Another indicator- India consumes tons of curcumin yet has much less PD than the US which consumes little.
Also, we have no way to translate the lab's exposure to that of the dinner table. That's important because many of these complex plants are bi-phasic and lose or even reverse their effects at high dosages. Those cells in the flask may have been blasted with a mega dose. We have no way of knowing.
The best evidence comes from the lab verifying tradition and confirmed by the patient. Turmeric has that. Have some curry?