Coffee fans will have to pause and think whether their level of consumption of this famous beverage day in and day out can bring them any harm in the light of recent reports from a group of food scientists from the down under. If the recommendations from these pundits are taken seriously, coffee consumption may have to be severely curtailed by those who are known coffee-addicts. For a typical South Indian family drinking coffee at least 2-4 times a day is a must and often such attachment to coffee has been described as addiction. May studies have brought out the fact those who consume coffee do not experience any withdrawal symptoms though craving for a cup of coffee can be experienced when it is not available readily.
The undesirable constituent in coffee that has been blamed for all the ill-effects attributed to it is caffeine. Caffeine is easily metabolized by the human liver using the hepatic microsomal enzymatic system, the metabolic end products being harmless. It is true that a typical cola beverage may contain much less caffeine compared to a cup of coffee. While a cup of coffee prepared using a brew by percolation may contain up to 135 mg of caffeine, drip brew derived coffee can have higher levels of caffeine, up to 175 mg per cup.
Coffee also contains some diterpene compounds like Kahweol and Cafestol which have been implicated in cardiovascular disease through their role in increasing the LDL concentration in blood. But coffee brew made with paper filter does not contain these harmful chemicals while metal filters allow them to pass through into the brew. In India good coffee beverage is made in metal filters but no data is available regarding the fate of these diterpenes when hot water is used for percolation.
The latest scare comes from New Zealand when the food authorities have sent out a warning to their citizens cautioning them against consuming coffee in high doses. According to the agency caffeine contained in coffee can cause irritability, anxiety, tremors, dizziness and insomnia. More alarming is the assertion that some people may experience short-term anxiety effects by consuming more than 3 mg of caffeine/kg body weight/day. This means that an adult should not drink more than two standard cups a day and for most healthy adults, up to 400mg of caffeine in total in a day. In case of children and old age population, with decreased liver function, the effect could be worse though reliable data is yet to emerge.