by Dr. Will Cole
Reactions to coffee seem strangely individual. Some people can drink it after dinner and go straight to sleep, while others have one cup in the morning and feel jittery, sweaty, or get heart palpitations. What gives? Meet your caffeine gene. It’s called CYP1A2 because it controls the enzyme CYP1A2, and its this enzyme that determines how you metabolize caffeine: fast, meaning you tolerate it well and it leaves your system quickly, or slow, meaning your body doesn’t get rid of it efficiently, so you feel its effects harder and longer.
Caffeine and your DNA.
We inherit two copies of the caffeine gene, one from mom and one from dad. If you have the fast variant, your liver breaks down caffeine quickly and efficiently. If you have two of the fast variants, you handle coffee (and tea and even energy drinks) like a boss, breaking down caffeine four times faster than those who have one or two of the slow variants of this gene. Are you one of the lucky ones? Here’s the breakdown:
- 40 percent of people are fast metabolizers, with two copies of the fast variant.
- 45 percent have one slow and one fast copy, so they are middle-of-the-road caffeine metabolizers.
- 15 percent carry two copies of the slow variant and are slow metabolizers.
So how do you know your genetic status? You might already suspect what it is by the way you react to caffeine, but a DNA test, which we run for people all around the world, will tell you for sure. Once you know, you can make better decisions about your caffeine use because the health effects of caffeine really are dramatically different depending on your metabolizer status, calling into question any general-population health advice about whether caffeine is “good” or “bad.”
If you’re a slow caffeine metabolizer:
You are much more likely to feel anxious jittery, and sweaty after consuming caffeine. You may get heart palpitations or even panic attacks. Caffeine withdrawal also commonly causes severe headaches in slow metabolizers, but feeling shaky and on edge aren’t the only health problems associated with caffeine. You also have:
1. Increased risk of high blood pressure (hypertension).
Some fascinating research published in the Journal of Hypertension found that slow metabolizers who drank a lot of coffee were significantly more likely to have high blood pressure. Amazingly, fast metabolizers actually had lower blood pressure after drinking coffee!
2. Increased risk of heart attack.
A similar study from the Journal of the American Medical Association (JAMA) found that drinking four or more cups of coffee a day was associated with a 36 percent increased risk of a heart attack, only among slow metabolizers.
3. Higher chance of digestive disorders.
Coffee isn’t the only caffeine source, of course. My beloved and oft-recommended green tea, which has only about a third the amount of caffeine as coffee, can trigger diarrhea, gas, and heartburn in some people with sensitive stomachs.
4. More stress and measurable cortisol spikes.
People who are sensitive to caffeine can see a spike in their stress hormone cortisol. This can be an issue especially with adrenal fatigue and other hormone problems. Some people have an initial spike in cortisol from caffeine but gain tolerance over time, while others don’t adapt to caffeine.
If you’re a fast metabolizer:
Remarkably, if you are a fast metabolizer and have a high tolerance for caffeine (for example, you can drink it all day without feeling jittery, or drink it at night and still fall asleep), caffeine is associated with a bunch of awesome health benefits:
1. Longer life.
A New England Journal of Medicine study found that people who drank coffee had a much lower risk of dying during the course of the study. Another large Japanese study published in JAMA found that people who drank five or more cups of green tea a day were also significantly less likely to die during the study period. Yet another study from Harvard showed coffee and tea drinkers’ overall risk of premature death is 25 percent lower than those who don’t drink these caffeinated drinks.
2. Faster metabolism.
Caffeine can boost your metabolism, increasing fat burning and even improve your exercise and/or athletic performance.
3. Better memory and mood.
Caffeine has been shown to improve cognitive function, decrease brain fog, and increase mental acuity. It can also increase the neurotransmitters serotonin and dopamine, improving mood. A study out of Harvard found that people who drank coffee were 20 percent less likely to suffer from depression. Green tea also contains L-theanine, which ramps up GABA production (your calm-down neurotransmitter) for a potent anti-anxiety effect. Put together, caffeine and L-theanine can have a synergistic effect, creating a potent combo for improving brain function. Coffee could even protect from dementia someday – in one study, coffee drinkers were found to have a full 60 percent lower risk of developing Alzheimer’s disease and up to 60 percent lower risk of Parkinson’s disease. Short version: caffeine is great for fast-metabolizer brains!
4. Lower cancer risk.
Both coffee and green tea have been associated with a significant decrease in cancer rates, including prostate cancer in men and colon cancer in women.
5. Better blood sugar + insulin balance.
Half of U.S. citizens are prediabetic or diabetic. Yikes! So there’s no denying we have a serious blood sugar problem. Caffeine to the rescue! Both coffee and green tea have been shown to decrease diabetes in separate studies.
Figure out what’s right for you.
The way we react to coffee is the perfect example of bioindividuality. As a functional medicine practitioner, I look at the complex genes that play a role in detoxing caffeine (there are more than just CYP1A2) as well as other factors that play a part, such as a person’s gut health, liver function, and mental health status. If caffeine isn’t a problem for you, and you want to get in on the sweet health benefits I mentioned above, most research agrees that the ideal amount is about four to five cups of coffee a day or about eight cups of green tea a day. And if you are a slow metabolizer? Avoid the health risks and stick with herbal tea, or good old water. The bottom line: You are unique, so find what’s right for you.
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