Doctor Oz welcomed sleep expert Dr Carol Ash on his TV show to discuss how coffee could be depleting your energy levels.
“We’re a sleep-deprived nation,” Dr Ash said, who said the majority of people are consuming coffee to just stay awake.
“There are three ways caffeine [the substance in coffee] can cause fatigue,” said Dr Ash.
“Caffeine binds adenosine receptors in the brain,” said Dr Ash. “Adenosine is a neurochemical in the brain that causes fatigue.”
Adenosine is also responsible for creating pressure to sleep, and it controls the restorative deep sleep state.
When caffeine binds to adenosine, it causes alertness, but it does not stop the production or build-up of adenosine.
Thus, when the caffeine wears off, you have a build-up of adenosine that suddenly floods the body, causing a crash.
Dr Ash stressed that people need eight to nine hours of sleep at night, so she encourages everybody to first “get the sleep that you need”.
She also strongly recommended that people limit the amount of caffeine they drink.
Dr Ash said people are better off only having one or two cups of coffee per day.
This is to prevent you from developing a tolerance to caffeine whereby you need to consume more to get the same effects.
“You never want to drink more than 400mg of caffeine in one day,” said Dr Ash, who is talking about all caffeinated beverages, not just coffee.
Caffeine lasts for six hours in the body, so it shouldn’t be consumed after 3pm, as it can disrupt your sleep.
Not only that, caffeine induces adrenaline, resulting in crash later on.
Most coffees also contain a lot of sugar if they are garnished with syrups, for example.
Three ways caffeine is making you feel more fatigued
- Caffeine binds to adenosine brain receptors
- Tolerance to caffeine
- Caffeine can disrupt sleep.
Dr Ash cautioned: “Caffeine can be addictive.” Even withdrawing from caffeine can lead to fatigue, so moderation is key.