Energy Drinks: What Happens to Your Body in the First 24 Hours and Their Long-Term Health Risks

Have you ever wondered what really happens inside your body after drinking a can of energy drinks? Those brightly colored cans promise a burst of energy, enhanced focus, and superhuman performance. It’s no surprise they’re especially popular among young people, particularly during exam periods or when they need a boost for daily or social activities. But are they as harmless as they seem? Experts from the Spanish Agency for Food Safety and Nutrition (AESAN) and various research studies warn about the health risks associated with their main ingredients. Let’s break down what happens in your body from the first sip and how continued consumption can lead to significant adverse effects.

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What’s Behind the Energy Rush? The Composition of Energy Drinks

Before we dive into their effects, it’s crucial to understand what these drinks contain. While there is no universally accepted definition, the European Food Safety Authority (EFSA) describes them as non-alcoholic beverages containing caffeine, taurine and/or vitamins, often mixed with other ingredients and marketed for their supposed stimulating and energizing effects.

In addition to high amounts of sugar, they may include substances like ginseng, guarana, and carbohydrates such as glucuronolactone. It’s important not to confuse them with isotonic drinks, which are designed to replenish water, sugar, and electrolytes during exercise—these do not contain caffeine or stimulants.

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The Energy Journey: Effects on Your Body in the First 24 Hours

From the moment an energy drink hits your lips, your body begins a process of absorption and response that can last for hours:

• First 10–15 minutes: The “rush” begins
  Caffeine starts to be absorbed almost immediately through the mouth, throat, and stomach lining, quickly entering the bloodstream. This triggers increased breathing, heart rate, and mental alertness. Your heart begins to beat faster, and blood pressure may rise.
• 30 to 60 minutes: Peak effects and the sugar bomb
  Caffeine reaches peak levels in your blood. You feel more alert and focused. However, most of these drinks are loaded with sugar—between 50 to 75 grams per can, which is triple the daily recommended maximum for children and teens—causing a rapid spike in blood glucose levels.
• 4 to 6 hours: Caffeine’s half-life and early fatigue
  In a healthy person, caffeine’s half-life is around 5.7 hours, though other studies place it between 5 and 6 hours. This means that half of the caffeine remains in your system for several hours. During this period, side effects such as nervousness, irritability, anxiety, and headaches may appear. Taurine has also been significantly linked to tremors and chest pain in adolescents.
• 12 to 24 hours: Energy hangover and insomnia
  Caffeine elimination can take up to 12 hours or more, depending on age, weight, and health status. Traces may linger for 35–42 hours. Common effects include insomnia and poor-quality sleep. Caffeine, being a regularly consumed drug, can cause withdrawal symptoms like headaches, irritability, and fatigue. Excessive urination is also commonly reported.

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Beyond the First Day: Long-Term Health Risks

Ongoing, excessive consumption of energy drinks doesn’t just perpetuate short-term effects—it can also lead to serious health issues:

• Cardiovascular problems
  The increase in blood pressure and heart rate isn’t just temporary. Excessive caffeine is linked to hypertension and arrhythmias. Severe cardiovascular events, including arrhythmias and sudden cardiac death, have been temporally associated with energy drink consumption. A 2015 study found that a single high-caffeine energy drink could dangerously raise blood pressure and stress hormone levels within 30 minutes.
• Addiction and withdrawal symptoms
  Regular use can lead to mild physical dependence, tolerance, and withdrawal symptoms like drowsiness, headaches, fatigue, and irritability. Caffeine intoxication and withdrawal are recognized in the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders).
• Mental and cognitive health
  Excessive consumption can result in insomnia, anxiety, nervousness, and palpitations, which—rather than improving focus—can keep users in a state of hyperarousal. It’s associated with increased anxiety and depression in adults, as well as symptoms of ADHD and violent behavior in adolescents.
• Obesity and type 2 diabetes
  The high level of simple sugars contributes significantly to overweight and obesity and is directly linked to type 2 diabetes and abnormal cholesterol/triglyceride levels.
• Kidney and brain damage
  High consumption has been linked to kidney problems and even reduced blood flow to the brain.

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Risky Ingredients and Dangerous Combinations

Each ingredient in energy drinks carries its own risks:

• Caffeine
  The main stimulant. A 250 ml can may contain 80 mg, and a 500 ml can up to 160 mg—equivalent to two espresso shots. Excessive intake can cause nervousness, irritability, anxiety, insomnia, memory and attention changes, headaches, and cardiovascular issues. Overdose can cause tachycardia, vomiting, seizures, and potentially death.
• Sugar
  Most contain 50–75 grams per can, far exceeding the recommended daily maximum. Even “sugar-free” versions use artificial sweeteners with unknown long-term effects.
• Taurine
  Though a natural amino acid, excessive taurine via energy drinks may negatively impact cognition and behavior, especially in adolescents and young adults. A single can may contain up to 2,000 mg—far above normal dietary intake.
• Ginseng and Guarana
  These herbal stimulants may cause side effects such as high blood pressure, headaches, anxiety, and arrhythmias. Guarana is an additional caffeine source, increasing the risk of adverse effects and has been linked to premature birth and low birth weight during pregnancy. Other additives like bitter orange can also cause cardiovascular side effects.

