Daily consumption of a certain form of curcumin improved memory and mood in people with mild, age-related memory loss. The research examined the effects of an easily absorbed curcumin supplement on memory performance in people without dementia, as well as curcumin's potential impact on the microscopic plaques and tangled in the brains of people with Alzheimer's disease. Found in turmeric, curcumin has previously been shown to have anti-inflammatory and antioxidant properties in laboratory studies. It has also been suggested as a possible reason that senior citizens in India, where curcumin is a dietary staple, have a lower prevalence of Alzheimer's disease and better cognitive performance.
Which word in the passage means earlier'?

Options

A. Performance
B. Absorbed
C. Properties
D. Previously