Scientists say there is no universal best time to drink coffee, as the boost people get from caffeine depends on their age, metabolism and how used they are to the drink, according to a report by Popular Science.
Caffeine works by stimulating the central nervous system and blocking adenosine, a substance that builds up gradually in the brain and causes feelings of tiredness. That is what makes people feel more alert and focused after a cup. But with regular consumption, the body adapts by increasing the number of adenosine receptors, meaning more caffeine is eventually needed to produce the same effect.
Why timing matters
Experts note that caffeine is absorbed quickly, with levels in the blood peaking roughly 30 to 60 minutes after it is consumed. Because of this, it makes sense to drink a cup of coffee about an hour before work, exercise or any other activity that requires concentration.
Coffee straight after waking up may not be as necessary as many assume, since the body should already be in a naturally alert state at that point. A more useful moment, experts suggest, is a few hours after waking, when a natural dip in energy tends to set in.
Age and dosage
As people get older, caffeine is cleared from the body more slowly and circadian rhythms shift, so it may be wiser for older adults to have their coffee earlier in the day. The dose also matters, and the caffeine content of a cup varies depending on the bean variety, the brewing method and the ratio of coffee to water. Among people who drink coffee regularly, a morning cup sometimes only partly eases the symptoms of going without caffeine overnight.
Experts advise against drinking coffee too close to bedtime. Anyone who struggles to fall asleep should cut out coffee in the afternoon or move their last cup earlier in the day.
Coffee on an empty stomach
Coffee on an empty stomach is not suitable for everyone either. In some people it increases nervousness, causes trembling or leads to frequent trips to the toilet, and those with sensitive stomachs are better off pairing it with food. However, the common claim that coffee on an empty stomach causes stomach ulcers is a myth, according to the report.
For most healthy adults, the benchmark is up to 400 milligrams of caffeine a day, roughly two to three cups of about 350 millilitres each. The main rule from experts is simple: do not drink coffee too late in the day, and do not overdo the amount.
