Dr. Silvia Casella
Medical Doctor
Gastroenterology Unit and Geriatric Unity,
Spedali Civili and University of Brescia (Italy)
From a biochemical point of view, coffee results to be a mixture of more than 100 components (1), from which the more significant are represented by the following:
From the point of view of Biological activity, the components of coffee are as follows:
Caffeine (1,3,7 trimethylxanathine): is a purine alkaloid, which can be easily found in coffee beans (fig. 1). Caffeine is an adenosine antagonist, an inhibitor to the central nervous system, therefore for this reason, coffee is a stimulant: Caffeine is rapidly and completely absorbed by the stomach and the small intestine, and subsequently is distributed to all the tissues, including the brain. The metabolism of caffeine occurs principally in the liver, where cytochrome P450 is activated. A small cup of coffee (50mg) contains 50 to 80 mg of caffeine. Actually the concentration of caffeine varies according to how it is prepared . In fact a recent analysis carried out on 14 different types of coffee sold in the USA, demonstrated that the same quantity of beverage (approx.240ml) the caffeine quote varied from 72 to 130 mg (2). Extraordinarily it was also shown that the content of caffeine of the same type of coffee bought from the same roasting mill, in six different days varied significantly.
Chemical structures of caffeine and adenosine
Diterpenes (cafestol and cafeolo): The consumption of coffee is associated in some studies to an increase of LDL cholesterol levels. But such a theory, has not been supported with excessive studies (3). Actually the entity of such an effect depends on the way the beverage is prepared and it is strictly tied to the production of these diterpenes (fig2). In particular we observe, that when coffee has boiled, for example, in Turkish coffee, Scandinavian and French the quantity of cafestol and cafeolo is very high (6-12mg), as in the now obsolete Italian boiled coffee (coffee from the pot, made by our grandmothers). While in filtered coffee, as in American coffee or Espresso coffee, the quantity of such elements is much more inferior (0,2 – 0,6mg/ cup) (4,5). This is easily explained by the fact that diterpenes are produced by coffee during boiling, but are also removed when a filter is used. At a Physiological level, it has been proven that in ileostomia patients, 70% of the diterpenes is absorbed by the bowel (6).
Cafestol and Kahweol
Chlorogenic acid: represents a foreign family (fig.3). That are formed between chinic acid and trans cinnamic (7). Coffee represents one of the major food sources of clorogenic acid and cinnamic acid (caffeic acid). Clorogenic acid has a powerful antioxidant effec (8,9), a cup of coffee contains from 18 to 90 mg. Thirty-three % of clorogenic acid ingested and 95% of caffeic acid is absorbed in the bowel. At this level 2/3 of the clorogenic acids ingested are metabolized by the intestinal microflora.
Chlorogenic Acid
Micronutrients: numerous micronutrients are found in coffee, they include; magnesium potassium, niacin and vitamin E, all these contribute to the beneficial effects that come from drinking this king of beverages (10).
A NEGATIVE MYTH TO DISPEL
For many years, it was thought that coffee, in particular caffeine, was harmful to our health. This is not actually the truth, coffee has several beneficial effects on our health. It is important to explain the motivation behind this false belief, in fact epidemiological studies were biased from the fact that patients who drank a lot of coffee were very often also heavy smokers and were those patients that did no lead a healthy lifestyle.
PROTECTIVE EFFECTS OF COFFEE
PROTECTIVE EFFECT ON LIVER
Liver damage is determined by a chronic inflammation which leads to a liver cirrhosis. In the liver cirrhosis, fibrotic tissue formation, progressive deterioration of the liver functions and causes a series of complications, first of all, liver cancer. The most common causes of liver cirrhosis are represented by the abuse of alcohol and viral hepatitis (B and C).
- Coffee and prevention of liver damage
Important serological markers of liver damage is the transaminase (ALT alanine aminotransferase) and GGT (glutamyl transferase). Different studies have shown that regular consumption of coffee helps reduce these markers (12). In particular, in an important study carried out in USA on 6000 adults affected by multiple forms of liver disease, was shown that a net reduction of the ALT levels to those patients consuming coffee regularly (13).
