A paper that's going to be published in the next issue of AGE the Journal of the American Aging Association could however help not just to bridge the widening gap between the ever-increasing number of epidemiological studies showing between moderate caffeine consumption and metabolic, cardiovascular, neurological, and cellular health (see list at the end of this post) and the conflicting evidence from experiments that investigate the acute response to caffeine ingestion in both caffeine-naive individuals and habitual caffeine consumers.
Consistent caffeine consumption is the key to "chronic health" ;-)
I am pretty sure this study won't close the lit on the never-ending debate about the pros and cons of caffeine consumption - mostly because it's a rodent study, but also in view of the fact that there is no definite border between "habitual consumption" and "chronic abuse", when it comes to a substance the stimulating side-effects of which can keep you functioning (and training!), when your body would otherwise long have called a halt.
Against that background it is important to realize that the rodents in the study at hand were leading a happy, more or less stress-free life. They consumed what you would consider a "healthy" diet for a rodent and had free access to a wheel, the average male and female Wistar who has neither television, nor Internet or a PlayStation in his or her cage, will actually make good use of.
CLA Destroys Body Fat: Effect Borders Pathological Lipodystrophy!"). Remember: Consistency is key! And some of the benefits of today's coffee may not show before you are in your late 70s... but let's get back to the results data from figure 1 and their implications for your current and future health:
- the decrease in visceral fat mass was not due exclusively to increased lipolysis
- the increase in insulin sensitivity induced by caffeine was not attributable to weight loss, increased NO production, caffeine-mediated antioxidant effects, decreased cortisol levels, or decreased SNS activity
- caffeine intake did not modify blood pressure, endogenous NO production, or antioxidant capacity in aged animals
- caffeine administration restored Glut4 expression in the elderly group, but it was not able to increase Glut4 expression above amaximal level in the 12Mgroup
- the rodents were kept on a normal diet, a healthy body weight is thus only a sign of overall metabolic health (remember: skinnier does not equal healthier!),
- the 42% lower visceral fat levels in what would be middle aged rodents (12 months) is one of the most significant predictors of healthy aging (optimal brain and metabolic health + no cancer), and
- the maintenance of skeletal muscle GLUT4 expression is of fundamental importance to ward of those increasingly common "age-related" diseases of which we already know that they are at least precipitated by insulin resistance and high glucose levels, such as Alzheimer's and "regular" dementia (e.g. Rönnemaa. 2008; Accardi. 2012; Williamson. 2012)
"[...] increase in insulin sensitivity induced by caffeine was not attributable to weight loss, increased NO production, caffeine-mediated antioxidant effects, decreased cortisol levels, or decreased SNS activity [so that caffeine effectively] restored [otherwise elevated] circulating NEFA in aged animals to values observed in young 3 M control rats." (Guarino. 2012)In the absence of increased NEFA levels, an increased sympathetic tone (=higher catecholamine and cortisol levels) and in the presence of optimal GLUT-4 expression and low visceral fat levels in the young and middle aged rodents, there is actually no reason why we would see any of the putative negative effects on glucose metabolism of about which you will probably have read and heard numerous times in the laypress.
Glucose management figures everywhere and so does coffee!
In view of the major role of glucose management in all sorts of the metabolic, endocrine and neurcrine diseases, it is thus no wonder that study after study finds beneficial effects of moderate caffeine consumption on...
- risk of heart failure (Mostofsky. 2012)
- perceptibility to arrhythmia (Klatsky. 2011)
- venous thromboembolism (Enga. 2011)
- general cardiovascular disease (Bøhn. 2012)
- dementia & Parkison's (Cao. 2012; Campdelacreu. 2012)
- diabesity (Hjellvik. 2011; Matsuura. 2012)
- pancreatic cancer (Dong. 2011), as well as
- bladder, breast, buccal and pharyngeal cancer (Yu. 2011)
- colorectal, endometrial, esophageal cancer (Yu. 2011)
- hepatocellular, leukemic, and prostate cancers (Yu. 2011)
- Accardi G, Caruso C, Colonna-Romano G, Camarda C, Monastero R, Candore G. Can Alzheimer disease be a form of type 3 diabetes? Rejuvenation Res. 2012 Apr;15(2):217-21.
