"It's not as dangerous as something like alcohol, where if we're abusing alcohol it makes us really sick and we don't actually function in the real world.
"It's a hard one because it [caffeine] actually helps us with energy and clarity of mind, and concentration, but on a negative side if you have too much of it, it's going to have a negative impact on your health in the long term."
How much coffee should we be drinking?
O'Hara says the ideal amount of caffeine intake is 200mg per day, the equivalent to two cups of coffee.
She says people who drink more than that may experience negative impacts on their health in the long term.
O'Hara advises the key is to drink caffeinated drinks in moderation, and not turn to coffee every time you feel a slump in concentration or energy throughout the day.
"We want to be able to enjoy it, but not [become] reliant on it to function."
How do we safely reduce our intake?
Going cold turkey and cutting out caffeine may mean people experience more severe withdrawal symptoms. Instead, O'Hara suggests people who want to cut back on their caffeine intake should do so slowly.
For example, she says someone who drinks four cups of coffee a day should cut back to three cups, and slowly reduce their intake over a week.
"If you're wanting to reduce it go slowly, don't try and reduce it too fast, I would suggest going down either half a cup or one cup a day."
