Swallow Tulsi leaves, never chew

It is widely believed that tulsi is Goddess Lakshmi's avatar and hence one should not chew the leaves but directly swallow them. But the actual science behind this is that though the tulsi leaf is healthy, it contains a little amount of Arsenic. Thus chewing it directly causes the teeth to become yellow or results in the degradation of enamel so ancestors adviced not to chew Tulsi leaves