A recent medical study announced that regular consumers of coffee have a relative risk of death higher than the others. Saying this, however, we shouldn’t ignore the fact that the lovers of the black drink, smoke more, drink more alcohol, eat more calories and red meat, and engage in physical activity less than the rest of the population.
Considering these biases, the authors of the study, published in the New England Journal of Medicine in may 17, 2012, have been able to isolate the specific effect of the coffee. And the result of the observation is quite different. The mortality would decrease by 10% in men and about 15% in women if drinking beyond two or three cups per day. The hot beverage, with or without caffeine, offers a protection against all causes of death except cancer, against which it is neutral.
Conducted in the United States between 1995 and 2008, that study is a follow-up of another study of 230000 men and 173000 women aged 50 to 71 years old. “No one has ever seen such a great cohort mobilized for such a subject before,” says Thomas Perneger, manager of the Department of clinical epidemiology at the University Hospital of Geneva (HUG). Although it is solid, this work is only observational. It therefore does not provide the formal proof of a causal relationship between coffee consumption and a decrease in mortality. We can’t say for the moment there is a close link between the two.”
Is Then Coffee Consumption Recommended?
Still, the doctors of Geneva wouldn’t go so far as to advise patients to start drinking coffee. But at least, this is a habit, he says, he will not have to worry about during his consultations.
Coffee even has some effects in psychiatry. A large observational study has examined the link that may exist between the coffee and the onset of depression. More than 50,000 women from the Nurses’ Health Study in the United States (one of the largest and oldest investigations on the health of women of the world) participated between 1996 and 2006. Published in the journal Archives of Internal Medicine, 26 September 2011, the study concluded there was a significant decrease in the onset of depressive episodes proportional to the dose of coffee gulped down by the participants.
“This result is important and encouraging, but the Nurses’ Health Study was not designed to recognize individuals suffering from anxiety disorders or sleep disorders, says Denis Rentsch, head of clinic at reception Service and emergency psychiatric at HUG. So, we can’t exclude that, instead of a decrease in depression among consumers of coffee, there was an increase of this disease in the ones drinking it. The latter are more likely to find the negative effects instead of those who renounce the black beverage, because they fear that because of this drink they could not sleep or will make them anxious. And maybe depression is more frequent in this category of the population.”
While we could still exclude the bias, the doctor believes that he would have to convince 1500 sober to drink three cups of coffee per day for a year in order to avoid a depressive episode during the same span of time. We can say that such measure would be inefficient from the view of public health.
Coffee protects the liver.
In an article published in the European Journal of Gastroenterology & Hepatology in November 2010, it finally appears that the coffee would also be a powerful protector against diseases of the liver. The review article, which provides a synthesis of the scientific literature published on this topic, shows as well as in alcoholics, the consumption of more than four cups a day seems to play a protective role against cirrhosis of the liver. In patients not addicted to alcohol, we find a similar trend although the results are not statistically significant.
“On the liver, the higher the dose of coffee is important, the more the effect is marked”
In the same way, a number of studies have shown that there is an inverse correlation between coffee consumption and, on the one hand, the development of liver cancer and, on the other, the number of decompensations of the liver during viral infections of the body.
“Again, it is each time relationships of correlation and not causation, says Thierry Favrod-Coune, head of clinical Unit of the dependencies in the medicine of first use of the HUG. We cannot exclude alternative explanations. That said, several elements speak in spite of everything, in favor of a causal relationship: the studies are concordant between them, the number of subjects enrolled is large, the populations studied are heterogeneous and, argument, particularly convincing, the higher the dose of coffee is important, the more the effect is marked.”
There is no reason to abandon your coffee!
More than a thousand chemicals
Consumption of coffee may bring many good effects on health. But what is the mechanism? This remains a mystery. However, one is for sure: the stimulant effects of caffeine are well known, but is not the only one. The benefits measured mortality are independent of the presence or absence of caffeine. This, except for death caused by an accident and for which the decaffeinated coffee does not, without surprise, no protection in contrast to regular coffee.
Also, the benefits on liver diseases (cirrhosis, cancer or viral infection), disappear if we replace coffee with tea, and that means theine and caffeine in reality are the same molecule.
The explanation lies, therefore, probably in more than one thousand chemical compounds that include coffee, among whom there are tens of bioactive principles. Among others, we can mention cafestol (a molecule that seems to increase slightly the rate of cholesterol in the blood, but who is stopped by the paper filters), the kahweol (a substance present in the arabica with many virtues), chlorogenic acid and an army of antioxidants (polyphenols, catechins and other flavonoids).
The effects of coffee on our body
- Increase alertness, concentration and memory, especially in people tired
- Decrease of the onset of depressive episodes
Decrease of mortality from all causes except cancer
- Beneficial effect on cancer of the endometrium and liver. However, the coffee has no influence on the mortality due to cancer
- Decrease in the risk of myocardial infarction in the healthy person, or patients whose disease has stabilized.
- Protective effect against cirrhosis of the liver in alcoholics
- Reduction of insulin resistance and a decrease in the incidence of type II diabetes
- Decrease the chance of Parkinson’s disease
- Decrease in the risk of developing Alzheimer’s disease
- Decreased risk of developing gout
Its side effects:
Insomnia, anxiety, panic attacks in susceptible individuals, or already suffering from psychiatric disorders
Effect of tolerance and withdrawal in a third of consumers, without that there is a true effect of dependence
The stimulant effect of caffeine may lead to a myocardial infarction in susceptible individuals or in patients where the disease has not yet stabilized.
Increase in the risk of osteoporosis in women classified as “at-risk” (over the age of 65 and a low intake of calcium)
The “excesses” of coffee during pregnancy may lead to miscarriage or development of tumors in the brain of the newborn., however, pregnant women dislike coffee
Other harmless delights
A widespread opinion is that the small pleasures of everyday life end up one day with a heavy cost to the health. In this pessimistic view, the café offers a nice counter-example. And it is not the only one.
Emblematic of the french paradox, the consumption of wine has its own advantages. A Danish study published in the Annals of Internal Medicine September 19, 2000 drives the nail. It shows that for moderate drinkers (between one and seven drinks per week), mortality due to coronary heart disease and cancers is lower than among abstainers. Drinkers are more intensive to see their relative risk of death increase, but it is necessary all the same consumption of half a dozen glasses of wine per day, so this risk exceeds again the sober.
An older study, published in the journal British Medical Journal of December 20, 1997, shows the importance of sexual pleasure for the health. Based on a group composed only of men, it yields an increase in the risk of death from all causes among people whose frequency of orgasms is low (less than once per month).Tags: caffeine, coffee, health, health benefits, study