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The Dangerous Combo: Energy Drinks and Alcohol

One of the most serious dangers—especially among youth—is mixing energy drinks with alcohol. Caffeine masks alcohol’s depressant effects on the central nervous system, leading to higher alcohol intake and increased risk of alcohol poisoning. This combo also raises blood pressure, causes palpitations, tachycardia, and insomnia.

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Most Vulnerable Populations: Children and Teens in the Spotlight

Energy drinks are particularly harmful for:

• Children and Adolescents
  The American Academy of Pediatrics and AESAN discourage their consumption. Their brains are still developing and are more vulnerable to adverse effects.
• Pregnant or Breastfeeding Women
  Should avoid them due to risks to the fetus and baby.
• People with Pre-existing Health Conditions
  Especially those with cardiovascular (e.g., hypertension, arrhythmias), neurological, or anxiety disorders, or caffeine sensitivity. Consumption in teens is linked to risky behaviors and mental health issues.

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Expert Measures and Recommendations

In response to growing concern, public health entities and governments are taking action:

• Spanish regions like Andalusia and Galicia have announced plans to ban energy drink sales to minors.
• The Spanish Society of Nutrition (SEÑ) has requested limiting container sizes to 250 or 330 ml.
• Taxation to increase prices could help reduce consumption.
• The American Academy of Family Physicians opposes selling and marketing these products to those under 18 in the U.S.
• Many of these drinks are labeled as “dietary supplements,” bypassing soft drink caffeine regulations.

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Healthy Alternatives for Lasting Energy

For sustainable energy, natural methods are key:

• Balanced Diet
  Focus on vegetables, fruits, nuts, and whole grains—like the Mediterranean diet.
• Proper Hydration
  Drink water. For intense physical activity, isotonic drinks are better than energy drinks for electrolyte replenishment.
• Sleep Hygiene
  Maintain regular sleep patterns and avoid screens before bed.
• Regular Exercise
  Moderate physical activity (2–3 hours per week) supports energy levels.
• Moderation and Awareness
  If you’re healthy and an adult, limit energy drinks to no more than one per day, and never mix with alcohol. Always check the label.

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In conclusion, while energy drinks may promise a quick energy boost, their health risks—especially for teens and young adults—are serious. From the initial spike in heart rate and blood pressure to long-term risks like addiction, sleep disorders, anxiety, and cardiovascular damage, these drinks can compromise both physical and mental well-being. It’s essential to choose healthier energy sources and for public policies to protect younger populations through tighter regulations and increased awareness about what we consume.

🧠 ENERGY DRINKS – FREQUENTLY ASKED QUESTIONS (FAQ)

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1. What happens in my body after drinking an energy drink?
✅ Within the first 10–15 minutes, your heart rate and blood pressure rise.
✅ After 30–60 minutes, caffeine and sugar peak—you feel more alert and focused.
✅ Within 4–6 hours, half the caffeine is still in your system; side effects may appear (nervousness, headaches).
✅ After 12–24 hours, caffeine withdrawal can cause insomnia, fatigue, and irritability.

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2. Which ingredients are the most dangerous in energy drinks?
☠️ Caffeine in high doses can cause heart palpitations, anxiety, seizures, or even death.
☠️ Sugar contributes to obesity, type 2 diabetes, and cardiovascular issues.
☠️ Taurine & Guarana affect the nervous system and pose higher risks in teens.
☠️ Ginseng & Herbal Additives may trigger high blood pressure, headaches, or arrhythmias.

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3. Is it safe to mix energy drinks with alcohol?
❌ No, it’s highly dangerous. Caffeine masks alcohol’s sedative effects, increasing alcohol intake, risk of alcohol poisoning, and heart-related complications like arrhythmias and insomnia.

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4. What are the risks for teenagers and children?
⚠️ Young brains are more vulnerable. Risks include:

• Anxiety, insomnia, and irritability
• Attention issues and aggressive behavior
• Higher risk of addiction and mental health problems

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5. What are the long-term effects of regular consumption?
🩺 Long-term risks include:

• Hypertension and cardiovascular diseases
• Sleep disorders and caffeine dependence
• Increased anxiety, depression, obesity, and kidney damage

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6. What are healthy alternatives to get an energy boost?
🌿 Try these natural methods:

• Eat a balanced diet rich in fruits, veggies, nuts, and whole grains
• Stay hydrated with water or electrolyte drinks (not energy drinks)
• Get quality sleep and maintain regular sleep patterns
• Engage in moderate physical activity (2–3 hours per week)
• If you’re an adult with no medical issues, limit energy drinks to one per day and never mix with alcohol

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7. Are energy drinks being regulated?
📜 Yes, for example:

Many are labeled as “dietary supplements,” which bypass soda caffeine regulations

Regions in Spain (like Andalusia and Galicia) aim to ban sales to minors

Nutrition experts suggest limiting can sizes and taxing these drinks

In the U.S., groups oppose sales and marketing to anyone under 18