Why Some People Can Sleep at Night Even After Having Caffeine?

General
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1

Have you ever seen someone who can drink a cup of coffee after dinner and still sleep like a baby? The reason is Genetics .

  • Our liver uses an enzyme called CYP1A2 to break down caffeine.

  • Variants in the CYP1A2 gene determine how fast that happens:

    Fast metabolizers clear caffeine quickly and feel only a mild buzz.

    Slow metabolizers keep caffeine in their system for hours, amplifying jitters and sleeplessness.

Brain Sensitivity:

  • Another gene, ADORA2A, affects how strongly adenosine receptors (the ones caffeine blocks) respond.

  • Some people inherit a version that makes them extra sensitive to caffeine’s stimulating effects.

Conclusion:

  • If you’re a slow metabolizer, your “cut-off time” for coffee might be early afternoon or even morning.

  • Fast metabolizers may enjoy multiple cups without major sleep disruption, though high intake can still raise heart rate or blood pressure.

Have you ever experienced something like this?

MBH/PS

5 Likes
2

Yes ,seen a person who drink coffee and sleep well.

3

I am a fast metaboliser, I usually drink multiple sips😁.

4

That explains so much! It’s fascinating how our genetics, specifically the CYP1A2 and ADORA2A genes, determine if we’re “fast” or “slow” caffeine metabolizers.

5

Thats so fascinating to hear a person drinking multiple sips of coffee and still sleeps like a baby. I usually prefer coffee in my exam times to make myself alert and concentrate which means i don’t feel dizzy at all.

6

Not everyone reacts to caffeine the same way—genetics, metabolism, tolerance, and even timing play a role. Some people break down caffeine faster or have a higher threshold to its stimulating effects, allowing them to fall asleep without much trouble. However, for others, the same cup of coffee can cause restlessness and insomnia. It’s a reminder that caffeine sensitivity is highly individual and knowing your own limits is key to healthy sleep.

7

Tats intresting to note .