Caffeine is a bitter substance found in coffee, tea, soft drinks, chocolate, kola nuts, and certain medicines. It has many effects on the body's metabolism, including stimulating the central nervous system. This can make you more alert and give you a boost of energy. For most people, the amount of caffeine in two to four cups of coffee a day is not harmful. However, too much caffeine can make you restless, anxious, and irritable. It may also keep you from sleeping well and cause headaches, abnormal heart rhythms, or other problems. If you stop using caffeine, you could get withdrawal symptoms. Some people are more sensitive to the effects of caffeine than others. They should limit their use of caffeine. So should pregnant and nursing women. Certain drugs and supplements may interact with caffeine. If you have questions about whether caffeine is safe for you, talk with your health care provider.
Introduction
Caffeine is a very common substance that we consume in food,
drinks, and medicines. More than 90% of people in the world use caffeine in one
form or another.
It is safe to consume caffeine in moderate amounts. Research
suggests there are some benefits of caffeine. However, for certain people,
doctors may recommend reducing the consumption of caffeine or stopping it all
together.
This program explains what caffeine is, presenting facts and
dispelling some myths about the consumption of caffeine.
Caffeine
Caffeine is a natural substance found in more than 60
plants! The most common plants that contain caffeine are coffee beans, tea
leaves, kola nuts, and cacao pods.
Caffeine can also be made in the lab. This is known as
synthetic caffeine. Synthetic caffeine is added to foods, drinks, and
medicines.
Caffeine stimulates the central nervous system. The central
nervous system includes the brain, spinal cord, and the other nerves in the
body. Caffeine causes a person to feel more alert and less tired.
The stimulant effect of caffeine reaches its peak level
within one hour of ingesting it and lasts from four to six hours. When people
use caffeine every day, their bodies get used to it. They don’t get the “good
effects” of feeling more awake and able to concentrate unless they use more of
it. This is called “tolerance.” Some studies show that caffeine causes a
physical dependence or addiction. If a person gets headaches or becomes
irritable after stopping caffeine consumption, then their body is physically
addicted to it. These signs are called withdrawal symptoms. Not all people have
the same response to caffeine. Some people report noticeable alertness while
others report little difference in alertness. Some have no withdrawal symptoms
while others do. People’s reaction to caffeine differs as the person’s age or
health changes.
Benefits
Many people drink caffeinated drinks to feel more awake and
alert for awhile. Many people report having more concentration and energy after
consuming caffeine.
Caffeine is used in both prescription and over-the-counter
medicines to treat tiredness or drowsiness. Caffeine can also improve the
effect of some pain medicine.
There is some research reporting benefits of caffeine
related to an improved immune system, and the ability to fight cancer and
prevent dementia. However, more studies are needed to confirm or refute such
observations.
Side Effects
Caffeine’s main effect on your body is to make you feel more
awake and alert for a while. However, it can also cause some side effects. The
most common side effect is making a person jittery or shaky.
Caffeine can make it hard to fall asleep, stay asleep, or
get a good night’s sleep. This side effect can be worse if you take in caffeine
a few hours before going to sleep.
Other side effects of caffeine are related to the heart. It
can make the heart beat faster or have an uneven heart rhythm. Caffeine may
also cause a rise in blood pressure.
Caffeine can cause headaches, nervousness, or dizziness,
particularly if a person stops taking it. These are some signs of withdrawal.
Caffeine is a diuretic; it causes the kidneys to get rid of
more water than they would otherwise. Because of this effect dehydration is
also a possible side effect.
Usually people consume caffeine with drinks containing water
and the excess loss of water does not cause dehydration. However, if the
ingested caffeine is concentrated the risk of dehydration becomes real.
When to Avoid Caffeine
It is safe for most people to drink beverages or eat food
that contain caffeine. However, how caffeine affects people varies from person
to person.
Some people with medical conditions should check with their
doctors before having a lot of caffeine. For example, people with too much acid
in the stomach or frequent heartburn should consider stopping caffeine.
Caffeine increases the release of acid in the stomach.
People with anxiety problems or panic attacks may find that
caffeine makes them feel jittery and more anxious.
