Most of us love a coffee. Making a coffee is generally something of a self indulgent practice, as well as potentially a handy way to shake off that ‘not quite woken up’ feeling in the morning.
Up to 400mg caffeine a day is considered safe, although the maximum dose recommended by sleep expert Greg Potter is 3mg per kilogram bodyweight. Caffeine content in coffee varies hugely, but you can think of a cup of instant coffee as 60mg, an espresso as 80mg and brewed coffee as 100-180mg. Tea is about 40mg per cup.
If you’re getting good quality sleep, you’re not relying on coffee to keep you going during the day, and you’re within reasonable limits of caffeine intake, then it’s probably no big deal to enjoy a coffee or two a day. Coffee is hugely researched, and there are a surprising amount of positives associated with coffee intake.
Of course, there is a flip side which I don’t think we appreciate – coffee can have a big impact on your sleep quality.
The way caffeine works to keep you awake is by blocking the feeling of tiredness. It tricks your body into feeling alert. The effects will peak about half an hour after you’ve drunk your coffee, but can last much longer than that.
Caffeine has a half life of about 5 hours (there are pretty big individual variations to this though with it taking up to 9 hours if you’re a slow metaboliser of caffeine and only a couple of hours if you’re a fast metaboliser – but let’s stick with the middle ground). This means that every 5 hours, the dose of caffeine in your system halves. So a double espresso at 8am is probably not going to have an impact on your sleep quality – but imagine the impact of the coffee you drink at 2-3pm, and the knock on effects. If you don’t sleep well that night, then you’re going to rely on caffeine even more the next day – you can create a vicious cycle without really noticing.
So, my advice is to stick within the recommended maximum caffeine intake each day, and enjoy it. But, become more aware of how caffeine fits into the picture of a healthy lifestyle and stop drinking caffeine before 2pm.