Ask Dr. Darria: Can Too Much Caffeine be Harmful?

Ask Dr. Darria: Can Too Much Caffeine be Harmful?

I start my morning with a cup of coffee and then drink several more cups throughout the day. Is this bad for my health?

Lately, we’ve been bombarded with coffee-related news: “Coffee raises risk of death.” “Coffee contains life-saving compounds.” Honestly, I wish they’d all just be quiet and let me enjoy my morning cup in peace. Don’t you?

But the conflicting reports made me wonder, and clearly you’re wondering, too. So I figured I’d dig more deeply -- after I’d had another cup of coffee.

Over the past few years, much of the news on coffee was positive. One study in Circulation said that people who drank two 8-ounce cups of coffee per day reduced their risk of heart failure by 11%. Another in the New England Journal of Medicine said that drinking two cups per day (8 ounces again) could prolong your lifespan.

Why the effect? Even the researchers weren’t sure. Results did show that coffee drinkers -- especially women -- were less likely to have diabetes. Others speculate that it’s due to the antioxidants in coffee.

The most recent study highlighted that people who drink over four 8-ounce cups of coffee per day (for a total of 28 cups per week) had higher risk of death, particularly in people under the age of 55. Again, it’s not totally clear why this was, and it’s definitely not clear that coffee itself increased the death risk -- but could be due to an association.

But there’s a pattern here -- two cups per day? Beneficial. However, there seems to be a point at which the benefits of coffee level off and can even become harmful. Most experts (and the latest study) agree that this is around four or more cups per day.

Also, watch out for “associated habits.” Studies show that people who drink more coffee are also more likely to smoke, eat too much red meat and not exercise. In people who had these habits as well, even the healthy amounts of caffeine were unable to correct for their unhealthy lifestyle.

So, maybe it’s not as confusing as we thought. Enjoy your coffee, but you may want to think twice if you’re reaching for that 4th or 5th… or 6th (come on, I know….) cup. Also pay attention to what else you’re reaching for (cigarettes, red meat). As great as those little antioxidants in coffee are, they won’t make up for other bad health habits.

Medically reviewed in August 2018.

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