Answer

No. In Jain Dharma, one should not smoke during upvas.

Explanation

Upvas is not only avoiding food; it is a spiritual practice meant to bring the soul closer to purity by reducing attachment, desires, and bodily indulgence.

Smoking goes against the spirit of upvas because:

• It is a form of sensual indulgence and dependency.
• It disturbs self-control and inner discipline.
• It can involve harm to living beings through fire, smoke, and careless handling.
• It keeps the mind attached to bodily cravings instead of spiritual reflection.

Spiritual Understanding

The purpose of upvas is to practice sanyam — restraint — and reduce passions such as attachment and craving. Smoking during upvas weakens the tapasya because it supports addiction and bodily desire.

Takeaway

During upvas, one should avoid smoking and instead focus on prayer, samayik, pratikraman, swadhyay, and peaceful self-control.