To anyone who is up before about 7am every day, caffeine is an essential part of the morning ritual and coffee has definitely formed it’s own little culture in Australia, where finding the elusive best cup of liquid gold is the aim of the game. Ever wondered the effects of this liquid gold beyond the feeling of being awake? Here are your answers!
What is caffeine?
Caffeine is a bitter compound naturally found mostly in tea and coffee plants that stimulate the central nervous system (brain and spinal cord).
What are the effects of caffeine on the body?
Caffeine mimics the naturally produced hormone adrenaline which cause a temporary burst in physical energy. The effects of caffeine include:
- Quickening of heart rate and breathing rate
- Irritability and anxiety
- Frequency of urination
- Excitability or restlessness
However, regular caffeine drinkers might know that just one cup of coffee doesn’t seem to cut it anymore to get that feeling of “awake” we are all after, this is known as caffeine tolerance. Caffeine dependency can also occur, so us weekday takeaway coffee drinkers seem to get the withdrawal headaches come Sunday other symptoms include tiredness and crankiness (or that just might be because Monday is coming…)
Where is caffeine found?
Caffeine is found in more than just coffee, here’s a list of caffeine-containing foods and drinks:
- Coffee (any kind: instant, drip or percolated, espresso)
- Black & green tea
- Chocolate or chocolate drinks
- Cola-type drinks
- Energy drinks containing guarana and/or taurine (natural sources of caffeine)
- Caffeine tablets (per tablet has about the same amount of caffeine as instant coffee)
Hot Topic: Caffeine & Pregnancy
Research seems to be a bit contentious on this topic leaving expectant mothers confused about whether they’ll have to kick the caffeine habit for 9 months. In general, research states that the established safe level is not yet well identified and caffeine should be avoided as it has been associated with increased risk of pregnancy loss. As a guide, caffeine during pregnancy should be limited 300 mg per day which is equal to 1-2 instant or drip coffees or 1.5 espresso coffees (including your beloved latte), or 3 cups of tea.
Hot Topic: Caffeine & Sport
The impact of caffeine on athletic performance comes from two proposed mechanisms:
- Reduced perception of effort when exercising – so the same task appears to be easier
- Reduced perception of fatigue
Some research shows that caffeine is more effective in athletes who aren’t regular drinkers of the liquid gold substance. Correct timing and dosing depends on the type of sport and body weight of the athlete and consultation with a Sports Dietitian would be best to determine the optimal regime for you. However, the diuretic and dehydrating effect of caffeine should really be considered for its use in sport.
Hot Topic: Caffeine & Weight loss
Can caffeine help you lose weight? Well it is known that caffeine suppresses appetite in some people, however it doesn’t show that it aids in weight loss. Another mechanism is that caffeine can increase your body temperature, which requires more calories to be burnt to produce that heat, again it’s unlikely this has a significant effect on weight. There is some evidence that green tea drinkers among overweight and obese adults appear to have small amount of weight loss however this was not considered enough to give healthy benefits and the weight loss was not likely to be maintained.
Hot Topic: Caffeine & Diseases
Caffeine in irritable bowel syndrome (IBS) and reflux – tends to be problematic for many. In terms of prevention of disease, coffee in particular has probable level evidence in decreasing the risk of endometrial cancers in women and liver cancers, however the amounts required to have this preventive effect vary between studies. There is also some evidence to suggest that caffeine intake can decrease the risk of dementia however the nature of the studies have prevented a definite statement on this association.
So it appears, there is some work to do in the realm of caffeine research in many aspects of nutrition ranging from sports to disease!