Everything You Need to Know About Caffeine

coffee caffeine

The media sends mixed messages about caffeine.   One day, deaths are blamed on caffeinated energy drinks.  The next, coffee decreases the risk for diabetes.  Like anything in life, the truth is not black or white.  Arming yourself with information can guide you towards decisions that best meet your needs and lifestyle.

How Much Caffeine Is In Food and Drink?

Caffeine is not limited to beverages. It is found in foods and as ingredients in certain over-the-counter medications.  If you are sensitive to caffeine, read product labels carefully.

In order for a product to be labeled as decaffeinated, the FDA requires 97.5% of the caffeine be removed. There has not been consistency in the marketplace and this has been documented in multiple studies. Variations may be attributable to random production error or even in user preparation.  For example, if a restaurant prepares “decaf” coffee but adds more ground coffee to less water, the final product will be more concentrated and may not meet the threshold for a true “decaf” product.

See Caffeine in Food and Drink.

What Are the Benefits?

Ask any coffee drinker about the benefits of their cup o’ Joe and you will hear about the big three:

  • Alertness
  • Concentration
  • Energy

These effects are commonly achieved at levels around 100mg-200mg daily.

There have been other benefits reported in small clinical studies, but more data and larger studies are needed to establish true cause and effect relationships.

IMPROVESREDUCES
Asthma symptomsAllergic reactions (reduction of histamine levels)
Exercise performance when taken immediately prior to exerciseColon cancer
Immune function (anti-inflammatory effects)Dementia
MemoryDiabetes
Liver disease
Migraine headaches (as a treatment)
Parkinson’s disease

What Are the Harms?

Caffeine has dose-related effects on the body.

SAFE (< 300mg per day)SYMPTOMS (300-500mg per day)TOXIC (> 500mg per day)
Generally well toleratedAnxietySymptoms listed to the left
InsomniaAbdominal pain
IrritabilityAddiction
NauseaHallucinations
NervousnessHeadache
Palpitations
Restlessness
Tremors

Breast disease:
  • It can increase fibrocystic changes in the breast tissue.  This can increase breast pain and discomfort.
  • There has been no data to suggest that caffeine increases breast cancer rates.
Cardiovascular disease:
  • Mild temporary increases in blood pressure (up to 10 points after one to two 6 oz cups of coffee) and heart rate are common.
  • Palpitations, especially PVCs (premature ventricular contractions) may occur in individuals sensitive to caffeine’s effects.
  • It has not been proven to directly increase cardiovascular disease, but it may increase risk for those with known underlying heart disease.
Osteoporosis:
  • Caffeine at levels > 300mg daily may increase calcium and magnesium losses in the urine, risking decreased bone density and osteoporosis.
  • Older individuals may be more sensitive to caffeine’s effects and at higher risk for secondary bone disease
Psychiatric illness:
  • Caffeine can trigger anxiety, panic attacks, and psychosis in patients with underlying disorders.
  • It can also increase the risk for manic episodes in bipolar (manic-depressive) patients.

How Much Caffeine Is Safe?

The FDA has reported deaths correlating with Monster Energy drinks. One 24-oz of Monster Energy contains 240mg of caffeine. Comparatively, one 12-oz Starbucks coffee has 260mg. That’s right, the same volume of Starbucks coffee more than double the caffeine than a single Monster Energy drink. Have you ever heard of death by Starbucks?  No?  Then it must make you wonder why Monster Energy has become the target of recent media hype.

Caffeine reaches toxic levels at intakes >500mg per day (see above) and may be fatal above 3,000mg per day.  Effects of caffeine may be intensified by co-morbid intake of alcohol or as a result of drug-drug interactions.  This may be the correlation between use of Monster Energy and the reported deaths.  Investigations remain underway.

Use this DEATH BY CAFFEINE calculator to see how much could be fatal according to an individual’s weight.

Does Caffeine Interfere With Medications?

It can have adverse effects (by impairing absorption or increasing drug concentrations in the bloodstream) when used in combination with the following medications and supplements:

AntibioticsPsychiatric MedicationsOther Medications
azithromycin (Zithromax)disulfiram (Antabuse)adenosine
ciprofloxacin (Cipro)fluvoxamine (Luvox)albuterol (Proventil)
clarithromycin (Biaxin)lithiumcimetidine (Tagament)
erythromycinolanzapine (Zyprexa)echinacea
norfloxacinhydrocodone/acetaminophen (Vicodin)
levothyroxine (Synthroid)
theophylline

In combination with alcohol, it has increased toxic effects. This may be the culprit for deaths relating to caffeinated energy drinks.

How Long Does Caffeine Stay in the Body?

Caffeine can affect sleep. Its half-life is 5 to 7 hours, i.e., it takes that long for half the caffeine to be metabolized by the liver and eliminated from the body. For most people, one or two cups of coffee in the morning will not affect their sleep patterns later that evening.

Is It Dangerous To Stop Caffeine?

Caffeine is a stimulant that affects the central nervous system.  It has addictive properties and can lead to withdrawal symptoms for people who have the equivalent of 2 cups of coffee or more. Withdrawal is annoying but not dangerous. Symptoms of withdrawal include:

  • Anxiety
  • Concentration difficulty
  • Depressed mood
  • Headache
  • Irritability

What Should You Do?

There is no reason to refrain from caffeine entirely unless you have risk factors. Drink it in safe limits, generally aiming for less than 300mg daily.  Decrease your caffeine intake if you take certain medications. When in doubt, ask your doctor for help.

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