Onion and garlic are considered to be taamsic in nature and are said to invoke carnal energy in the body. Onions also produce heat in the body Garlic along with onion is known as Rajogini, which means a substance that can make one lose grip over their instincts. This makes it difficult to differentiate between your desires and priorities.. Maybe our ancestors did have a reason for everything, which we might not understand. It is good to understand our culture and why ancestors did certain things in certain ways. However, to include onion and garlic on festivals is individual choice....