Would silica have the same effect as activated charcoal?
The silica gel granules are granular silicon dioxide (SiO2), the same matrial from what is the normal sand.

The pure SiO2 has the same effect to health as when you eat sand.

But because the granules are larger, may cause appendix problems (im not an doc). Anyway, this is not chemical related problem.

It can cause dehydratation or other problems, what is caused by it absorbtion capabality.

The bigger problem is, than the standard silica gel granules aren't pure SiO2.  The common additivas are what causes color change when it is moistured,  like cobalt chloride or others and thise compounds can be toxic!

So, don't eat it!