One of the most famous powerups must be the Super Mushroom. It's an iconic powerup in the Mario series, and has been used in many parodies. But all of these parodies portray the Super Mushroom as an edible product. Is this an accurate depiction, though? Let's explore this in a mini-theory.
Bigger is better
In the games, the Super Mushroom gives the user the ability to grow in size. This allows them to take an extra hit when attacked by enemies, and break blocks with their fists. Essentially, it gives the user enhanced strength and durability. Further more, it seems that you can use them to give vehicles a speed boost.
There are also variants of the powerup. First of all, you have the Poisonous Mushroom, which is what it says it does, it poisons the user. The user could use their current powerup or even die. A more useful powerup is the Mega Mushroom, which will allow the user to grow to enourmous sizes for a temporary amount of time.
Aside from that there are some mushrooms that grant other powers, but they've mostly just been seen as one-off powerups, like the Bee Mushroom or the Golden Mushroom.
To eat or not to eat
Now the first question one must ask is, is it safe to eat a mushroom? The answer is yes, it is. At least, if we can believe the Mario RPG series, like Paper Mario or the Mario & Luigi series.
In these games, the Super Mushrooms are used to heal Mario or his party members. They do that by being ingested by our heroes, which makes sense. Eating is seen as a way to improve your health.
But here's the main problem. Eating these mushrooms don't automatically make Mario grow. Apparently just eating them isn't sufficient, there has to be more to it. So what would trigger this reaction?
You've got the touch
The way the powerup is portrayed is that it activates once you touch it with any part of your body. This is true for all main Mario games, but another big hint is how it's portrayed in Super Smash Bros.
You might think, how is that game even relevant? Well, here's the thing. Super Smash Bros. tries to portray everything as accurate as possible, and with most edible items, the characters actually pick them up and put them in their mouth before usage. But that's not the case with the Super Mushroom, that one's activated by touch.
So, case closed, Super Mushrooms are activated by touch, not by ingesting them. But there's still a few issues with this. For example, Super Mushrooms can be eaten, which means they don't activate immediately on touch. You can also see them being held during any Mario Kart tournament. So, what's the deal with that?
The Shrooms have eyes
As you've noticed by now these mushrooms have something odd about them. They seem to have eyes. So does that mean they're sentient? Probably, to a certain extent. Each Super Mushroom moves, and it often seems to move away from the protagonist initially.
However, Mario just needs to touch the mushroom to get its powers. It appears that these mushrooms have a certain control over how or when it triggers its powers, or maybe it's aware of the intent of the user. However, why would it then allow the user to eat it? Well, because technically, it's just sentient. It's like eating a plant. We know it used to be very alive until it gets processed. We then eat dead plants.
Everybody wants a piece of magic
But where do people think that these Super Mushrooms are to be eaten to grow? Well, most theorized that originally, the mushrooms drew inspiration from the cake that made Alice grow in Alice in Wonderland. While Miyamoto was in a way inspired by the story, his reasoning was different. Instead, he said in an interview with NPR that he associated mushrooms with magic.
Well of course getting an item and growing big is sort of a mysterious thing to have happen. And so we thought, what's the most mysterious item that we could make this so it makes sense why they're getting bigger? And if you think of stories like Alice in Wonderland and other types of fairy tales, mushrooms always seem to have a mysterious power, and so we thought the mushroom would be a good symbol for why they get it and get big.
So, while this isn't direct proof that Mario isn't eating it, it does point to it not being used in that way, and actually, it would make sense if the Super Mushroom's powers didn't come from eating the mushroom, in a meta way. Nintendo is a child friendly company, and mushrooms that give powers by eating them sounds a lot like recreational drugs. Nintendo wouldn't really want to be associated with drugs, I assume. Instead, it would be easier to explain that a simple magical touch would make Mario grow.
The right touch
So, how would I imagine it would work? It starts with the Super Mushroom coming out of the block. The Super Mushroom is literally a magical item, so, naturally, it has the ability to move, and move away from sentient beings. However, once it's touched it can sense the intention of the user, whether it has to be stored or used immediately.
It also is a nutritient item. It's not entirely made out of magic, so it can actually fill up the stomache, and eating generally is associated with health. It could also explain how karts in Mario Kart get a speed boost. Its magical energy could be used to power up the engine itself temporarily.