[blargey]

Culinary turmeric is about ~3% curcuminoids by weight (and only 60-70% of that is curcumin specifically). Curcumin also has low oral bioavailability, typically offset by taking a large dose (1000mg) and combining with piperine - even ignoring the piperine, that 1g of curcumin amounts of 66g of turmeric.

The average Indian household does not use 60g of turmeric per person per day. More like 1.5-2g per person per day, or ~30mg of curcumin, and without much to improve absorption.

Curcumin can, in fact, interact with anticoagulants and affect iron absorption at high supplemental doses, which is not a concern at culinary amounts.

There are reasons to be skeptical of the clinical evidence for curcumin supplementation, but "the heterogenous population of India isn't experiencing widespread miracle cures from culinary turmeric" is not one of them.

(And yes, garlic extract is also a thing, also extremely concentrated compared to eating whole garlics or seasoning with garlic powder, and has antiplatelet/anticoagulant activity that one should be aware of before taking such supplements)