The Effects of Caffeine From Soda

Caffeine has a wide range of effects on the body; the effects and their severity depend on the person who is drinking the soda and the amount of caffeine in the beverage (or servings of the beverage). Some people report only a feeling of alertness from the caffeine in a soda. Though many people rely on caffeine for a morning boost, it can also have many negative effects. Jitters, sleeplessness, irritability and an increased heart rate are a few of the less desirable effects of caffeine. The caffeine in a soda may even have effects that are not immediately felt: Recent research shows that caffeine may reduce the risk of stroke and heart attack.

Energy Jolt

• Caffeine, a stimulant, is found not only in soda but also in coffee, tea and chocolate. It is a bitter substance that has numerous effects on the body, including on metabolism and the central nervous system. This is why some people who drink soda or coffee in the morning report feeling more alert.
  Caffeine also acts as a diuretic; it affects kidneys and can cause dehydration, according to the American Heart Association.
  The amount of caffeine in soda varies from brand to brand. According to MayoClinic.com, there are 36 to 38mg of caffeine in 12 oz. of Pepsi. The same serving of Mountain Dew contains 54mg of caffeine. By contrast, 8 oz. of brewed coffee contains between 95 and 200mg of caffeine.
  Most people can handle between two and four cups of coffee every day without suffering adverse effects, according to the National Institutes of Health. However, everyone's body is different, and certain people--including pregnant women--should avoid caffeine, whether it comes from a soda or another beverage.

Heart Health

• There is conflicting information about the effects of caffeine on heart health; many sources recommend that individuals check with healthcare providers if they are concerned about how caffeine might affect heart health.
  Moderate intake (1 to 2 cups of coffee per day) is endorsed by the American Heart Association. However, the association also acknowledges that studies on caffeine and heart health are inconclusive.
  A recent study that was detailed at an AMA conference in San Francisco and reported by the National Institutes of Health found that coffee drinkers had a lower risk of hospitalization because of irregular heart rhythm; soda drinkers were not studied.
  Another report revealed at the same conference found a link between caffeine and high blood pressure, but concluded that the risk was "modest."
  The National Institutes of Health points out that several studies on caffeine and heart health have been criticized for being conducted in a less-than-thorough way; some experts doubt the credibility of the studies as a result.

Sleepless Nights

• Caffeine may be a welcome wake-up aid, but it can also keep people up at night. Caffeine's effects can last four to seven hours, according to Dr. Lawrence Epstein of Harvard Medical School. Caffeine can prevent a person from falling asleep, and from staying asleep. The effects can be stronger in older people, who are at a greater risk for disrupted sleep caused by caffeine.

Effects on Mood

• Caffeine is valued for its perk-up abilities, but family and friends may not appreciate the other emotional and behavioral consequences of too much of a good thing.
  Caffeine (and caffeine withdrawal) can cause irritability. One study at the National University of Singapore found that caffeine decreased relaxation and increased anxiety, tension and nervousness among its subjects.