Love coffee? You’ll love these new studies

Coffee drinking used to come with a dose of concern. I often heard health enthusiasts announcing with pride that they quit things like sugar, red meat and alcohol; coffee would be lumped in for extra credit. And while going easy on sugar and alcohol gets broadening scientific support with the passage of time, quitting coffee – which still might be advisable for some specific people – is something research never really backed.

With time, more and better research is proving the exact opposite about the coffee habit.

A new large study, published in JAMA Internal Medicine looked at the coffee drinking habits of half a million people in the United Kingdom, not all of them moderate drinkers – participants in the study drank up to 8 cups of coffee a day.

The study found that drinking coffee was inversely associated with all cause death for all consumption levels – even for heavy drinkers. Ground coffee’s association with lower mortality was somewhat stronger than that of instant coffee, but all coffee preparations were linked to better outcomes.

The researchers also looked at what’s called slow metabolizers: people who break down caffeine slowly, and are therefore more likely to be sensitive to its effects. Might these people be susceptible to heart disease related to caffeine lingering in their blood? People were especially concerned about high blood pressure and heart attacks within this sub-population. The study looked at genetic polymorphisms that predisposed people to be slow metabolizers and it turns out, in these people too, coffee was associated with lower mortality.

This study is observational, and although it tries to account for confounders such as age, obesity and smoking, its results only prove an association. In nutritional habits that last a lifetime we’re not likely to ever see a double blind, placebo controlled interventional study that can prove causation outright.

But this analysis joins many others, and the evidence seems to repeatedly point in one direction, so a statistical fluke is not very likely.

A study of 185,000 Americans published in Annals of Internal Medicine last year showed lower risk of death in African Americans, Japanese Americans, Latinos, and whites. Another study of more than half a million Europeans from 10 countries found lower mortality and that didn’t vary among the participating countries. A meta analysis in BMJ last year reviewed 201 relevant studies, and concluded that coffee is safe, and that 3-4 cups a day are associated with health benefits rather than with harm.

The secret ingredient? It probably isn’t caffeine

Caffeine, which is the psychoactive stimulant ingredient in coffee, and one of the main reasons people turn to coffee for a pick-me-up, is just one of thousands of components in the magic bean. Coffee is very high in antioxidants, and the whole food – bean – is much more than its parts.

This new study in JAMA found that decaffeinated coffee was associated with the same reduction in mortality. So did many others.

So, should coffee be part of your healthy regimen?

How come we had coffee this wrong until recently, you may ask? It might be our misanthropic belief that if we enjoy something this much – and I personally really do – there must be something wrong with it. Early studies that did not account for known unhealthy behaviors such as smoking and inactivity, which used to be more common among heavy coffee drinkers, also gave the wrong impression.

But not everyone should be chugging coffee.

Coffee isn’t for children – major health organizations, including the American Academy of Pediatrics recommend that kids avoid caffeine in coffee and energy drinks altogether, at least until age 12. Pregnant women should limit coffee at about 2 cups a day.

Remember, also, that coffee at its essence a calorie free, unsweetened drink. Some coffee drinks have so much cream and sugar that they’re true calorie bombs, and these studies showing health benefits are not about those treats. If you want coffee to be part of a healthy routine, make sure that coffee doesn’t make you reach for a sweetener, or a cookie. Or a cigarette.

These studies provide further evidence that if you enjoy your coffee you can do so free of guilt. If you don’t like coffee or find that it interferes with your sleep or makes you jittery I don’t think the science is quite there to suggest you should adopt the habit.

Dr. Ayala