Slow Caffeine Metabolism: The Reason Some People Who Drink Coffee Could Be at Higher Risk for a Heart Attack

8 years ago | Heart health

By Joy Stephenson-Laws JD, Founder

Some of my favorite beverages contain caffeine. Besides coffee, my delicious, caffeinated drinks include lattes, macchiatos, green tea, Thai iced tea and Tia Maria (a dark liqueur made originally in Jamaica with Jamaican coffee beans).

Not only are caffeinated drinks delicious, there are many reported health benefits such as the following:

Reduced inflammation associated with aging
Protection against type 2 diabetes and cardiovascular disease
Lowered rates of depression among women
Lowered risk of liver cancer and other liver diseases
Lowered risk of Alzheimer’s and dementia
Increased fat burn potential (especially before a workout)
Relief from constipation

So, I have always felt ‘satisfied,’ happy and healthy when I drank caffeinated drinks like Thai iced teas while dining at Thai restaurants or the occasional brown cow when I go on vacation. I never over indulged except for the occasional refill. I noticed I was a bit ‘hyper’ whenever I had more than one drink but figured that was a good thing considering my laid back personality. After all, I should have ‘good caffeine genes’ - my grandfather died at the ripe old age of 106 after drinking a couple cups of coffee daily for most of his adult life.

However, this past holiday season, drinking caffeinated beverages caused more than just hyperactivity. My heart rate increased after drinking a few cups of tea, my blood pressure was significantly elevated at 184/93, and that’s after taking the blood pressure readings a few times with two separate monitors to ensure accuracy.

When this occurred, I immediately stopped drinking the tea I was enjoying and waited a few minutes to take the blood pressure readings again. Luckily, the numbers started to drop, my heartbeat slowed and I took steps to have the blood pressure reduced to close to normal before going to sleep.

I discussed my experience with pH doctor, Pauline Jose, who reminded me certain teas have large amounts of caffeine, and it was possible I was a slow caffeine metabolizer. I did not ask her what that meant at the time and figured I would take the time to educate myself on the issue. In the meantime, I simply refused to drink caffeinated drinks due to my fear of getting high blood pressure.

Further research disclosed a study published in JAMA about slow caffeine metabolizers.

The study involved more than 4,000 people in Costa Rica. The participants who were slow caffeine metabolizers increased their risk of heart attack by 36% if they drank two to three cups of coffee daily. Their risk increased to 64% if they drank four or more cups daily.

I later confirmed, via genome testing, that I was indeed a slow metabolizer of caffeine. My results included the following quote: “Your genotype indicates that you are a slow caffeine metabolizer, having a higher risk of caffeine-induced heart attack. People with this genotype have a low caffeine consumption.”

There are more technical explanations of course. And for those of you who are also interested in the technical aspects, the relevant genes are the AHR and CYP1A2 genes. Apparently, there is an enzyme in the liver that metabolizes caffeine, p450 1A2 (CYP1A2) and it works differently in different people. Some people, like me, are slow metabolizers while others are rapid metabolizers. This means that slow metabolizers keep caffeine longer in their systems, and this may cause myocardial infarction.

My takeaway from all this was that for slow caffeine metabolizers like myself, caffeine consumption may increase my risk for heart attack. Some people may be strongly affected by a small amount of caffeine, while others are less sensitive to caffeine and drink a lot of coffee habitually. These types of caffeine responses may be due to genetic differences.

So for all you slow caffeine metabolizers, be proactive about heart attacks by watching your caffeine intake. When it comes to caffeine, what’s good for the goose may not be good for the gander.

Enjoy your healthy life!

The pH professional health care team includes recognized experts from a variety of health care and related disciplines, including physicians, health care attorneys, nutritionists, nurses and certified fitness instructors. To learn more about the pH Health Care Team, click here.