11 Essential Facts About Caffeine

• By Wyatt Myers | Medically reviewed by Cynthia Haines, MD

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  As any habitutal coffee drinker knows, caffeine is a stimulant and a drug. Consume too much, and you’ll find yourself addicted and at-risk for associated health problems. But at the same time, study after study has shown that moderate consumption of caffeine-rich foods such as coffee, tea, and dark chocolate can help lower your risk of heart disease, diabetes, stroke, and cancer — partially because these foods are all rich sources of disease-fighting antioxidants. But before you pour another cup of joe or open that soda, here’s what you need to know.
  • ll rich sources of disease-fighting antioxidants. But before you pour another cup of joe or open that soda, here’s what you need to know.
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    Caffeine Can Be a Mood Booster

    The health benefits of caffeine are far-reaching — as long as it's consumed in moderate amounts, says Rania Batayneh, MPH, a nutritionist and owner of Essential Nutrition for You, a nutrition consulting firm. "Caffeine stimulates the release of dopamine, a neurotransmitter that activates an area of gray matter in the brain responsible for alertness and productivity," she says. Because dopamine regulates mood, a cup of coffee can improve your mood, at least temporarily, a new study presented at the American Academy of Neurology's 65th Annual Meeting finds. But in the same study, people who drank the most soda were 30 percent more likely to develop depression than those who drank no soda, suggesting that the source of your caffeine — and its amount of added sugar — might be key to whether it has a mood-boosting benefit.
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      Coffee Can Lower Risk of Oral Cancer

      A study by the American Cancer Society found a strong relationship between caffeinated coffee intake and oral cancer death risk. Of the 968,432 men and women studied who were cancer-free at enrollment, 868 died due to oral cancer during the 26-year study period. Researchers found those who drank more than four cups of caffeinated coffee per day had about half the risk of death from oral cancers as those who only occasionally drank a cup of Joe. The study was published online in theAmerican Journal of Epidemiology.
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        Too Much Caffeine Can Have Risks

        The news is not all good when it comes to caffeine, however. “Caffeine is a drug, and like any other drug, it can have harmful effects when ingested in high amounts,” Batayneh cautions. “At doses of more than 500 milligrams (mg), which is about the amount in 4 cups of coffee, caffeine has been found to cause nervousness, irritability, insomnia, an upset stomach, muscle tremors, and an irregular heartbeat.”
        Some studies have found that caffeine can reduce your bone’s ability to absorp calcium. However, an analysis at Creighton University in Omaha, Neb., found that caffeine-caused bone loss mainly affects elderly woman, and that it can be offset by adding milk to your coffee. A research review published in the American Journal of Clinical Nutritionlast year found that caffeine causes short-term blood pressure spikes, so people with high blood pressure are often advised to watch their caffeine intake.
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          As any habitutal coffee drinker knows, caffeine is a stimulant and a drug. Consume too much, and you’ll find yourself addicted and at-risk for associated health problems. But at the same time, study after study has shown that moderate consumption of caffeine-rich foods such as coffee, tea, and dark chocolate can help lower your risk of heart disease, diabetes, stroke, and cancer — partially because these foods are all rich sources of disease-fighting antioxidants. But before you pour another cup of joe or open that soda, here’s what you need to know.
        • 

          Caffeine Can Be a Mood Booster

          The health benefits of caffeine are far-reaching — as long as it's consumed in moderate amounts, says Rania Batayneh, MPH, a nutritionist and owner of Essential Nutrition for You, a nutrition consulting firm. "Caffeine stimulates the release of dopamine, a neurotransmitter that activates an area of gray matter in the brain responsible for alertness and productivity," she says. Because dopamine regulates mood, a cup of coffee can improve your mood, at least temporarily, a new study presented at the American Academy of Neurology's 65th Annual Meeting finds. But in the same study, people who drank the most soda were 30 percent more likely to develop depression than those who drank no soda, suggesting that the source of your caffeine — and its amount of added sugar — might be key to whether it has a mood-boosting benefit.
        • 

          Coffee Can Lower Risk of Oral Cancer

          A study by the American Cancer Society found a strong relationship between caffeinated coffee intake and oral cancer death risk. Of the 968,432 men and women studied who were cancer-free at enrollment, 868 died due to oral cancer during the 26-year study period. Researchers found those who drank more than four cups of caffeinated coffee per day had about half the risk of death from oral cancers as those who only occasionally drank a cup of Joe. The study was published online in theAmerican Journal of Epidemiology.
        • 

          Too Much Caffeine Can Have Risks

          The news is not all good when it comes to caffeine, however. “Caffeine is a drug, and like any other drug, it can have harmful effects when ingested in high amounts,” Batayneh cautions. “At doses of more than 500 milligrams (mg), which is about the amount in 4 cups of coffee, caffeine has been found to cause nervousness, irritability, insomnia, an upset stomach, muscle tremors, and an irregular heartbeat.”
          Some studies have found that caffeine can reduce your bone’s ability to absorp calcium. However, an analysis at Creighton University in Omaha, Neb., found that caffeine-caused bone loss mainly affects elderly woman, and that it can be offset by adding milk to your coffee. A research review published in the American Journal of Clinical Nutritionlast year found that caffeine causes short-term blood pressure spikes, so people with high blood pressure are often advised to watch their caffeine intake.
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          Find Just the Right Amount of Caffeine

          If you do choose to partake in caffeine, moderate consumption is best. “A healthy individual should try to consume less than 300 to 400 mg of caffeine a day, which is roughly equal to three 6-ounce cups of coffee, four cups of tea, or six cans of soda,” Batayneh says. Pregnant women and people with high blood pressure should limit their intake to 150 to 200 mg a day, and children should consume no more than 50 mg daily. “At levels higher than this,” she warns, “uncomfortable symptoms such as restlessness and irritability may develop.”
          

