What is Caffeine? Caffeine is a natural substance found in tea, coffee, and cacao plants. It helps you feel more awake by blocking a chemical in your brain called adenosine, which usually makes you feel tired (1, 2). Caffeine has been around for thousands of years, with the first tea made in 2737 B.C, and stories about coffee go back to an Ethiopian shepherd noticing that his goats got more energetic after eating coffee beans (3).
How Caffeine Works When you drink something with caffeine, it quickly enters your bloodstream. It then travels to your brain, where it blocks adenosine, making you feel less sleepy. It also increases other brain chemicals like dopamine and norepinephrine, which help with focus and mood. You can feel the effects of caffeine as soon as 20 minutes after drinking it, and it reaches its strongest effect after about an hour (4, 5).
Caffeine’s Effect on Mood and Brain Function Caffeine blocks adenosine and increases chemicals in your brain that improve mood and alertness. Research shows that drinking 2–3 cups of coffee a day can lower the risk of depression by 13% and may reduce the risk of neurodegenerative diseases like Alzheimer’s by 28–60% (6, 7, 8, 9).
Benefits of Caffeine Consumption
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Better Focus – Caffeine helps you stay awake and alert, making it easier to focus on tasks (10, 11).
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Improved Physical Performance – Caffeine can increase endurance during exercise by helping the body use fat for energy (12, 13).
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Boosted Metabolism – Caffeine can slightly increase how many calories you burn, which may help with weight control over time (14, 15).
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Lower Risk of Some Diseases – Moderate coffee consumption has been linked to a reduced risk of type 2 diabetes, Alzheimer’s, Parkinson’s, and certain cancers (16).
Drawbacks of Caffeine Consumption
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Increased Heart Rate – Caffeine can raise your heart rate, especially in higher doses. People with heart conditions may need to watch their caffeine intake (17, 18).
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Anxiety – Caffeine can cause feelings of anxiety and jitters, especially if you consume too much (19, 20).
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Sleep Problems – Having caffeine late in the day can make it harder to fall asleep, as it stays in your system for several hours (21).
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Dependence and Withdrawal – Drinking caffeine regularly can lead to dependence, and quitting may cause headaches or fatigue (22).
Caffeine’s Effect on Heart and Blood Pressure Caffeine can cause a small increase in heart rate and blood pressure. This is usually temporary but may last longer in people with high blood pressure (23).
Caffeine and Anxiety Some people find that caffeine makes them feel more anxious, as it increases adrenaline in the body. If you’re prone to anxiety, it’s best to drink caffeine in moderation (24).
Caffeine and Sleep Problems Caffeine blocks the brain chemical that helps you feel sleepy, so drinking it too late in the day can disrupt sleep. Caffeine can stay in your system for 3 to 7 hours, so it’s better to avoid it in the late afternoon or evening (25).
L-Theanine: Reducing Caffeine’s Jitters L-theanine is an amino acid found in green tea. It helps to calm the brain without making you feel tired. When combined with caffeine, L-theanine can reduce feelings of jitteriness and help with focus and relaxation (26, 27). Green tea naturally contains both caffeine and L-theanine, making it a good choice for a smoother energy boost.
Conclusion Caffeine can improve mood, focus, and energy, but it’s important to drink it in moderation to avoid sleep problems, anxiety, or dependence. Combining it with L-theanine, found in green tea, can give you a more balanced energy boost without the jitters.
References
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https://www.newscientist.com/definition/caffeine/
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https://www.foodrepublic.com/1293755/history-origin-tea-china-accident-changed-world/
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https://thecoffeeguru.net/the-story-of-kaldi-the-goat-herder-how-an-ethiopian-legend-shaped-the-worlds-coffee-culture/
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https://science.howstuffworks.com/caffeine4.htm
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https://www.thehealthy.com/food/heres-how-much-caffeine-is-in-coffee-experts-say/
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https://www.bbc.com/future/article/20201028-the-benefits-of-coffee-is-coffee-good-for-health
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https://www.hopkinsmedicine.org/health/wellness-and-prevention/9-reasons-why-the-right-amount-of-coffee-is-good-for-you
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https://nutritionsource.hsph.harvard.edu/food-features/coffee/
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https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/coffee-and-health/faq-20058339
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https://favy.com/coffee-clubs/psychology-of-coffee-on-mood