Posted on July 10, 2012 - 1 Comment
Coffee is in the news again with a new report published by the New England Journal of Medicine in May, 2012. This study, run by the National Cancer Institute, tracked the coffee consumption, and general health, of over 400,000 older adults (ages 50 to 71) for almost 14 years. What they found was those who drank 4 or 5 cups of coffee daily had a lower risk of death, than those who drank little or no coffee.
Ever since the development of coffee as a beverage, about 500 years ago, there has been debate as to its benefits versus its dangers. As coffee spread throughout Europe, the Middle East and the Americas, the dangers perceived were cultural, and it has been banned repeatedly for both political and religious reasons. Now we debate its health benefits.
Coffee berries contain the coffee “beans”, and are produced by several species of a small evergreen bush of the genus “Coffea”. One of the most popular beverages in the world, coffee was the world’s seventh-largest (legal) agricultural export by value in 2005. According to the National Coffee Association, about 65% of Americans drink coffee on a daily basis, averaging 3.2 cups daily (I will assume that the figures are roughly accurate for Canadians as well.)
Since controversy is associated with the impact of coffee cultivation on the environment, organic coffee is now an expanding market. Because coffee is traditionally a “third-world cash crop” I strongly advise that one make every effort to buy and drink organic coffee. Such cash crops are commonly loaded with pesticides. Since all the studies referred to in this article were most certainly not organic, I believe any benefits associated with coffee will be much stronger if we are drinking organic coffee.
Now back to the coffee and longevity study. In the initial phase of data analysis it appeared that coffee reduced longevity, until the numbers were adjusted for those who smoked and had other risk factors. Then the numbers indicated that those men who drank one cup per day had a 6% lower risk of death during the course of the study. Those who drank 2 or 3 cups daily had a 10% lower risk of death and those who drank 4 to 5 cups daily had a 12% lower risk. Once men got up to 6 or more cups daily the risk factor ceased to improve and dropped back to a 10% lower risk of death, compared to those who drank no coffee.
The benefits were even better for women. Women who drank one cup per day had a 5% lower chance of dying during the course of the study, compared with women who drank no coffee. Those who drank 2 or 3 cups daily were 13% less likely to die, and those who drank 4 to 5 cups daily were 16% less likely to die. Again, once we got above 6 cups daily the trend reversed and the benefit dropped to a 15% lower mortality rate.
The results of the study were defined as such: “Inverse associations were observed for deaths due to heart disease, respiratory disease, stroke, injuries and accidents, diabetes, and infections, but not for deaths due to cancer. Results were similar in subgroups, including persons who had never smoked and persons who reported very good to excellent health at baseline.” (Study)
The actual conclusion of this study was as follows: “In this large prospective study, coffee consumption was inversely associated with total and cause-specific mortality. Whether this was a causal or associational finding cannot be determined from our data.” But at least, “the results offer some reassurance that it’s not a risk factor for future disease” said Neal Freedman the leader of the study.
What the study summary is saying is that the authors can’t be sure if the coffee caused good health or if drinking coffee was simply associated with good health. This is better illustrated by considering the similar conclusion of a study showing that wine drinkers were slimmer than beer drinkers. If the relationship was causal then wine makes you slim and beer makes you fat. But if the relationship was associational then it meant that wine drinkers, who are generally from a better educated class, tend to exercise more and have a better diet, and as a result are slimmer. Whereas the beer drinkers, being less well educated, may be feasting on pub food and exercising less, which is really what is making them fatter. But, in this case we do have the antioxidant content of the coffee to support the idea that the relationship is causal.
It should be pointed out that the link between coffee consumption and lowered mortality was strongest for those who had never smoked. As well, they found that the benefit seemed to hold even for those who drank mostly decaffeinated coffee. Rob van Dam, an epidemiologist at the National University of Singapore, who has been involved in other coffee studies, commented: “If these are real biological effects, they seem to have to do with the substances in coffee that are not caffeine.”
We do know from other research that the presence of powerful antioxidants in coffee have been shown to prevent cellular free radical damage. A recent study showed that roasted coffee, rich in antioxidants and chlorogenic acid lactones, protected primary neuronal cell cultures against hydrogen peroxide-induced cell death, a form of free radical damage. (Study)
Takayuki Shibamoto, a professor of environmental toxicology, says that, based on his preliminary study, the antioxidants in a cup of coffee might be equal to the amount found in three oranges. “You have to drink it in about 20 minutes after it is brewed,” Shibamoto said. (Article) I’m sure you may have noticed a funky taste in your mouth after drinking some commercial coffees. That is the taste of rancid oils found in coffee that has been sitting around for too long. At that point the benefits of the antioxidants have dissipated and the coffee is probably doing more harm than good.
Over time many scientific studies have examined the relationship between drinking coffee and an array of health issues. Some of these findings have been contradictory as to whether coffee is good for you or bad for you. And the method used to prepare coffee is one factor in the discrepancy in findings. Coffee prepared using paper filters removes oily components called diterpenes that are present in unfiltered coffee, which have been associated with increased risk of coronary heart disease via elevation of low-density lipoprotein (LDL) levels in blood. Metal filters, used in Bodums, and to make espresso, and Americano style coffees, do not remove the oily components of coffee. These acids whether removed or remaining, may also have other effects yet to be discovered.
A 22-year study done by the Harvard School of Public Health concluded that “the overall balance of risks and benefits of coffee consumption are on the side of benefits.” Another study showed that men who drank 6 or more cups of coffee per day were found to have a 20% reduction in developing prostate cancer. (Study)
Other studies have suggested that coffee consumption reduces the risk of Alzheimer’s disease, Parkinson’s disease, heart disease, type 2 diabetes, cirrhosis of the liver and gout. (Study)
A 2009 study showed that those who consumed a moderate amount of coffee or tea (3–5 cups per day) during midlife were less likely to develop dementia and Alzheimer’s disease in later in life, compared to those who drank little or no coffee. (Study)
Coffee is a known ergogenic aid: that is it improves sports performance. But this only occurs if it is used occasionally. The benefits to the athlete cease if it is used consistently.
Coffee has beneficial effects against type 2 diabetes but that is not due to its caffeine content, since the positive effects of consumption are greater in those who drink decaffeinated coffee. A Chinese study reported that two of the major components of coffee (caffeic acid and chlorogenic acid) seem to be responsible for this effect.
New research presented at the American chemical Society spring conference reported that an extract of green coffee bean was an effective weight loss agent. Subjects were given capsules to swallow three times a day, taking between 700 and 1000mg or a placebo. They did not change their calorie intake during the trial. Though the study only involved 16 people, those on the supplement lost an average of 17.5 pounds in 22 weeks, reducing their overall body weight by over 10%. The researchers believe that the coffee bean extract works by reducing the absorption of fat and glucose in the digestive tract, and by reducing insulin levels.
Green coffee bean extract is sold in a variety of strengths, usually containing from 30% to 50% chlorogenic acid. Since, as we have seen above, the chlorogenic acid is responsible for stabilizing insulin levels, in diabetes studies, we can see a mechanism whereby the weight loss could logically occur.
NEXT TIME PART TWO OF COFFEE AND HEALTH: THE DOWNSIDE OF COFFEE