The main substance in coffee is caffeine, which stimulates every part of the body:
- It stimulates the brain and makes you feel wide awake, energetic and better able to concentrate.
- It increases the heartbeat and improves circulation.
- It enables muscles to work better.
- It aids digestion by increasing acid production in the stomach.
- It stimulates the kidneys to increase the production of urine.
Remember, besides coffee, caffeine is also found in tea, cocoa beverages, candy bars and soft drinks.
You’ll know you take too much caffeine or coffee if you experience:
- restlessness, jumpiness, anxiety and difficulty sleeping
- an irregular heartbeat
- twitching muscles
- Pain in your stomach or intestines.
You also can develop caffeine tolerance. This means you need more and more caffeine to get the desired effect. If you become dependent on caffeine, you have withdrawal symptoms (tiredness, headache or irritability) from going without it.
A reasonable amount of caffeine is 200-300 mg per day.
- A 5-ounce cup of regular coffee might contain from 30 to 200 mgs of caffeine, depending on the amount of coffee grounds used and whether it was instant or brewed. The average cup of coffee contains 100 mg of caffeine.
- A 5-ounce cup of tea is likely to contain from 20 to 100 mgs of caffeine.
- Energy drinks contain around 80 mg of caffeine in an 8-ounce serving.
Good Coffee Habits
Here are some other tips to help you keep your coffee habit as healthy as possible:
- Some people are more tolerant of caffeine more than others
- Most research suggests that drinking 1 to 3 cups of coffee a day (up to 300 milligrams of caffeine) does not seem to have any negative effects in most healthy people. However, pregnant women, children, people with heart disease or peptic ulcers and the elderly may be more susceptible to the effects of caffeine and are advised to restrict caffeine.
- Be aware that the caffeine content of coffee varies widely depending on roasting and brewing methods as well as the size of the cup you’re drinking. For example, a recent study showed that a 16-ounce cup of the house blend at Starbucks had an average of 259 milligrams of caffeine compared with only 143 milligrams in the same-sized cup of coffee at Dunkin Donuts.
- Although coffee is the main source of caffeine for many people, other items, such as soft drinks, tea, chocolate and cold and headache medicines also contain caffeine and can add substantially to your daily caffeine quota.
- Some medications may interact with caffeine. Consult with your health care provider or pharmacist about potential interactions with caffeine whenever you take medications.