A Guide to Caffeine

Do you rely on a cup of tea or coffee to kick-start your day? Or reach for a can of coke when you’re in need of an afternoon pick-me-up? Rely on an energy drink after a big night out?

Caffeine is one of the most popular substances in the world – consumed in some form or other by almost every culture around the globe. But are you aware of exactly how it affects you and your health?

What is caffeine?

Caffeine occurs naturally in more than 60 different types of plants. It is also produced artificially and added to certain foods.

For Australians, coffee is the most popular source of caffeine, and it’s easy to see why. The delicious aroma, rich taste, and unmistakable buzz from a cup of coffee is hard to beat. It’s one of life’s simple pleasures, and has become completely ingrained in Aussie culture. Can you imagine a catching up with a friend or sitting through a meeting without a hot cuppa in hand?

While most people still get their caffeine in the traditional form of a cup of coffee or tea (or in what’s become another traditional form – a bottle of Coke), energy drinks can also be a source of caffeine. Guarana is the active ingredient in many of these energy drinks, with just 4 grams of guarana containing a huge 160 mg of caffeine. That’s twice the amount of caffeine contained in an ordinary cup of instant coffee.

Caffeine is also found in some chocolate, painkillers and over-the-counter tablets such as No-Doz.

The espresso effect

Caffeine affects different people in different ways. The amount of caffeine you’ve consumed, your age, any medications you’re taking, any alcohol you drink, the time of day you consume your caffeine, your mood, your level of tiredness, and how sensitive your body is in general, all make a difference to how caffeine affects you and your body.

  • Many people tout the ability of caffeine to wake you up, boost your energy, and pick you up when you’re feeling flat. Some studies have even shown that caffeine can improve memory, powers of reasoning, athletic performance, motor skills and reaction times. (However, improved performance as a result of caffeine intake can also be considered an effect of addiction!)
  • Sleep disturbance is one of the more negative effects of caffeine consumption. Some people find that as little as one cup of coffee can interfere with their sleeping patterns. However, if you stop caffeine consumption at least five hours before sleeping, the effects should be minimal. For minimal disturbance, aim to enjoy your cup of coffee before midday, to give your body plenty of time to wind down before bed time.
  • Other negative effects of caffeine include a loss of calcium and potassium from your body, which can cause sore muscles and delay your recovery after exercise.
  • Among the lesser known effects of caffeine are that it raises your body temperature and makes your digestive system produce more acid. Polyphenols found in coffee and tea can also interfere with iron absorption, so if you’re at risk of anaemia, it’s best to drink caffeinated beverages an hour before a meal, rather than afterward.
  • Caffeine is also a diuretic, so it dehydrates your body and sends you to the toilet more often.

Is it addictive?

Caffeine is a drug. Most people who drink caffeine on a regular basis develop a tolerance for its effects. This means that, over time, you need to drink more and more cups of coffee, tea, coke or energy drinks to get the caffeine buzz you’ve learned to rely on. However, caffeine is generally safe to consume at an amount of up to 250 mg per day (about two cups of drip coffee or three shots of espresso). However, consuming large amounts regularly (over 350 mg/day) may cause caffeine dependency (caffeinism) and have adverse health impacts.

The fact that many people experience caffeine withdrawal symptoms when they suddenly reduce heavy coffee drinking habits further indicates that caffeine is an addictive substance. As little as 1-2 cups of coffee (100-200 mg caffeine) daily can produce withdrawal effects, which are immediately relieved by consuming caffeine. However, unlike many other addictive substances, caffeine can be given up fairly easily by most people.

Caffeine and weight control

If you drink black coffee or tea without milk, the only thing caffeine may do is stimulate your appetite, making you desire a biscuit to go with your drink! There are almost no calories contained in black coffee, black tea, or diet soft drinks.

However, if a double-cream frappuccino is more your style, your waistline will pay a high price for your caffeine habit. Of course, it’s not the caffeine that’s the problem, it’s the copious amounts of sugar, cream, milk, flavoured syrup and other “goodies” that may be added to your brew.

If you’re trying to lose weight or improve your weight control, don’t forget to consider how many calories you’re drinking when you have a coffee, tea or soft drink. For some people, giving up their daily full-cream milk latte and replacing it with a lower calorie drink like a long black or espresso is all it takes to help them lose excess weight.

Here are the calories, fat and carbs contained in some of the most popular caffeinated beverages.

Cals Fat Carbs
Coffee with 2 tbsp reduced fat milk and 1 packet sugar 50 5g 3.5g
Caffe Latte with whole fat milk 300ml (Gloria Jean’s) 171 10g 12g
Grande Latte with non-fat milk (Starbucks) 160 0 20g
Grande Cappuccino with whole fat milk (Starbucks) 150 8g 13g
Skim milk cappuccino 300ml (coffee shops) 78 0 15g
Grande Latte with soy milk (Starbucks) 210 6g 28g
Chai Latte with low fat milk (Hudsons) 129 4g 19g
Grande Frappuccino Blended Coffee, caramel, with whipped cream (Starbucks) 430 16g 61g

Tips on cutting down on your caffeine habit

Interestingly, decaffeinated drinks might not be the answer to your coffee addiction…

If you decide to give up or cut down on caffeine, you may experience withdrawal symptoms including fatigue, drowsiness, headaches, body aches and irritability. These negative effects will stop after a few days, so hang in there.

