Caffeine goes into effect quickly. If you drink one cup of coffee, it could take as little as under an hour for you to begin feeling the effects. The half-life of caffeine is the amount of time it takes the body to eliminate one half of the caffeine that was consumed. One 1980 study determined the half-life for adults to be 5.7 hours, but in general, the half-life of caffeine is typically four to six hours. Once the half-life is over, the remaining half of the caffeine might stay in your body for an extended amount of time, but you won't feel the effects as strongly.
Caffeine is a natural stimulant found in tea and coffee. Popular caffeinated soft drinks were created in the late 1800s and were followed by highly caffeinated energy drinks. Today, 90 percent of adults in North America consume caffeine every day.
When caffeine is consumed, it stimulates the brain and central nervous system, preventing drowsiness and keeping the consumer awake. Caffeine is absorbed into the body through membranes, so as you take your first sip, the caffeine is entering your system through the lining of your mouth, throat, and stomach. It only takes 45 minutes for 99 percent of the consumed caffeine to be absorbed.
Once caffeine enters your bloodstream, it travels to the liver, which breaks the caffeine down into compounds and sends them to other organs, where the compounds affect different functions of the body. The organ most affected by caffeine is the brain. The caffeine blocks the adenosine receptors in the brain, which are the neurotransmitters that signal to the brain that it is time for relaxation, rest and sleep.
Because the caffeine's effects can last between four to six hours, it is important to keep your caffeine consumption to the morning hours or, at the latest, early afternoon. If you're feeling drowsy at your desk at 3 p.m. on a workday, know that if you choose to drink a cup of joe you might still be feeling the effects into the night, which can negatively impact and disrupt your sleep schedule.
Caffeine half-life is impacted by functions that can vary from person to person. If someone with a compromised liver ingests caffeine, their half-life could be much longer than the typical four to six hour period. The enzyme CYP1A2 is the gene which metabolizes the caffeine in the liver, so if there is any differing in this DNA sequence, the person's body will metabolize and process the caffeine differently than what is normal.
Different genetic makeups can lead to three levels of caffeine sensitivity -- hypersensitivity, normal sensitivity, and hyposensitivity. People who are hypersensitive to caffeine react strongly to small amounts of the stimulant, whereas those with hyposensitivity can consume a large amount of caffeine without really feeling any effects.
Caffeine has been linked to several health benefits, including reducing the risk of liver damage, promoting life longevity, and reducing the risk of cancer. A 2009 study published in the International Journal of Cardiology even found that drinking between one and four cups of coffee a day can reduce the risk of heart disease by 16 to 18 percent.
The most common negative health effects from consuming caffeine are on sleep. Though caffeine makes you feel wide awake and alert, it is just covering the symptoms of drowsiness and doesn't replace your need for sleep. If you have trouble falling asleep, check out these tips for how to fall asleep fast. Along with difficulty sleeping, caffeine can also induce anxiety, restlessness and an irregular heartbeat.
While consuming 200-400 milligrams of caffeine a day is the average, it is highly recommended you do not exceed 500-600 milligrams in one day. Exceeding this limit can cause your body to experience caffeine overdose symptoms, which include anxiety, jittering, sweating, insomnia, nausea, dizziness, heart palpitations, vomiting and even cardiac arrest. Just earlier this year, a 16-year-old in South Carolina died after overdosing on caffeine. In two hours, he had consumed a coffee, a large Mountain Dew and an energy drink.
Different drinks and foods contain different amounts of caffeine, and will thus affect your body for varying lengths of time. Espressos have the highest amount of caffeine, with 240-720 milligrams of caffeine per every 8 ounces.
Here are some popular beverages and their caffeine count, per 8 oz sizes:
Espresso: 240-720 mg
Coffee: 102-200 mg
Yerba mate: 65-130 mg
Energy drinks: 50-160 mg
Brewed tea: 40-120 mg
Soft drinks: 20-40 mg
Decaffinated coffee: 3-12 mg
Cocoa beverage: 2-7 mg
Chocolate milk: 2-7 mg
Brainjet is devoted to providing you with all of the craziest, most eye-opening, and overall most interesting information out there.