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What’s in Energy Drinks? What are the Health Effects?

You’ve probably heard how the high levels of caffeine and sugar in energy drinks cause ill health effects, but extreme amounts and combinations of all the ingredients in these drinks are more likely the culprit. Health issues from energy drinks vary widely and are severe enough to have triggered a large increase in poison control calls and emergency room (ER) visits. More of these medical emergencies involved males (14,905) than females (5,878).

The reported health issues were:

  • Stomach upset
  • Nervous/restless
  • Mood changes/confusion
  • Headache
  • Sweating
  • Increased/irregular heart rate
  • Seizures
  • Withdrawal
  • High blood pressure
  • Chest pain
  • Dehydration
  • Kidney stones and failure
  • Death

After surveying energy drinks and their health issues (Part 1), it is time to look at their ingredients. Due to the lack of regulation and because, often, many ingredients are part of a secret “recipe,” this is not an easy task, though we do know a few of the common ingredients. These are examined below. Herbs are a large part of energy drinks, but beware: “all-natural” is not “all-safe” (poison ivy is all-natural!).

Caffeine and Guarana

Caffeine, a stimulant that affects the brain, spinal cord and respiratory system is addictive, causes withdrawal symptoms if stopped suddenly and is added in large amounts to energy drinks and shots. Energy drinks contain natural sources of caffeine, both synthetic and natural (such as Guarana, a highly caffeinated seed from a shrub grown in South America), but caffeine content information is often incorrect on the labels. Energy drinks contain 80 – 400 milligrams (mg) of caffeine per serving, and many have more than one serving per container. The highest level in soda (pop) is 54 mg in 12 ounces (Mountain Dew). Brewed coffee is about 100-150 mg in eight ounces.

Caffeine doses over 400 mg/day can cause:

  • Agitation/confusion/psychological disorders
  • High blood pressure
  • Headaches
  • Stomach pain/nausea/vomiting
  • Medication interactions (blood thinners and antidepressants)
  • Seizures
  • Heart issues – fast rate, irregular beats, lack of oxygen to the heart, heart failure
  • Death


Taurine is an amino acid that affects the liver and fat digestion. It is found naturally in meat (not bull testicles), fish, eggs and dairy products. Typical daily intake is about 400 mg for most adults, but energy drinks have 1000 mg per serving, often in a synthetic version.

Taurine causes:

  • Diarrhea or constipation
  • Nausea
  • Headache
  • Dizziness
  • Difficulty walking
  • Psoriasis flare up


Ginseng is a stimulant from the root of the ginseng plant. The safety of ginseng used in high levels or in combination with the other stimulants in high levels, as in energy drinks or shots, is unknown. The safe dose is assumed to be 200–400 mg per day.  Energy drinks are reported to contain from eight to 400 mg per serving.

Ginseng causes:

  • Insomnia
  • Female reproductive health issues
  • Fast and irregular heart rates
  • Fluid retention
  • High blood pressure
  • Headache
  • Dizziness
  • Diarrhea
  • Personality changes
  • Rashes
  • Dangerously low white blood cells


Used as a “detoxifier” in energy blends, glucuronolactone has not been determined to be effective or safe. The amount in energy drinks is unknown. It can cause:

  • Disorientation/dizziness
  • Fast heart rate
  • Kidney disease


Inositol is a complex sugar found in plants that functions in nerve impulse transmission. The amount in energy drinks is unknown because it is one of the proprietary ingredients. Inositol has side effects including:

  • Dizziness
  • Headache
  • Tiredness
  • Stomach upset
  • Severe allergic reaction
  • Gallbladder disease
  • Gout (arthritis form)
  • Kidney and liver disease
  • Chest pain
  • Diabetes

Some energy drinks and shots also contain extremely high levels of vitamins known to cause severe side effects. Who needs 8333 percent of the daily-recommended intake of any vitamin? What does it do to you? The answers: nobody, and it can make you sick – too much of anything is not a good idea.

Considering the side effects seen in many of their known ingredients, it is not hard to imagine a relationship between energy drink consumption and the lists of health issues that could require medical attention. Extreme moderation or elimination of the energy drinks or shots from your diet is sensible health management to prevent illness and other work related health issues.

[Kim Dennison is the Medical Professional for the Michigan Laborers’ Training and Apprenticeship Institute located in Perry, MI.]

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