To minimise withdrawal symptoms, reduce your caffeine intake gradually, especially if you usually consume a significant amount. Try swapping one or two of your normal drinks with herbal teas, coffee alternatives (like Ecco or Caro), caffeine-free soft drink, or fruit juices. Gradually reduce one drink per week, until you are below the 200 mg mark.

Decaffeinated drinks

Decaffeinated beverages may not be the healthy alternative you’re looking for. A recent study published in Circulation: Journal of the American Heart Association found markedly elevated blood pressure and increased nervous system activity when occasional coffee drinkers drank a triple espresso, regardless of the amount of caffeine it contained.

These results suggest that something else in coffee – not the caffeine itself – is responsible for cardiovascular activation. Coffee contains several hundred different substances, so most of these are still present in decaffeinated drinks too.

However, some people find that if full-strength caffeine drinks affect them too adversely, decaffeinated versions can be a better alternative – particularly when it comes to avoiding sleep disruption.

Is coffee helpful or harmful?

Research into the impacts of coffee on health is overwhelming; in the past few decades more than 19,000 studies have been conducted into this little bean! The most recent findings suggest that, despite some drawbacks, for many people a moderate amount of coffee may be more helpful than it is harmful.

The table below highlights some recent findings – however, keep in mind that the results of these studies are general and more research needs to be done.  If you have specific questions, it’s best to discuss these with your doctor.

Health area Coffee research To drink or not to drink? Current thinking:
Arteries Small doses, even as little as one cup of coffee, can cause temporary suffering of the blood vessel walls. In sensitive individuals, limit caffeine to 100mg a day.
Blood cholesterol Oil compounds in unfiltered coffee (espresso and cafeteria style) appear to raise cholesterol. Drinking filtered coffee will not affect blood cholesterol.
Cancer IFIC says claims linking coffee and caffeine to certain cancers are not supported by medical research. It’s no longer believed that coffee or caffeine contribute to these cancers. Keep to a healthy, well-balanced diet that may or may not include caffeine.
Colon cancer Scientists recently discovered the presence of a highly active compound (methylpyridinium) in coffee that may prevent colon cancer. This anti-cancer compound is found in caffeinated, decaffeinated and instant coffees. Drink moderate amounts of any of these to experience these benefits.
Diabetes A recent Harvard study shows 6 cups of coffee a day dramatically reduces your risk of Type 2 diabetes, particularly in men. If you choose to drink coffee, also be sure to eat well, exercise, and maintain a healthy weight as these approaches can prevent the onset of Type 2.
Fertility There is very little evidence, but caffeine may affect the time it takes to get pregnant and increase your risk of miscarriage or low birth-weight. It may also affect sperm motility in men. Not enough evidence to support these suggestions. However if you have fertility complications, cutting out caffeine won’t hurt.
Gallstones A comprehensive 10-year Harvard study found that people who drink coffee are at a lower risk of gallstones. 2-3 cups of caffeinated coffee a day may reduce your risk of gallstones by around 40%.
High blood pressure and cardiovascular disease Some studies associate caffeine with increased blood pressure, while others show there is only a weak connection. There are few links between caffeine and heart attack or stroke. If you have an existing problem with high blood pressure, watch your caffeine intake. Keep consumption below 200mg a day.
Liver disease A 2004 study found those who drank more caffeine had fewer liver abnormalities. More research is needed. Limit caffeine to 200-250mg per day.
Osteoporosis Excess caffeine can increase risk of osteoporosis and fractures. If calcium intake is above 800 mg a day, caffeine has little detrimental effect on bone density.
Parkinson’s Disease Studies have shown coffee consumption can decrease your risk of Parkinson’s Disease. However, women who are heavy coffee drinkers and undergo hormone replacement therapy are 1.5 times more likely to develop PD than heavy coffee drinkers who don’t have HRT. 3-4 cups of caffeinated coffee a day may decrease risk of PT, but if you’re undergoing HRT be sure to talk to your doctor about drinking coffee.
Pregnancy Caffeine does reach the foetus and may disrupt the developing baby’s rest periods. Newborns may experience caffeine withdrawal. Pregnant women should avoid caffeine.
Rheumatoid arthritis Research suggests that an ingredient in coffee other than caffeine may contribute to rheumatoid arthritis. Four cups daily may increase risk of developing rheumatoid arthritis by 50%.
Stress Caffeine is a stimulant. It increases heart rate, adrenaline and stress levels. If your anxiety levels are high, keep your caffeine intake down.

References :

This article was compiled in consultation with Calorie King experts and in reference to the following sources:

Daniel S W Tan, ‘Coffee Consumption and Risk of Type 2 Diabetes Mellitus’,  Lancet, Volume 361: Issue 9358, pg 702

E.W. Karlson et al., ‘Coffee Consumption and Risk of Rheumatoid Arthritis’, Arthritis Rheum, Nov 2003, 48 (11), pp 3055-60

Eduardo Salazar-Martinez, MD, PhD et al., ‘Coffee Consumption and Risk for Type 2 Diabetes Mellitus’, Annals of Internal Medicine, January 2004, 140 (1), pp 1-8

T. Lloyd et al., ‘Bone Status among Postmenopausal Women with Different Habitual Caffeine Intakes: A Longitudinal Investigation’, American Journal of Clinical Nutrition, 1997, Volume 65, pp 1826-1830

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