The media are welcoming research published by Southampton University, claiming that 3 to 4 cups of coffee per day can reduce our likelihood of cancer. What the press reports fail to mention is that this quantity of caffeine, if consumed later in the day will reduce sleep quality, potentially leading to far wider health risks.
Considerably more evidence exists linking poor sleep to increased risk of:
- Heart disease
- Premature ageing
Coffee has a 6 hour half-life and so when drunk late in the day or even during the afternoon will still be in our systems when we want to shut off in the evening and go to sleep. Good sleep involves our brains and bodies cycling through different states, as our brain waves slow, our emotions are regulated and our memories consolidated. After a good night’s sleep, our bodies should feel stronger, our mood brighter and our ability to remember and prioritize facts will be much improved from the night before.
It is well understood amongst sleep scientist, that caffeine reduces our brains’ ability to properly pass through these sleep cycles
. For some, this will result in waking having not sorted through the important from meaningless data from the day before. Leading to a sense of confusion and anxiety. If this poor sleep is repeated night after night over a sustained period more serious mental illness can result, including clinical depression.
Physiologically, impaired sleep weakens our immune system. Our susceptibility to serious health conditions including, but not exclusively cancer is heightened. It’s worth noting that the Southampton University study focussed on just one form of liver cancer.
A cup or two of coffee first thing in the morning will help to raise our sense of alertness but the use of coffee throughout the day, to counter tiredness will only lead to another poor night. If this pattern is repeated the consequences to our physical and mental health far outweigh the moderate benefits claimed by today’s reports.