“Who’s addicted to caffeine? Not ME“, you say in an offended tone.
In the United States, 73% of children and 87% of adults are regularly using caffeine .
Over the years, caffeine has been abused and modified with sugars, food coloring and unpronounceable additives. Coffee is the most commonly ingested form of caffeine but there is a whole line of beverages and products that range from being psychologically damaging to overwhelming with health benefits.
Not all caffeine is bad for you.
In fact, caffeine in itself is not bad. It’s the frequency, amounts and the dependencies people have to them that are most concerning. Most people need their coffee to get them functioning enough to start or continue their day. It takes a toll on your adrenal glands for someone who has already pushed their stress to the max.
I explain caffeine abuse to my patients with this analogue:
Imagine you have a pair of soaked sponge. They are so full that the minute you pick them up they spill over with excess water.
These are your healthy adrenal glands that are spilling over with adrenaline, epinephrin, cortisol and other energy-producing and stress-regulating hormones.
With each task you take on in life you start to squeeze the sponges, little by little:
- College parties
- Cramming for exams
- Find work in a big city
- Buying a car
- Moving in with your boyfriend
- Planning your wedding
- Planning your honeymoon
- Paying off your debt
- Having your first child
- Getting promoted
- Moving, etc
And if you don’t take the time to re-charge your batteries, or in this case re-fill your sponges, they will slowly start to dry out.
When your daily tasks start to become major stressors and you fall into a reactive mindset, caffeine can save the day.
Caffeine does a fantastic job at squeezing your sponges (aka. stimulating your adrenals) to release more water (aka. energy-producing and stress-regulating hormones).
Unfortunately, when you’re in survival mode you are often not taking the time to properly rest and nourish your adrenals. So, your sponges start to dry up even more. You require more cups of coffee to wring out the last few drops of adrenaline and cortisol until you eventually reach “adrenal fatigue”.
Your body is no longer able to function properly and you can physically collapse. This is often seen after someone finishes a big project, goes out to celebrate and then immediately gets sick.
Of course the mechanisms of action for caffeine are much more complex than that.
Like many addictions, when caffeine is abused it can do us great harm. However, it’s properties are beneficial and can be healthful when used appropriately and with the proper adrenal support.
Caffeine is “the world’s most popular drug”
Caffeine is a methylxanthine compound that mainly causes neuro-hormonal stimulation and activation of the sympathetic nervous system . This results in an increase in blood catecholamines and cortisol that allows the body to adapt to stressors [3, 14].
In the heart, caffeine acts as an adenosine receptor antagonist, which begin reactions that mimick the effects of epinephrine . The secretion of epinephrine (and norepinephrine) increase the force and rate of heart contraction, thereby raising blood pressure and heart rate .
Caffeine has been used by many to enhance mood and energy, improve athletic performance, as a medicine (ie. headache relief, diuretic, antioxidant), but most commonly to counteract the effects of insufficient sleep .
But like any effective drug, there are potential negative side effects. Let’s have a look at the actions of caffeine:
Cognitive and mental support
Studies of caffeine on cognitive and mental acuity show conflicting data. There are many studies finding acute caffeine use consistently improves psychomotor speed and vigilance, simple and choice reaction times, increases alertness, improves short-term recall, and lowers perceived fatigue .
However, these studies measure cognitive abilities pre- and post-dose, which may show an exaggerated effect if the participant is experiencing a period of caffeine deprivation prior to receiving a single bolas dose .
Some studies use non-habituated caffeine users to remedy this study flaw and still experience similar positive performance enhancing effects from caffeine .
Other studies found no significant impact on reaction time, vigilance, or decision-making and may in fact cause long-term negative impact in motor skills, memory, and learning with frequent use .
Overall, caffeine use as a cognitive stimulant may be beneficial if not abused or as a replacement for insufficient sleep.
Caffeine at a dose of 300 mg has been shown to increase anxiety and tension, especially when paired with stressful tasks . Patients with panic disorders have an increased sensitivity to low doses of caffeine, showing signs of anxiety, nervousness, fear, and tremors .
Hallucinatory experiences are reported with >300 mg of caffeine (~7 cups of coffee) per day, which may be due to the physiological effects of cortisol release during stressful periods .
Caffeine increases acute risk for atrial fibrillation (irregular heart contraction) and myocardial infarction (heart attacks) in those with existing heart conditions [B]. These cases are especially seen at high caffeine doses and in combination with other stimulants, as seen with some energy drinks .