          Caffeine May Lessen Stroke Risk

          One of the surprising health benefits of caffeine has to do with stroke risk. Previously, it was thought that coffee consumption might increase your risk for stroke. But a recent study of 83,000 women published in Circulation, the journal of the American Heart Association, found that the women who drank more coffee had a slight decrease in their overall stroke risk.
          

          Caffeine May Help ADHD

          Another area where the perception of caffeine is changing is attention deficit hyperactivity disorder, or ADHD. Once thought to be a cause of ADHD, caffeine is now thought to be a potential treatment for the disease because, in moderate doses, caffeine enhances the ability to focus. Although more research on the topic is still needed, one mom made headlines last year when she announced that her second-grade son drinks coffee twice daily as an effective treatment for his ADHD — and she pointed out that she’s far from the only parent trying it.
          

          Caffeine May Not Help Weight Loss

          Although many people think of zero-calorie coffee as a diet aid, research has not confirmed that coffee can boost weight loss. “Caffeine can speed up metabolism, resulting in a few more calories burned throughout the day,” Batayneh says. “But high intake of caffeine can also lead to the production of cortisol, the ‘stress hormone,’ which has been linked to weight gain and, of course, stress.” Plus, most studies have found that the increased calorie burn from caffeine is not enough to produce real weight loss.
          

          Caffeine Mainstays Are Preferred

          When it comes to choosing your sources of caffeine, our experts almost unanimously voted in favor of the natural sources of coffee and tea over the potentially dangerous amount of caffeine, sugar, and other additives in sodas and energy drinks. “Coffee and tea, in moderate doses, contain many antioxidants and a respectable amount of caffeine, offering both feelings of alertness, increased mood, and long-term health benefits,” Batayneh says.
          

          Caffeinated Concoctions Spell Trouble

          “Energy drinks, energy shots, and sodas are manufactured to provide quick boosts of energy with little nutritional benefit,” Batayneh warns. “Some energy drinks can contain as much as 70 grams of sugar — the equivalent of 17.5 teaspoons.”
          Worse yet, energy drinks and shots can be dangerous because of their unnaturally high levels of caffeine combined with ingredients such as guarana (a stimulant), taurine (an amino acid that regulates energy levels and heartbeat), and ginseng (a root that is believed to increase energy). “Ingesting all of these at once can lead to caffeine toxicity, in which an irregular heartbeat, jitteriness, and irritability take over,” she adds. “These ingredients can also interact with prescription drugs and antibiotics, decreasing their effectiveness and possibly causing other harmful side effects.”
          
          AeroShot

          Inhalable Caffeine Might Be the Next Big Thing

          From caffeinated gum to energy shots to drinks, manufacturers are constantly dreaming up new ways to ingest caffeine. One of the newest and buzziest methods on the market is the inhalable caffeine supplement AeroShot, a lipstick-sized container that contains B vitamins and 100 mg of caffeine, which is the equivalent of a large cup of coffee. To take an AeroShot, consumers simply inhale a fine powder that instantly dissolves in their mouth.
          

          Caffeine Improves Recognition of Positive Words

          You may be more likely to notice the bright side after two or three healthy cups of coffee, according to a new study from Ruhr University in Germany. Researchers found that consuming 200 mg of caffeine 30 minutes before a task resulted in faster and more accurate recognition of words with positive connotations. They did not see a change in processing of neutral or negative words, however. Emotional word recognition has to do with caffeine's dopaminergic effects in language-dominant parts of the brain, the researchers believe.
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      Too Much Caffeine Can Have Risks

      The news is not all g
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• 

  Caffeine Can Be a Mood Booster

  The health benefits of caffeine are far-reaching — as long as it's consumed in moderate amounts, says Rania Batayneh, MPH, a nutritionist and owner of Essential Nutrition for You, a nutrition consulting firm. "Caffeine stimulates the release of dopamine, a neurotransmitter that activates an area of gray matter in the brain responsible for alertness and productivity," she says. Because dopamine regulates mood, a cup of coffee can improve your mood, at least temporarily, a new study presented at the American Academy of Neurology's 65th Annual Meeting finds. But in the same study, people who drank the most soda were 30 percent more likely to develop depression than those who drank no soda, suggesting that the source of your caffeine — and its amount of added sugar — might be key to whether it has a mood-boosting benefit.
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  Coffee Can Lower Risk of Oral Cancer