Anecdotal evidence says that eating a banana, exercising and taking vitamin C may neutralize the effects of caffeine, but none of these things are scientifically proven to help. Image Credit: Jill Chen/iStock/Getty Images

Whether you drank too many cups of coffee or downed an energy drink, you may experience jitters, irregular heartbeat, an upset stomach and other caffeine side effects. From drinking water to eating a banana, find out what really works for neutralizing the effects of too much caffeine.

Tip Anecdotal evidence says that eating a banana, exercising and taking vitamin C may neutralize the effects of caffeine, but none of these things are scientifically proven to help. Your best bet is to drink plenty of water while waiting for the caffeine to move through your system.

How Much Caffeine Is Safe?

You may know that caffeine is found in coffee, tea, chocolate and soda, but the National Poison Control Center reports that you may be ingesting more caffeine than you realize. Energy drinks, caffeine pills, energy shots and diet pills often have high amounts of caffeine. This stimulant is also added to certain foods, chewing gum, mints, bottled water and even lip balm.

The U.S. Food and Drug Administration (FDA) says that healthy adults can safely have up to 400 milligrams of caffeine per day. This is the equivalent of four or five cups of coffee. However, some people are sensitive to caffeine and may experience side effects even when taking a few sips.

A caffeine overdose may occur at around 1,200 milligrams of caffeine, reports the FDA. Dietary supplements with high concentrations of caffeine can be dangerous and are not recommended. Children, teens and pregnant women should avoid caffeine. The same goes for women who are breastfeeding or trying to conceive.

Make sure you carefully check food labels to determine the exact amount of caffeine. For example, the FDA reports that a 12-ounce can of soda has 30 to 40 milligrams of caffeine, while an 8-ounce cup of coffee provides 80 to 100 milligrams. Green tea and black tea contain around 30 to 50 milligrams of caffeine, while energy drinks can have up to 250 milligrams per 8 ounces.

Potential Side Effects of Caffeine

Caffeine is a natural substance that is derived from coffee beans, cocoa beans and tea leaves, but it can also be produced synthetically. The FDA reports that it may have beneficial effects, such as increased alertness and energy, when consumed in moderation.

Read more: 14 Legit Ways Coffee Can Boost Your Health

After you ingest caffeine, you will feel the peak effects within 30 to 60 minutes, states the American Academy of Sleep Medicine. The stimulant has a half-life of three to five hours. This is the time it takes for your body to get rid of half the drug. For example, if you drink one cup of coffee with 80 milligrams of caffeine, you may still have 40 milligrams of this substance left in your system after five hours or so.

That's why it's recommended not to drink caffeine for at least six hours before bedtime. There are several variables, such as your weight and metabolism, that affect how long the caffeine stays in your system. According to the FDA, common caffeine side effects may include:

Jitters, shaky hands

Headache

Insomnia

Anxiety

Irritability

Fast heart rate

Nausea or upset stomach

The National Poison Control Center reports that serious side effects, which may result from a caffeine overdose, often include vomiting, heart palpitations and high blood pressure. Overdosing on caffeine is unlikely to happen, but it may lead to seizures and even death. If you experience severe adverse reactions, seek medical attention immediately.

Counteracting Caffeine Side Effects

If you scour the internet for ways to counteract caffeine's side effects, you will find lots of anecdotal advice. Eating a banana, exercising and eating fruits rich in vitamin C certainly won't hurt, but there is no scientific evidence that doing these things will stop the jitters or neutralize the caffeine in your system.

The best thing you can do is to stay hydrated by drinking water and to wait for the caffeine to pass through your system. The University of Washington advises against eating caffeine-containing foods, such as chocolate, during this time frame.

If you have diarrhea, drink an electrolyte replacement beverage. Take a walk to relieve anxiety and jitters. Practicing deep breathing or meditation may help slow down breathing and decrease anxiety until the caffeine has left your system. Figure out how much of this stimulant you can tolerate and keep it under that limit to avoid the negative caffeine side effects.