Tachycardia (fast heart rate) and arrhythmia (irregular heart rate) symptoms, typically arise with > 200 mg of caffeine ingestion and has been shown to adversely affect arterial stiffness .
Although studies of chronic caffeine use have reported no overall increase in atrial fibrillation (AF) risk, acute caffeine consumption increases blood renin, epinephrine and norepinephrine levels, blood pressure, heart rate and ECG markers for AF .
However, coffee and tea also contain important antioxidant sources that can decrease inflammation and heart tissue dysfunction, and can be protective against AF .
Exercise and fat loss support
Caffeine supplementation can aid in improving exercise performance by increasing muscle endurance, glycogen resynthesis (form of energy), and help facilitate fat loss .
The adrenal hormones released with caffeine consumption allows free fatty acids to be used by the muscle during exercise and spares glycogen use, which improves physical performance .
Exercise in itself is an anti-diabetic medicine. It increases exercise-induced insulin sensitivity responses. Despite pure caffeine supplementation enhancing exercise performance, it may reduce the exercise-induced blood glucose regulation .
Special Report: Green Coffee Bean
Green coffee bean and caffeine have come and gone as the latest weight loss fad. Does it really work? Let’s look at the research :
- Green coffee bean by weight is composed of 50% Chlorogenic acid and 3% caffeine.
- Chlorogenic acid has been reported to increase blood glucose disposal during oral glucose tolerance testing (OGTT) in animals and humans.
- One study showed no effect on glucose and insulin concentrations when green coffee bean was consumed post-exercise.
- However, other studies using higher doses of chlorogenic acid (450 mg) given to exercisers 30-60 minutes prior to activities, showed a significant decrease in blood glucose levels due to the delayed peak effect of chlorogenic acid.
- Another small study used chlorogenic acid enriched instant coffee with overweight and obese participants for 12-weeks and found a significant effect on the absorption and utilization of glucose from their diet. When compared to the control group who only drank instant coffee, the chlorogenic acid enriched group lost an average of 5.4 kg to the 1.7 kg control group .
Most people abuse caffeine for it’s stimulating effect in the early mornings to counter lack of sleep. Others use it mid-day to defeat food comas, boredom, or exhaustion.
However, when stimulants are taken too late in the day, especially 2 hours before bed, sleep quantity and quality is severely affected.
Even a study with a group of female athletes who took caffeine 45 minutes prior to intense exercise for 90 minutes in the evening experienced sleep latency and impaired sleep quality .
Many studies have found supporting evidence that tea is a powerful anti-cancer agent, but what about isolated caffeine?
Clinical findings demonstrate various anti-cancer properties of caffeine and caffeic acid against breast cancer (estrogen and non-estrogen dominant) that may sensitize tumor cells to Tamoxifen treatment and reduce breast cancer growth .
Reduced risk of Parkinson’s Disease
High black tea and coffee intake was significantly associated with lowered risk of Parkinson’s disease . However, in women using hormone therapy, high intake was correlated to an increased Parkinson’s disease risk and mortality . There are conflicting result with this study, which requires more research to be conducted.
Acute caffeine ingestion can increase urine volume and kidney function. This prompts concerns for fluid balance especially during exercise and sporting events . However, with adequate hydration before exercise these concerns are unwarranted .
Although there is an increase in urine and calcium excretion, caffeine-containing beverages have actually shown to lower the risk of kidney stones .
People with chronic renal conditions should carefully monitor their caffeine consumption to avoid excessive burden on their kidneys.
Reduced iron absorption
Excess caffeine has been shown to decrease absorption of non-heme iron (non-meat sources), and therefore caution should be taken in people with iron-deficient anemia, especially vegan and vegetarians . However, caffeine seems to affect iron status only in those with current risk of anemia .
Pregnancy, children and caffeine
Prenatal coffee ingestion was negatively associated with Behavior Rating Scale of the infant . Caution should be taken by men who heavy consume energy beverages and food supplements to avoid the potentially deleterious effect of caffeine on sperm quality . Moderate consumption of caffeine appears to be safe to male reproductive health .
Research suggests an association between coffee and tea consumption in children younger than 2 years old with type 1 diabetes and a 3-fold risk of severe kindergarten obesity . Children and adolescent caffeine increases risk of depression, sleep difficulties, overweight, substance use, and concerning physiological, behavioral, and psychological effects .
Who’s the Caffeine King?
The amount of caffeine in your food and beverages depends on the quality, process and source. The Caffeine Database is a good reference checker to ensure you’re staying below Health Canada’s daily caffeine limit of 400 mg/d.