- Coffee and prevention of liver cirrhosis
The consumption of coffee is inversely associated with the risk of developing liver cirrhosis in different case studies (14), in two prospective cohort studies it was noted that a correlation with a reduced risk of mortality, in those with liver cirrhosis on an alcoholic level (15). A study conducted for 8 years on more than 120.000 subjects, found that there was a 22% reduction of the mortality risk for alcoholic cirrhosis for every cup of coffee consumed a day (16). In another study carried out for 17 years, where more than 51000 subjects were taken into consideration, it was noted that there was a 40% reduction of mortality in those who consumed at least 2 cups of coffee a day compared to those that did not drink coffee at all (17).
- Coffee and reducing the risk of liver cancer
Now numerous studies have evidenced a correlation between the consumption of coffee and the reduced risk of developing liver cancer. The most recent study published in March 2011, carried out in Singapore on 63.257 subjects average aged to advanced with a high level risk of liver cancer (18). What was extraordinarily demonstrated was that compared to those subjects that did not drink coffee, those that did and drank 3 cups o more of coffee a day had a 44% reduction risk of developing liver cancer. Different studies have pointed out how caffeine and chlorogenic acid inhibit liver carcinogenesis, as it was also demonstrated for diterpenes.
- Increasing the percentage of SVR in hepatitis HCV
Chronic hepatitis from the hepatitis virus C (HCV) today is treated with the combination of two drugs: pegylated interferon and ribavarin. The probability of healing is variable depending on the genotype of the virus and on a series of interchanging and non-interchanging factors. In general the probability of healing with an antiviral therapy can go from 30-40% in the less easy cases and from 80-90% in the easier ones. Extraordinary is the discovery, however and very recent, that coffee determines the increase in probabilities of success in the antiviral therapy and treating hepatitis (19).
PREVENTION OF DIABETES
Diabetes Mellitus type 2 is a metabolic disorder characterized by the high concentration of glucose in the blood and a number of serious vascular and neurological complications. Prevention of Type 2 diabetes mellitus. Numerous studies have been published over the past years that have correlated a reduced risk of developing diabetes mellitus with the introduction of appropriate quantities of coffee. The two major prospective cohort studies that have analyzed this correlation are Health Professional Follow Up Study (41.934 men enrolled) and the Nurses’ Health Study (84.276 women enrolled) (20) . In both groups it was observed a 54% reduction and 29% respectively, the risk in developing diabetes mellitus in those who drank an adequate quantity of coffee, compared to those that did not drink coffee at all. Recently a systematic review on 9 perspective studies, that included more than 193,000 subjects, demonstrated a reduction of diabetes mellitus type 2 of 35% in those who consumed 6 cups/day and 28% in those that drank from 4 to 6 cups/day, compared to those who drank less than 2 cups a day (21).
PREVENTION OF PARKINSON’S DISEASE
Numerous studies have underlined a correlation with the consumption of coffee and reducing the risk of developing Parkinson’s disease (22). A study has demonstrated that those that assumed on a regular basis at least 1 cup of coffee a day had the risk of developing Parkinson’s disease over the following 10 years, halved, compared to those that did not drink coffee at all (23). In the cohort study it an inverse correlation was observed between coffee consumption and the risk of developing the disease, in women that did not undertake hormone therapy post menopausal, while such correlation is not evidenced in those that did take the hormone (24). It is interesting to note that the consumption of coffee determines a frank reduction of the prodromal symptoms of Parkinson’s Disease, in particular behavior alterations, sleeping disorders and altered taste (25). Parkinson’s disease is characterized by the degeneration of the dopaninergic neurons in the “substantia nigra”. The live studies carried out demonstrated that the consumption of coffee reduces the risk of Parkinson’s disease through the protective effect that it has towards the dopaminergic neurotoxicity (26).
