In our family too, there are a few who avoid garlic and onion on grounds of orthodoxy.
I too am a strict vegetarian and avoid even cake but I personally feel that if milk and honey, which are both animal products, can be certified clean why this taboo against onion and garlic especially when these are known to be good for health. I am not ready to accept the common belief that these stir up baser instincts in people.
Actually its not been explained properly and words like "stir up baser instincts " do make it sound very judgmental.
From what I read before that certain types of food have a lower prana index that sort of make the mind a tad bit less receptive to finer tuning of a spiritual kind.
Even the much loved Coffee comes under this becos it actually restricts the blood supply to the brain.
When we treat a migrane which is due to dilatation of the blood vessels we prescribe caffeine and ergotamine tablets too to make the blood vessels constrict as to decrease the throbbing of the headache.
Now imagine if we take coffee daily..it does cause vasoconstriction and slight dependency on it and lack of perfusion of finer matter in brain.
But at the same time coffee does have its benefits to the body in terms of anti oxidants etc.
same with garlic and onion they do have medicinal properties but at the same time it is not high on the Prana scale as in its less conducive for finer tuning of the mind for a spiritual aspirant but its fine for a person who would like to lead a just normal life.
Its just like how some people who wants more protein eat non veg and some dont.
Prana count of non veg food is lower becos the energy of non veg is second level but veg food is 1st level energy becos its stores energy direct from the sun.
Its all logic finally and up to us to choose what we prefer or what our body tells us to choose.