The most common forms of caffeine are: coffee, tea, soda, energy drinks, sweet foods and medication.
Coffee is the world’s favorite beverage, with an estimated 1.5 billion cups drunk per day .
Studies show an increase risk in cardiovascular heart disease (CVD) with more than 6 cups of coffee per day in former or current smoker . In patients with confirmed CVD, heavy coffee consumption (>10 cups/d) was associated with a significant risk of sudden cardiac arrest .
On the other hand, there appears to be no association between moderate coffee intake and cardiovascular events, even in patients with a history of myocardial infarction .
Note: Unfiltered coffee has a significant source of cafestol and kahweol compounds that raise cholesterol and can be detrimental to your health.
Here are the stats on the amounts of caffeine in coffee:
Even the same amount of drip coffee (16oz) from different beans, brews and stores contain a surprising range of caffeine content:
Tea is the second most consumed beverage worldwide .
Caffeinated tea is produced from the leaves, buds or delicate stems of plants, most commonly Camellia genus.
It contains several chemical compounds such as polyphenols (mainly catechins), caffeine (2-4%), theophylline, L-theanine. Polyphenols are responsible for tea’s significant anti-oxidant and anti-carcinogenic properties .
Drinking at least 4 cups of tea per day (irrespective of the type) may reduce the risk of type 2 diabetes by 20% .
The 3 main types of teas vary based on flavor, color and composition:
- Black tea – full fermentation of the plant
- Oolong tea – semi-fermentation
- Green tea – no fermentation
1 tsp of dried leaves in 8 ounces of boiling water makes 1 cup of tea, equivalent to 14-65 mg of caffeine . Caffeine content increases with the length of steeping and younger tea leaves .
Consuming 8 cups of caffeinated tea or less per day minimizes any risk of excess caffeine intake .
Drinking at least 3 cups of black tea reduces the risk of cardiovascular disease  and has a strong protective effect against Parkinson’s disease .
Green tea has anti-oxidant properties 6x stronger than black tea . Regular consumption of green tea is a strong preventative factor for bladder, lung, stomach, prostate, and colon cancer .
In addition to it’s strong anti-oxidant effects, green tea also has many other health benefits:
- improves cholesterol levels
- decrease risk of heart disease
- reduces neuro-degenerative disease risk
- increase alertness and focus
- calms digestive system
- protects cartilage
- supports kidney function
Special Report: Yerba Mate
Yerba mate is a popular drink in South America. It is a crop tree native to the subtropical rainforest of Argentina, Brazil and Paraguay.
The dried leaves and aerial parts of the Ilex paraguariensis plant contains the caffeine (1.5 mg/g), chlorogenic acid (2.1 mg/g), phenole and saponin compounds that are used as everyday substitutions for coffee .
Yerba mate has significant anti-oxidant properties and has been used for weight loss in obese patients .
Caffeinated soda products not only cause excessive stimulation and irregular blood glucose regulation in children and adults, but also and increases risk of obesity, diabetes, cardio-metabolic diseases and osteoporosis .
Soda pop (in general) is harmful, especially to children, because of it’s acidic nature that can decrease the amount of Calcium absorption into healthy bone formation and growth . It also increases the risk of calcium-based kidney stones  and dental cavities .
The worst soda offenders for high levels of caffeine are:
ENERGY DRINKS AND SHOTS
Especially among adolescents and young adults, energy drink consumption represents a global public health problem .
Energy drinks are a relatively new phenomenon. In the United States, nearly 200 new brands of energy drinks were launched between 2006 and 2007, and in 2004, 1.5 billion cans of Red Bull were sold . In 2011, the FDA reported energy drinks sold $6.38 billion of products and accounted for over 20,000 emergency room visits. Meanwhile, caffeine based energy shot products accounted for $1.3 billion in sales in 2011 .
A Korean sales analysis on the market showed that energy drinks are sought mostly by young people and athletes – those in their teens and 20s accounted for 23% and 41% of the consumers, respectively .
Energy drinks and shots, such as Monster, Red Bull, Hot Six, 5-Hour Energy and Full Throttle contain stimulants and other substances, including high doses of caffeine along with taurine, ginseng, guarana, theophylline, sugars, vitamins, amino acids, and herbs .
Although manufacturers of energy drinks claim that these beverages are beneficial in that they can boost energy, physical performance, and improve cognitive performance, there is insufficient scientific evidence to support these claims .
The US Food and Drug Administration does not adequately regulate the marketing of energy drinks in the United States. The caffeine content in these energy drinks ranges from 50 mg to 500 mg .
