It’s the ability to evoke response from the ‘reward center’ of our brain that makes most of the addictive drugs out there lethal. Latest set of studies have found that sugar brings the same response to these reward centers as alcohol, heroine, or cocaine.
Despite having a similar impact, sugar has no immediate unpleasant effect. However, on the longer term, it could lead to some problems.
This also explains why the sugar based industries did not suffer badly during the great depression during the 1930s and without knowing it, people could’ve been addicted to sugar. Concrete conclusions about the addictive nature of sugar are yet to be made.