Caffeine can be found in coffee, tea, chocolate, soft drinks, and energy drinks. It is a central nervous system stimulant so people use it to increase wakefulness, enable faster and clearer flow of thought, increase focus, and improve general body co-ordination. In some situations it has been found to improve performance in sport and in moderate amounts may even decrease the risk of some cancers. But that doesn’t mean that it is really good for you.
Caffeine is one of the most common causes of health problems I see in practice. Excess caffeine intake manifests as many disorders such as:
- Chronic fatigue
- Weight gain
- Increased risk of cardiovascular disease
- High blood pressure
- Type 2 diabetes
- Poor judgment
- Lowered mood
- Decreased ability to learn and retain information
- A higher risk of accidents and injury
Caffeine can cause:
- Heart palpitations
- Increased the risk of bladder cancer and osteoporosis
It is a diuretic so can also cause dehydration. It is addictive and people can build up a tolerance to it so they have to drink more to get the same stimulating effects.
Because caffeine is a stimulant it can cause sleep disorders. It takes 6 hours for the body to clear half the caffeine taken in. This means that at 10pm when you are trying to sleep there is still half the caffeine from that 4pm coffee in your system. This length of time increases with age and impaired liver function. Oral contraceptive use doubles it while pregnancy can triple it. Some medications can increase it by ten times. Due to the length of time it takes the body to clear caffeine, it should not be consumed after about noon, and some people may find they need to eliminate it all together to get a good sleep.
What is a safe amount of caffeine?
There are no standards for a safe limit of caffeine. Food Standards Australia New Zealand recommends no more than 3mg per kg of body weight. So for someone weighing 70kg this is 210mg per day. Most energy drinks have about 80mg so should be limited to two a day based on their caffeine content. They still contain all the sugar of soft drinks though so should be avoided. A Starbucks Grande coffee has 330 mg of caffeine so these should only be for special occasions.
Due to its addictive quality, stopping caffeine consumption can cause withdrawal symptoms including:
- Inability to concentrate
- Pain in the stomach, upper body, and joints.
These may appear 12 to 24 hours after discontinuation of caffeine intake, peak at roughly 48 hours, and usually last from 2 to 9 days.
The benefits of caffeine are negligible so really it is best not to drink caffeine at all. If you must, only drink it in the morning. Children should never drink caffeine and teenagers, pregnant women and people on certain medications should limit their intake.
To see the caffeine content in your favourite drink check out this website: