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Caffeine consumption: what you need to know for tomorrow morning

Caffeine consumption and genetics

Do you ever worry about your caffeine consumption?

Asking for a friend.

Truth be told, I drink about 3-5 cups (how “cup” is actually defined on a coffeemaker, not physical mugs) of coffee a day. I tell myself that I need to be better about switching to green tea in the afternoons, at least, but I’m not sure I can start my morning with a steaming cup of tea.

So, what’s so bad about caffeine? Can it be good? Does it matter the source? Let’s take a look at a few popular drinks and how their caffeine count breaks down in milligrams, in addition to the health benefits of caffeine, potential side effects and risks, and how to lower your caffeine intake.

Oh, and this wouldn’t be the Gene Food blog if we didn’t start by giving you the nutrigenomic angle.

Caffeine consumption and genetics

As we’ve pointed out on the custom nutrition plan page, as well as on a number of our individual genes pages listed in our guide, such as ADORA2A, ADA and VDR, caffeine impacts everyone a little differently based on genetics.

For example, certain genotypes in the CYP1A2 gene (C allele) are associated with slower caffeine metabolism, and therefore are more prone to that “jittery” caffeine feeling after a cup of coffee or even tea.

And although the internet is full of articles touting the digestive benefits of coffee because it increases hydrochloric stomach acid, people on an anti-Candida diet tend to avoid consuming caffeine. Why?

Proponents claim its because caffeine can weaken your immune system (by causing stress) and also because caffeine consumption elevates blood sugar, which feeds Candida. (R) These folks do have some science on their side; take a look at this study that appeared in the American Journal of Clinical Nutrition for more.

For a primer on Candida overgrowth, check out John’s recent post, Candida controversy: is yeast overgrowth overblown or blowing up?

Caffeine’s effect on the body: Benefits and risks

The “most widely consumed drug in Western society,” caffeine is absorbed quickly into our system. In fact, 99% of ingested caffeine is absorbed and distributed to all tissues and organs. (R) So, bottom line, unlike curcumin, which isn’t readily absorbed, caffeine packs a punch.

We all know that caffeine before bed is a no-no, but even caffeine ingested 6 hours before sleep — those afternoon coffee pick-me-ups, for example — have been found to have significant effects on sleep disruption. (R) Caffeine increases cortisol levels, which regulate energy balance, and those who consistently drink caffeine have reduced response to cortisol. (R)

Caffeine also can make you need to pee, so people with overactive bladder should avoid or be cautious consuming it. (R)

That said, there are plenty of health benefits of caffeine, or at least the beverages you may be drinking that contain caffeine. For example, green tea is loaded with antioxidants, while coffee increases cognitive functionality and mediates Nrf2 pathway stimulation. (R)

However, there is evidence that it’s not the caffeine that drives these health benefits, but the antioxidants in the tea and coffee. For example, this study found that telomere length was actually decreased in those who regularly consumed caffeine, but increased in those who consumed coffee. (R)

Wondering what in the world is a telomere? Aaron did an excellent write up a few months back titled: Can telomeres predict lifespan? For a little more technical breakdown of telomere genetics, check out the TERT gene page.

Your caffeine source matters

Point is that not all caffeine sources are created equal. What you’re ingesting with the caffeine matters greatly.

For example, soda is basically liquid sugar, and even diet soda containing aspartame has been linked to adverse side effects (including being potentially carcinogenic). (R) Energy drinks, too, have led to hundreds of thousands of emergency room visits, with symptoms including feeling shaky or jittery, insomnia, palpitations, GI upset, headache, chest pain, and even seizures. (R)

Higher levels of caffeine intake of any kind may raise serum cholesterol and lead to heart health problems. We already know that pregnant women shouldn’t drink caffeine, but fertile women who drink more than 500 mg of caffeine per day may have a more difficult time getting pregnant due to increased oxidative stress. (R)

Similarly, in certain VDR genotypes, caffeine consumption in women was linked to a greater risk for osteoporosis. For more on that, see: VDR genotypes, caffeine and bone density.

Caffeine content by popular beverages

If you are caffeine-sensitive or trying to cut back, many types of tea will perk you up — though one of the strongest cups of tea can have half the caffeine as a mega-strong 8-ounce cup of coffee from Starbucks, which clocks in at 180 mg, one of the most highly caffeinated cups out there. (R)

Actual caffeine content in tea or coffee can vary based on cultivation, preparation, and brewing time, so some really strong green teas may have more caffeine than black tea. But usually, coffee is the winner, here. (R)

Caffeine comparison

Beverage typeCaffeine per cup (8 oz)
Coffee (brewed)95-165 mg
Energy drink27-164 mg
Black tea (brewed)25-48 mg
Cola24-46 mg
Green tea (brewed)25-29 mg
Decaf coffee (brewed)2-5 mg

Moderate caffeine intake — 400 mg per day — is generally considered safe from adverse effects such as general toxicity, cardiovascular problems, poorer bone health, and more. (R) Just make sure you are measuring an actual cup. Some coffee mugs fit more than 8 ounces, and grabbing a venti iced coffee from a Starbucks drive-thru is going to set you pretty far back on your caffeine goals for the day.

Does yerba mate have caffeine in it?

Chocolate and yerba mate are both tea — “South American’s green tea,” by nickname. It’s an infusion of leaves made from plants that thrive in this region. Compared to an average cup of coffee containing 85 mg of caffeine, mate has 78 mg — topping off the mate pot, though, may lead to consuming increased amounts of caffeine pretty quickly. (R)

In addition to caffeine, mate contains theobromine, which is predominantly found in cocoa. Cocoa can be an excellent source of antioxidants, and theobromine actually reduces blood pressure, whereas caffeine increases it.

So, with the two crossing each other out, potentially, the benefits of mate may override other teas and coffee. Though, like green tea, mate increases satiety and increases the breakdown of fat in our bodies, so we may be looking at healthy weight-loss goals being met just a little sooner if we choose any tea over coffee. (R)

How can I reduce the amount of coffee I drink?

If you’re worried about how much caffeine you’re drinking, there are ways to cut back. Or maybe it’s time to switch up your beverage of choice. As mentioned above, yerba mate might be a great alternative for those looking for a caffeine boost but concerned about their blood pressure.

Remember, a moderate amount of caffeine is OK for adults who are healthy. That can be anywhere from 200 to 400 mg. Caffeine also lurks in other things we eat, like chocolate, and in some over-the-counter medications. You can track your daily caffeine intake in a food journal, which I do.

If you’re a habitual coffee drinker consuming well over the 400-mg recommended limit, you’ll want to gradually reduce your caffeine intake. Don’t just go from 9 cups a day to none. Caffeine withdrawal, and its symptoms, are real, and include headache, fatigue, irritability, and more. (R)

Start slow, and see if you can swap out one cup of coffee for tea, or begin mixing in some decaf. Try also drinking a big glass of water in the morning before your first cup of coffee. One thing I’ve found that has been working for me is taking a magnesium supplement with my breakfast.

Because of our processed-food diets today, many people are magnesium-deficient and they don’t know it. This mineral is responsible for more than 300 enzymatic reactions in our bodies, making it essential for physiological functions like heart rhythm, nerve function, and muscle relaxation. (R) Magnesium also has been shown to help increase energy and reduce anxiety, so it may be a good substitute for that caffeine boost some people love without some of the side effects.

Since beginning the research on this blog post, I’m down to just 2 cups of coffee a day. How about you?

Amber Krosel

Amber Krosel is a Gene Food experience writer and official taste tester. She loves beer, her boyfriend and her adopted pup.

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