I woke up this morning to the headlines that yet another study had been done of coffee to see whether it was actually healthy or unhealthy to have our daily cup. Since we drink coffee ubiquitously, there is also been a continuing desire by scientists to study and understand the effects of drinking coffee on our bodies. This study was published in the Annals of Internal Medicine.
Fortunately for those of us who are coffee aficionados, studies increasingly have been showing that drinking coffee regularly may have a positive effect on delaying premature death. Over the past five years, multiple studies have shown that regular consumption of coffee is associated with us on average, living longer.
The classic study to report on the health benefits of coffee was published in 2012 in the New England Journal of Medicine and was titled “Association of Coffee Drinking with Total and Cause-Specific Mortality”. That study examined the association of coffee drinking with subsequent total and cause specific mortality among a very large population of 229,119 men and 173,141 women from the National Institutes of Health–AARP Diet and Health Study who were 50 to 71 years of age at baseline.
Although there have been many subsequent studies regarding the consumption of coffee and health, we really haven’t done much about saying what kind of coffee are we consuming. Is it weak coffee? Or is that a hearty espresso? If we put sugar in our coffee does that cancel out all health effects? How about artificial sweeteners?
An article published today in the annals of internal medicine concluded from analysis of a very large British database that people who drink one and ½ to 3 ½ cups of coffee per day were 29% to 31% less likely to die from any cause during the seven-year study period. And that result did not seem to change whether people consume their coffee black or sweetened it with a small amount of sugar. The data for this study represented more than one half million participants in the UK Biobank.
This study found the data linking consumption of coffee whether unsweetened or sweetened with sugar to be directly associated with reduced mortality. The results were not so clear with respect to artificial sweeteners as the data as to which subjects use which artificial sweeteners was less clear.
The conclusion of the study was, “moderate consumption of unsweetened and sugar sweetened coffee is associated with lower risk for death.”
Not so very long ago, coffee was considered a possible carcinogen by the World Health Organization. By 2016 coffee research found that the beverage was not associated with an increased risk of cancer. In fact, statistically coffee was found to decrease the risk of certain cancers. Nonetheless, in 2018 California passed legislation that coffee must bear a cancer warning.
Caffeine has long been suspected of being the active compound that would make coffee good or bad for one’s health, but the truth is that coffee is chemically very complex and is difficult to tell whether the effects observed are from the caffeine or from other chemicals in the beans.
Coffee and cancer
It appears that coffee may affect how cancers develop. Here the results might be primarily good for coffee (and for us). Some of the polyphenols (there are over 8000 polyphenols which are micronutrients that naturally occur in plants) in coffee have been shown to prevent cancer cell growth in animal studies. Caffeine itself may have the power of interfering with the growth of cancer cells and subsequent spread.
Coffee also appears to reduce inflammation and improve antioxidant response which is not only a risk factor for many cancers, inflammation is known to have other deleterious effects on the body. The American Institute for Cancer Research concluded that the risk for endometrial and liver cancers might be reduced in regular coffee drinkers.
Type II diabetes
In seemingly contradictory results, we know that caffeine can increase blood sugar in the short term but longer-term studies have shown that regular coffee drinkers have a measurably lower risk of developing type II diabetes compared to nondrinkers. One large-scale meta-study of people with type II diabetes followed for a period of 20 years showed that the more coffee a person had to drink per day was directly associated with lowering the risk of developing type II diabetes. The effect ranged up to 33% reduction for drinkers of 6 cups of coffee a day. The same result has been found in other studies.
Caffeine is a stimulant which affects the central nervous system. As such, the medical community worried that it might be bad for heart health. In fact, available evidence suggests that drinking coffee regularly may lower the risk of heart disease and stroke. Analysis of the large Nurses Health Study database showed those drinking four or more cups of coffee each day were associated with a 20% lower risk of stroke as compared with non-coffee drinkers. Interestingly, decaffeinated coffee also reduced the incidence of strokes by 11%. The consumption of other caffeinated drinks had no such effect, so it is reasonable to conclude that the results are from other compounds in coffee rather than caffeine.
Looking at the data for a large number of women (37,514) concluded a 21% risk of heart disease was associated with drinking 2 to 3 cups of coffee a day. Similarly, meta-analysis of studies of both men and women found a favorable link of a 21% lower risk of cardiovascular disease death among coffee drinkers as compared to nondrinkers.
Polyphenols, which occur naturally in coffee, can act as antioxidants reducing inflammation of cells. Large-scale studies have shown coffee drinkers are less likely to become depressed than nondrinkers. In fact, the risk of suicide in men was found to be 45% lower for those who drink 2 to 3 cups of coffee daily and 53% lower among those who drank four or more cups daily. Data analysis suggests the result may be from the caffeine in coffee, so decaffeinated coffee does not have the same result.
Studies have shown the consumption of coffee reduces the probability of developing Parkinson’s disease. It is thought this may be caused by the caffeine in coffee tending to protect cells in the brain that produce dopamine. Here are the results seem to suggest the more coffee you drink the better. A Finnish study found the greatest benefit for those who drink at least 10 cups of coffee per day!!!
There have been a limited number of studies of the effects of coffee consumption on the probability of developing Alzheimer’s disease. Because of the small number of studies, scientists have been reluctant to draw strong conclusions. One study (CAIDE studying cardiovascular risk factors in aging and dementia) suggested that those drinking 3 to 5 cups of coffee a day in middle age was associated with a significantly decreased risk of Alzheimer’s disease later in life.
Consistent with other studies, a large study of more than 200,000 participants for up to 30 years found that drinking large amounts of coffee appeared to lower the risk of early death from all causes by 15%. These results seem to be consistent across caffeinated decaffeinated and instant coffees.
The bottom line
There is a growing body of evidence from studies of the effects of drinking coffee to suggest that coffee might be beneficial with its associated reduced risk for several chronic diseases. In particular, data suggests that coffee may be beneficial for cancers and cardiovascular diseases.
So drink up!