Women who are pregnant or planning to become pregnant should
avoid consuming large amounts of caffeine because too much caffeine may
interfere with normal development of the growing baby. If you are pregnant, ask
your doctor what he recommends regarding caffeine.
Sources of Caffeine
The following section discusses the main sources of
caffeine. We will consider that a cup of dark American coffee has 150 mg of
caffeine. A 150 ml cup not a 500 ml gigantic cup! Remember, different brands of
coffee, chocolate, and teas have different amount of caffeine. The way you brew
the coffee affects the amount of caffeine too. The more you brew it, the higher
the concentration of caffeine. A 2 oz energy drink 5-hour has 200 mg of
caffeine. A light cup of American coffee has on average 100 mg of caffeine. A
power drink such as Jolt Cola® has 100 mg of caffeine in 12 oz. A dark cup of
tea has 80 mg of caffeine. A cup of light tea has 40 mg. A 12 oz can of
Coca-Cola® has 64 mg of caffeine. Dr. Pepper® has 61 mg and Mountain Dew® has
55 mg. A 1 oz shot of espresso has about 50 mg of caffeine, but it is
concentrated in a small volume of coffee. A 30 ml cup of Turkish coffee has
about 30 mg of caffeine. A 40 gram bar of dark chocolate has 40 mg of caffeine.
Now here is a list of alternative products low in caffeine: A cup of hot cocoa
has 8 mg of caffeine. A 46 g single bar of Kit Kat® chocolate has 5 mg of
caffeine. A cup of decaf coffee has 4 mg of caffeine. A 12 oz can of 7up or
Sprite has 0 mg of caffeine! Herbal teas do not generally have caffeine.
Decaffeinated coffee is not totally free of caffeine. It still contains a very
small amount of caffeine. Always read the food label to see specific
information about caffeine content. Manufacturers may change their formula and
different brands of the same product include different amount of caffeine.
Risk of Poisoning
Caffeine is very safe. However, any substance or chemical
can be poisonous if consumed in doses beyond what the body can tolerate.
Caffeine is no exception. It can kill if consumed in large quantities. However,
such situations are extremely rare.
An overdose can happen if a person consumes a concentrated
amount of caffeine from medications or energy drinks in a short period of time.
Oral doses of more than 10 grams the equivalent of 100 cups of coffee can be
fatal in adults. You should seek emergency medical treatment if you or a loved
one consumed a large dose of caffeine. Symptoms of caffeine overdose in adults
include one or more of the following symptoms:
Breathing problems
Convulsions
Muscle twitching
Rapid heart beat
Vomiting
Hallucinations
Recommendations
Studies suggest that moderate amounts of caffeine are not
harmful. Moderate depends on the size, age, and health of the person. Some
doctors suggest 100 to 200 mg of caffeine each day, but each person is a little
different.
Experts agree that 600 mg or more of caffeine each day is
too much. This is about four to seven cups of coffee. If you get more than 600
mg of caffeine each day, you may want to consider cutting back.
The “moderate amount” is less for adolescents and children.
Young children should not drink caffeinated drinks on a regular basis. Their
caffeine intake from foods, like chocolate, should not be more than 100 mg per
day.
Energy drinks have a high concentration of caffeine. An
adult or child could easily exceed the recommended moderate amount from energy
drinks. You should determine your “moderate amount” of caffeine based on how
you feel. It can range from 150 mg (one cup of American coffee) to 600 mg (4
cups) per day. Here are some signs that you may be drinking too much caffeine:
You have insomnia
You become restless and irritable
Your heartbeat becomes fast or your heart starts skipping
beats
You have muscle tremors
Remember that you may want to cut out caffeine all together
if it causes you stomach ulcers or heartburn. Check with your doctor.
Summary
Caffeine is a very common substance that we consume in food,
drinks, and medicines. More than 90% of people in the world use caffeine in one
form or another. There are some benefits of caffeine. For example, caffeine causes
a person to feel more alert and less tired by stimulating the central nervous
system. However, taking in too much caffeine can also cause some side effects,
and in extreme rare cases, even death. How caffeine affects people varies from
person to person. Talk to your doctor about how much caffeine you should take
in each day, or if you should avoid caffeine all together.
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