No trial exists, so there is nothing to summarize
Take the useful part first. Nobody has run a human study showing that supplemental silica does anything for memory, for focus, for attention, or for any other measure of thinking.
That is not a complaint about thin evidence or mixed evidence. There is no study to describe, no effect size to quote, and no number of weeks to tell you to wait.
The biology that is real, and what it is about
Dismissing silicon outright would be its own kind of inaccuracy, because genuine science is attached to it. Silicon turns up in connective tissue work: the laying down of collagen, the condition of bone, the proteins giving tissue its structure. The review usually cited is Jugdaohsingh's, from 2007, and its subject is dietary silicon intake and bone.
Bone and connective tissue. Which is exactly why you find silica sold for nails, for hair, for skin, for the skeleton — a silica supplement for healthy aging stands on its own evidence there. A bamboo silica supplement aimed at hair and nails is on that ground; a bamboo extract supplement aimed at memory is not.
Why the silica comes from a grass
Bamboo is a grass — the biggest one there is, and among the quickest growing plants on the planet. Silicon gets pulled up out of the soil and laid down throughout the plant, and that mineral scaffolding is a good part of how a hollow stem ends up carrying real load.
Nothing else in the plant world holds as much. An extract of the stem can be specified at seventy per cent silica or higher, and that concentration is the reason bamboo ends up supplying the silica across a range of products — not any tradition of use.
What it is actually doing in the bottle
Contributing a mineral, and a structural one at that. That is the whole of the claim and the accurate end of it.
You will also see bamboo extract antioxidant support printed on labels. That phrase describes plant chemistry; it is not a statement about thinking, and it should not be read as one.
If your rule is that nothing belongs in a cognitive formula unless a cognitive trial stands behind it, that is a defensible rule. Applied here it removes bamboo extract and it removes D-Glucosamine, and you are left with four.
Saying this where it costs us something
A page printing only the agreeable half of every ingredient's story is not telling you anything; it is arranging things. And saying so is free unless you do it somewhere it loses you a sale.
This is that page. When a seller will separate the ingredients doing the work from the ones riding along, what they say about the first group becomes a good deal easier to believe. Research on an isolated ingredient is not research on a finished product, and no trial has tested this finished formula.
Two corrections while we are here
On the phrase “six botanicals”. Bamboo extract really is a botanical, so it is not what makes that phrase wrong. D-Glucosamine is — it is processed rather than grown, and from shellfish rather than any plant. Count it properly and you have five plant extracts plus one amino sugar.
On safety. Silicon in the diet is well tolerated and already present in ordinary food and water. At the amounts used in supplements, bamboo extract has no commonly reported interactions of any significance.