, thereby increasing the number of calories burned.
As a consequence of the high levels of FFA released, more fat calories
are burned than would otherwise be available without the use of
caffeine.
By itself, caffeine is has a minor role in fat loss. When used in
conjunction with other fat loss methods, it increases fat loss
dramatically. The prevalence of caffeine in the global diet and its
enviable safety record4 make it a supplement to be considered for any
fat loss program.
References
1. Nawrot P, Jordan S, et al. Effects of caffeine on human health. Food Addit Contam, 2003 Jan;20(1):1-30.
2. Paluska SA. Caffeine and exercise. Curr Sports Med Rep, 2003 Aug;2(4):213-9.
3. Tharion WJ, Shukitt-Hale B, et al. Caffeine effects on
marksmanship during high-stress military training with 72 hour sleep
deprivation. Aviat Space Environ Med, 2003 Apr;74(4):309-14.
4. Juhn MS. Ergogenic aids in aerobic activity. Curr Sports Med Rep, 2002 Aug;1(4):233-8.
5. Acheson KJ, Gremaud G, et al. Metabolic effects of caffeine in
humans: lipid oxidation or futile cycling? Am J Clin Nutr, 2004
Jan;79(1):40-6.
6. Acheson KJ, Zahorska-Markiewicz B, et al. Caffeine and coffee:
their influence on metabolic rate and substrate utilization in normal
weight and obese individuals. Am J Clin Nutr, 1980 May;33(5):989-97.
7. Dulloo AG, Geissler GA, et al. Normal caffeine consumption:
influence on thermogenesis and daily energy expenditure in lean and
postobese human volunteers. Am J Clin Nutr, 1989 Jan;49(1):44-50.
8. Astrup A, Buemann B, et al. The effect of ephedrine/caffeine
mixture on energy expenditure and body composition in obese women.
Metabolism, 1992 Jul;41(7):686-8.
9. Butcher RW, Baird CE, et al. Effects of lipolytic and
antilipolytic substances on adenosine 3',5'-monophosphate levels in
isolated fat cells. J Biol Chem, 1968 Apr25;243(8):1705-12.
10. Schimmel RJ. Interactions between catecholamines, methyl
xanthines and adenosine in regulation of cyclic AMP accumulation in
hamster adipocytes. Biochim Biophys Acta, 1980 Apr 17;629(1):83-94.
11. Hawke TJ, Allen DG, et al. Paraxanthine, a caffeine metabolite,
dose dependently increases [Ca2+]I in skeletal muscle. J Appl Physiol,
2000;89:2312-7.
12. Denton RM, McCormack JG. Ca2+ as a second messenger within
mitochondria of the heart and other tissues. Annu Rev Physiol,
1990;52:451-66.
13. Issekutz B, Paul P, et al. Oxidation of plasma FFA in lean and obese humans. Metabolism, 1968 Jan;17(1):62-73.
14. Groop LC, Bonadonna RC, et al. Role of free fatty acids and
insulin in determining free fatty acid and lipid oxidation in man. J
Clin Invest, 1991 Jan;87(1):83-9.
15. Ha TN, Fryer MW. Inhibitory effects of (+/-)-propanolol on
excitation-contraction coupling in isolated soleus muscles of the rat.
Br J Pharmac
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Research and Review 
