Caffeine – The good, the bad and the ugly

By Tom 0
30 April 2015

As part of my current role I carry out health checks on clients. We call these Health MOT’s. They’re a 12-point health assessment where we check lots of various aspects of a given persons health. This includes going through their medical history, current lifestyle habits such as caffeine intake, smoking, water intake and sleep statistics. The assessments also include medical data such as BMI (Body Mass Index), blood pressure, resting heart rate and blood glucose and cholesterol levels to name a few. Within these assessments I find it interesting to correlate how a persons blood pressure, energy levels and cholesterol levels are affected by caffeine intake and current nutritional habits.

One thing is for sure, 90% of the clients in the assessments have no idea on caffeine, herbal teas, green teas and their effects on health. Here I will explain more on the effects of caffeine, what it does to our bodies and how our body reacts, why herbal teas are beneficial and everyone should be drinking them and also the pros and cons of drinking the ‘detox diet’ green tea.

What is caffeine?

If you’re going to take anything away from this article, let it be this – caffeine is the most used drug in the world. Yes I said drug. Under normal circumstances and consumed in moderation it has proven to have health benefits, but misused, it can cause health issues.

Caffeine itself is a chemical, a chemical that is naturally produced and is found in some plants. It is part of a group of naturally occurring substances called methylxanthines. Caffeine occurs naturally in over 60 types of leaves, seeds or fruits from plants. Caffeine can be found in:

  • Coffee Beans – Seed

    Coffee Tree

  • Tea Leaves – Leaves
  • Kola Nuts – Seed
  • Cacao Beans – Seed
  • Guarana – Seed
  • Yerba Mate – Leaf
  • Yoco – Bark

Interestingly, while caffeine resides in the leaves of certain plants, it acts as a natural pesticide to protect the plant from being eaten by insects, paralyzing and killing them.

Caffeine in it’s purified form looks like a white powder. This white powder is very bitter and as such, is the main reason it is added to some soft drinks (to give them the bitter taste). It is considered an addictive stimulant because it:

  • stimulates the central nervous system
  • increases heart rate
  • increases respiration
  • has psychotropic properties (mood altering)
  • acts as a mild diuretic

It can be bought over the counter as a medication to help aid drowsiness, tiredness and improve the effect of some pain relievers (FDA – opens in new window).

pro-plusDietary supplementation sources include:

  • capsules
  • powders
  • tablets
  • energy shots
  • energy drinks

So if caffeine is a drug, is it safe?

Yes, when consumed in moderation it has no dangerous or negative effects. Consumed in moderation means about 4 or 5 cups of coffee a day, maximum, according to the FDA. This is the equivalent of around 400mg per day for the average healthy adult. For reference, the following list details common beverages with their caffeine content:

  • Coffee, Brewed, 40-180mg per cup
  • Coffee, Instant, 30-120mg per cup
  • Coffee, Decaffeinated, 3-5mg per cup
  • Tea, Brewed, 20-90mg per cup
  • Tea, Instant, 28mg per cup
  • Coca Cola, 32mg
  • Diet Coca Cola, 42mg

In the current research, caffeine can have dangerous side effects on health. The effects that caffeine has on a persons body depend on how much they have consumed and their tolerance to caffeine. It can be a beneficial substance when needed to wake us up first thing in the morning but when it is abused, the following could happen:

  • shaking
  • increased heart rate
  • irregular heart beat
  • high blood pressure
  • headaches
  • nervousness
  • dehydration
  • lack of sleep
  • dizziness

How does caffeine work?

1280px-Caffeine_and_adenosine.svgCaffeine is absorbed into the blood and body tissue after oral consumption with absorption almost complete at around 45 minutes afterwards. Adenosine is a chemical that is present in all human cells; in the brain it is an inhibitory neurotransmitter. It binds to the adenosine receptors in the brain which means that it can act as a central nervous system depressant.

Adenosine promotes sleep and suppresses arousal by slowing down nerve activity. Adenosine binding also causes blood cells in the brain to dilate; to increase oxygen intake during sleep. When awake, the levels of adenosine in the brain rise each hour.

Caffeine looks like adenosine to a nerve cell and caffeine binds to the adenosine receptors. As caffeine utilises all the receptors adenosine binds to, the cells can no longer sense adenosine. Instead of slowing down, the cells speedup.

Caffeine blocks adenosine’s ability to open up the brain’s blood vessels, causing them to constrict – this is the reason caffeine is used in pain reliever medicine for headaches. If the headache is vascular, the caffeine closes down the blood vessels and gives relief.

With caffeine blocking adenosine, there is an increase in the firing of neurons in the brain. The pituitary gland observes the increased activity and perceives it as an emergency, so it releases hormones that tell the adrenal glands to produce adrenaline (epinephrine). Adrenaline is the “fight or flight” hormone and it has a number of effects on your body:

  • dilates pupils
  • increases heartbeat
  • constricts surface blood vessels, increasing blood pressure
  • slows blood flow to stomach
  • releases sugar from the liver into the bloodstream for extra energy
  • tightens muscles

Are there dangerous levels?

Yes – it’s shown that more than 500 – 600mg a day may cause side effects such as:

  • nervousness
  • insomnia
  • restlessness
  • irritability
  • diarrhea
  • nausea
  • muscle tremors
  • stomach upset
  • increased heartbeat

But.. Caffeine can be good

It has been shown that caffeine can be beneficial in many ways, when consumed in moderation and not relied on as a ‘pick me up’ all day. The benefits include:

  • Weight Loss – This can occur through appetite suppression and also calorie burning as caffeine may stimulate thermogenesis.
  • Alertness – A 75mg serving of caffeine has been shown to increase attention and alertness. It has also been said that that caffeine is comparable to sleep when a break is needed from driving.
  • Sports Performance – When mixed with carbohydrates, it can help replenish muscle glycogen stores faster after exercise. It is also noted that caffeine can also relieve post-workout muscle pain by up to 48%.
  • Can reduce the effects of type II diabetes by up to 11% (cited here – opens in new window)

Caffeine and Hormone function

Research has shown we tend to consume more caffeine when we are stressed. It could be that we are studying for an exam or trying to purchase a new house. Either way, consuming caffeine has an effect on a hormone called Cortisol. Cortisol is our “stress” hormone, when levels of Cortisol increase in our body as a by-product of adrenaline, our stress levels start to rise. Physiological symptoms of stress can include:

  • lethargy
  • headaches
  • chest pain and/or rapid heartbeat
  • upset stomach
  • nervousness and/or shaking

Let’s conclude

So, what do we think? Is caffeine good, bad or just plain ugly? I’ll let you decide. I certainly won’t tell people to stop drinking caffeine but simply consume it in moderation. Yes, it has health benefits, but as we have read above, it also has negative health effects. Combine 10 cups of coffee a day with little or no exercise, high blood pressure and no medication, you’re in for a real treat. What would I recommend? Cut your caffeine intake, exercise regular, speak to your GP and also take a look at nutritional therapy to see how we can aid the reduction of stress, high blood pressure and pick your energy levels up naturally so you don’t have to ask caffeine for help.

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author: Tom

Tom has been in the fitness industry for over 8 years. He is qualified in functional movement, Kettlebells, Boxercise, Nutrition and many other qualifications. Tom is also the founder and director of ActivityX. For more information on Tom, see his trainer profile.