So far there is no scientific evidence to substantiate the marketing claims made by the manufacturers of energy drinks.   The proprietary formulas which contain ingredients such as taurine and vitamins B6 and B12 have NOT been proven to increase energy.  The boost in mental and physical performance obtained from drinking energy drinks is mainly due to the stimulant effects of caffeine and nothing else.  Caffeine is well-known as a drug which increases alertness, reaction time, physical endurance and may improve athletic performance.   But the manufacturers of "energy drinks" continue to market their products with special ingredients that give you energy.  The claims are unfounded and are essentially a way for them to sell caffeinated products at increased cost to the consumer.   

BOTTOM LINE:  "Energy drinks" will provide a mental and physical performance edge, but it's not due any special ingredients.  You can get the same benefits from simply drinking coffee.  Save your money.

     Lately the media has been reporting that "energy" drinks such as 5-Hour Energy shots and Monster Energy may be attributed to several deaths.    In all likelihood the deaths were probably due to massive intakes of these stimulant drinks.    The primary ingredient responsible for the stimulant effect is of course caffeine.   A bottle of 5-Hour Energy may contain more than twice the amount of caffeine found within a cup of coffee.  Consumer Reports has stated that up to 400mg of caffeine daily is safe for healthy adults.  High doses of caffeine can cause symptoms such as restlessness, nervousness, insomnia, and tremors.  Excessively high doses can trigger seizures and an unstable heart rhythm.  
     With so many people drinking these beverages, you'd think a lot more people would be dying.  Certainly, many have reported feeling ill after drinking these products.    Any product consumed in inordinate amounts can adversely affect your health.   Common sense is needed.  The products in question here will not likely be taken off the market because injuries are not likely to occur when the product is consumed per the label recommendation.   The manufacturer of 5-Hour Energy recommends not to drink more than two bottles per day spaced several hours apart.  Those who've never tried this product should drink only half a bottle and wait 10 minutes before drinking the rest.  Those sensitive to the effects of caffeine should consult their doctor before drinking "energy" drinks.  
     "Energy" drinks are not going away anytime soon since the demand is large for these products.  Unfortunately the people who usually drink "energy" beverages are the ones who tend to be sedentary and feel they need a boost of energy.  The boost of energy from imbibing these drinks is short-lasting whereas the energy resulting from exercise lasts much longer and is the better alternative.  Best of all:  exercise costs nothing!   Keep in mind that these drinks are not an alternative to rest or sleep.   Forcing your body to stay alert when it requires sleep is certainly not healthy.  

     Research has shown there is evidence that refined or processed carbohydrates (characterized by large sugar content) seem to create a drug-like effect within the brain, thus causing addictive qualities mimicking alcohol addiction.  In essence, food behaves like a drug in terms of how it affects the brain, psychologically as well as physiologically.  This is not really news for most of us.  We know certain foods have addictive qualities (think potato chips and ice cream).  The human body loves fat, sugar and salt.  Why?  Because fat is a macronutrient which is a slow-burning, long-term source of energy for the body needed for survival when food is scarce.  Because sugar is a macronutrient (carbs) which is a fast-burning, short-term source of energy needed by the body.  Because salt consists of electrolytes (i.e., sodium and chloride) needed by the body for cellular pH balance.  
      Excessive sugar intake may be addicting physiologically as well as psychologically.   To wit, sugar affects the dopamine receptors within the brain, making us feel good.  Sodas are an excellent example of sugar addiction since they are a concentrated source of energy within many people's diets.  Many become addicted to soda and need their daily fix or else experience withdrawal symptoms such as irritability, anxiety and depression.  
     The caffeine within coffee, like sugar, has a drug-like effect within the brain which makes us feel good.  We know that caffeine is a drug because it stimulates the dopamine receptors which mediate pleasure.  (Now we know why people flock to Starbucks every day--it's to get their drug fix).  If their is a down-regulation of dopamine within the brain, one will feel a need to get more sugar and more caffeine in order to satisfy the urge to obtain the same pleasure.   Indeed, research has indicated that overweight and obese people seem to have this down-regulation of dopamine which lends itself to an increasing need for more sugar.   Since sugar contains calories, it makes sense that a chronic sugar addiction may cause one to become overweight or obese.
     If sugar, caffeine, fat, and salt have addictive-like effects on the brain, then does that mean all foods having these substances are inherently bad for the body?  The answer is no.  The natural sugar found within fruits is not nearly as concentrated as the sugar found within refined foods made in the lab (think high-fructose corn syrup).    Fats and salts are added to chips to make them more tasty and addictive but potatoes are inherently not unhealthy.  
     Sugars, fats and salt are added to foods to make them more sweet, have more mouth feel (thicker texture), and more salty because the body and the brain loves these ingredients.  It's simple:  our brains are hard-wired to eat carb-rich, fat-laden foods because the body needs sugar and fat to survive.  Regularly eating foods which have unnatural concentrations of sugars, fats, and salts (as well as man-made chemicals) may indeed turn us into junkies.  Yes, fast-food is addictive because it contains plenty of sugars, fats and salt to satisfy the palate.  The regular consumption of fast food may indeed produce long-term neuroadaptations within the brain reward and stress pathways.   Restricting fast-food and/or excessive sugar consumption may cause a withdrawal effect within the brain causing depression and anxiety.  
     If refined carbs behave like a drug within the brain, can psychological therapy resolve one's addiction to chips or ice cream, thus staving off bodyweight gain as a result of fat retention?   Theoretically, this may be the case.  But there are easier ways to lessen the addiction to chips and/or ice cream:

• Create new habits.  Go for a walk when an urge for a candybar occurs.  The exercise will lessen the immediate wanting for a quick sugar fix.  
• Keep a food journal.  Just the act of writing down the foods that you eat will provide a wake-up call to eat healthier foods.
• Reward yourself.  Choose a small goal and then reward yourself when you accomplish the goal.  Healthy rewards (e.g., a movie, bath, bike ride) make for healthy habits.

     Coffee is one of the most consumed beverages worldwide so it's really not at all that surprising that researchers have been studying its effects on the human body.  As such, much information has been discovered regarding coffee's benefits and possible negative effects.  
     
The Pros of Coffee Consumption:

• Coffee contains antioxidants, vitamins and minerals
• Research has indicated drinking coffee may reduce the risk of diseases and ailments including:

         *  Parkinson's
         *  Alzheimer's
         *  Type-2 diabetes
         *  Gallstones
         *  Some cancers (e.g., oral, colon, skin, esophageal, pharyngeal, breast, prostate)
         *  Asthma attacks
         *  Heart rhythm problems
         *  Strokes
         *  Liver cirrhosis

• Coffee may increase pain threshold
• Coffee is a stimulant which heightens focus and motivation

The Cons of Coffee Consumption:

• Excessive coffee consumption can affect normal sleep patterns
• May cause auditory hallucinations
• Hampers absorption of some vitamins and minerals (e.g., magnesium, zinc, iron)
• Can raise blood pressure
• As a mild diuretic, coffee can lead to dehydration and the depletion of water-soluble vitamins B and C as well as some minerals (e.g., calcium, iron, zinc)
• Coffee can stain the teeth
• The acidity in coffee can aggravate heartburn 
• Coffee is a crop which is heavily sprayed with pesticides

For your information, the following is the average caffeine content per cup (in mg):

• Drip coffee:  115-175
• Expresso:  100
• Brewed:  80-135
• Instant:  65-100
• Decaf, brewed:  3-4
• Decaf, instant:  2-3