Why can't some people eat onions, ginger and garlic?

Part of it is psychological factors, but most of them don't eat this, because of men's instinct, these three things will release odor to stimulate the senses. According to people who have evolved, feeling is to let you decide what to eat away from, which is a shortcoming of biology, so people will instinctively avoid things that are harmful to them.

For a typical garlic, the sulfur smell of garlic is honest in the smell of the substance, and most people think it stinks. The so-called garlic kills pathogenic bacteria, which is a dangerous component of these organisms.

But people's preference for these smells is not excluded. For example, gasoline (toxic) likes to ask about the smell of matches or the smell of gunpowder explosion, just like people who like the smell of onion, ginger and garlic.

Vomiting is also a manifestation of psychological stress or tension, which will produce a reflex to keep you away from these substances.

There are still some people who can't eat onions, ginger and garlic because of physical reasons, such as congenital allergies.