Energy drinks are widely promoted to increase energy and enhance mental alertness and physical performance.
Next to multivitamins, energy drinks are the most popular dietary supplement consumed by American teens and young adults. According to the National Center for Complementary and Integrative Medicine, men between the ages of 18 and 34 years consume the most energy drinks, and almost one-third of teens between 12 and 17 years drink them regularly.
There are two kinds of energy drink products. One is sold in containers similar in size to those of ordinary soft drinks. The other kind, called “energy shots,” is sold in small containers holding 2 to 2-1/2 ounces of concentrated liquid.
Caffeine is a major ingredient in both types of energy drink products — at levels of 70 to 240 mg in a 16-ounce drink and 113 to 200 mg in an energy shot. For comparison, a 12-ounce can of cola contains about 35 mg of caffeine, and an 8-once cup of coffee contains about 100 mg.
Energy drinks also may contain other ingredients such as guarana (another source of caffeine sometimes called Brazilian cocoa), sugars, taurine, ginseng, B vitamins, glucuronolactone, yohimbe, carnitine and bitter orange.
The amounts of caffeine in energy drinks vary widely, and the actual caffeine content may not be identified easily. Some energy drinks are marketed as beverages and others as dietary supplements. There is no requirement to declare the amount of caffeine on the label of either type of product.
In several studies, energy drinks have been found to improve physical endurance, but there is less evidence of any effect on muscle strength or power. Energy drinks may enhance alertness and improve reaction time, but they may also reduce steadiness of the hands.
A growing body of research shows that energy drinks can have serious health effects, particularly in children, teenagers and young adults. Large amounts of caffeine may cause serious heart and blood vessel problems such as heart rhythm disturbances and increases in heart rate and blood pressure. Caffeine also may harm children’s still-developing cardiovascular and nervous systems. Additional concerns include:
-- Caffeine use may also be associated with anxiety, sleep problems, digestive problems and dehydration.
-- People who combine caffeinated drinks with alcohol may not be able to tell how intoxicated they are; they may feel less intoxicated than they would if they had not consumed caffeine, but their motor coordination and reaction time may be just as impaired.
-- Excessive energy drink consumption may disrupt teens’ sleep patterns and may be associated with increased risk-taking behavior.
-- A single 16-ounce container of an energy drink may contain 54 to 62 grams of added sugar; this exceeds the maximum amount of added sugars recommended for an entire day.
- 1 to 1-1/2 cups fresh spinach
- 2 cups pineapple, mixed berry, or other 100% juice
- 1 banana
- 1-1/2 cups frozen mixed berries
- 1 (6 ounce) container low-fat yogurt
- 1 cup ice
Wash hands with soap and water.
Gently wash spinach under cold running water. If spinach is marked “pre-washed” or “ready-to-eat,” use the spinach without further washing. Place spinach in blender with juice. Blend thoroughly.
Add remaining ingredients and blend.
Makes 4 servings.
Nutrition information per serving: Calories 150, total fat 1g, saturated fat 0g, sodium 40mg, total carbohydrates 34g, fiber 3g, total sugars 23g, protein 4g, vitamin a 6%, vitamin c 125%, calcium 12%, iron 7%.