Coffee - Our Beloved Drink Part II

Coffee - Our Beloved Drink Part II

May 03, 2013 0 Comments

Staying Lean with Coffee

Sweet, sweet espresso; not just a precondition to the enjoyment of many peoples’ morning, but a growing body of study continues to cement its position as provider of a plethora of health benefits.  In this instalment, we explore the boost coffee can provide to a weight-management strategy as we have already explored the abundant antioxidant potential of the coffee bean in: Coffee, Our Beloved Drink Part I.

Serious research is exploring the relationship between coffee consumption and body composition. Fortunately for coffee lovers, most of this research finds significant benefits to be gained from consuming a daily brew, or two. Some of coffee’s impact on fat loss and weight management stems from its antioxidant capacities, by increasing overall metabolic rate, greater thermogenesis, the regulation of blood-glucose levels, fat oxidation, and regulating feelings of satiety. It is fascinating to observe how coffee’s positive influence on weight management happens through several bodily mechanisms and results from various substances packed in to this little bean.

Antioxidants and Weight Management

Brewed coffee is a complex mix of bioactive compounds, made up of pre-roast substances together with those formed during the roasting process, such as melanoidins. Many of its constituents, including polyphenols and chlorogenic acid contribute to coffee’s powerful antioxidant properties, which epidemiological research has found prevents or delays age-related diseases. The antioxidant content of coffee, while reducing oxidative damage, also supports weight management. Since high levels of oxidative stress promote insulin resistance, the elevated antioxidant defences provided by coffee help prevent weight gain.
Some researchers have found that the potent antioxidant, chlorogenic acid can help with the regulation of hunger and satiety, however these findings are disputed. Another study worth considering, out of the University of Calgary, however, found that coffee mediates levels of gut peptides, which are hormones that are intimately involved in managing feelings of satiety and the secretion of insulin.

Blood Glucose Levels

The roasting process all coffee undergoes, causes a portion of chlorogenic acid to be transformed into quinides. These compounds have been observed to regulate blood-glucose levels, and steady blood-glucose levels are known to be one of the most effective ways to manage weight. This helps avoid the ‘sugar crash’ many people experience on diets filled with sugar and carbohydrates.

In addition to quinides, a review of studies published in the American Journal of Clinical Nutrition has argued that the levels of magnesium in coffee help increase insulin sensitivity. There are many benefits to long-term magnesium intake, but most significant to this discussion is the reduced risk of type 2 diabetes and an overall lower body mass.

It goes without saying that coffee beverages can have both a positive and negative effect on weight-management. Brewed coffee itself does not adversely affect diet. Rather, the additions that usually follow (milk, sugar, cream, etc.), are the problematic ingredients, as they pack the higher caloric loads in addition to spiking blood sugar. One important aspect to note with the case of sugar, is that its addition to coffee has been found to negate the boost in insulin sensitivity that would otherwise result from drinking black coffee on its own!  Take your coffee black.

Metabolic Rate and Thermogenesis

Another study from Columbia University that conducted multiple experiments with coffee, found significant increase in metabolic rate after consuming a cup. An important point to note is that this increased rate was still observed three hours after coffee was ingested. This study found that decaffeinated coffee also had an significant effect on metabolic rate, only 10% lower than the mean increase caused by caffeinated brew.

Some of these effects on metabolism can be attributed to coffee’s increase of thermogenesis, which is essentially the body’s increased use of energy through heat production. The thermogenic effect of caffeine happens by affecting the cardiovascular system (mostly by changing heart rate), and through the production of lactate and triacyglercerol. The energy required to digest, assimilate, process and store food, otherwise called the thermic effect of food (TEF), was also observed to significantly increase after a meal with coffee. One last way the study out of Columbia observed that coffee stimulated metabolic rate was through greater oxidation of fat.

Caffeinated vs. Decaf

Most studies consulted for this article reported significant findings with the consumption of three to four cups a day. However, this quantity may not be possible or even advisable for most because of people’s varied reaction to caffeine. It is true that caffeine has independently been shown to cause greater thermogenesis, lipolysis (the process of fat breakdown) and fat oxidation (the conversion of fatty acids into usable forms of energy). In spite of this, the weight management benefits observed by most studies found similar results from the consumption of decaffeinated coffee, implying that non-caffeine compounds found in coffee can help people decrease body weight. Interestingly, an unpublished study out of the University of Warsaw found that dark roast coffee (the least caffeinated roast) was the more effective in reducing body weight than lighter roasts.

One last impact of coffee on weight management relates to physical activity and mental drive, but this will be covered with much more detail in a coming article. In the meantime, it is useful to know that the use of caffeine has also been found to improve athletic performance through its ergogenic effect (i.e. increasing endurance, power, speed). Numerous studies have also found consumption of coffee to be correlated with overall higher rates of activity in individuals.

More information on coffee and athletic and training performance coming soon!

Sources:

Acheson, K. J, B. Zahorska-Markiewicz, van Dam RM, Hu FB. “Coffee Consumption and risk of type 2 diabetes:a systematic review.” JAMA 2005; 294:97–104

Arnolov, Johan, Bengt Vessby, “Coffee Consumption and Insulin Sensitivity.” JAMA, 2004: 91: 10

Bakuradze, Tamara, Nadine Boehm1, Christine Janzowski, Roman Lang, Thomas Hofmann, Jean-Pierre Stockis, Franz W. Albert, Herbert Stiebitz, Gerhard Bytof, Ingo Lantz, Matthias Baum and Gerhard Eisenbrand, “Antioxidant-rich coffee reduces DNA damage, elevates glutathione status and contributes to weight control: Results from an intervention study.” Mol. Nutr. Food Res. 2011, 55, 793–797

Bidel S, Hu G, Sundvall J, Kaprio J, Tuomilehto J. “Effects of coffee consumption on glucose tolerance, serum glucose and insulin levels—a cross-sectional analysis.” Horm Metab Res 2006;38:38–43

Clifford, M. N. (1999) “Chlorogenic Acids and Other Cinnamate: Nature, Occurrence and Dietary Burden.” J. Sci. Food Agric. 79:362-372.

Dulloo A, Geissler C, Horton T, Miller D. “Normal cafeine consumption: influence on thermogenesis and daily energy expenditure in lean and postobese human volunteers.” Am J Clin Nutr 1989;49:44 –50

Greenberg, James, Carol N Boozer, and Allan Geliebter, “Coffee, diabetes, and weight control.” Am J Clin Nutr 2006;84:682–93

Petrie HJ, Chown SE, Belfie LM, et al. “Caffeine ingestion increases the insulin response to an oral-glucose-tolerance test in obese men before and after weight loss.” Am J Clin Nutr 2004;80:22– 8

Salinardi, Taylor C;Rubin, Kristin Herron;Black, Richard M;St-Onge, Marie-Pierre. “Coffee Mannooligosaccharides, Consumed As Part of a Free-Living, ...” The Journal of Nutrition; Nov 2010; 140: 11-21

Thom, E. “The Effect of Chlorogenic Acid Enriched coffee on glucose absorption in healthy volunteers and its effect on body mass.” Journal International Medical Research. 2007; 35:900-908.

Tunnicliffem Jasmine M. and Jane Shearer. “Coffee, glucose homestasis, and insulin resistance: physiological mechanisms and mediators.” Applied Physiology and Nutrition Metabolism. 2008: 33: 1290-1300

There are 0 comments for this entry. Leave a comment below »

Leave a comment. *Required

Commenting is not available in this channel entry.