Energy drinks and shots were primarily designed for athletes to increase physical performance. It’s reported that 74% of elite level athletes ingest caffeinated products (with carbohydrates and protein sources) prior to competition to gain numerous benefits such as improved endurance performance, strength performance, reaction time, fat oxidation, and a reduction in subjective perceived exertion .
However, several studies have found that there is no significant improvement in physical or mental performance when comparing caffeine to energy drinks with taurine or niacin .
Therefore, the benefits of energy drinks, such as Red Bull are most likely due to the effects of caffeine, with the other ingredients not likely to offer additional benefit .
Another reason to avoid energy drinks and shots are the acute negative effects that have been reported for triggering cardiac arrhythmias and increase in blood pressure and heart rate leading to atrial fibrillation . Other studies have suggested energy drinks can precipitate first-onset seizures, contribute to strokes and cause renal impairment from the diuretic effects . Further long-term studies are required on the negative effects of energy drinks.
Chocolate, stimulating herbs and certain nutraceuticals have become a common form of sweet caffeinated snacks. The dosages of caffeine are often much lower than the previous beverages we’ve discussed, with dark chocolate (>70% cacao) having many anti-oxidant and cardiovascular health benefits.
Certain medications contain caffeine to act as headache relief (ie. Excedrin) and for restoring mental alertness (ie. NoDoz). These medications can be avoided by careful management of caffeine withdrawal (see below) and adequate sleep.
Isolated caffeine supplementation may be helpful in doses <400 mg/d for improving exercise performance, but is best taken with carbohydrates and protein . Improved physical performance have been found in athletes taking between 2.5-3 mg/kg body weight of caffeine prior to exercise .
The Key Take Home Message
- The daily limit of caffeine intake is 400 mg
- Beverages with > 0.15 mg/mL of caffeine are highly caffeinated drinks and should be avoided by those sensitive to caffeine, such as children and pregnant woman 
- Health Canada recommends the daily caffeine intake for children should be < 2.5 mg/kg of body weight .
- Pregnant women should limit coffee consumption to < 3 cups/d (<300 mg caffeine) in order to avoid risk of spontaneous abortion or impaired fetal growth 
- People with iron-deficiency should limit their caffeine intake 
- Drinking moderate amounts (3-4 cups/d) of filtered coffee and caffeinated teas can be full of health benefits [14, 24]
- Avoiding caffeine products before bed
- Avoid high doses of caffeine if you have a history of heart complications, high blood pressure, tachycardia, anxiety, panic attacks, seizures, severe kidney disease, or history of tobacco use
- Don’t drink energy drinks, they aren’t any more beneficial than caffeine and have potential negative side effects [19, 21]
- Carefully monitor your health if you do frequently consume energy drinks or high doses of caffeine
- Keep hydrated with pure water while consuming caffeine
- Caffeine can improve neuromuscular function when taken prior to exercise, with a potential to reduce blood glucose and fat loss
- But more importantly, EXERCISE to lose fat
- Caffeine intake > 3 mg/kg of body weight resulted in side effects such as stomach pain, anxiety, hypersensitiveness, faster heartbeats 
- Large doses > 10g have been fatal and result in rare cases of rhabdomyolysis and acute renal failure 
How to avoid caffeine withdrawal
If you’ve ever decided to give up your energy drink addiction or start to reduce your daily intake of coffee, you might have noticed a few key caffeine withdrawal symptoms, such as:
Here are important tips to remember while weaning off of your caffeine addiction:
- Replace your current caffeine intake with teas (black, green, yerba), coffee, or supplements to start. This will keep the your caffeine levels more regulated and avoid a drastic crash
- Slowly reduce consumption of products with high caffeine content. Don’t go from 10 RockStars a day to a cup of green tea in a week.
- Support your adrenals prior to and during stressful events. Adaptogenic herbs such as Ashwaghanda, Rhodiola, Astragalus, and Eleuthrococcus.
- Protect your heart and mind with a healthy well balanced meal full of colorful vegetables, lean protein and healthy fats (ie. fish, coconut, olive oil, nuts and seeds)
- Start a sleep routine by doing healthy sleep hygiene practices before you go to bed, going to sleep at consistent time, and getting 7-9 hours per night
- Drink more water to stay hydrated and focused
- Exercise and keep your body releasing feel good hormones and sweating with daily activities
- Maintain a healthy state of mind with regular practices, such as meditation, deep breathing, and gratitude journalling
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