REDUCING THE RISK OF SUICIDE
Prospective studies carried out in the USA has demonstrated a significant inverse correlation between regular consumption of coffee and suicide risk (27,28). This study carried out in California over a period of 10 years and conducted on more than 128,000 subjects, evidenced a risk reduction in suicides of 13% for each cup of coffee consumed daily. In the same way another study was carried out on 86,000 women that drank more than 2 cups of coffee daily had the risk halved, compared to those that did not drink coffee at all (19).
PREVENTION OF COLORECTAL CANCER
Generally the consumption of coffee has been inversely correlated to the risk of colorectal cancer in numerous case studies, but not confirmed in prospective cohort studies. A test that analyzed the results of 12 single case studies and 5 prospective studies, has evidenced a reduction of cancer risk up to 24% in those that drank 4 cups of coffee a day compared to those that drank 2 cups of coffee (29). Similarly, in a study carried out in USA, a 48% reduction of cancer risk was observed in those that drank up to 2 coffees a day in respect to those that drank 3 (30). Different mechanism were proposed to explain the association between the consumption of coffee and the reduction of developing colorectal cancer, but still there is no clear exiopathogenetical theory that can fully explain such condition.
CAUTION TOWARDS THE QUANTITY OF COFFEE
Of course, as for all substances, you must not exceed or exaggerate in the quantity of coffee drunk daily, (an exaggerated quantity would be more than 5/6 cups a day). In particular those that suffer high blood pressure must not abuse of this drink. This does not mean that certain people should not drink coffee, in fact it has been proved that a moderate consumption of 2/3 cups a day does not interfere with hypertension. The same is for those people that suffer from hypercholesterolemia. We recommend it better not to exceed 2 cups of coffee a day, moreover for homemade coffee we recommend you to use a filter, in order to eliminate the diterpenes (as thoroughly explained on the first page).
CONCLUSIONS
It was thus shown that coffee has excellent qualities, and can prevent, if taken in small quantities, numerous conditions.
Like all substances, moderation is imperative, do not exceed 3 cups of coffee a day.
For a correct and healthy lifestyle we recommend a balanced diet, daily exercise, no smoking or alcohol, but you will be happy to hear you say that it is allowed, even recommended, a good cup or two of coffee!
BIBLIOGRAPHY
1 Spiller M.A., 1998. The chemical components of coffee. In: Caffeine. Pp 97-161. Spiller G.A., Ed., CRC Press, Boca Raton.
2 McCusker RR., Goldberger BA., Cone EJ. Caffeine content of speciality coffees. J Anal Toxicol. 2003; 27(7): 520-522.
3 Thelle DS., Heyden S., Fodor JG. Coffee and cholesterol in epidemiological and experimental studies. Atherosclerosis. 1987; 67: 97-103.
4 Urgert R., Katan MB. The cholesterol-raising factor from coffee beans. Annu Rev Nutr. 1997; 17: 305-324.
5 Gross G., Jaccaud E., Huggett AC. Analysis of the content of the diterpenes cafestol and kahweol in coffee brews. Food Chem Toxicol. 1997; 35(6): 547-554.
6 De Roos B., Meyboom S., Kosmeijer-Schuil TG, Katan MB. Absorption and urinary excretion of the coffee diterpenes cafestol and kahweol in healthy ileostomy volunteers. J Intern Med 1998; 244: 451-460.
7 Clifford MN. Chlorogenic acids and other cinnamates-nature occurrence and dietary burden. J Sci Food Agric. 1999; 79: 362-372.
8Iwai K., Kishimoto N., Kakino Y., Mochida K., Fujita T. In vitro antioxidative effects and tyrosinase inhibitory activities of seven hydroxycinnamoyl derivatives in green coffee beans. J Agric Food Chem. 2004; 52(15): 4893-4898.
9 Olthof MR., Hollman PC., Buijsman MN., Van Amelsvoort JM., Katan MB. Chlorogenic acid, quercetin-3-rutinoside and black tea phenols are extensively metabolized in humans. J Nutr. 2003; 133(6): 1806-1814.
10 U.S. Department of Agriculture and Agricultural Research Service. 2004. USDA Nutrient Database for Standard Reference, Release 17. http://www.nal.usda.gov/fnic/foodcomp.