- Bøhn SK, Ward NC, Hodgson JM, Croft KD. Effects of tea and coffee on cardiovascular disease risk. Food Funct. 2012 Jun;3(6):575-91.
- Campdelacreu J. Parkinson disease and Alzheimer disease: environmental risk factors. Neurologia. 2012 Jun 13.
- Cao C, Loewenstein DA, Lin X, Zhang C, Wang L, Duara R, Wu Y, Giannini A, Bai G, Cai J, Greig M, Schofield E, Ashok R, Small B, Potter H, Arendash GW. High Blood caffeine levels in MCI linked to lack of progression to dementia. J Alzheimers Dis. 2012;30(3):559-72.
- Dong J, Zou J, Yu XF. Coffee drinking and pancreatic cancer risk: a meta-analysis of cohort studies. World J Gastroenterol. 2011 Mar 7;17(9):1204-10.
- Enga KF, Braekkan SK, Hansen-Krone IJ, Wilsgaard T, Hansen JB. Coffee consumption and the risk of venous thromboembolism: the Tromsø study. J Thromb Haemost. 2011 Jul;9(7):1334-9.
- Gasior M, Jaszyna M,Munzar P,Witkin JM, Goldberg SR. Caffeine potentiates the discriminative-stimulus effects of nicotine in rats. Psychopharmacology (Berl). 2002; 162:385–395
- Guarino MP, Ribeiro MJ, Sacramento JF, Conde SV. Chronic caffeine intake reverses age-induced insulin resistance in the rat: effect on skeletal muscle Glut4 transporters and AMPK activity. Age (Dordr). 2012 Sep 14.
- Hjellvik V, Tverdal A, Strøm H. Boiled coffee intake and subsequent risk for type 2 diabetes. Epidemiology. 2011 May;22(3):418-21.
- Jafari A, Kherad N, Melekirad AA. Effect of short-term caffeine supplementation on downhill running induced inflammatory response in non-athletes. Journal of Cell. Winter 2012; 2(4):377-385
- Klatsky AL, Hasan AS, Armstrong MA, Udaltsova N, Morton C. Coffee, caffeine, and risk of hospitalization for arrhythmias. Perm J. 2011 Summer;15(3):19-25.
- Matsuura H, Mure K, Nishio N, Kitano N, Nagai N, Takeshita T. Relationship between coffee consumption and prevalence of metabolic syndrome among Japanese civil servants. J Epidemiol. 2012;22(2):160-6.
- Mostofsky E, Rice MS, Levitan EB, Mittleman MA. Habitual coffee consumption and risk of heart failure: a dose-response meta-analysis. Circ Heart Fail. 2012 Jul 1;5(4):401-5. Epub 2012 Jun 26.
- Nature.com Reviews. Heart failure: Moderate coffee consumption linked with reduced risk of HF. Nat Rev Cardiol. 2012 Jul 17;9(9):492.
- Rönnemaa E, Zethelius B, Sundelöf J, Sundström J, Degerman-Gunnarsson M, Berne C, Lannfelt L, Kilander L. Impaired insulin secretion increases the risk of Alzheimer disease. Neurology. 2008 Sep 30;71(14):1065-71.
- Williamson R, McNeilly A, Sutherland C. Insulin resistance in the brain: An old-age or new-age problem? Biochem Pharmacol. 2012 Sep 15;84(6):737-45.
- Yu X, Bao Z, Zou J, Dong J. Coffee consumption and risk of cancers: a meta-analysis of cohort studies. BMC Cancer. 2011 Mar 15;11:96.