food and the body
Why are onion and garlic avoided in some Hindu households?
What the tradition says
Onion and garlic are often placed among the rajasic and tamasic foods, the kinds thought to raise heat and restlessness or to dull the mind. Because of this they are seen as a distraction from a calm, devotional state. Many who follow a sattvic path avoid them, and they are commonly left out of temple cooking and of food prepared during fasts and festivals.
Where it comes from
The association of these foods with the lower qualities of mind appears in Ayurvedic and yogic thinking and has been carried down through certain communities more strongly than others. It has never been a single rule for all Hindus. How strictly it is kept depends a great deal on region, community, and family.
In everyday life
Many families simply cook without onion and garlic for festivals and for food offered at the temple, and keep them in everyday meals. Restaurants often label such dishes as suitable for those who avoid them. Abroad, people usually follow whatever their family has always done.