We’ve heard for years about studies done here in the United States, which found that drinking coffee is associated with decreased mortality — a lower risk of heart disease, stroke, accidents, and depression, among other things. A study published in May, 2012 in the New England Journal of Medicine found that when people drank coffee daily, they decreased their risk of death from most causes during the study’s 14-year period: men reduced it by 10 percent, and women by 15 percent. These results were the same, whether people drank decaffeinated coffee or regular coffee. It was considered an important study because it involved more than 400 thousand participants — a large group, as medical studies go.
Other recent studies found that coffee-drinking does not increase the risk of death from heart disease, stroke or cancer, all three of which are major causes of death in the United States. In one study, even people who drank as many as six cups of regular coffee a day did not seem to have a higher rate of mortality.
So, many people, including doctors, were surprised to learn the results of a study published in August, 2013 in the Mayo Clinic journal Proceedings. That study found that drinking more than four cups of coffee a day, or 28 cups a week, was associated with a greater mortality rate from all causes for people who were under 55 years old.
Researchers found that younger men who exceeded the 28-cup weekly number had a 56 percent greater risk of death from all causes, while younger women who exceeded 28 cups doubled their risk of death from all causes, when both groups were compared to others in the study who drank less. The heavier coffee drinkers still had a greater risk of death, even when smoking vs. not smoking was factored in.
For this latest study, Dr. Chip Lavie, a cardiologist at the John Ochsner Heart and Vascular Institute in New Orleans, and his colleagues, looked at data from more than 40 thousand study participants aged 20 to 87, who were part of a long-term study conducted between 1971 and 2002, which measured different aspects of lifestyle and health. Researchers followed up with participants for an average of 17 years. Older participants — that is, those who were 55 and up — were not found to be negatively affected by drinking more than 28 cups a week. The study found only caffeinated coffee to be linked to higher mortality rates in the younger subjects, and not decaf.
Dr. Lavie pointed out that one possible limitation in his study was that participants were only asked one time about their coffee-drinking habits, which may have changed over time. The study may also not have controlled for smoking sufficiently; most of the heavy coffee drinkers were also smokers.
Many studies done in the 1980’s failed to control for the link between coffee consumption and cigarette smoking, resulting in research findings that cast coffee in a bad light. As subsequent studies factored in smoking vs. non-smoking habits, evidence started to appear about coffee’s seeming health-promoting effects.
Dr. Lavie concluded that while there may be even other factors, as yet unknown, that influence a person’s mortality risk, besides their coffee-drinking, he would strive to drink three or fewer cups of coffee on most days.
Another important point for coffee drinkers to consider is what they put in their coffee. Excessive sugar is bad for us; artificial sugar substitutes may be even worse, possibly increasing the risk of serious health complications like stomach cancers; and non-dairy creamers, popular as they are, usually are chock full of artificial chemicals and hydrogenated oils. Hydrogenated oils have been linked in past studies to heart disease.
By Jamell Andrews