11Willet W.C., Stampfer M.J., Manson J.E., et all. Coffee consumption and coronary heart disease in women. A ten-year follow-up. JAMA 1996; 275: 458-462.
12 Tanaka K., Tokunaga S., Kono S et all. Coffee consumption and decreased serum gamma-glutamyltransferase and aminotransferase activities among male alcohol drinkers. Int J Epidemiol. 1998; 27: 438-443.
13Ruhl CE., Everthart JE. Coffee and caffeine consumption reduce the risk of elevated serum alanine aminotransferase activity in the United States. Gastroenterology. 2005; 128: 24-32.
14 Corrao G., Lepore AR., Torchio P et all. The effect of drinking coffee and smoking cigarettes on the risk of cirrhosis associated with alcohol consumption. A case-control study. Provincial Group for the Study of Chronic Liver Disease. Eur J Epidemiol. 1994; 10: 657-664.
15 Klatsky AL, Armstrong MA. Alcohol, smoking, coffee and cirrhosis. Am J Epidemiol. 1992; 136; 1248-1257.
16 Klatsky AL, Armstrong MA., Friedman GD. Coffee, tea and mortality. Ann Epidemiol. 1993; 3; 375-381.
17 Tverdal A., Skurtveit S. Coffee intake and mortality from liver cirrhosis. Ann Epidemiol. 2003; 13: 419-423
18 Johnson S, Koh WP, Wang R, Govindarajan S, Yu MC, Yuan JM. Coffee consumption and reduced risk of hepatocellular carcinoma: findings from the Singapore Chinese Health Study. Cancer Causes Control. 2011 Mar;22(3):503-10. Epub 2011 Jan 22.
19 Freedman ND, Curto TM, Lindsay KL, Wright EC, Sinha R, Everhart JE; HALT-C Trial Group. Coffee Consumption is Associated with Response to Peginterferon and Ribavirin Therapy in Patients with Chronic Hepatitis C. Gastroenterology. 2011 Mar 1. [Epub ahead of print]
20 Salazar –Martinez E., Willet WC., Ascherio A., et all. Coffee consumption and risk for type 2 diabetes mellitus. Ann Intern Med. 2004; 140: 1-8
21 Van Dam RM., Hu FB. Coffee consumption and risk of type 2 diabetes: a sistemic review. JAMA. 2005; 294: 97-104
22 Hernan MA., Takkouche B., Caamano-Isorna F., et all. A meta-analysis of coffee drinking, cigarette smoking, and the risk of Parkinson’s disease. Ann Neurol 2002; 52: 276-284.
23 Ascherio A., Zhang SM., Hernan MA. Prospective study of caffeine consumption and risk of Parkinson’s disease in men and women. Ann Neurol. 2001; 50: 56-63.
24 Ascherio A., Weisskopf MG., O’Reilly EJ. Coffee consumption, gender, and Parkinson’s disease mortality in the cancer prevention study II cohort: The modifying effects of estrogen. Am J Epidemiol. 2004; 160: 977-984.
25 Ascherio A., Chen H. Caffeinated clues from epidemiology of Parkinson’s disease. Neurology. 2003; 61: s51-s54.
26 Schwarzschild MA., Chen JF, Ascherio A. Caffeinated clues and the promise of adenosine A(2A) antagonists in PD. Neurology. 2002; 58: 1154-1160.
27 Kawachi I., Willet WC., Colditz GA et all. A prospective study of coffee drinking and suicide in women. Arch Intern Med. 1996; 156: 521-525.
28 Klatsky AL., Armstrong MA., Friedman GD. Coffee, tea and mortality. Ann Epidemiol. 1993; 3: 375-381.
29 Giovannucci E. Meta-analysis of coffee consumption and risk of colorectal cancer. Am J E pidemiol. 1998; 147: 1043-1052.
30 Michels KB., Willet WC., Fuchs CS., Giovannucci E. Coffee, tea and caffeine consumption and incidence of colon and rectal cancer. J Natl Cancer Inst. 2005; 97: 282-292.
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